PRO-C Vitamin C Abstracts

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PRO-C is a full-spectrum vitamin C and antioxidant supplement designed and sold by integratedhealth.com. The following abstracts support and explain the vitamin C antioxidant ingredient spectrum in PRO-C.

 

Glutathione in PRO-C Vitamin C

Glutathione in foods listed in the National Cancer Institute’s Health Habits and History Food Frequency Questionnaire.

Jones DP,   Coates RJ,   Flagg EW,   Eley JW,   Block G,   Greenberg RS,   Gunter EW,   Jackson B

In: Nutr Cancer (1992) 17(1):57-75

Glutathione (GSH) is an antioxidant and anticarcinogen that is present in plant and animal tissues that form the bulk of the human diet. Recent studies show that GSH is absorbed intact in rat small intestine and that oral GSH increases plasma GSH concentration in humans. To provide a database for epidemiological studies of dietary intake of GSH and risk of diseases in humans, we have measured the content of GSH in the foods listed in the National Cancer Institute’s Health Habits and History Questionnaire. Foods were purchased in the Atlanta area and prepared as most commonly consumed in the United States. GSH analyses were performed using a high-performance liquid chromatography technique with a method of additions to correct for losses during sample preparation. A separate set of samples was run after treatment with dithiothreitol to measure the total of GSH and its disulfide forms (GSH). The results show that dairy products, cereals, and breads are generally low in GSH; fruits and vegetables have moderate to high amounts of GSH; and freshly prepared meats are relatively high in GSH. Frozen foods generally had GSH contents similar to fresh foods, whereas other forms of processing and preservation generally resulted in extensive loss of GSH. Thus this database will allow researchers to examine the relationship between dietary GSH and risk of cancers and other diseases.

Physiological control and cell specificity of glutathione transport.
Bai C

In: Diss Abstr Int [B] (1992) 53(4):1732

Glutathione is an important antioxidant and anticarcinogen that is absorbed intact in the small intestine and transported into certain epithelial cells. This dissertation focuses on the physiological control of glutathione absorption in the small intestine and the identification of cell types that can utilize glutathione from the plasma. Phenylephrine was found to stimulate transepithelial transport of glutathione in rat small intestine with physiological concentrations of glutathione in the lumen. Oral administration of phenylephrine plus glutathione caused an increase of glutathione concentration in rat blood plasma. To examine whether glutathione transport could be altered by acclimatization to physiological stimulation, the effects of hypoxia on glutathione transport and enzyme activities involved in glutathione-related detoxication in small intestine were studied. Glutathione transport was impaired by hypoxia in small intestine, but glutathione-related detoxication enzyme activities from the mucosal scrapings were not substantially affected. These changes decreased the capability of intestine to detoxify dietary lipid peroxides. To determine whether glutathione transport was age-dependent, glutathione homeostasis and protection against oxidative injury in neonatal alveolar type II cells were examined. The neonatal cells were able to synthesize glutathione from its amino acid precursors and were also able to take up intact glutathione from the extracellular medium. An increase in cellular glutathione concentration was associated with a protection of cells against oxidative injury. Thus, neonatal alveolar type II cells have the same transport capability as that of the adult cells. The cell specificity of glutathione transport was studied using a fluorescent probe for glutathione. Based on this indicator, fluorescence microscopy and HPLC analysis indicated that alveolar type II cells in lung preferentially took up glutathione. In summary, this dissertation establishes that glutathione uptake in the small intestine is a process that is hormonally regulated and altered by changes in physiological state. It further shows that consequent increases in plasma glutathione can result in enhanced delivery of glutathione to specific cell types in an organ. Thus, oral supply of glutathione for nutritional or therapeutic purposes must be considered specifically with regard to physiological state and cells targeted for treatment. (Full text available from University Microfilms International, Ann Arbor, MI, as Order No. AAD92-24386.)

Restoration of blood total glutathione status and lymphocyte function following alpha-lipoic acid supplementation in patients with HIV infection.
Jariwalla RJ, Lalezari J. Mansour SE, Kumar A, Gangepurkar B, Nakamura D

In: J Altern Complement Med. 2008 Mar:12(2):139-46

California Institute for Medical Research, San Jose, CA, USA. r.jariwalla@drrath.com
OBJECTIVES: To determine whether supplementation with alpha-lipoic acid (ALA), a glutathione-replenishing disulfide, modulates whole blood total glutathione (GSH + GSSG) levels and improves lymphocyte function in human immunodeficiency virus (HIV)-infected subjects with history of unresponsiveness to highly active antiretroviral treatment (HAART). DESIGN AND SETTING: Randomized, double-blinded, placebo-controlled trial conducted at two study sites: an eye clinic at a county hospital in San Jose and a research clinic in San Francisco, California. SUBJECTS: A total of 33 HIV-infected men and women with viral load >10,000 copies/cm(3), despite HAART, aged 44-47 years, approximately 36% nonwhite, were enrolled. INTERVENTION: Patients were randomly assigned to receive either ALA (300 mg three times a day) or matching placebo for 6 months. MAIN OUTCOME MEASURES: The change over 6 months in blood total glutathione status, lymphocyte proliferation response to T-cell mitogens, CD4 cell count, and viral load in patients receiving ALA compared to placebo. RESULTS: The mean blood total glutathione level in ALA-supplemented subjects was significantly elevated after 6 months (1.34+/-0.79 vs. 0.81+/-0.18 mmol/L) compared to insignificant change (0.76+/-0.34 vs. 0.76+/-0.22 mmol/L) in the placebo group (ALA vs. placebo: p=0.04). The lymphocyte proliferation response was significantly enhanced or stabilized after 6 months of ALA supplementation compared to progressive decline in the placebo group (ALA vs. placebo: p<0.001 with phytohemagglutinin; p=0.02 with anti-CD3 monoclonal antibody). A positive correlation was seen between blood total glutathione level and lymphocyte response to anti-CD3 stimulation (R(2)=0.889). There was no significant change in either HIV RNA level or CD4 count over 6 months in the ALA-supplemented compared to the control group. CONCLUSION: Supplementation with alpha-lipoic acid may positively impact patients with HIV and acquired immune deficiency syndrome by restoring blood total glutathione level and improving functional reactivity of lymphocytes to T-cell mitogens.

Glutathione inhibits HIV replication by acting at late stages of the virus life cycle.
Palamara AT,   Perno CF,   Aquaro S,   Bue MC,   Dini L,   Garaci E

In: AIDS Res Hum Retroviruses (1996 Nov 1) 12(16):1537-41

We investigated the effect of glutathione on the replication of human immunodeficiency virus (HIV) in chronically infected macrophages, a known reservoir of the virus in the body. We found that exogenous GSH strongly suppresses the production of p24gag protein as well as the virus infectivity. This is related to a dramatic decrease in both budding and release of virus particles from chronically infected cells (either macrophages or lymphocytes), together with a selective decrease in the expression of gp120, the major envelope glycoprotein, rich in intrachain disulfide bonds and thus potentially sensitive to the effect of a reducing agent such as GSH. Overall data suggest that GSH can interfere with late stages of virus replication. This would be in agreement with data obtained in cells exposed to herpesvirus type 1 (a DNA virus) or to Sendai (an RNA virus), showing that the suppression of virus replication by GSH is related to the selective inhibition of envelope glycoproteins. These results suggest a potential role of GSH in combination with other antivirals in the treatment of virus-related diseases.

Glutathione directly inhibits late stages of the replication cycle of HIV and other viruses.
Palamara AT,   Perno CF,   Milanese G,   Balestra E,   Di Francesco P,     Favalli C,   Garaci E

In: Int Conf AIDS (1993 Jun 6-11) 9(1):231 (abstract no. PO-A25-0579)

OBJECTIVES: To assess the ability of glutathione (GSH), a major intracellular antioxidant, to interfere with virus replication in chronically-infected cells, and to evaluate its potential mechanism of action. METHODS: Monocyte/macrophages chronically infected with HIV (HIV-M/M), and VERO cells infected with herpes virus-1 (HSV-1), were treated with GSH added at different time points after infection. RESULTS: GSH induced a substantial inhibition of virus protein production in HIV-M/M at non-toxic concentrations. A kinetics of virus replication clearly shows that GSH-mediated HIV-inhibition is maintained overtime in HIV-M/M. By contrast, AZT and interferon alpha were completely ineffective in HIV-M/M. A similar effect of GSH was achieved in HSV-1-infected VERO cells. Indeed, complete inhibition of HSV-1 replication, both in term of cytopathic effect and virus titer, was achieved when GSH was added before virus challenge. Substantial inhibition of HSV-1 replication was also obtained when GSH was added 24 hours after virus challenge. Similar results were achieved in an RNA virus model. Such activity of GSH seems to be related to a decrease and/or inactivation of specific virus proteins. CONCLUSIONS: These overall data suggest that GSH antiviral activity affects mainly late stages of replication, i.e. protein synthesis and/or virus assembly. Moreover, such effect is not virus specific, and seems to be due, at least in these models, to a direct antiviral effect upon virus replication more than to a cytokine-mediated phenomenon. These results also suggest the potential use of GSH in the therapy of different virus infections, including HIV.

The effectiveness of a mixture of beta-carotene, alpha-tocopherol, glutathione, and ascorbic acid for cancer prevention.
Shklar G,   Schwartz J,   Trickler D,   Cheverie SR

In: Nutr Cancer (1993) 20(2):145-51

Previous studies have shown that beta-carotene and alpha-tocopherol can act synergistically to inhibit the growth of experimentally induced oral cancer. The initial studies on the synergistic anticancer activity of antioxidants have been extended to include reduced glutathione and ascorbic acid. Sixty male hamsters (4-5 wks old) were divided into six equal groups. Groups 1-6 were treated with 7,12-dimethylbenz[a]anthracene (DMBA) (0.5% solution). Group 2 received a mixture containing equal amounts of beta-carotene, dl- alpha-tocopherol (vitamin E), glutathione, and l-ascorbic acid (vitamin C) (12.5 micrograms) delivered orally by pipette. Groups 3-6 were treated with beta-carotene alone (50 micrograms), vitamin E alone (50 micrograms), glutathione (50 micrograms) alone, and vitamin C alone (50 micrograms). Animals were euthanized at 12 and 14 weeks. Tumors were counted and measured, and tumor burden was calculated for each experimental group. The mixture of antioxidants significantly reduced tumor burden, whereas the beta-carotene, vitamin E, and reduced glutathione treatments also reduced tumor burden. beta- Carotene and glutathione provided greater levels of chemoprevention than vitamin E as single agents. In contrast, vitamin C treatment produced no antitumor effect but increased tumor burden by Week 14. This mixture of antioxidants produced a significant synergistic chemoprevention of oral cancer.

The enzymatic antioxidant system in blood and glutathione status in human immunodeficiency virus (HIV)-infected patients: effects of supplementation with selenium or beta-carotene [published erratum appears in Am J Clin Nutr 1996 Dec;64(6):971]
Delmas-Beauvieux MC,   Peuchant E,   Couchouron A,   Constans J,     Sergeant C,   Simonoff M,   Pellegrin JL,   Leng B,   Conri C,
Clerc M

In: Am J Clin Nutr (1996 Jul) 64(1):101-7

To investigate the effects of selenium or beta-carotene supplementation in human immunodeficiency virus (HIV)-infected patients, who are known to have deficiencies of selenium and vitamin A, we evaluated the blood enzymatic antioxidant system, including superoxide dismutase (SOD), selenodependent glutathione peroxidase (GPX), and catalase (Cat); glutathione (GSH) status; and plasma selenium concentration. The placebo group consisted of 18 HIV- infected patients with no supplementation, the selenium group was composed of 14 patients receiving oral selenium treatment, and the beta-carotene group comprised 13 patients receiving oral beta- carotene supplementation. All groups were studied for 1 y. At the beginning of the study, a significantly higher SOD activity (P < 0.001) was observed in all HIV-infected patients compared with uninfected control subjects, and GPX activity at baseline was higher in the placebo (P < 0.004) and selenium (P < 0.014) groups than in the control subjects. These higher enzyme activities could be related to an increased synthesis of these enzymes in erythrocyte precursors under oxidative stress. Moreover, we observed significantly lower GSH values in all HIV-infected patients than in control subjects at the beginning of the study (P < 0.001). After selenium or beta-carotene supplementation, no significant difference was observed for SOD activity compared with baseline. On the contrary, GPX activity increased significantly after selenium treatment (P < 0.04 between 3 and 6 mo), whereas a slight increase was found after beta-carotene treatment. Similarly, a significant increase in GSH values was observed at 12 mo compared with baseline both after selenium supplementation (P < 0.001) and beta-carotene supplementation (P < 0.01). Because GPX and GSH play an important role in the natural enzymatic defense system in detoxifying hydrogen peroxide in water, selenium supplementation could be of great interest in protecting cells against oxidative stress. The lower efficiency of beta-carotene could be attributed to the seriousness of the pathology at the time of recruitment into the beta-carotene group.

Exhaustive physical exercise causes oxidation of glutathione status in blood: prevention by antioxidant administration.
Sastre J,   Asensi M,   Gasco E,   Pallardo FV,   Ferrero JA,   Furukawa T,     Vina J

In: Am J Physiol (1992 Nov) 263(5 Pt 2):R992-5

We have studied the effect of exhaustive concentric physical exercise on glutathione redox status and the possible relationship between blood glutathione oxidation and blood lactate and pyruvate levels. Levels of oxidized glutathione (GSSG) in blood increase after exhaustive concentric physical exercise in trained humans. GSSG levels were 72% higher immediately after exercise than at rest. They returned to normal values 1 h after exercise. Blood reduced glutathione (GSH) levels did not change significantly after the exercise. We have found a linear relationship between GSSG-to-GSH and lactate-to-pyruvate ratios in human blood before, during, and after exhaustive exercise. In rats, physical exercise also caused an increase in blood GSSG levels that were 200% higher after physical exercise than at rest. GSH levels did not change significantly. Thus, both in rats and humans, exhaustive physical exercise causes a change in glutathione redox status in blood. We have also found that antioxidant administration, i.e., oral vitamin C, N-acetyl-L- cysteine, or glutathione, is effective in preventing oxidation of the blood glutathione pool after physical exercise in rats.

The effect of glutathione and vitamins A, C, and E on acute skin flap survival.
Hayden RE,   Paniello RC,   Yeung CS,   Bello SL,   Dawson SM

In: Laryngoscope (1987 Oct) 97(10):1176-9

Vitamins A, C, and E act as antioxidants and as free radical scavengers in biological systems. Glutathione is involved in several reactions in vitamin metabolism and also plays an important role in cell membrane protection against lipid peroxidation by free radicals. We sought to use these natural defense mechanisms against oxygen free radicals formed during reperfusion of ischemic skin flaps. An acute axial random skin flap model was utilized in the rat. Vitamins or glutathione were administered by oral gastric tube or intravenously in the perioperative period, and survival of the flap was measured at 1 week. Glutathione, beta-carotene, ascorbic acid and alpha-D- tocopherol showed mean flap survival of 84% to 89%, each of which was significantly improved over saline controls (67% p less than .0005). The mechanisms and biochemistry of these vitamins, and their interactions with other vitamins and with glutathione, are discussed, along with clinical implications of free radical scavenging and skin flap survival.

Effect of glutathione depletion on sunburn cell formation in the hairless mouse.
Hanada K,   Gange RW,   Connor MJ

In: J Invest Dermatol (1991 Jun) 96(6):838-40

Cutaneous protection against ultraviolet B (UVB) radiation damage by endogenous glutathione (GSH) was evaluated in the epidermis of the hairless mouse by measuring the influence of GSH depletion on sunburn cell (SBC) formation. Cellular GSH exerts antioxidant effects and recent studies have suggested a role for oxygen radicals in the production of SBC. Hairless mice (Skh/h 1) received oral treatment with buthionine S,R-sulfoximine (BSO), an irreversible inhibitor of gamma-glutamylcysteine synthetase, to deplete cutaneous GSH; 4 d later their ears were exposed to UVB radiation. BSO treatment significantly reduced GSH levels in the epidermis to 10-15% of control levels. Twenty-four hours after UVB exposure, SBC counts in the ears of animals with and without BSO treatment were measured, and those exposed to UVB were found to have increased. Greater numbers of SBC were found in the ears of BSO-treated mice exposed to 15 or 20 mJ/cm2 UVB, than in non-BSO-treated mice exposed to the same UVB doses. At higher UVB doses, there were no statistically significant differences between the groups. The results show that endogenous GSH provides the epidermis with measurable protection against injury by low or moderate UVB doses.

 

 

N-acetylcysteine (NAC) in PRO-C Vitamin C

Inhibition of invasion, gelatinase activity, tumor take and metastasis of malignant cells by N-acetylcysteine.

Albini A,   D’Agostini F,   Giunciuglio D,   Paglieri I,   Balansky R,     De Flora S

In: Int J Cancer (1995 Mar 29) 61(1):121-9

The thiol N-acetylcysteine (NAC) is currently considered one of the most promising cancer chemopreventive agents by virtue of its multiple and coordinated mechanisms affecting the process of chemical carcinogenesis. Recent studies have shown that an unpaired cysteine residue in the propeptide plays a key role in inactivation of latent metastasis-associated metalloproteinases: the present study was designed to assess whether NAC could also affect tumor take, invasion and metastasis of malignant cells. As assessed by zymographic analysis, NAC completely inhibited the gelatinolytic activity of type- IV collagenases in the cells tested (gelatinases A and B). Moreover, NAC was efficient in inhibiting the chemotactic and invasive activities of tumor cells of human (A2058 melanoma) and murine origin (K1735 and B16-F10 melanoma cells as well as C87 Lewis lung carcinoma cells) in Boyden-chamber assays, which are predictive of the invasive and metastatic properties. Reduced glutathione (GSH) had a similar, although less effective activity. The number of lung metastases decreased sharply when B16-F10 murine melanoma cells, injected i.v. into nude mice, were pre-treated with NAC and resuspended in medium supplemented with 10 mM NAC. In other experiments NAC was given in drinking water, starting 48-72 hr before subcutaneous inoculation of either B16-F10 cells or of their highly metastatic variant B16-BL6, or intramuscular injection of LLC cells. In all experiments NAC treatment decreased the weight of the locally formed primary tumor and produced a dose-related delay in tumor formation. Spontaneous metastasis formation by B16-F10 and B16-BL6 tumors was slightly yet significantly reduced by oral administration of NAC. However, this was not observed for Lewis lung tumors. These data indicate that NAC affects the process of tumor-cell invasion and metastasis, probably due to inhibition of gelatinases by its sulfhydryl group, with the possible contribution of other mechanisms, including the potent antioxidant activity of this thiol.

 

Grape seed proanthocyanidins and Antioxidants in PRO-C

Protective effects of grape seed proanthocyanidins and selected antioxidants against TPA-induced hepatic and brain lipid peroxidation and DNA fragmentation, and peritoneal macrophage activation in mice.

Bagchi D,   Garg A,   Krohn RL,   Bagchi M,   Bagchi DJ,   Balmoori J,     Stohs SJ

In: Gen Pharmacol (1998 May) 30(5):771-6

1. The comparative protective abilities of a grape seed proanthocyanidin extract (GSPE) (25-100 mg/kg), vitamin C (100 mg/kg), vitamin E succinate (VES) (100 mg/kg) and beta-carotene (50 mg/kg) on 12-O-tetradecanoylphorbol-13-acetate (TPA)-induced lipid peroxidation and DNA fragmentation in the hepatic and brain tissues, as well as production of reactive oxygen species by peritoneal macrophages, were assessed. 2. Treatment of mice with GSPE (100 mg/kg), vitamin C, VES and beta-carotene decreased TPA-induced production of reactive oxygen species, as evidenced by decreases in the chemiluminescence response in peritoneal macrophages by approximately 70%, 18%, 47% and 16%, respectively, and cytochrome c reduction by approximately 65%, 15%, 37% and 19%, respectively, compared with controls. 3. GSPE, vitamin C, VES and beta-carotene decreased TPA-induced DNA fragmentation by approximately 47%, 10%, 30% and 11%, respectively, in the hepatic tissues, and 50%, 14%, 31% and 11%, respectively, in the brain tissues, at the doses that were used. Similar results were observed with respect to lipid peroxidation in hepatic mitochondria and microsomes and in brain homogenates. 4. GSPE exhibited a dose-dependent inhibition of TPA- induced lipid peroxidation and DNA fragmentation in liver and brain, as well as a dose-dependent inhibition of TPA-induced reactive oxygen species production in peritoneal macrophages. 5. GSPE and other antioxidants provided significant protection against TPA-induced oxidative damage, with GSPE providing better protection than did other antioxidants at the doses that were employed.

The effect of antioxidants on MNNG-induced stomach carcinogenesis in rats.
Balansky RM,   Blagoeva PM,   Mircheva ZI,   Stoitchev I,   Chernozemski I

In: J Cancer Res Clin Oncol (1986) 112(3):272-5

The effect of vitamins A, C and E, butylated hydroxytoluene (BHT) and glutathione (GSH) on gastric carcinogenesis induced by N-methyl-N- nitro-N-nitrosoguanidine (MNNG) was investigated. Male and female BD- VI rats 2-3 months old received a single oral application of MNNG dissolved in corn oil. The male rats were divided into four groups: Group-I: MNNG 250 mg/kg by intubation; Group-II: MNNG + vitamin C daily in the drinking water (400 mg/l); Group-III: MNNG + vitamin C (400 mg/l) + 100 g of milk broth (for each of 10 rats) containing vitamin A (40,000 IU), vitamin E (0.5 g) and BHT (0.1 g) three times a week. The treatment with antioxidants started 7 days before the MNNG administration and continued until the end of experiment. Group- IV rats received MNNG + oxyferriscorbone, i.p. as a single dose of 1.0 mg/kg, daily during the week before and the week after MNNG exposure and than 3 times a week till the end of the experiment. Female rats were divided into two groups: Group-I: MNNG 333 mg/kg by intubation; Group-II: MNNG + GSH orally at a dose of 100 mg/rat 1 h before and 5, 24, 48, and 72 h after MNNG intubation. The incidence of gastric tumors after 15 months of treatment was as follows: male rats, 82.4% in Group-I, 40.0% in Group-II, 40.7% in Group-III, and 50.0% in Group-IV; female rats; 72.7% in Group-I, and 36.0% in Group- II.

 

Comparative study of the anti-HIV activities of ascorbate and thiol- containing reducing agents in chronically HIV-infected cells.
Harakeh S,   Jariwalla RJ

In: Am J Clin Nutr (1991 Dec) 54(6 Suppl):1231S-1235S

To elucidate the action of vitamin C on pathogenic human retroviruses, we investigated and compared the effects of noncytoxic concentrations of ascorbic acid (AA), its calcium salt (Ca- ascorbate), and two thiol-based reducing agents [glutathione (GSH) and N-acetyl-L-cysteine (NAC)] against human immunodeficiency virus (HIV)-1 replication in chronically infected T lymphocytes. Ca- ascorbate reduced extracellular HIV reverse transcriptase (RT) activity by about the same magnitude as the equivalent dose of AA. Long-term experiments showed that continuous presence of ascorbate was necessary for HIV suppression. NAC (10 mmol/L) caused less than twofold inhibition of HIV RT and conferred a synergistic effect (approximately eightfold inhibition) when tested simultaneously with AA (0.426 mmol/L). In contrast, nonesterified GSH (less than or equal to 1.838 mmol/L) had no effect on RT concentrations and did not potentiate the anti-HIV effect of AA. These results further support the potent antiviral activity of ascorbate and suggest its therapeutic value in controlling HIV infection in combination with thiols.

Oxygen free radical scavenging abilities of vitamins C and E, and a grape seed proanthocyanidin extract in vitro.
Bagchi D,   Garg A,   Krohn RL,   Bagchi M,   Tran MX,   Stohs SJ

In: Res Commun Mol Pathol Pharmacol (1997 Feb) 95(2):179-89

Proanthocyanidins, a group of polyphenolic bioflavonoids, have been reported to exhibit a wide range of biological, pharmacological and chemoprotective properties against oxygen free radicals. We have assessed the concentration-dependent oxygen free radical scavenging abilities of a grape seed proanthocyanidin extract (GSPE), vitamin C and vitamin E succinate (VES) as well as superoxide dismutase, catalase and mannitol against biochemically generated superoxide anion and hydroxyl radical using a chemiluminescence assay and cytochrome c reduction. A concentration-dependent inhibition was demonstrated by GSPE. At a 100 mg/l concentration, GSPE exhibited 78- 81% inhibition of superoxide anion and hydroxyl radical. Under similar conditions, vitamin C inhibited these two oxygen free radicals by approximately 12-19%, while VES inhibited the two radicals by 36-44%. The combination of superoxide dismutase and catalase inhibited superoxide anion by approximately 83%, while mannitol resulted in an 87% inhibition of hydroxyl radical. The results demonstrate that GSPE is a more potent scavenger of oxygen free radicals as compared to vitamin C and VES.

Clinical and capillaroscopic evaluation of chronic uncomplicated venous insufficiency with procyanidins extracted from vitis vinifera
Costantini A,   De Bernardi T,   Gotti A

In: Minerva Cardioangiol (1999 Jan-Feb) 47(1-2):39-46

BACKGROUND: The pharmacological treatment of non-complicated chronic venous insufficiency is a current and well-debated topic. The introduction of new products with action on the venous system, improved knowledge on the physiopathology of venous insufficiency and the possibility provided by new analytical instruments, have given new impulse to the consolidation of the clinical value of phlebotonics in this indication. METHODS: In light of this, 24 patients with non-complicated chronic venous insufficiency were treated with oral administration of Oligomeric Proanthocyanidins (Pycnogenols-OPC) 100 mg/day. To evaluate the therapeutic efficacy of the treatment, an instrumental evaluation by optical probe capillaroscope was employed in addition to the traditional subjective clinical parameters: swelling, itching, heaviness and pain. The videocapillaroscope examination was performed at the lower third of the leg and the first toe. Edema in the capillaroscopic field, the number of observable capillaries and the capillary dilatation were the parameter chosen to evaluate the efficacy of treatment. All patients completed the study with no reports of adverse events during the period of observation. RESULTS: The results obtained show a positive clinical response (improved or absent symptoms) in over 80% of patients, with significant improvement of symptoms already evident after the first 10 days of treatment. The mechanism of action of the OPCs explains the rapid reduction of the swelling of the lower limbs and correlated with this are the other evaluable symptoms: heaviness and itching. Particularly striking results were observed for itching and pain which completely disappeared during the course of therapy in 80% and 53% of the patients respectively. Noteworthy is the good correlation between the clinical and instrumental data, with improvement in a total of 70% of patients. CONCLUSIONS: The results obtained in the course of this clinical experience, with evident improvement already during the first weeks of treatment, the absence of adverse events added to the benefit of a once-a-day administration, justify the use of OPC in the treatment of non- complicated chronic venous insufficiency.

Antiexudative and capillaritonic effects of procyanidines isolated from grape seeds (V. Vinifera).
Zafirov D,   Bredy-Dobreva G,   Litchev V,   Papasova M

In: Acta Physiol Pharmacol Bulg (1990) 16(3):50-4

A purified and enriched fraction, containing procyanidines, was isolated from grape seeds of Bulgarian sorts of Vitis Vinifera. The effects of procyanidines on the local oedema, produced by subplantar injection of carrageenin and dextran in the hind rat paw, were studied. We also tested their effect on the capillary permeability using intravenous injection of Evans blue and local irritation by xylene. Procyanidines at a dose of 2 mg/kg applied orally three times daily for 6 days inhibited the carrageenin-induced hind paw oedema. On the same schedule of administration these compounds inhibited the dextran-induced oedema 4 hours after the development of the process. Procyanidines stabilized the capillary wall and prevented the increase of capillary permeability caused by local cutaneous application of xylene.

Proanthocyanidin-rich extract from grape seeds attenuates the development of aortic atherosclerosis in cholesterol-fed rabbits.
Yamakoshi J,   Kataoka S,   Koga T,   Ariga T

In: Atherosclerosis (1999 Jan) 142(1):139-49

The aim of this study was to evaluate the antiatherosclerotic effect of proanthocyanidin-rich extracts from grape seeds in cholesterol-fed rabbits. Proanthocyanidin-rich extracts (0.1% and 1% in diets [w/w]) did not appreciably affect the changes in serum lipid profile of cholesterol-fed rabbits. The level of cholesteryl ester hydroperoxides (ChE-OOH) induced by 2,2′-azobis(2-amidinopropane- dihydrochloride (AAPH) were lower in the plasma of rabbits fed proanthocyanidin-rich extract plus cholesterol than in the plasma of rabbits fed cholesterol alone, but not in the low-density lipoprotein (LDL). Aortic malondialdehyde (MDA) content decreased in rabbits fed proanthocyanidin-rich extract. Feeding proanthocyanidin-rich extracts (0.1 and 1% in the diet) to rabbits significantly reduced severe atherosclerosis in the aorta. Immunohistochemical analysis revealed a decrease in the number of oxidized LDL-positive macrophage-derived foam cells in atherosclerotic lesions in the aorta of rabbits fed proanthocyanidin-rich extract. When proanthocyanidin-rich extract was administered orally to rats, proanthocyanidin was detected in the plasma by Porters method but not in the lipoproteins (LDL plus VLDL). In an in vitro experiment using human plasma, proanthocyanidin-rich extract added to the plasma inhibited the oxidation of cholesteryl linoleate in LDL, but not in the LDL isolated after the plasma and the extract were incubated in advance. These results suggested that proanthocyanidins, the major polyphenols in red wine, might trap reactive oxygen species in aqueous series such as plasma and interstitial fluid of the arterial wall, thereby inhibiting oxidation of LDL and showing an antiatherosclerotic activity.

High protection by grape seed proanthocyanidins (GSPC) of polyunsaturated fatty acids against UV-C induced peroxidation.
Bouhamidi R,   Prevost V,   Nouvelot A

In: C R Acad Sci III (1998 Jan) 321(1):31-8

The antioxidative effects of grape seed proanthocyanidins (GSPC) were studied in three in-vitro models in which polyunsaturated fatty acids (PUFAs) in aqueous solution and mice liver or brain microsomes were used as oxidative substrates, and UV-C irradiation as the pro-oxidant system. Analysis of UV-C induced lipid peroxidation was carried out by two methods: gas liquid chromatography of residual PUFAs and release of thiobarbituric acid-reactive substances (TBARs) measured by TBA reaction. Results indicate that PUFAs are more radiosensitive when incorporated in single component micelles than in mixed component micelles or microsomes. In every case, PUFA peroxidation was inhibited by low concentrations of GSPC (2 mg/L) while epigallocatecin (EGC) and epigallocatechin gallate (EGCG) monomers, at an equivalent level of epicatechin, exhibited no efficacy in our experimental conditions. This latter effect might be explained by a synergistic action of flavan-3-ol monomers, dimers and oligomers contained in the grape seed extract.

Enhancement of antioxidant and phase II enzymes by oral feeding of green tea polyphenols in drinking water to SKH-1 hairless mice: possible role in cancer chemoprevention.
Khan SG,   Katiyar SK,   Agarwal R,   Mukhtar H

In: Cancer Res (1992 Jul 15) 52(14):4050-2

Following the oral feeding of a polyphenolic fraction isolated from green tea (GTP) in drinking water, an increase in the activities of antioxidant and phase II enzymes in skin, small bowel, liver, and lung of female SKH-1 hairless mice was observed. GTP feeding (0.2%, w/v) to mice for 30 days significantly increased the activities of glutathione peroxidase, catalase, and quinone reductase in small bowel, liver, and lungs, and glutathione S-transferase in small bowel and liver. GTP feeding to mice also resulted in considerable enhancement of glutathione reductase activity in liver. In general, the increase in antioxidant and phase II enzyme activities was more pronounced in lung and small bowel as compared to liver and skin. The significance of these results can be implicated in relation to the cancer chemopreventive effects of GTP against the induction of tumors in various target organs.

 

Selenium in PRO-C Vitamin C

Serum selenium concentrations in rheumatoid arthritis.
O’Dell JR,   Lemley-Gillespie S,   Palmer WR,   Weaver AL,   Moore GF,     Klassen LW

In: Ann Rheum Dis (1991 Jun) 50(6):376-8

Selenium is a trace element and an essential part of the enzyme glutathione peroxidase, which protects cells from oxidative damage. Selenium has been shown to have antiproliferative, anti-inflammatory, antiviral, and immune altering effects. Serum selenium concentrations in 101 patients with seropositive rheumatoid arthritis were found to be significantly lower than those in 29 normal, healthy controls (mean (SD) 148 (42) v 160 (25) micrograms/l) and also lower than those in eight patients with fibrositis (148 (42) v 166 (25) micrograms/l). It is speculated that serum selenium concentrations may modulate the effect of viral or other infections in subjects with the appropriate genetic background and in this way enhance the development or progression of rheumatoid arthritis.

Studies on selenium in top athletes.
Dragan I,   Ploesteanu E,   Cristea E,   Mohora M,   Dinu V,   Troescu VS

In: Physiologie (1988 Oct-Dec) 25(4):187-90

The authors performed a controlled trial in 18 top athletes (9 weight lifters and 9 rowers, girls) in order to make evident some chronic and acute effects (antioxidant) of selenium. Nonprotein–SH (essential glutathione), lipid peroxides (MDA-malondialdehyde), glucose-6-phosphate dehydrogenases (G-6-PDH) and fructose-1,6- diphosphate aldolase in serum, have been recorded initially on basal conditions, after 3 weeks of treatment (100 micrograms/day selenium or placebo) and again after 3 weeks of treatment, also on basal conditions, when crossing over the groups (between a free interval of 10 days). In another trial we registered these parameters on basal conditions and after two hours of hard training accompanied by a per oral administration of 150 micrograms selenium (respectively placebo). The results show significant changes under selenium treatment of the peroxides, G-6-PDH and light changes, not significant of the nonprotein–SH, changes which could suggest an antioxidant effect of this element.

 

Alpha-Lipoic acid in PRO-C Vitamin C

Alpha-Lipoic acid as a biological antioxidant.
Packer L   Witt EH   Tritschler HJ

In: Free Radic Biol Med (1995 Aug) 19(2):227-50

alpha-Lipoic acid, which plays an essential role in mitochondrial dehydrogenase reactions, has recently gained considerable attention as an antioxidant. Lipoate, or its reduced form, dihydrolipoate, reacts with reactive oxygen species such as superoxide radicals, hydroxyl radicals, hypochlorous acid, peroxyl radicals, and singlet oxygen. It also protects membranes by interacting with vitamin C and glutathione, which may in turn recycle vitamin E. In addition to its antioxidant activities, dihydrolipoate may exert prooxidant actions through reduction of iron. alpha-Lipoic acid administration has been shown to be beneficial in a number of oxidative stress models such as ischemia-reperfusion injury, diabetes (both alpha-lipoic acid and dihydrolipoic acid exhibit hydrophobic binding to proteins such as albumin, which can prevent glycation reactions), cataract formation, HIV activation, neurodegeneration, and radiation injury. Furthermore, lipoate can function as a redox regulator of proteins such as myoglobin, prolactin, thioredoxin and NF-kappa B transcription factor. We review the properties of lipoate in terms of (1) reactions with reactive oxygen species; (2) interactions with other antioxidants; (3) beneficial effects in oxidative stress models or clinical conditions.

Effect of antioxidants on radical intensity and cytotoxic activity of eugenol.
Satoh K,   Ida Y,   Sakagami H,   Tanaka T,   Fujisawa S

In: Anticancer Res (1998 May-Jun) 18(3A):1549-52

The effect of antioxidants on the radical intensity of 2-methoxy-4-(2- propenyl)phenol (eugenol) was investigated, using ESR spectroscopy. Eugenol produced radicals in alkaline solutions, with an optimum pH of 9.5. The intensity of eugenol radical was a positive function of its concentration, reaching a plateau level at 100 mM. The eugenol radical was rapidly diminished under alkaline conditions. Water- soluble antioxidants, such as cysteine, N-acetyl-L-cysteine, glutathione and sodium ascorbate, completely scavenged the eugenol radical. Gallic acid at lower doses significantly, but not completely, scavenged the eugenol radical. Among water-insoluble antioxidants, terpenes (beta-carotene, retinol, lycopene) effectively scavenged the eugenol radical, whereas phenolic compounds (alpha- tocopherol, Trolox) were inactive. Millimolar concentrations of eugenol were cytotoxic against human salivary gland and oral squamous carcinoma cell lines. Addition of sodium ascorbate or beta-carotene reproducibly reduced the cytotoxic activity of eugenol. The applicability of the antioxidants in dentistry was discussed.

 

 

Enhancement of antioxidant and phase II enzymes by oral feeding of green tea polyphenols in drinking water to SKH-1 hairless mice: possible role in cancer chemoprevention.
Khan SG,   Katiyar SK,   Agarwal R,   Mukhtar H

In: Cancer Res (1992 Jul 15) 52(14):4050-2

Following the oral feeding of a polyphenolic fraction isolated from green tea (GTP) in drinking water, an increase in the activities of antioxidant and phase II enzymes in skin, small bowel, liver, and lung of female SKH-1 hairless mice was observed. GTP feeding (0.2%, w/v) to mice for 30 days significantly increased the activities of glutathione peroxidase, catalase, and quinone reductase in small bowel, liver, and lungs, and glutathione S-transferase in small bowel and liver. GTP feeding to mice also resulted in considerable enhancement of glutathione reductase activity in liver. In general, the increase in antioxidant and phase II enzyme activities was more pronounced in lung and small bowel as compared to liver and skin. The significance of these results can be implicated in relation to the cancer chemopreventive effects of GTP against the induction of tumors in various target organs.

 

N-Acetyl Cysteine in PRO-C Vitamin C

N-acetyl cysteine enhances the response to interferon-alpha in chronic hepatitis C: a pilot study.
Beloqui O,   Prieto J,   Suarez M,   Gil B,   Qian CH,   Garcia N,     Civeira MP

In: J Interferon Res (1993 Aug) 13(4):279-82

Hepatitis C virus (HCV) is an RNA virus that replicates in both the liver and lymphoid cells. Interferon-alpha (IFN-alpha) is a useful treatment of chronic hepatitis C (CHC) although resistance to this drug occurs frequently. The mechanisms underlying resistance to IFN remain unknown. In this work, we have measured the levels of glutathione in plasma and peripheral lymphoid cells from 15 healthy controls and 24 CHC patients, 10 of whom were without treatment and 14 showed high serum alanine aminotransferase (ALT) values despite therapy with lymphoblastoid IFN for more than 4 months. In all patients, glutathione levels in plasma and in mononuclear cells were depressed in comparison to controls. In IFN-unresponsive patients, the addition of 600 mg tid of oral N-acetyl cysteine (NAC), a glutathione precursor, resulted in a steady decrease of ALT values in all patients, with complete normalization in 41% of cases after 5-6 months of combined therapy. Administration of NAC alone for 1 month was without effect in the 10 patients that were not receiving IFN. Supplementation of IFN with NAC induced a near normalization of intralymphocytic glutathione, but plasma levels were only moderately increased. HCV replication was markedly inhibited in lymphocytes and viremia was cleared in one of the 8 patients tested. In conclusion, NAC enhances the response to IFN in CHC. Controlled studies are needed to ascertain whether antioxidant therapy might act in synergy with IFN in chronic viral hepatitis.

N-acetylcysteine and glutathione as inhibitors of tumor necrosis factor production.
Peristeris P,   Clark BD,   Gatti S,   Faggioni R,   Mantovani A,     Mengozzi M,   Orencole SF,   Sironi M,   Ghezzi P

In: Cell Immunol (1992 Apr) 140(2):390-9

TNF is a major mediator in the pathogenesis of endotoxic shock, and its inhibition has a protective effect in various animal models of sepsis or endotoxin (lipopolysaccharide, LPS) toxicity. LPS treatment also induces an oxidative damage mediated by increased production of reactive oxygen intermediates. N-Acetylcysteine (NAC) is an antioxidant and a precursor of the synthesis of glutathione (GSH) and was reported to protect against LPS toxicity and LPS-induced pulmonary edema. In this study we investigated the effect of NAC on TNF production and LPS lethality in mice. The results indicated that oral administration of NAC protects against LPS toxicity and inhibits the increase in serum TNF levels in LPS-treated mice. The inhibition was not confined to the released form of TNF, since NAC also inhibited LPS-induced spleen-associated TNF. On the other hand, the inhibitor of GSH synthesis, DL-buthionine-(SR)-sulfoximine (BSO), had the opposite effect of potentiating LPS-induced TNF production, and this was associated with a decrease in liver GSH levels. Repletion of liver GSH with NAC reversed this effect. NAC was also active in inhibiting TNF production and hepatotoxicity in mice treated with LPS in association with a sensitizing dose of Actinomycin D. These data indicate that GSH can be an endogenous modulator of TNF production in vivo. On the other hand, NAC pretreatment did not inhibit other effects of LPS, particularly induction of serum IL-6, spleen IL-1 alpha, and corticosterone, in the same experimental model, suggesting that the observed effect could be specific for TNF.

Reduction of oxidative stress by oral N-acetyl-L-cysteine treatment decreases plasma soluble vascular cell adhesion molecule-1 concentrations in non-obese, non-dyslipidaemic, normotensive, patients with non-insulin-dependent diabetes.
De Mattia G,   Bravi MC,   Laurenti O,   Cassone-Faldetta M,   Proietti A,     De Luca O,   Armiento A,   Ferri C

In: Diabetologia (1998 Nov) 41(11):1392-6

To assess in vivo effects of antioxidants on vascular cell adhesion molecule (VCAM)-1 expression, circulating soluble VCAM-1 and intraerythrocytic reduced glutathione (GSH) and GSH disulphide (GSSG) concentrations were evaluated in non-insulin-dependent diabetic patients without complications (9 men, 6 women, 48 +/- 6 years old) before and after 1 month of either oral N-acetyl-L-cysteine (1.200 mg/day) or placebo treatments, given in randomized, cross-over, double-blind fashion. Ten healthy subjects (7 men, 3 women, 52 +/- 4 years old) served as control subjects. Baseline plasma VCAM-1 concentrations were higher (p = 0.007) in non-insulin-dependent diabetic patients (707.9 +/- 52.5 ng/ml) than in control subjects (627.3 +/- 84.6 ng/ml). Intraerythrocytic GSSG content was higher (non-insulin dependent diabetic patients: 0.618 +/- 0.185 micromol/g Hb; control subjects: 0.352 +/- 0.04 micromol/g Hb, p = 0.0002), whereas intraerythrocytic GSH concentrations were lower (p = 0.001) in non-insulin dependent diabetic patients (6.0 +/- 0.7 micromol/g Hb) than in control subjects (7.1 +/- 0.5 micromol/g Hb). The mean GSH:GSSG ratio was also lower (p = 0.0001) in the first (10.9 +/- 4.5) than in the second group (20.2 +/- 1.4). Circulating VCAM-1 and intraerythrocytic GSH concentrations were negatively correlated in non-insulin diabetic patients (r = 0.605, p = 0.01). Treatment with N- acetyl-L-cysteine decreased plasma VCAM-1 (p = 0.01) and intraerythrocytic GSSG (p = 0.006) but increased GSH concentrations (p = 0.04) and the GSH:GSSG ratio (p = 0.004) in non-insulin dependent diabetic patients. Our data indicate that the vascular endothelium is activated in non-insulin dependent diabetes. Antioxidant treatment counterbalanced such endothelial activation. Thus, antioxidant agents might protect against oxidant-related upregulation of endothelial adhesion molecules and slow down the progression of vascular damage in non-insulin dependent diabetes.

The effect of oral N-acetylcysteine on lung glutathione levels in idiopathic pulmonary fibrosis
Meyer A,   Buhl R,   Magnussen H

In: Eur Respir J (1994 Mar) 7(3):431-6

Idiopathic pulmonary fibrosis (IPF) is characterized by an increased oxidant burden and by a deficiency of glutathione, a major antioxidant, in the lung epithelial lining fluid (ELF). Therefore, a rational therapeutic approach is to reverse the imbalance between oxidants and antioxidants in the lung by enhancing the antioxidant screen. With this background, the aim of our study was to evaluate oral N-acetylcysteine (NAC) as a strategy to augment lung glutathione levels in patients with IPF. Concentrations of total glutathione in bronchoalveolar lavage fluid (BALF) were quantified spectrophotometrically, before and following oral therapy with 3 x 600 mg NAC per day for 5 days, in 17 nonsmoking patients with biopsy- proven IPF. The volume of ELF recovered by BAL was determined using the urea method. Pretherapy, total glutathione levels in ELF in IPF patients were significantly less than normal (187 +/- 36 vs 368 +/- 60 microM), in contrast to levels in BALF (0.99 +/- 0.12 vs 1.18 +/- 0.19 microM). Following therapy with oral NAC, glutathione levels in BALF were 1.54 +/- 0.24 microM (a significant increase compared to pretherapy), whereas the increase in ELF levels (319 +/- 92 microM) did not reach significance. The therapy was well-tolerated, and all routine clinical and bronchoscopic parameters remained unchanged. It is thus feasible and safe to augment deficient lung glutathione levels in patients with IPF; thereby, potentially augmenting pulmonary antioxidant protection.

Protection by N-acetylcysteine against pulmonary endothelial cell damage induced by oxidant injury
Sala R,   Moriggi E,   Corvasce G,   Morelli D

In: Eur Respir J (1993 Mar) 6(3):440-6

The protective effect of N-acetylcysteine (NAC) against oxidant lung injury was investigated in a model of acute immunological alveolitis in the rat. Intrapulmonary immune complex deposition into rat lungs, induced by intratracheal infusion of immunoglobulin G (IgG) anti- bovine serum albumin (BSA) antibodies and intravenous injection of the antigen, caused lung damage associated with a marked decrease in [14C]5-hydroxytryptamine ([14C]5HT) uptake capacity, taken as a biochemical marker of endothelial cell function. The oral administration of a single dose of NAC (2 mmol.kg-1) 60 min before antigen/antibody (Ag/Ab) treatment was effective in preventing pulmonary endothelial cell [14C]5HT uptake loss induced by immune complex deposition. The mechanisms involved in this lung protective action of NAC were investigated by studying the antioxidant activity of NAC on hypoxanthine/xanthine oxidase-induced lung damage in vitro, and the effectiveness of the drug as lung glutathione (reduced form) (GSH) precursor in diethylmaleate-depleted rats. The results obtained provide further evidence on the ability of NAC to reduce the susceptibility of lung tissue to free radical-induced damage, by potentiating the antioxidant defence systems.

 

Miscellaneous PRO-C Vitamin C

Biochemical and morphological studies on the effects of anthocyans and vitamin E on carbon tetrachloride induced liver injury.
Mitcheva M,   Astroug H,   Drenska D,   Popov A,   Kassarova M

In: Cell Mol Biol (Noisy-le-grand) (1993 Jun) 39(4):443-8

The effects of the natural antioxidants-anthocyans and vitamin E (in a solubilized pharmaceutical form) on carbon tetrachloride-induced liver injury in rats are studied. The changes in the activity of serum transaminases (ALAT and ASAT), the content of the reduced glutathione and cytochrome P-450 as well as the intensity of the processes of lipid peroxidation are assessed. The anthocyans exert a protective effect comparable to that of vitamin E on liver cells. The favorable effects of the combination of the antioxidants on the content of the reduced glutathione and on the processes of lipid peroxidation are more intensely expressed. The morphological changes occurring in hepatocytes correlate with the results of the biochemical studies. It is evident that both substances have a marked hepatoprotective activity.

Oxidant-protease interaction in the lung. Prospects for antioxidant therapy.
Buhl R,   Meyer A,   Vogelmeier C

In: Chest (1996 Dec Dec) 110(6 Suppl):267S-272S

In inflammatory lung disorders, oxidants and proteases complement each other in their potential to destroy lung parenchyma. It is therefore rational to combine therapeutic strategies aimed at augmenting the antiproteolytic defenses of the lung in diseases such as emphysema with antioxidant strategies. In the healthy lung, the oxidant burden is balanced by the local antioxidant defenses. However, both an increased oxidant burden and/or decreased antioxidant defenses may reverse the physiologic oxidant-antioxidant balance in favor of oxidants, leading to lung injury. This concept points to an obvious therapeutic strategy: augmentation of the antioxidant screen of the lung to prevent oxidant-mediated tissue damage. Studies using reduced glutathione (GSH), the major pulmonary antioxidant, as a model therapeutic agent demonstrated that GSH can be administered directly to the respiratory epithelial surface by aerosol and is fully functional as an antioxidant both in vitro and in vivo. In pulmonary diseases such as idiopathic pulmonary fibrosis or following HIV infection, GSH aerosol therapy not only normalized deficient pretherapy GSH levels in the lung, but was capable of favorably influencing cellular events such as oxidant release by pulmonary inflammatory cells. The same was true for oral antioxidant therapy with N-acetylcysteine, a glutathione precursor. These results suggest that it is possible to use antioxidants to reverse the imbalance between oxidants and antioxidants at the site of oxidant injury to prevent the progressive tissue damage in lung disorders characterized by high oxidant states. Antioxidants, alone and in combination with antiproteases, merit further long-term studies for clinical therapy.

Hyperglycemia-induced thrombin formation in diabetes. The possible role of oxidative stress.
Ceriello A,   Giacomello R,   Stel G,   Motz E,   Taboga C,   Tonutti L,     Pirisi M,   Falleti E,   Bartoli E

In: Diabetes (1995 Aug Aug) 44(8):924-8

Diabetes is characterized by the existence of a thrombosis-prone condition, possibly related to hyperglycemia. However, the mechanism linking hyperglycemia to the activation of the coagulation cascade is still unclear. It has been recently suggested that diabetes is accompanied by increased oxidative stress. In this work, the possibility that oxidative stress may be involved in the hyperglycemia-induced coagulation activation has been evaluated. Prothrombin fragment 1 + 2 (F1 + 2), which represents a reliable marker of the amount of thrombin released in the circulation, has been chosen for studying thrombin formation in vivo. In nine type II diabetic patients and in seven healthy control subjects, matched for age and body mass index, three different experiments were performed: oral glucose tolerance test (OGTT), intravenous antioxidant glutathione (GSH) administration for 2 h, and OGTT plus intravenous GSH administration. Samples were drawn at -15 min and every 30 min from 0 to 180 min. During the OGTT, F1 + 2 significantly increased in both diabetic and healthy subjects. GSH administration during OGTT normalized this phenomenon. GSH administration alone significantly decreased F1 + 2 in diabetic patients, while no effect was observed in the normal subjects. These data suggest that hyperglycemia may induce thrombin activation, possibly inducing an oxidative stress, and that antioxidant GSH may counterbalance this effect.

Hyperglycemia-induced circulating ICAM-1 increase in diabetes mellitus: the possible role of oxidative stress.
Ceriello A,   Falleti E,   Motz E,   Taboga C,   Tonutti L,   Ezsol Z,     Gonano F,   Bartoli E

In: Horm Metab Res (1998 Mar) 30(3):146-9

ICAM-1 is one of the most important intercellular adhesion molecules involved in atherogenesis. Previous studies reported increased circulating ICAM-1 plasma levels in NIDDM patients with or without vascular complications. It has been suggested that an acute increase of plasma glucose may produce an oxidative stress in man, and in vitro studies have demonstrated that high glucose and free radicals induce cellular expression of ICAM-1. In this study, three different experiments were performed in nine NIDDM patients and in seven matched healthy controls: oral glucose tolerance test, antioxidant glutathione i.v. administration for two h, oral glucose tolerance test plus glutathione i.v. administration. Blood samples were drawn at -15 min and every 30 min from 0 to 180 min. During the oral glucose tolerance test, circulating ICAM-1 plasma levels significantly increased in both diabetic and normal subjects. Glutathione administration during the oral glucose tolerance test abolished this phenomenon. Glutathione administered alone significantly decreased circulating ICAM-1 plasma levels in diabetic patients, while no effect was observed in the normal subjects. These data suggest that hyperglycemia may induce an increase of circulating ICAM-1 plasma levels through an oxidative stress, and that the antioxidant glutathione counterbalances this effect. These data support the hypothesis of a causal relationship linking hyperglycemia, oxidative stress and atherogenesis in diabetes mellitus.

 

Mitochondrial glutathione oxidation correlates with age-associated oxidative damage to mitochondrial DNA.
de la Asuncion JG,   Millan A,   Pla R,   Bruseghini L,   Esteras A,     Pallardo FV,   Sastre J,   Vina J

In: FASEB J (1996 Feb) 10(2):333-8

Mitochondria may be primary targets of free radical damage associated with aging. We have found that mitochondrial glutathione is markedly oxidized with aging in rats and mice. The oxidized to reduced glutathione ratio rises with aging in the liver, kidney, and brain. The magnitude of these changes is much higher than that previously found in whole cells of any species previously studied. In the liver, this ratio (expressing GSSG as a percent of GSH) changed from 0.77 +/- 0.19% (n=5) in young rats to 2.47 +/- 1.25% (n=5) in old ones, i.e., 320% of the controls. In the brain and kidney, values for old rats were, respectively, 600 and 540% higher than those of young rats. A marked oxidation of mitochondrial glutathione also occurred in mice. Aging also caused an increase in 8-oxo-7,8-dihydro-2′-deoxyguanosine levels in mtDNA in rats and mice. Oral antioxidant administration protected against both glutathione oxidation and mtDNA damage in rats and mice. Finally, we have found a direct relationship between mtDNA damage and mitochondrial glutathione oxidation. This occurs both in rats (r=0.95) and in mice (r=0.98). This relationship, which has been observed for the first time in these studies, underscores the role of glutathione in the protection against free radical damage that occurs upon aging.

Delayed tumor onset in transgenic mice fed an amino acid based diet supplemented with red wine solids (Meeting abstract).
Clifford AJ,   Powers TJ,   Ebeler SE,   Ebeler JD,   Bills ND,     Hinrichs SH

In: FASEB J (201994) 8(5):A720

Common dietary phenols, tannins, catechins, anthocyanins and hydroxycinnamates perform beneficial functions by serving as antioxidants, antimicrobials, antivirals, antimutagens and anticarcinogens. Wines retain some of the natural phenols of grapes. Studies that have utilized wine have confirmed the results obtained with phenols or phenolic fractions. To determine the effect of feeding red wine solids (residue after lyophilizing) on the age at tumor onset and on the concentrations of phenolics in tissues and tumors, we bred heterozygous transgenic mice carrying the human T- lymphotropic virus type 1 tax1 (transactivator) gene and systematically assigned their offspring at weaning (within litters) to a nutritionally adequate amino acid based diet (control) or to the same diet supplemented with the lyophilized residue from 0.75 L red table wine/kg diet. Our results show that the age at tumor onset was significantly delayed in transgenic mice fed an amino acid based diet supplemented with red wine solids. Fifty percent of the transgenic mice fed the control diet already had developed tumors before the first tumor appeared in mice fed the supplemented diet. The first tumor appeared at 55 days of age in transgenic mice fed the control diet but not until 74 days of age in those fed the supplemented diet. Use of the transgenic mouse model and chemically defined diets where test nutrients can be rigidly controlled, offer great potential for possibly identifying the components of dietary fruits and vegetables that reduce cancer risk.

The polyphenolic content of fruit and vegetables and their antioxidant activities. What does a serving constitute?
Paganga G,   Miller N,   Rice-Evans CA

In: Free Radic Res (1999 Feb) 30(2):153-62

Analysis of the major flavone, flavonol, anthocyanidin and hydroxycinnamic acid constituents (and their glycosides) of onion, tomato, egg plant and apple has been undertaken and the antioxidant activities of the phenolic extracts determined. The major phenolic antioxidant components of egg plant are chlorogenic acid in the flesh and a delphinidin conjugate in the skin. In the case of apple, the major phenolic antioxidants detected are chlorogenic acid, procyanidins/catechin compounds, rutin and phloridzin. Quercetin glycosides are well-known to be the major phenolic components of onion. Assessment of the antioxidant activities of a serving of 100g fresh weight fruit, vegetable and comparison with previously reported findings for 150 ml beverage (500 ml portion in the case of beer), expressed in micromol Trolox equivalents show that the antioxidant activities of 1 glass (150 ml) red wine equivalent to 12 glasses white wine equivalent to 2 cups of tea equivalent to 4 apples equivalent to 5 portions of onion equivalent to 5.5 portions egg plant equivalent to 3.5 glasses of blackcurrant juice equivalent to 3.5 (500 ml) glasses of beer equivalent to 7 glasses of orange juice equivalent to 20 glasses of apple juice (long life).

Late onset administration of oral antioxidants prevents age-related loss of motor co-ordination and brain mitochondrial DNA damage.
Pallardo FV,   Asensi M,   Garcia de la Asuncion J,   Anton V,   Lloret A,     Sastre J,   Vina J

In: Free Radic Res (1998 Dec) 29(6):617-23

We have studied the effect of aging on brain glutathione redox ratio, on brain mitochondrial DNA damage and on motor co-ordination in mice and the possible protective role of late onset administration of sulphur-containing antioxidants. Glutathione redox ratios change to a more oxidized state in whole brain with aging but the changes are much more pronounced when this ratio is measured in brain mitochondria. The levels of 8-oxo-7,8-dihydro-2 ‘-deoxyguanosine in mitochondrial DNA are much higher in the brain of old animals than in those of young ones. Late onset oral administration of sulphur- containing antioxidants partially prevents oxidation of mitochondrial glutathione and DNA. There is an inverse relationship between age- associated oxidative damage to mitochondrial DNA and motor co- ordination in old mice.

 

Procyanidin oligomers selectively and intensively promote proliferation of mouse hair epithelial cells in vitro and activate hair follicle growth in vivo.

Takahashi T,   Kamiya T,   Hasegawa A,   Yokoo Y

In: J Invest Dermatol (1999 Mar) 112(3):310-6

We have previously reported that proanthocyanidins extracted from grape seeds possess growth-promoting activity toward murine hair epithelial cells in vitro and stimulate anagen induction in hair cycle progression in vivo. This report constitutes a comparison of the growth-promoting activity of procyanidin oligomers and the target cells of procyanidins in the skin. Results show that procyanidin dimer and trimer exhibit higher growth-promoting activity than the monomer. The maximum growth-promoting activity for hair epithelial cells with procyanidin B-2, an epicatechin dimer, reached about 300% (30 microM) relative to controls (= 100%) in a 5 d culture. Optimum concentration of procyanidin C-1, an epicatechin trimer, was lower than that of procyanidin B-2; the maximum growth-promoting activity of procyanidin C-1 was about 220% (3 microM). No other flavonoid compounds examined exhibit higher proliferative activities than the procyanidins. In skin constituent cells, only epithelial cells such as hair keratinocytes or epidermal keratinocytes respond to procyanidin oligomers. Topical application of 1% procyanidin oligomers on shaven C3H mice in the telogen phase led to significant hair regeneration [procyanidin B-2, 69.6% +/- 21.8% (mean +/- SD); procyanidin B-3, 80.9% +/- 13.0%; procyanidin C-1, 78.3% +/- 7.6%] on the basis of the shaven area; application of vehicle only led to regeneration of 41.7% (SD = 16.3%). In this paper, we demonstrate the hair-growing activity of procyanidin oligomers both in vitro and in vivo, and their potential for use as agents to induce hair growth.

Thioctic acid. {alpha lipoic acid}

In: Notes Undergr (1995 Apr/May)(no 30):2

Thioctic acid (Thioctacid 300 or alpha-lipoic acid) is a strong antioxidant that helps lower the level of liver enzymes. For people with AIDS (PWAs) taking oral antibiotics and/or antiviral agents, it is important to have balanced levels of liver enzymes. Thioctic acid also has been found to elevate the level of glutathione and reactive oxidants, and increase CD4 and CD8 levels in PWAs. Doses of thioctic acid at 300 to 600 mg per day have been shown to be safe, however, higher doses can cause thrombocytopenia. Regular blood monitoring is recommended since the drug can deplete minerals, particularly iron, in the body.

Review of studies on chemoprevention with tea polyphenolic compounds in the United States (Meeting abstract).
Boone CW

Non-serial; Current Strategies of Cancer Chemoprevention, 13th
International Symposium on Cancer. July 6-9, 1993, Sapporo, Japan, 1993:24

Studies in the US are reviewed on the chemopreventive effects of green and black tea phenolics by Conney AH et al. Oral administration of aqueous extracts of green tea phenolics (GTP) inhibited both initiation and promotion stages of carcinogenesis in mouse skin (carcinogen/promoter: DMBA/TPA, UV light/TPA, DMBA/UV light), in mouse lung (induced by DEN, NNK), and in rat esophagus (induced by NMBzA). Most importantly, GTP in the drinking water of mice produced partial regression of already established papillomas induced by DMBA or UV light. In one case, complete regression of 4% of established tumors occurred. Some effects produced by GTP that are possibly related to the mechanism of their chemopreventive effect include inhibition of phase I enzymes (cytochrome P450 mixed function oxygenases), enhancement of phase II enzymes (glutathione-S- transferase and quinone reductase) and enhancement of antioxidant enzymes (glutathione peroxidase and catalase).