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Natural Phytochemical Nrf2 Activators for Chemoprevention

Dr. Hank Liers here considers mechanisms involved in the activation of transcription factor Nrf2. Nrf2 is encoded by the NFE2L2 gene. Nrf2 can induce expression of genes encoding for antioxidant enzymes. Thus, it contributes to regulation of oxidative stress. Dr. Liers’ interest regards use of natural phytochemical Nrf2 activators for improving health. Also, see his post, “New Directions for Preventing Free-Radical Damage”(06.27.19).

INTRODUCTION
Nrf2 SIGNALING, FOODS, AND HEALTH

Dr. Hank Liers, PhD nrf2 activatorsDespite progress in the early detection and treatment of cancer, overall mortality rates for most cancers of epithelial origin have not declined during the past three decades. Consequently, in recent years attention has been directed to cancer prevention.

Carcinogenesis can be viewed as a multistep process in which the genes controlling proliferation, differentiation, and apoptosis are transformed and altered under selective environmental pressures.

Tumor development involves three distinct, yet closely linked, phases: initiation, promotion, and progression. The initiation phase is a rapid and irreversible event that occurs when a normal cell is exposed to a carcinogenic event. Frequently, unrepairable or misrepaired DNA damage happens in the initiation phase.

Promotion and progression processes are relatively longer processes than the initiation stage, and are considered reversible. Using various animal cancer models, scientists found that all three cancer development stages can be intervened by treatment with natural (or synthetic) chemicals.

Epidemiological and population studies also establish a close relationship between incidence of cancer and consumption of certain types of food.

The term “chemoprevention” was first coined in 1976 by Michael Sporn, when he referred to prevention of malignancy development by vitamin A and its synthetic analogs. Since then, chemoprevention has been adopted as one of the major tactics to modulate the process of carcinogenesis. Many research studies have proven this strategy is effective in reducing the incidence of cancer in well-defined high-risk groups.

Chemoprevention is by definition the use of natural (or pharmacologic) agents to inhibit the development of invasive cancer. The chemicals with a cancer preventive activity are referred to as chemopreventive agents. A chemopreventive agent can inhibit carcinogenesis either by blocking the DNA damage at initiation stage or by arresting or reversing the processes at promotion and progression stages. Most of the chemical substances used in cancer chemoprevention studies are natural phytochemicals found in food.

On the basis of the inhibition stages, chemopreventive agents have been classified into two categories, namely blocking agents and suppressing agents. Blocking agents act by preventing carcinogens from reaching the target sites, from undergoing metabolic activation, or from subsequently interacting with crucial cellular macromolecules such as DNA, RNA, and proteins at initiation stages.

Suppressing agents, on the other hand, inhibit the malignant transformation of initiated cells at either the promotion or the progression stage. Some agents may work on all three stages of carcinogenesis, and are hence classified into both categories.

DIETARY PHYTOCHEMICALS ARE NATURE’S CHEMOPREVENTIVE AGENTS

Many different animal models and cancer cell lines have been used to evaluate the chemopreventive values of phytochemicals, and have led to the discovery of new classes of chemopreventive agents. These agents include isothiocyanates (such as sulforaphane) from cruciferous vegetables, polyphenols from green and black tea, curcuminoids (from turmeric root), stilbenes such as resveratrol (from giant knotweed plant), flavonoids such as quercetin, and anthocyanidins (from many fruits and soybeans).

Progress also has been made in understanding the mode of action of newly identified chemopreventive agents. Exposure to the chemopreventive agents produces certain level of reactive oxygen species (ROS) or electrophiles, and causes mild oxidative/electrophilic stresses in cells.

Ultimate Protector+

Such mild oxidative stresses are sufficient to initiate the signaling pathways that, in turn, can activate a variety of cellular events, such as induction of phase II detoxification enzymes and antioxidant enzymes, expression of tumor-suppressor genes, and inhibition of cell proliferation and angiogenesis.

In order to survive under a variety of environmental or intracellular stresses, our cells have developed highly efficient protective mechanisms to protect themselves from oxidative or electrophilic challenges. Proteins that comprise phase II detoxification and antioxidant enzymes provide an enzymatic line of defense against reactive oxygen species. These enzymes include superoxide dismutase (SOD), catalase, glutathione peroxidase, glutathione S-transferase (GST), and glutamate cysteine ligase.

Induction of phase II and antioxidant enzymes are regulated at the DNA/gene level by antioxidant responsive element (ARE). ARE-mediated gene expression plays a central role in the cellular defense against cellular oxidative damage.

Experimental evidence supports the view that induction of ARE-mediated cytoprotective enzymes is a critical and sufficient mechanism to enable protection against carcinogenesis provoked by environmental and endogenous insults.

One of the key ARE-binding transcription factors is Nrf2. Induction of cytoprotective enzymes in response to ROS, electrophiles, and chemopreventive agents is a cellular event that is highly dependent on Nrf2 protein.

Nrf2 BOOSTS CELL DETOXIFICATION AND ANTIOXIDANT ENZYMES

By activating Nrf2 signaling, chemopreventive agents can increase cellular detoxification and antioxidant enzymes, thereby enhancing removal of reactive carcinogens and blocking carcinogenesis. This hypothesis has been tested in many studies.

For example, a study with sulforaphane (an isothiocyanate present abundantly in cruciferous vegetables) has shown that oral administration of this phytochemical could effectively block benzo[a]pyrene-induced forestomach tumors in mice. This protective effect was abrogated in mice that could not produce Nrf2, supporting a critical role of phase II detoxification and antioxidant enzymes in the prevention of carcinogenesis by chemopreventive agents.

Nrf2 is normally bound in the cytoplasm of cells to a protein called KEAP1. However, when an appropriate phytochemical agent attaches to a kinase receptor on the cell wall a phosphate group is released that causes the Nrf2 to be released. The Nrf2 then migrates into the cell nucleus and causes an antioxidant enzyme, such as SOD, to be released. This endogenously produced enzyme then can protect against ROS, electrophiles, and chemopreventive agents.

In practice, it has been found that a combination of multiple polyphenols works significantly better than single ingredients at activating Nrf2. In fact, in one experiment it was found that a combination of five ingredients all known to be Nrf2 activators was 18 times more effective than any single ingredient. Furthermore, it was found that this combination of five ingredients  increased levels of SOD by 30% and catalase by 56% after 120 days.

ULTIMATE PROTECTOR+
A POWERFUL, NATURAL Nrf2 ACTIVATION FORMULA FOR GREATER HEALTH

In view of the above information and the fact that new and more effective ingredients are available, we have updated our exceptional formula designed to maximize activation of Nrf2 in the body. This new product is ULTIMATE PROTECTOR+. It is among the most advanced, natural Nrf2 activator formula on the market today.

We include a broad range of Nrf2 activators in ULTIMATE PROTECTOR+. These activators source from a wide variety of freeze-dried and concentrated fruits, vegetables, and herbs. These include USP-grade non-GMO Vitamin C , SFB® standardized fruit blend (~50% polyphenols, high-ORAC powder: 9,000 µmole TE/g) from Grape, Cranberry, Pomegranate, Blueberry, Apple, Mangosteen, Bilberry, Chokeberry, and Goji Berry), Curcumin(standardized extract with 95% curcuminoids), Trans-Resveratrol(98% from Giant Knotweed), Green Tea Extract(90% polyphenols, 50% EGCG),  and VinCare® Whole Grape Extract (>80% polyphenols, ORAC>19,000 µmole TE/g). In addition the product contains Calcium Malate and Magnesium Malate, that support ATP and enzyme product and Bioperine® (a patented black pepper extract that significantly enhances absorption of all ingredients and is a known Nrf2 activator).

Phytochemicals provided by the array of freeze-dried and concentrated fruits, vegetables, and herbs in the formula include: Polyphenols, Phenolic acids, Proanthocyanidins (OPCs), Anthocyandins, Catechins, Glucosinolates, Zeaxanthin, Lutein, Lycopene, Beta Carotene, Chlorogenic acid, Ellagic acid, Quercetin, Quinic acid, Trans-Resveratrol, Ferulic acid, Punicalagins, Phloridzin, Polysaccharides, Xanthones and more.

In addition to these Nrf2 activators (above), ULTIMATE PROTECTOR+ contains an extremely broad array of plant based antioxidants from the same sources described above, as well as from non-GMO USP grade Vitamin C. All ingredients in this product have been used in chemoprevention protocols, as well as in protocols aimed at preventing free-radical damage in the body.

Ultimate Protector is now available on the HPDI website!

 

Ultimate Protector+Ultimate Protector+ is new and improved

 

REFERENCES

“Resveratrol induces glutathione synthesis by activation of Nrf2 and protects against cigarette smoke-mediated oxidative stress in human lung epithelial cells.”  Am J Physiol Lung Cell Mol Physiol 294: L478–L488, 2008.

“Nrf2 as a master redox switch in turning on the cellular signaling involved in the induction of cytoprotective genes by some chemopreventive phytochemicals.” Planta Med. 2008 Oct; 74(13): 1526–39. Epub 2008 Oct 20.

“Nrf2: a potential molecular target for cancer chemoprevention by natural compounds.” Antioxid Redox Signal. 2006 Jan–Feb; 8(1–2):99–106.

“Cancer chemoprevention by phytochemicals: potential molecular targets, biomarkers and animal models.” Acta Pharmacol Sin. 2007 Sep; 28(9): 1409–21.

“Natural dietary anti-cancer chemopreventive compounds: redox-mediated differential signaling mechanisms in cytoprotection of normal cells versus cytotoxicity in tumor cells.” Acta Pharmacol Sin. 2007 Apr; 28(4): 459–72.

“Anticarcinogenesis by dietary phytochemicals: cytoprotection by Nrf2 in normal cells and cytotoxicity by modulation of transcription factors NF-kappa B and AP-1 in abnormal cancer cells.” Food Chem Toxicol. 2008 Apr; 46(4): 1257–70. Epub 2007 Sep 15.

“Signal transduction events elicited by cancer prevention compounds.” Mutat Res. 2001 Sep 1; 480–481: 231–41.

“Targeting specific cell signaling transduction pathways by dietary and medicinal phytochemicals in cancer chemoprevention.” Toxicology. 2010 Dec 5; 278(2): 229–41. Epub 2009 Oct 20.

“NF-kappa B and Nrf2 as potential chemopreventive targets of some anti-inflammatory and antioxidative phytonutrients with anti-inflammatory and antioxidative activities.” Asia Pac J Clin Nutr. 2008; 17 Suppl 1:269–72.

“Regulation of NF-E2-Related Factor 2 Signaling for Cancer Chemoprevention: Antioxidant Coupled with Antiinflammatory.” Antioxid Redox Signal. 2010 Dec 1; 13(11): 1679–98. Epub 2010 Aug 17.

“Molecular targets of dietary phenethyl isothiocyanate and sulforaphane for cancer chemoprevention.” AAPS J. 2010 Mar; 12(1): 87–97. Epub 2009 Dec 15.

“Dietary chemopreventive compounds and ARE/EpRE signaling.” Free Radic Biol Med. 2004 Jun 15; 36(12): 1505–16.

 “Multiple molecular targets in cancer chemoprevention by curcumin.” AAPS J. 2006 Jul 7; 8(3): E443–9.

ADDITIONAL RESOURCES

Ultimate Protector™

The Amazing Healing Potential of Natural Nrf2 Activators – by Dr. Hank Liers

Preventing Free-Radical Damage Using Ultimate Protector™ – by Dr. Hank Liers

New Directions for Preventing Free-Radical Damage  – by Dr. Hank Liers

Ultimate Protector and the Role of Foundational Supplements for Health – by Fred Liers, PhD

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ULTIMATE PROTECTOR INGREDIENTS – BROCCOLI AND BROCCOLI SPROUTS

Dr. Hank Liers, PhD biography about us HPDI integratedhealth formulator founder CEO scientist physicistUltimate Protector contains broccoli and broccoli sprouts powder, as well as components from 29 different fruits, vegetables, and herbs. Each of these ingredients contain substances that may be considered to be polyphenols, antioxidants, and Nrf2 activators. In this article, I will explore the ingredient “broccoli and broccoli sprouts powder,” which is a component of VitaVeggie from Futureceuticals.

VitaVeggie® is an all-vegetable, high-antioxidant (ORAC) capacity blend rich in phenolics from vegetable concentrates, as well as fully intact vegetable phytochemicals from freeze-dried vegetable powders. VitaVeggie combines the nutrients and antioxidants of broccoli, broccoli sprouts, tomatoes, spinach, kale, carrots, brussels sprouts, and onion.

Broccoli Sprouts ultimate protector nrf2

Broccoli Sprouts

This robust vegetable powder is also rich in glucosinolates and sulphoraphane, compounds commonly found in cruciferious vegetables that research suggests contribute to healthy internal antioxidant status by stimulating the body’s endogenous (internal) antioxidant system. VitaVeggie is standardized to minimum levels of 2000 ppm glucosinolates and 1000 ppm sulphoraphane.

SULFORAPHANE

In 1992 a team of Johns Hopkins University scientists isolated a cancer-fighting phytochemical in broccoli called glucoraphanin, which is the glucosinolate precursor of sulforaphane.

When chewed, broccoli releases glucoraphanin and myrosinase, an enzyme found in another part of the plant cell, which work together to produce sulforaphane, which in turn activates a transcription factor (Nrf2) in the cell. After activation, Nrf2 then translocates to the nucleus of the cell, where it aligns itself with the antioxidant response element (ARE) in the promoter region of target genes.

The target genes are associated with processes which assist in regulating cellular defenses. Such cytoprotective genes include that for glutathione. Around 200 genes have been well-characterized, and as many as 1700 may be related to this aspect of cellular defense. The 1992 study was followed by the discovery in 1997 that glucoraphanin is found in higher concentrations in three- to four-day-old broccoli sprouts, at least 20 times the concentration of full-grown broccoli.

STUDIES DEMONSTRATING THE BENEFITS OF BROCCOLI AND BROCCOLI SPROUTS

Implications of Cancer Stem Cell Theory for Cancer Chemoprevention
by Natural Dietary Compounds

Abstract

The emergence of cancer stem cell theory has profound implications for cancer chemoprevention and therapy. Cancer stem cells give rise to the tumor bulk through continuous self-renewal and differentiation. Understanding the mechanisms that regulate self-renewal is of greatest importance for discovery of anti-cancer drugs targeting cancer stem cells. Naturally occurring dietary compounds have received increasing attention in cancer chemoprevention. The anti-cancer effects of many dietary components have been reported for both in vitro and in vivo studies. Recently, a number of studies have found that several dietary compounds can directly or indirectly affect cancer stem cell self-renewal pathways. Herein we review the current knowledge of most common natural dietary compounds for their impact on self-renewal pathways and potential effect against cancer stem cells. Three pathways (Wnt/β-catenin, Hedgehog, and Notch) are summarized for their functions in self-renewal of cancer stem cells. The dietary compounds, including curcumin, sulforaphane, soy isoflavone, epigallocatechin-3-gallate, resveratrol, lycopene, piperine, and vitamin D3, are discussed for their direct or indirect effect on these self-renewal pathways. Curcumin and piperine have been demonstrated to target breast cancer stem cells. Sulforaphane has been reported to inhibit pancreatic tumor initiating cells and breast cancer stem cells. These studies provide a basis for preclinical and clinical evaluation of dietary compounds for chemoprevention of cancer stem cells. This may enable us to discover more preventive strategies for cancer management by reducing cancer resistance and recurrence and improving patient survival.

Targeting cancer stem cells with sulforaphane, a dietary component from broccoli and broccoli sprouts.

Abstract

Many studies have supported the protective effects of broccoli and broccoli sprouts against cancer. The chemopreventive properties of sulforaphane, which is derived from the principal glucosinolate of broccoli and broccoli sprouts, have been extensively studied. Recent research into the effects of sulforaphane on cancer stem cells (CSCs) has drawn lots of interest. CSCs are suggested to be responsible for initiating and maintaining cancer, and to contribute to recurrence and drug resistance. A number of studies have indicated that sulforaphane may target CSCs in different types of cancer through modulation of NF-κB, SHH, epithelial-mesenchymal transition and Wnt/β-catenin pathways. Combination therapy with sulforaphane and chemotherapy in preclinical settings has shown promising results. In this article, we focus on the effects of sulforaphane on CSCs and self-renewal pathways, as well as giving a brief review of recent human studies using broccoli sprout preparations.

Sulforaphane, a dietary component of broccoli/broccoli sprouts,
inhibits breast cancer stem cells.

Abstract

PURPOSE:

The existence of cancer stem cells (CSCs) in breast cancer has profound implications for cancer prevention. In this study, we evaluated sulforaphane, a natural compound derived from broccoli/broccoli sprouts, for its efficacy to inhibit breast CSCs and its potential mechanism.

EXPERIMENTAL DESIGN:

Broccoli nrf2 activator ultimate protector ingredient ARE

Broccoli

Aldefluor assay and mammosphere formation assay were used to evaluate the effect of sulforaphane on breast CSCs in vitro. A nonobese diabetic/severe combined immunodeficient xenograft model was used to determine whether sulforaphane could target breast CSCs in vivo, as assessed by Aldefluor assay, and tumor growth upon cell reimplantation in secondary mice. The potential mechanism was investigated using Western blotting analysis and beta-catenin reporter assay.

RESULTS:

Sulforaphane (1-5 micromol/L) decreased aldehyde dehydrogenase-positive cell population by 65% to 80% in human breast cancer cells (P < 0.01) and reduced the size and number of primary mammospheres by 8- to 125-fold and 45% to 75% (P < 0.01), respectively. Daily injection with 50 mg/kg sulforaphane for 2 weeks reduced aldehyde dehydrogenase-positive cells by >50% in nonobese diabetic/severe combined immunodeficient xenograft tumors (P = 0.003). Sulforaphane eliminated breast CSCs in vivo, thereby abrogating tumor growth after the reimplantation of primary tumor cells into the secondary mice (P < 0.01). Western blotting analysis and beta-catenin reporter assay showed that sulforaphane downregulated the Wnt/beta-catenin self-renewal pathway.

CONCLUSIONS:

Sulforaphane inhibits breast CSCs and downregulates the Wnt/beta-catenin self-renewal pathway. These findings support the use of sulforaphane for the chemoprevention of breast cancer stem cells and warrant further clinical evaluation.

 

Dietary sulforaphane-rich broccoli sprouts reduce colonization and attenuate gastritis in Helicobacter pylori-infected mice and humans.

Abstract

The isothiocyanate sulforaphane [SF; 1-isothiocyanato-4(R)-methylsulfinylbutane] is abundant in broccoli sprouts in the form of its glucosinolate precursor (glucoraphanin). SF is powerfully bactericidal against Helicobacter pylori infections, which are strongly associated with the worldwide pandemic of gastric cancer. Oral treatment with SF-rich broccoli sprouts of C57BL/6 female mice infected with H. pylori Sydney strain 1 and maintained on a high-salt (7.5% NaCl) diet reduced gastric bacterial colonization, attenuated mucosal expression of tumor necrosis factor-alpha and interleukin-1beta, mitigated corpus inflammation, and prevented expression of high salt-induced gastric corpus atrophy. This therapeutic effect was not observed in mice in which the nrf2 gene was deleted, strongly implicating the important role of Nrf2-dependent antioxidant and anti-inflammatory proteins in SF-dependent protection. Forty-eight H. pylori-infected patients were randomly assigned to feeding of broccoli sprouts (70 g/d; containing 420 micromol of SF precursor) for 8 weeks or to consumption of an equal weight of alfalfa sprouts (not containing SF) as placebo. Intervention with broccoli sprouts, but not with placebo, decreased the levels of urease measured by the urea breath test and H. pylori stool antigen (both biomarkers of H. pylori colonization) and serum pepsinogens I and II (biomarkers of gastric inflammation). Values recovered to their original levels 2 months after treatment was discontinued. Daily intake of sulforaphane-rich broccoli sprouts for 2 months reduces H. pylori colonization in mice and improves the sequelae of infection in infected mice and in humans. This treatment seems to enhance chemoprotection of the gastric mucosa against H. pylori-induced oxidative stress.

 

Sulforaphane absorption and excretion following ingestion of a semi-purified broccoli powder rich in glucoraphanin and broccoli sprouts in healthy men.

From: http://www.ncbi.nlm.nih.gov/pubmed/21240766

Nutr Cancer. 2011;63(2):196-201. doi: 10.1080/01635581.2011.523495, Cramer JMJeffery EH.

Abstract

Sulforaphane (SF) is a chemopreventive isothiocyanate (ITC) derived from the myrosinase-catalyzed hydrolysis of glucoraphanin, a thioglucoside present in broccoli. Broccoli supplements often contain glucoraphanin but lack myrosinase, putting in question their ability to provide dietary SF. This study compared the relative absorption of SF from air-dried broccoli sprouts rich in myrosinase and a glucoraphanin-rich broccoli powder lacking myrosinase, individually and in combination. Subjects (n=4) each consumed 4 meals consisting of dry cereal and yogurt with 2 g sprouts, 2 g powder, both, or neither. Blood and urine were analyzed for SF metabolites. The 24 h urinary SF recovery was 74%, 49%, and 19% of the dose ingested from broccoli sprouts, combination, and broccoli powder meals, respectively. Urinary and plasma ITC appearance was delayed from the broccoli powder compared to the sprouts and combination. A liver function panel indicated no toxicity from any treatment at 24 h. These data indicate a delayed appearance in plasma and urine of SF from the broccoli powder relative to SF from myrosinase-rich sprouts. Combining broccoli sprouts with the broccoli powder enhanced SF absorption from broccoli powder, offering the potential for development of foods that modify the health impact of broccoli products.

One of several challenges in design of clinical chemoprevention trials is the selection of the dose, formulation and dose schedule of the intervention agent. Therefore, a cross-over clinical trial was undertaken to compare the bioavailability and tolerability of sulforaphane from two of broccoli sprout-derived beverages: one glucoraphanin-rich (GRR) and the other sulforaphane-rich (SFR). Sulforaphane was generated from glucoraphanin contained in GRR by gut microflora or formed by treatment of GRR with myrosinase from daikon (Raphanus sativus) sprouts to provide SFR. Fifty healthy, eligible participants were requested to refrain from crucifer consumption and randomized into two treatment arms. The study design was as follows: 5-day run-in period, 7-day administration of beverages, 5-day washout period, and 7-day administration of the opposite intervention. Isotope dilution mass spectrometry was used to measure levels of glucoraphanin, sulforaphane and sulforaphane thiol conjugates in urine samples collected daily throughout the study. Bioavailability, as measured by urinary excretion of sulforaphane and its metabolites (in approximately 12 hour collections after dosing), was substantially greater with the SFR (mean = 70%) than with GRR (mean = 5%) beverages. Interindividual variability in excretion was considerably lower with SFR than GRR beverage. Elimination rates were considerably slower with GRR allowing for achievement of steady state dosing as opposed to bolus dosing with SFR. Optimal dosing formulations in future studies should consider blends of sulforaphane and glucoraphanin as SFR and GRR mixtures to achieve peak concentrations for activation of some targets and prolonged inhibition of others implicated in the protective actions of sulforaphane.

SUMMARY

Broccoli–and especially broccoli sprouts with its high content of sulforaphane–contain important polyphenols, antioxidants, and Nrf2 activators that help make Ultimate Protector an outstanding nutritional supplement. Broccoli and broccoli sprouts have been used extensively in nutritional healing protocols for almost 25 years now.

Continued research shows a growing list of health benefits for these nutritional substances, especially relating to Nrf2 activity and ability to provide significant chemoprevention. They add an important vegetable profile to the ingredient mix in Ultimate Protector™.

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