Increasing Nrf2: A Master Regulator of the Aging Process

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Nuclear factor (erythroid-derived 2)-like 2, also known as NFE2L2 or Nrf2, is a transcription factor. The Nrf2 pathway is “the primary cellular defense against the cytotoxic effects of oxidative stress.”

Activation of Nrf2 results in the induction of many cytoprotective proteins. These include, but are not limited to, the following:

  • NAD(P)H quinone oxidoreductase 1 (Nqo1)
  • Glutamate-cysteine ligase, catalytic (Gclc) and glutamate-cysteine ligase, modifier (GCLM)
  • Heme oxygenase-1 (HMOX1, HO-1)
  • The glutathione S-transferase (GST) family
  • The UDP-glucuronosyltransferase (UGT) family
  • Multidrug resistance-associated proteins (Mrps)

A wide variety of dietary components have been shown in vitro or cell culture to activate Nrf2 and directly increase activity of phase II enzymes; these include:

  • epigallocatechin gallate (EGCG)
  • resveratrol
  • curcumin and its metabolite tetrahydrocurcumin, which has greater phase II activity
  • cinnamaldehyde
  • caffeic acid phenyethyl ester
  • alpha lipoic acid
  • alpha tocopherol
  • lycopene
  • apple polyphenols (chlorogenic acid and phloridzin)
  • gingko biloba
  • chalcone
  • capsaicin
  • hydroxytyrosol from olives
  • allyl sulfides from garlic
  • chlorophyllin
  • xanthohumols from hops

The beneficial effects of these phytochemicals have been demonstrated in numerous animal and human studies, particularly their chemopreventative and antioxidant abilities; these effects may be explained by their indirect stimulation of antioxidant enzyme production and phase II detoxification through Nrf2 signaling. (Source: Life Extension)


References:

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Hsieh TC, Lu X, Wang Z, Wu JM. Induction of quinone reductase NQO1 by resveratrol in human K562 cells involves the antioxidant response element ARE and is accompanied by nuclear translocation of tran-scription factor Nrf2. Med Chem 2006; 2: 275 – 85

Nayak S and Sashidhar RB. Metabolic intervention of aflatoxin B1 toxicity by curcumin. J Ethnopharmacol 2010;127 (3) : 641-4

Osawa T. Nephroprotective and hepatoprotective effects of curcuminoids. Adv Exp Med Biol 2007;595 : 407-23

Liao BC, Hsieh CW, Liu YC, Tzeng TT, Sun YW, Wung BS. Cinnamaldehyde inhibits the tumor necrosis factor-alpha-induced expression of cell adhesion molecules in endothelial cells by suppressing NF-kap- paB activation: Effects upon IkappaB and Nrf2. Toxicol Appl Pharmacol 2008; 229: 161 – 71

Lii CK, Liu KL, Cheng YP et al. Sulforaphane and alpha-lipoic acid upregulate the expression of the pi class of glutathione S-transferase through c-jun and Nrf2 activation. J Nutrition 2010;140 (5) : 885-92

Feng Z, Liu Z, Li X, et al. α-Tocopherol is an effective Phase II enzyme inducer: protective effects on acrolein-induced oxidative stress and mitochondrial dysfunction in human retinal pigment epithelial cells. J Nutr Biochem 2010;21 (12) : 1222-31

Wang H and Leung LK. The carotenoid lycopene differentially regulates phase I and II enzymes in dimethylbenz[a]anthracene-induced MCF-7 cells. Nutrition 2010;26 (11-12) : 1181-7

Veeriah S, Miene C, Habermann N et al. Apple polyphenols modulate expression of selected genes related to toxicological defence and stress response in human colon adenoma cells. Int J Cancer 2008;122 (12) : 2647-55

Liu XP, Goldring CE, Wang HY, Copple IM, Kitteringham NR, Park BK. Extract of Ginkgo biloba induces glutathione-S-transferase subunit-P1 in vitro. Phytomedicine 2009; 16(5):451–455

Liu YC, Hsieh CW, Wu CC, Wung BS. Chalcone inhibits the activation of NF-kappaB and STAT3 in endothelial cells via endogenous electrophile. Life Sci 2007; 80: 1420 – 30

Joung EJ, Li MH, Lee HG, Somparn N, Jung YS, Na HK et al. Capsaicin in- duces heme oxygenase-1 expression in HepG2 cells via activation of PI3K-Nrf2 signaling: NAD(P)H:quinone oxidoreductase as a potential target. Antioxid Redox Signal 2007; 9: 2087 – 98

Zhu L, Liu Z, Feng Z et al. Hydroxytyrosol protects against oxidative damage by simultaneous activation of mitochondrial biogenesis and phase II detoxifying enzyme systems in retinal pigment epithelial cells. J Nutr Biochem 2010;21 (11) : 1089-98

Gong P, Hu B, Cederbaum AI. Diallyl sulfide induces heme oxygenase-1 through MAPK pathway. Arch Biochem Biophys 2004; 432: 252 – 60

Zhang Y, Guan L, Wang X, Wen T, Xing J, Zhao J. Protection of chloro- phyllin against oxidative damage by inducing HO-1 and NQO1 ex- pression mediated by PI3K/Akt and Nrf2. Free Radic Res 2008; 42: 362–71

Dietz BM, Kang YH, Liu G et al. Xanthohumol isolated from Humulus lupulus Inhibits menadione-induced DNA damage through induction of quinone reductase. Chem Res Toxicol 2005;18 (8) : 1296-305

Surh YJ, Kundu JK, Na HK. 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;74 (13) : 1526-39


Informational Reference:

Nrf2.com