Sulforaphane But Not Ascorbigen
Sulforaphane but not ascorbigen, indole-3-carbinole and ascorbic acid activates the transcription factor Nrf2 and induces phase-2 and antioxidant enzymes in human keratinocytes in culture.
Exp Dermatol. 2009 Jun 23.
Wagner AE, Ernst I, Iori R, Desel C, Rimbach G.
Institute of Human Nutrition and Food Science, Christian-Albrechts-University, Kiel, Germany.
Experimental Dermatology 2009.
Abstract: Nrf2 is a basic leucine zipper transcriptional activator essential for the coordinated transcriptional induction of phase-2 and antioxidant enzymes. Brassica vegetables contain phytochemicals including glucoraphanin, the precursor of sulforaphane (SFN) and glucobrassicin, the precursor of indole-3-carbinole (I3C) and ascorbigen (ABG). The degradation products SFN, I3C and ABG may be capable of inducing cytoprotective genes in skin. In this study, we tested the potency of SFN, ABG and I3C in affecting Nrf2-dependent gene expression in human keratinocytes in culture. SFN but not ABG and its precursors I3C and ascorbic acid induced Nrf2 dependent gene expression at a relatively low concentration (5 mumol/l). Induction of Nrf2 due to SFN was accompanied by an increase in mRNA and protein levels of NADPH quinone oxidoreductase 1, heme oxygenase 1 and gamma-glutamylcysteine-synthetase. Furthermore, SFN elevated cellular glutathione levels and antagonized tumor necrosis factor-alpha-induced NFkappaB transactivation. Therefore, sulforaphane treatment may present a strategy for enhancing the cellular defense mechanisms in skin.
Note from ISS: Several crucifer sprouts including broccoli sprouts are currently the most potent natural source of sulforaphane known. They often produce 10 to 100 times the amount of sulforaphane as their corresponding mature vegetables.
“Broccoli sprouts have a very high concentration of sulforaphane since this compound originates in the seed and is not made in the plant as it grows. One sprout contains all of the sulforaphane that is present in a full grown broccoli plant.”
“Nutrition and cancer: a review of the evidence for an anti-cancer diet” Nutr J. 2004 Oct 20;3:19, Donaldson MS. Hallelujah Acres Foundation, 13553 Vantage Hwy, Ellensburg, WA 98926, USA.