P450 cytochrome curcumin

Oetari, S. et al., Effects of curcumin on cytochrome P450 and glutathione S-trans-ferase activities in rat liver, Biochem. Pharmacol., 51, 39, 1996. 

DNA damage in the presence of cytochrome P450s (CYPs) and Cu(II) in vitro or in cells [Yoshino et al., 2004 Ahsan et al., 1999]. At higher concentrations curcumin exhibited genotoxicity and cytotoxicity in different systems [Cao et al., 2007]. At last, in vivo intervention trials using typical antioxidants such as ascorbate or carotenes yielded mostly disappointing results in terms of protection against oxidation-related diseases, sometime even increased the incidences of diseases [Stevenson and Hurst, 2007 Dinkova-Kostova and Talalay, 2008]. Obviously, the direct antioxidant capacity of plant phenolic compounds cannot explain their cytoprotective activities. 

To better understand the health effects of plant phenolic compounds and to better utilize them, it is necessary to know the molecular mechanisms by which plant phenolic compounds induce cytoprotective enzymes. In vitro studies indicated that plant phenolic compounds such as curcumin often inhibited the enzymatic activities of GST, UGT, SULT as well as cytochrome P450s [Oetari et al., 1996], suggesting that the induction of cytoprotective enzyme activities could not be explained by direct interaction with plant phenolic compounds. On the other hand, much evidence indicates that the increased activity of cytoprotective enzymes are mainly attributable to enhanced transcriptional activation and enzyme synthesis [Holtzclaw et al., 2004]. 

Ciolino HP, Daschner PJ, Wang TT, Yeh GC. 1998. Effect of curcumin on the aryl hydrocarbon receptor and cytochrome P450 1A1 in MCF-7 human breast carcinoma cells. Biochem Pharmacol 56 197-206. 

Administration of 4 g/kg turmeric or 0.4 g/kg curcumin for 2 or 3 weeks caused an increase in cytochrome P450 and cytochrome b5 levels in lactating mice and their pups (Singh et al. 1995). One other pharmacological study indicated that the active constituents and/or metabolites of turmeric cross into breast milk (Singh et al. 1996). 

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