The inhibition of the mammalian DNA methyltransferase 3a (Dnmt3a) by dietary black tea and coffee polyphenols

<p>Abstract</p> <p>Background</p> <p>Black tea is, second only to water, the most consumed beverage globally. Previously, the inhibition of DNA methyltransferase 1 was shown by dietary polyphenols and epi-gallocatechin gallate (EGCG), the main polyphenolic constituent of green tea, and 5-caffeoyl quinic acid, the main phenolic constituent of the green coffee bean.</p> <p>Results</p> <p>We studied the inhibition of DNA methyltransferase 3a by a series of dietary polyphenols from black tea such as theaflavins and thearubigins and chlorogenic acid derivatives from coffee. For theaflavin 3,3 digallate and thearubigins IC₅₀values in the lower micro molar range were observed, which when compared to pharmacokinetic data available, suggest an effect of physiological relevance.</p> <p>Conclusions</p> <p>Since Dnnmt3a has been associated with development, cancer and brain function, these data suggest a biochemical mechanism for the beneficial health effect of black tea and coffee and a possible molecular mechanism for the improvement of brain performance and mental health by dietary polyphenols.</p