Dietary green and white teas suppress UDP-glucuronosyltransferase UGT2B17 mediated testosterone glucuronidation

► White and green tea suppresses the glucuronidation of testosterone by the UGT2B17. ► Three catechins in tea were identified as active compounds affecting the UGT2B17. ► Catechins are not substrates for UGT2B17 but inhibit testosterone glucuronidation. ► Inhibition of UGT2B17 by dietary components may raise circulating levels of testosterone. ► Inhibition of UGT2B17 may affect relative glucuronide urinary levels and thus the T/E ratio.