In vitro modulatory effects of Andrographis paniculata, Centella asiatica and Orthosiphon stamineus on cytochrome P450 2C19 (CYP2C19)

Eupatorin (3′,5-dihydroxy-4′,6,7-trimethoxyflavone), a flavonoid isolated from Orthosiphon stamineus, showed potent inhibitory effect on catalytic activity of human CYP2C19.