angiotensin-converting enzyme inhibition and angiotensin II receptor antagonism, cyclooxygenase-1 and -2 inhibition, 5-hydroxytryptamine-reuptake inhibition and drug transporters in the placenta.

St John's wort is known to have an effect on certain liver enzymes which break down drugs. The plant derivative can act as an enzyme inducer—increasing the clearance of hormonal contraceptives.

The absorbance was measured at 340 nm every minute for continuous 5 minutes (Brogden and Barber, 1990). The enzyme kinetics were computed, and GST activity was calculated as mol/min/mg of protein. 10 ...