St Johnʼs Wort induces intestinal P-glycoprotein/MDR1 and intestinal and hepatic CYP3A4 - Dürr, D; Stieger, B; Kullak-Ublick, G A; Rentsch, K M; Steinert, H C; Meier, P J; Fattinger, K (Clin Pharmacol Ther, 2000)