Excretion of 20(S)-protopanaxatriol and its ocotillol type epimers metabolites in rats / 国际药学研究杂志

ABSTRACT

Objective To explore the excretion of the 20 (S)-protopanaxatriol (PPT) and its metabolites ocotillol type epimers (M1 and M2) in urine, feces samples and the excretion of Ml and M2 in bile samples. Methods The concentration of PPT, Ml and M2 in urine, feces samples and the concentration of Ml and M2 in bile samples were determined by the LC-MS/MS methods with or without the hydrolization by β-glucuronidase. Results After intragastric(ig) administration of PPT, the cumulative excretion rate for 72 h of PPT, Ml and M2 in feces were 14.88%, 1.34% and 0.084%, respectively. With the hydrolization by β-glucuronidase, the cumulative excretion rate for 72 h of PPT, Ml and M2 in feces were 14.77%, 1.36% and 0.085%, respectively. However, the epimers and PPT were hardly detected in urine. After ig administration of M1 or M2, the accumulation excretion rate were 4.41% for M1 and 47.2% for M2 in feces, while both epimers were hardly detected in urine. After ig administration of M1 or M2, the 36 h cumulative biliary excretion rate was 3.01% for M1, and only 0.068% for M2. The 36 h cumulative biliary excretion rate of M1 was 8.80% after intravenous administration, while only 1.24% for M2. Conclusion After ig administration of PPT, a small amount of PPT and its metabolites (Ml, M2) are excreted by the feces but little via urine, and there are stereoselectivity differences in biliary excretion between M1 and M2.