Murine metabolism and absorption of lancemaside A, an active compound in the roots of Codonopsis lanceolata

Lancemaside A, a triterpenoid saponin isolated from the roots of Codonopsis lanceolata, has been reported to ameliorate the reduction of blood testosterone levels induced by immobilization stress in mice. In the present study, we investigated the metabolism and absorption of lancemaside A in mice. After oral administration of lancemaside A at 100 mg/kg body weight, the unmetabolized compound appeared rapidly in plasma (t (max) = 0.5 h). Lancemaside A has a low bioavailability (1.1%) because of its metabolism by intestinal bacteria and its poor absorption in the gastrointestinal tract. Furthermore, we identified four metabolites from the cecum of mice after oral administration of lancemaside A: codonolaside II, echinocystic acid, echinocystic acid 28-O-beta-D: -xylopyranosyl-(1 --> 4)-alpha-L: -rhamnopyranosyl-(1 --> 2)-alpha-L: -arabinopyranosyl ester, and echinocystic acid 28-O-alpha-L: -rhamnopyranosyl-(1 --> 2)-alpha-L: -arabinopyranosyl ester. Among these metabolites, codonolaside II and echinocystic acid were detected in plasma, and their t (max) values were 4 and 8 h, respectively. These findings should be helpful for understanding the mechanism of the biological effect of lancemaside A.