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 - β - d -xylopyranosyl-(1 → 4)- α - l -rhamnopyranosyl-(1 → 2)- α - l -arabinopyranosyl ester, and echinocystic acid 28- O - α - l -rhamnopyranosyl-(1 → 2)- α - 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.