Objective To study cycloartane triterpenoids from Astragalus membranaceus var. mongholicus and their protective effects against cisplatin-induced renal injury. Methods The constituents were isolated from non-polysaccharide fractions of the aqueous extract of Astragalus membranaceus var. mongholicus by employing multiple chromatographic techniques including silica gel, Sephadex LH-20 and ODS. Their structures were identified based on the physicochemical properties as well as spectroscopic and spectrometric data. Their protective activities against renal injury were evaluated by detecting the cell viability of human renal proximal tubular epithelial (HK-2) cells injured by cisplatin. Results Four cycloartane triterpenoids were isolated from Astragalus membranaceus var. mongholicus and identified as 12-carboxy-20,24,25-trihydroxy-3-(β-D-xylopyranosyloxy)-6-(β-D-glucopyra- nosyloxy)-7(8)-ene-9,10-secocycloartane (1), astragaloside II (2), astragaloside Ⅳ (3) and astragaloside Ⅰ (4). Additionally, compounds 2 and 3 could significantly improve the decreased cell viability induced by cisplatin (P < 0.05). Conclusion Compound 1 is a novel homocycloartane triterpenoid named homoastragaloside A, and compounds 2 and 3 exhibit protective effects against renal injury.

Astragalus membranaceus(Fisch.) Bge.var.mongholicus(Bge.) Hsiao  /  saponins  /  cycloartane  /  homoastragaloside A  /  renal protective activity