Protective effect and mechanism of action of saponins isolated from the seeds of gac (Momordica cochinchinensis Spreng.) against cisplatin-induced damage in LLC-PK1 kidney cells.

This study was performed to investigate the renoprotective effect and mechanism of Momordicae Semen, gac seeds, against the cisplatin-induced damage in LLC-PK1 kidney cells. In order to identify the active components, three major saponins were isolated from extract of the gac seed, gypsogenin 3-O-β-d-galactopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-d-glucuronopyranoside (1), quillaic acid 3-O-β-D-galactopyranosyl(1→2)-[α-L-rhamnopyranosyl(1→3)]-β-D-glucuronopyranoside (2), and momordica saponin I (3). Compounds 1 and 2 ameliorated cisplatin-induced nephrotoxicity up to 80% of the control value at both 5 and 25μM. Phosphorylation of MAPKs was decreased along cisplatin treatment after treatment with compounds 1 and 2. These results show that blocking the MAPKs signaling cascade plays a critical role in mediating the renoprotective effect of Momordicae Semen extract and compounds 1 and 2.