Abstract: In this study,the antioxidant activity in vitro of total saponins in kernel of Xanthoceras sorbifolia bunge and the inhibition of proliferation and apoptosis on HepG2 cells were studied.Firstly,the contents of extract was proved to contain triterpenoid saponin with the concentration of 520 ±19.1 mg/g.Secondly,using vitamin C as a positive control,the antioxidant activity in vitro of total saponins was investigated.The results showed that the reducing power of total saponins in X.sorbifolia kernels was stronger than that of VC,but the scavenging ability of DPPH free radical was weaker than that of Vc.Finally,the anti-cancer activity of saponins was evaluated with MTT assay.It was found that the optimal processing time was 24 h and IC₅₀ of total saponins was 9.7±0.39 mg/L in the inhibition of total saponins on HepG2 cells.The induced-apoptosis effect of total saponins on HepG2 cells was proved by cell morphology and fluorescence staining method.The flow cytometry experiments showed that HepG2 cells apoptosis was happened at later period of cell life and this apoptosis effect may be concentrated in S phase of the cell cycle.

Key words: Xanthoceras sorbifolia kernels, total saponins, antioxidant activity, HepG2 cells, cell apoptosis