摘要

Introduction: This study investigates the antidiabetic activity of the polysaccharides extracted from the fruits of four common Schisandraceae medicinal plants, which might provide some guidance in the application for the treatment of diabetes. Materials and methods: Four crude polysaccharides, CSCP, CSSP, CSRP, and CSNP, were extracted from the fruits of four common Schisandraceae medicinal plants by water extraction and alcohol precipitation method. Their chemical characteristics were determined. In vitro antioxidant properties of four polysaccharides (0.125-2.0 mg/ml) were investigated, including the scavenging ability on hydroxyl radicals, superoxide anion radicals, and DPPH. Moreover, the potential antidiabetic activity of four polysaccharides (0.125-2.0 mg/ml) was also investigated by alpha-glucosidase inhibition assay. Results: EC50 values of scavenging ability on hydroxyl radicals, superoxide anion radicals, DPPH for CSCP and CSSP were 1.18 and 1.39 mg/mL, 0.89 and 1.02 mg/mL, 0.58 and 0.49 mg/mL, respectively. EC50 values of inhibitory activity on a-glucosidase for CSCP and CSSP were 0.93 and 1.42 mg/mL, respectively. Discussion: CSCP and CSSP have a satisfactory antioxidant effect, and should be ideal natural antioxidants. Furthermore, CSCP and CSSP are also a-glucosidase inhibitors due to their lower EC50, indicating that their may play a positive role in the treatment of diabetes.