Preliminary study on antiplatelet aggregation of 10 anthraquinones in Rhei Radix et Rhizoma based on bioassay / 中草药

ABSTRACT

Objective To evaluate the ability of the antiplatelet aggregation of ten anthraquinone derivatives in Rhei Radix et Rhizoma by using bioassay method, and to screen for the indicators that can be used to control the quality of rhubarb wine processing product. Methods Platelet aggregation instrument was used to determine the platelet aggregation rate induced by ADP in vitro and calculate the antiplatelet aggregation rates of 10 anthraquinone derivatives (aloe-emodin, rhein, emodin, chrysophanol, physcion, aloe-emodin-8-O-β-D-glucoside, rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside, chrysophanol-8-O-β-D-glucoside, and physcion-8-O-β-D-glucoside) at different concentrations. The biopotency was calculated by bioavailability software. In order to verify the accuracy of the bioassay results, the estimated inhibition constant of rhein and chrysophanol-8-O-β-D-glucoside in P2Y12 protein receptor were determined by molecular docking software. Results The bioassay results showed that the antiplatelet potencies of rhein and emodin were significantly higher than those of aloe-emodin, chrysophanol and physcion. Compared with the antiplatelet biopotency of aspirin, the antiplatelet potencies of rhein and emodin were 5.02 and 5.15 times higher than that of aspirin, which indicated that rhein and emodin have strong inhibitory effect on ADP-induced platelet aggregation. However, the antiplatelet potencies of aloe-emodin, chrysophanol and physcion were equivalent of that of aspirin. The antiplatelet potencies of aloe-emodin-8-O-β-D-glucoside, rhein-8-O-β-D-glucoside, emodin-8-O-β-D-glucoside, chrysophanol-8-O-β-D-glucoside, and physcion-8-O-β-D-glucoside were higher 4.13, 4.46, 9.31, 5.46, and 7.80 times than that of aspirin, respectively, which indicated that the five anthraquinone glucosides had a strong ability to antagonize ADP-induced platelet aggregation. The results of molecular docking showed that P2Y12 protein had different selectivity to 10 anthraquinone derivatives, especially for rhein, chrysophanol-8-O-β-D-glucoside, and the estimated Ki value were 5.73 and 2.51 μmol/L, respectively, indicating that rhein, chrysophanol-8-O-β-D-glucoside produced a strong inhibitory effect on P2Y12 protein at a lower concentration level. Moreover, the activity of chrysophanol-8-O-β-D-glucoside was stronger than rhein, which was consistent with their measured intensity of antiplatelet aggregation. Conclusion All results showed that there were some differences among antiplatelet potencies of 10 anthraquinone derivatives, and finally the screening of rhein, emodin can be used as evaluation indicators to control the quality of rhubarb wine processing product.