[Ethanol extraction technology of Epimedii Folium and protective effect of ethanol extract on chondrocyte]

Uniform design-comprehensive scoring method was used to investigate the effects of ethanol dosage, ethanol concentration and extraction time, based on the evaluation index from transfer rates of epimedin A, epimedin B, epimedin C, icariin and baohuoside Ⅰ, which are the main active components in Epimedii Folium. Furthermore, the optimum conditions for the ethanol extraction process were determined by multiple linear stepwise regression and empirical test. Then, the ethanol extract of Epimedii Folium prepared according to the optimized technological conditions was used to intervene the injury model of chondrocyte induced by interleukin-1 beta(IL-1β). Annexin V-FITC/PI staining flow cytometry was used to detect the apoptotic rate of chondrocyte and analyze the effect of ethanol extract of Epimedii Folium on chondrocyte injury model. The optimum conditions of ethanol extraction were as follows. Crude powder of Epimedii Folium was added with 18 times of 70% ethanol solution, and extracted for twice in the refluxing process, for 60 minutes each time. Under the conditions, the extraction rates of the above five active components were 94.21%, 94.76%, 93.85%, 96.17% and 96.85%, respectively. The optimized ethanol extraction process of Epimedii Folium was reasonable, feasible and reproducible. This ethanol extract could significantly reduce the early apoptotic rate, late apoptotic and necrotic rate, total apoptotic rate(P<0.05 or P<0.01) of chondrocyte injury model induced by IL-1β, suggesting that the ethanol extract of Epimedii Folium can inhibit the apoptosis of chondrocytes induced by IL-1β to a certain extent, which lays a foundation for further study on its prevention and treatment of osteoarthritis.