Variation of epimedins, icariin and total flavonoids and evaluation of antioxidant activities of Epimedii Folium in different areas of China

In order to investigate the current quality status of Epimedii Folium in China and to provide evidence to produce functional foods containing Epimedii Folium, contents of epimedin A, epimedin B, epimedin C, icariin and total flavonoids in 33 batches of Epimedii Folium in Chinese markets were determined by high performance liquid chromatographic and ultraviolet spectrophotometric methods, respectively. Antioxidant activities of Epimedii Folium were measured by DPPH (1, 1-diphenyl-2-picrylhydrazyl) and ABTS (2, 2'-azino-bis (3-ethyl-6-sulfonic acid) diammonium salt) assays. Epimedin A, epimedin B, epimedin C, icariin and total flavonoids in different batches of Epimedii Folium varied in the range of 0.37~3.01, 0.25~5.22, 0.46~19.27, 0.41~13.40, 18.29~68.73mg/g, respectively. EC50 values of alcoholic extracts of Epimedii Folium changed in the range of 0.27~3.51μg/mL (DPPH assay) and 4.71~21.96μg/mL (ABTS assay) , respectively. DPPH·radical-scavenging activities of all samples of Epimedii Folium were higher than that of ascorbic acid (VC) . A large variation of flavonoid contents and antioxidant activities was found among Epimedii Folium purchased from different areas. There was a relatively close relationship between antioxidant activities of Epimedii Folium and contents of epimedin C and total flavonoids (range of R2:0.5648~0.8626) , whereas antioxidant activities have comparatively poor correlation with contents of epimedin A, epimedin B and icariin (range of R2:0.3550~0.6395) .