Prenylflavonoid Contents of Five Epimedii Herba and Their Antioxidant Activity in PC12 Cells

This study was conducted to comparatively evaluate antioxidant activity of five species of Epimedium genus (Epimedium koreanum, E. brevicornum, E. pubescens, E. sagittatum and E. wushanense) and their protective effects on neuronal PC12 cells. The contents of individual penylflavonoids in five Epimedium species were also examined using HPLC/DAD. Five Epimedium plants were composed of icariin, icariside I, II, icaritin and epimedin A-C. Icariin was most predominant among all detected prenylflavonoids at all species studied. Icariin contents were in the order of E. koreanum (3.66 mg·g DW) > E. wushanense (1.98 mg·g DW) > = E. sagittatum (1.87 mg∙g -1 DW) > E. pubescens (1.60 mg∙g DW) > E. brevicornum (0.75 mg∙g DW). The highest antioxidant values studied via ORAC, DPPH, ABTS and FRAP assay were found in E. koreanum extract among the species. In addition, the neuroprotective effect of E. koreanum extract was strongest among studied via MTT, LDH and DCH-DA assay using H2O2-damaged PC12 cells species. All tested Epimedium plants extract showed neuronal cell protective effects in a dose-dependent manner. These results indicated that Epimedium plants extract has potent antioxidant and neuronal protective effects and E. koreanum extract had the highest activities among tested five species especially.