Variation of epimedins A - C and icariin in ten representative populations of epimedium brevicornu maxim., and implications for utilization

The concentration variations of main flavonoids, epimedins A-C and icariin, among ten representative populations of Epimedium brevicornu Maxim. were assessed by HPLC. The populations were collected during the flowering stage and included 419 individual samples. Remarkable variations within and among populations were detected. SXXA Population (see Fig.1) was an outlier due to its significant low concentrations (<1.00-4.46mg/g). But even without SXXA, significant concentration differences among populations were still observed in epimedin A (2.31-8.42mg/g), epimedin B (6.67-55.7mg/g), epimedin C (5.39-23.0mg/g), icariin (8.50-39.9mg/g), and their total (29.1-123mg/g). All populations except SXXA showed much higher concentrations than the recommended standards (i.e. 5mg/g for icariin and 13mg/g for the total). A high-concentration-population structure, estimated both by principal component analysis (PCA) and unweighted pair group method with averaging (UPGMA) cluster analysis, based on Euclidean distances, was observed. Both methods allowed separation of the populations in four groups defined by the concentrations of four main flavonoids. The populations (SXLC and SXQS) located in north of Yellow River were clustered together and characterized by highest concentrations of epimedin B, icariin, and their total. Considering of the high concentrations of main flavonoids and abundant resources, E. brevicornu could be exploited as a good medical resource for Herba Epimedii and would offer a tremendous potential for commercial development, but SXXA population should be paid special attention, and further study is needed.