[Quality inspection of commercial Bupluri Radix samples in Guangzhou: an ELISA for determining saikosaponin A content using anti-saikosaponin A monoclonal antibody].

OBJECTIVE To inspect the quality of commercially available Chaihu (Bupluri Radix, a common traditional Chinese herbal drug) in Guangzhou by determining the content of saikosaponin A (SSa) using enzyme-linked immunosorbent assay (ELISA). METHODS A competitive ELISA system using mouse anti-saikosaponin A monoclonal antibody was established for determining SSa content. Commercial samples of Chaihu were obtained from 10 drug stores in Guangzhou, and SSa contents in the methanol extracts of these samples were determined using the ELISA system. RESULTS The detection range of this competitive assay was 0.16-2.5 µg/ml for determining SSa contents. In the 10 commercial Chaihu samples, SSa contents in the methanol extract determined by this method ranged from 0.32 µg/mg to 6.87 µg/mg, and 3 samples showed a SSa content lower than the minimum requirement documented in the Chinese Pharmacopeia. CONCLUSION This competitive ELISA is sensitive, rapid, economic and environment-friendly for SSa determination, especially suitable for batch determination. The results of SSa detection for the commercial Chaihu samples demonstrate an uneven quality of Chaihu in Guangzhou market, suggesting the necessity of more rigorous quality control measures for this drug.