Study on the radical scavengers in the traditional Chinese medicine formula Shengmai San by HPLC–DAD coupled with chemiluminescence (CL) and ESI–MS/MS

Shengmai San (SMS) has been used for the treatment of cardiovascular disease in Asia for long-time. It has been reported that SMS can protect against oxidative stress and tune immune response in patients. In this paper, a high performance liquid chromatography–diode array detection–chemiluminescence (HPLC–DAD–CL) method for on-line detection was successfully applied to screen antioxidants in complex SMS extracts. The H2O2 scavenging activity of every fraction of SMS extracts was measured to evaluate each contribution to the total anti-oxidative activities of the prescription, followed by structures identification of the main active components by LC/MS/MS. HPLC–DAD–CL method was also applied for comparing the scavenging rates of main active components between the individual herbs and SMS. Interestingly, we found that the scavenging activities of main components detected in the individual herbs were different from those in SMS. The experimental data indicated that drug interactions during decocting process could result in the changes of the antioxidants’ solubility. This study demonstrated that HPLC–DAD–CL on-line assay was a useful technique for rapidly screening and identifying bioactive components from complex multi-herbal prescription.