Screening active components of herbal drug based on their affinity

How to screen active components of herbal drugs is still a hot topic of pharmacologists and pharmaceutical chemists. The main aim of the study was to establish a strategy to tract the active components in early stage based on the fact, that a compound (component) can not take systematic effect without binding to a biomolecule of organism. Affinity constants (KD or KD) and relative affinity indexes (Ac and RRT) of the components were calculated, and the values of affinity indexes were used to forecast their activity. This strategy was used to screen active components of Erigeron breviscapus and obtained anticipated results. The calculated affinity indexes (Ac and RRT) suggested that, plasma, serum, and especially platelet were the likely targets for E. breviscapus, while red blood cell was not. As for the identified components, isochlorogenic acid B and chlorogenic acid were proved compounds that had anti-platelet activity, while caffeic acid was not. The results of the present study were consistent with previous reports largely. Therefore, the strategy is useful for screening active components of herbal drugs, especially in early stage.