Mechanism of baicalin compatibility in chinese medicine formula Banxia Xiexin Decoction () by pharmacokinetics and indirect competitive enzyme-linked immunosorbent assays in mice.

OBJECTIVE: To determine the effects of different formulations of Banxia Xiexin Decoction ( , BXD) on the pharmacokinetics of baicalin (BAL) in mice.

METHODS: Pungent, bitter, and sweet components of BXD (totaling 7 Chinese herbs) were formulated into the following groups: K (bitter herbs), XK (pungent and bitter herbs), KG (bitter and sweet herbs), and BXD (all 7 herbs) groups. These different formulations were administered intragastrically in mice, and blood was collected via the tail vein for continuous monitoring. BAL, which is a main active constituent in Scutellaria baicalensis Georgi., was detected in this study. Indirect competitive enzyme-linked immunosorbent assays (icELISAs) based on anti-BAL-monoclonal antibodies were employed to determine BAL concentrations in each group.

RESULTS: The concentrations of BAL in blood samples from mice in the K and XK groups were lower than those in other groups. In all groups, BAL concentrations peaked at around 1-1.5 h and again at 5-7 h. There were no significant differences in the timing of peak BAL concentrations between groups. However, the peak concentrations and area under curve (AUC)0-36 h in the KG and BXD groups were almost 3 times of those in the K and XK groups.

CONCLUSIONS: Differing compatibilities of BXD caused dissimilar pharmacokinetics of BAL. Moreover, we demonstrated a method for the continuous detection of blood concentrations of Chinese medicines in mice, and icELISA may be a feasible technique for the study of pharmcokinetic mechanisms of Chinese medicine.