Differences Between the Concentrations in Rabbit Body Fluid of Berberine Hydrochloride, Chlorogenic Acid, Baicalin, and Their Minimal Inhibitory Concentrations

To explore the relationship between the heat-clearing and detoxicating functions and the bacteriostatic actions of berberine hydrochloride (Ber. H), chlorogenic acid (Chlo. A), and baicalin (Bai), their concentrations in rabbit body fluid were compared with their minimal inhibitory concentrations (MICs). Their concentrations in rabbit blood and tissue fluid were determined by reversed-phase high performance liquid chromatography, and their MICs to Escherichia coli were determined by tube dilution method. The results showed that the peak concentrations of Ber. H, Chlo. A, and Bai in rabbit blood were 3.2, 5.03, and 7.63 μg mL−1, and in rabbit tissue fluid were 0.12, 0.11, and 0.12 μg mL−1, respectively. Their MICs to E. coli were, respectively, 1.0 × 103, 3.75 × 103, and 6.75 × 103 μg mL−1, which were far higher than the concentrations in rabbit body fluids. This study indicates that Ber. H, Chlo. A, and Bai have weak bacteriostatic actions and do not reach their effective inhibitory concentrations in rabbit body fluids, and their heat-clearing and detoxicating functions are independent on the bacteriostatic actions.