Pharmacokinetic Effects of Baicalin on Cerebral Ischemia-reperfusion after iv Administration in Rats

Objective To investigate the pharmacokinetic effects of baicalin on cerebral ischemia-reperfusion (I/R) after iv administration in rats. Methods The cerebral I/R rats were induced by occluding the bilateral carotid arteries of normal rats for 2 h, followed by reperfusion. The resultant animals were immediately iv administrated with baicalin (90 mg/kg), whilst the same dose of baicalin was injected to the normal rats. Plasma samples were collected at different time to construct pharmacokinetic profiles by plotting drug concentration vs time. Quantification of baicalin in rat plasma was achieved using a simple and rapid HPLC method. Results In normal rats, the major parameters of distribution half-life, elimination half-life, area under the plasma concentration-time (AUC), apparent volume of distribution (Vd), and clearance (CL), estimated by an open two-compartmental model, were 0.8868 min, 26.0968 min, 149.6204 mg/min·L, 4.765 L/kg, and 0.5776 L/ kg·min), respectively. However, in I/R rats, the corresponding parameters were 2.084 min, 34.4998 min, 260.0188 μg·min/L, 5.9376 L/kg, and 0.334 L/(kg·min), respectively. Conclusion The cerebral I/R could significantly increase AUC and Vd values, decrease CL values, and prolong the terminal half-life of baicalin. These findings suggest that the injuries of I/R could play an important role in pharmacokinetic process of baicalin.