Chronopharmacokinetics of puerarin in diabetic rats

Puerarin injection has been widely used for clinic treatment of diabetes recently. To assess the relationship between the administration time of puerarin and the blood concentration of puerarin as well as its pharmacokinetic parameters, the diabetic rat model was used in current study. The rats were randomly divided into morning and evening groups according to the administration time. After the puerarin injection, blood glucose was tested in order to know whether the efficiency of puerarin was influenced by its concentration and pharmacokinetic parameters. Our results show that the average concentration of puerarin in the evening group is significantly higher than that in the morning group. The numbers of t1/2α, t1/2β, CL and AUC(0-∞) are significantly different between the morning and evening groups. The blood glucose level in the evening group was lower than that in the morning group. The speed of its onset is higher and the blood glucose level declines much more significantly in the evening group. These findings suggest that the concentration and pharmacokinetic parameters of puerarin affect its efficiency in diabetic rats. Therefore, it might be better to give puerarin in evening than in the morning for the mellitus treatment.