PHARMACOKINETICS STUDY OF PUERARIN ABSORPTION IN BLOOD AFTER CONSUMPTION OF PUERARIA TUBEROSA WATER EXTRACT (PTWE) BY RATS

The aim of the study was to analyse pharmacokinetics of puerarin absorption from blood Pueraria tuberosa tuber water extract (PTWE) and its hypoglycaemic response. Peaks of puerarin have been standardized with different types of mobile phase at 254 nm by HPLC-UV and prepared the calibration curve of puerarin. The extract was administered to the rat and their blood was collected at different time interval. The circulating PTWE in plasma was extracted with the help of acetonitryl by liquid-liquid extraction method. The extracted samples were then injected into the HPLC in order to estimate the puerarin absorption from PTWE in blood at different time interval. The concentration of blood puerarin was calculated by plotting its standard calibration curve. Further hypoglycaemic response of PTWE was also studied in diabetic rat model. The absorbed puerarin peak was found at 254 nm and its retention time (RT) is 1.6 minutes by using the mobile phase of Methanol: Ammonium acetate 10 mM buffer (60:40). After calibration, the value of Cmax was 21.04 µg/ml, Tmax 4 hr and total AUC as 209.04 µg hr/ml of absorbed puerarin. Through in vivo study, it has also been found that PTWE significantly reduces the enhanced hyperglycaemia in diabetic rats, within 8 days of treatment. The present study clearly indicated the puerarin concentration was maximum at a time interval of 4 hr and exist in rat blood plasma upto 12 hours after oral consumption of PTWE. PTWE down regulates hyperglycemia, thus act as potential anti-diabetic drug responding in short duration of time. In addition, these results provide a new approach to study the pharmacokinetic evaluation of herbal drugs (PTWE) by estimating active components (puerarin) from herbal drugs.