Simultaneous quantification of flavonoids in blood plasma by a highperformance liquid chromatography method after oral administration of Blumea balsamifera leaf extracts in rats

The leaves of Blumea balsamifera are used as a folk medicine in kidney stone diseases in South-East Asia. Phytochemical investigation revealed leaves contained a number of flavonoids. In view of these, the present work was aimed to quantify and preliminary pharmacokinetic investigation of five flavonoids viz. dihydroquercetin-7,4′-dimethyl ether (I), dihydroquercetin-4′-methyl ether (II), 5,7,3′,5′-tetrahydroxyflavanone (III), blumeatin (IV) and quercetin (V) in rat plasma following oral administration (0.5g/Kg) of B. balsamifera leaf extract in rats. Quantification was achieved by using a validated, reproducible high-performance liquid chromatographic method. The mean recoveries of I, II, III, IV and V were 90.6, 93.4, 93.5, 91.2 and 90.3% respectively. The limit of quantification was 25 ng/mL for I and IV, 10 ng/mL for II and III and 100 ng/mL for V respectively. The within day and day-to-day precision for all the compounds were 10%. The validated HPLC method herein was applied for pharmacokinetic studies and the main pharmacokinetic parameters were: t1/2 (hr) 5.8, 4.3, 2.9, 5.7 and 7.3, Cmax (ng/mL) 594.9, 1542.9 1659.9, 208.9 and 3040.4; Tmax (hr) 4.7, 1.0, 1.0, 3.5 and 2.3; AUC0-∞ (ng hr/mL) 5040, 5893, 9260, 1064 and 27233 for I, II, III, IV and V respectively. The developed method was suitable for pharmacokinetic studies and this preliminary study also revealed significant absorption after oral dosing in rats.