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.