Reverse phase HPLC method validation for estimation of polyphenols in medicinal plants and their possible role in reticence of xanthine oxidase activity

The objective of this study was to investigate simple, sensitive, specific and reliable high-performance liquid chromatography method for determination of seven polyphenols viz. gallic acid, catechin, rutin, ellagic acid, umbelliferone, quercetin, and kaempferol in medicinal plants. i.e. Cornus capitata Wall. (leaves), Clematis grata Wall. (whole plant), Evolvulus nummularis (L.) L. (whole plant), Roylea cinerea (D. Don) Baill. (leaves and stem). Different polyphenols were detected and quantified in all the plant extracts. The chromatographic separation of seven polyphenols was achieved by reverse phase high-performance liquid chromatography (Shimadzu, Kyoto, Japan) 250 x 4.6 mm enable-C18G column (i.d., 5 mu m) using linear gradient elution of buffer (0.5% orthophosphoric acid, 1.36 g KH2PO4 in 1 L of water) and acetonitrile with a flow rate of 1 mL/min at lambda 280 nm. Standard calibration curves were linear in the range of 1.95-1000 mu g/mL. The method was validated for linearity, accuracy, repeatability, limit of detection, and limit of quantification. Increased oxidativestress may be attributable to increased xanthine oxidase activity which leads to hyperuricemia. Results revealed that the C. capitata (leaves) extract showed 50% inhibiton at 66.76 mu g/mL against xanthine oxidase (in vitro). Results of the present study suggest the Cornus capitata Wall. (leaves) extract can be helpful in the treatment of hyperuricemia.