Antioxidant and anti-inflammatory properties Hymenodictyon excelsum bark

Hymenodictyon excelsum Wall. (Rubiaceae) is a middle sized deciduous tree found in Himalayan regions of India and traditionally used for medicinal purposes. The present study was carried out to evaluate the antioxidant and in vitro anti-inflammatory activity of methanol extract of H. excelsum bark. The antioxidant activity H. excelsum was evaluated by means of various in vitro and in vivo antioxidant assays. In addition in vitro anti-inflammatory activity was studied using inhibition of protein denaturation and human red blood cell (HRBC) membrane stabilization methods. Total phenolic content was also measured by standard assay method. The results indicate that methanol extract of H. excelsum produced concentration dependent free radical scavenging property in various in vitro antioxidant assays. Similarly, a gradual increase in the hepatic enzyme activities was found by the extracts with their increasing doses for the extract treated mice compared to the control. Total phenolic content was found to be 97.30 μg/mg of extract. The maximum membrane stabilization of extract was found to be 74.21 ± 0.4 % at a dose of 1000 μg/0.5 ml and that of inhibition of protein denaturation was found to be 82.64 ± 0.6 % at a dose of 250 μg/ml. Reductive ability of the extract was also tested where dose dependent reducing capability was observed. From the results it can be concluded that H. excelsum bark extract had remarkable antioxidant and in vitro anti inflammatory activities. © 2012 Institute of Oriental Medicine, Kyung Hee University.