Abstract

INVESTIGATION OF ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITY OF ROOTS OF RUMEX NEPALENSIS

Shankar Raj Devkota, Keshav Raj Paudel, Kushal Sharma, Ananda Baral, Sumit Bahadur Baruwal Chhetri, Pravin Parajuli Umesh Thapa, and *Kalpana Parajuli Baral

ABSTRACT

Inflammation and oxidative stress is associated with many of the acute and chronic diseases which have been troubling mankind. Rumex nepalensis has been used ethno-medicinally for the alleviations of pain and various inflammatory conditions in the western Nepal. The present study was performed to determine in vitro antioxidant activity and in vivo anti-inflammatory activity of R. nepalensis ethanolic extract. In vitro antioxidant activity was evaluated by 2, 2-diphenyl-picrylhydrazyl (DPPH) assay, nitric oxide (NO) scavenging activity, chelating assay and thio barbituric acid reactive substance (TBARS) assay. Three doses, 50 mg/kg, 100 mg/kg, and 200 mg/kg of R. nepalensis were tested for anti-inflammatory activity in carrageenan induced rat paw edema model. The ethanolic extract of R. nepalensis produced dose dependent inhibition of DPPH radicals with IC50 value of 15.84 μg/ml, showing almost similar effect with standard drug ascorbic acid (IC50 : 14.32μg/ml). Likewise, it also scavenges the NO radicals with IC50 value of 146.4 μg/ml. It also inhibited the lipid-peroxidation mediated by oxidizing agent. Similarly, R. nepalensis can dose dependently chelate the metal induced oxidation or enzyme activation with IC50 value of 97μg/ml. In carrageenan induced inflammation model, R. nepalensis oral extracts produced dose dependent inhibition of rat paw edema significantly (p< 0.05) compared to the control group and 200 mg/kg dose produced maximum percent inhibition of rat paw edema (60.86%) at 3 hour. Thus, we found that the ethanolic extract of R. nepalensis showed potent in vitro antioxidant activity and in vivo anti-inflammatory activity.

Keywords: Rumex nepalensis, antioxidant, anti?inflammatory, lipid-peroxidation.