In vivo and In vitro evaluation of free radical scavenging potential of methanol extract of Desmodium gangeticum root: A possible explanation through GC Mass analysis

Desmodium gangeticum root is considered extensively in the indigenous system of medicine as an anti inflammatory, anti microbial agent in many Asian countries. Oxidative stress plays a major role in the biochemical and pathological changes associated with myocardial ischemic-reperfusion injury. The current investigation focuses on the in vitro and in vivo free radical scavenging property of the aqueous extract of Desmodium gangeticum (DG) root on experimentally induced ischemic reperfused rat heart. The free radical scavenging potential was studied in vitro by using different antioxidant models such as DPPH, super oxide scavenging activity, hydroxide scavenging activity and nitric oxide scavenging activity. Aqueous extract of DG, 50 or 100 mg/kg body weight was administrated once daily for 30 days orally in Wister rats to evaluate the in vivo free radical scavenging potential. Thereafter, hearts were isolated and subjected to ischemic reperfusion injury with the help of Langendroff apparatus. The experimental group consists of normal, ischemic control, reperfusion control and drug. Lipid peroxide products (thiobarbituric acid reactive substances) were significantly increased during ischemia and ischemic-reperfusion. The enzymes (superoxide dismutase, catalase, glutathione peroxidase and glutathione reductase) in the myocardial tissue homogenate showed a significant decrease during ischemia and ischemic-reperfusion. Pre treatment of rats with DG (50 or 100mg / kg b.wt.) orally for 30 days daily caused a significant effect in the activity of antioxidant enzymes. The in vitro antioxidant study was found to inhibit lipid per-oxidation (LP) and scavenge hydroxyl and superoxide radicals. Concentration needed for 50% inhibition of DPPH, superoxide scavenging activity, hydroxide scavenging activity and nitric oxide scavenging activity were found to be 38.5, 21, 50.5, 50µg/ml respectively. Administration of DG to normal rats did not have any significant effect on any of the parameter studied. The results of our study showed that DG possesses activity to scavenge the free radical generated during ischemia and ischemic-reperfusion.