Free Radical Scavenging and Antioxidant effects of Tolfenamic Acid in L-NAME-Induced Hypertensive Rats

Objectives: The aim of this study was to determine the antioxidant and free radical scavenging properties of tolfenamic acid (TA) against N-Nitro-L-arginine methyl ester hydrochloride (L-NAME) induced hypertension.

Materials and Methods: The rats were divided into five groups at random: Group I (control rats), Group II (control TA), Group III (L-NAME), Group IV (L-NAME+TA), and Group V (L-NAME+Enalapril). For four weeks, rats were given L-NAME (40mg/kg body weight) dissolved in drinking water to induce hypertension. Intraperitoneal injections of TA (50mg/kg body weight) and enalapril (0.7 mg/kg body weight) were given to rats.

Results: The results showed that the In vitro free radical scavenging effect of TA on DPPH and ABTS was concentration dependent. In vivo studies with L-NAME resulted in increases in blood pressure, lipid hydroperoxides (LOOH), and thiobarbituric acid reactive substances (TBARS). In addition, the level of the non-enzymatic antioxidant reduced glutathione (GSH) and other enzyme antioxidant activities in the heart and aorta, including superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (Gpx), are reduced. The level of nitric oxide metabolism in the erythrocyte aorta of L-NAME rats was increased.

Conclusions: These findings imply that tolfenamic acid acts as an antihypertensive and antioxidant agent in L-NAME-induced hypertension.