Protective Effect of Metformin against Acute Inflammation and Oxidative Stress in Rat

Preclinical Research The antidiabetic drug, metformin, can inhibit the release of inflammatory mediators in several disease conditions. The present study was carried out to evaluate the efficacy of metformin in ameliorating edema formation, oxidative stress, mediator release and vascular changes associated with acute inflammation in the rat carrageenan model. Metformin dose-dependently inhibited paw swelling induced by carrageenan and normalized the tissue levels of the inflammatory markers myeloperoxidase and nitrite. It also maintained oxidative homeostasis as indicated by near normal levels of the oxidative stress markers glutathione, thiobarbituric acid reactive substances, catalase and superoxide dismutase. The histopathology of the paw tissue in metformin-treated animals was similar to that in normal paw and had similar effects to diclofenac. In a rat peritonitis model, metformin reduced vascular permeability and cellular infiltration. In conclusion, this study shows that metformin has a potential for use in treating various inflammatory conditions.