Comparative Study of the Effects of Topically Used Insulin and Simvastatin on Thermal Induced Burn in Diabetic Albino Rats

AbstractBackground: Diabetic wound healing is a major compli-cation that may be delayed or impaired. This is resulting from abnormalities in inflammatory and oxidative stress responses, impaired growth factors production, angiogenic responses and collagen deposition.Aim of the Work: The aim of this work was to investigate and compare possible effects of topical insulin and simvastatin on the tissue repair capacity, their anti-inflammatory and anti-oxidant effects.Material and Methods: Sixty male Wister Albino rats were divided into 5 equal groups, group1 normal burned received vehicle, group 2 diabetic burned received vehicle, group 3 diabetic burned received insulin in vehicle, group 4 diabetic burned received simvastatin in vehicle and group 5 diabetic burned received insulin in saline all applied topically. At certain end recording points (3rd, 7th, 14th and 21st days post burning) wound contraction percentage % was calculated and serum tumor necrosis factor-a (TNF-a), blood reduced glutathione and serum malonaldialdehyde (MDA) levels were estimated and dissected burn specimens were prepared for histopathological and immunohistochemical staining for VEGF and a-SMA.Results: Insulin and simvastatin produced more than satisfactory results evidenced by significant improvement in the whole studied parameters.Conclusion: Insulin and simvastatin have anti–inflamma-tory, antioxidant and angiogenic effects improving the healing properties. Although they both in vehicle exhibited similar effectiveness in regard the investigated parameters, they exhibited superiority over insulin in saline.