Effects of topical melatonin and vitamin E in a rat ischemic wound model

Objective: Reactive oxygen species are known to increase on a chronic wound background. We therefore investigated the possible efficacy of the topical administration of melatonin and vitamin E, known to have radical scavenging properties, in the ischemic wound model. Methods: Forty Sprague-Dawley type adult male rats were divided into 4 groups as normal wound, ischemic group, and with vitamin E or melatonin applied to the ischemic wound. Bipedicular flap surgery to the shaved back of the rats was used to induce ischemia. A full-thickness skin lesion was produced by punch biopsy in each animal 3 days after this procedure. The punch biopsy procedure was performed without the flap surgery in the normal wound group. The vitamin E and melatonin administration continue twice a day for a total of 7 days after the wound was formed. Results: Hydroxyproline (OH-proline) and malonyldialdehyde (MDA) levels and superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) enzyme activities were measured on the wound tissues removed by excisional biopsy at the end of the procedure. The MDA levels were significantly decreased in the groups receiving vitamin E and melatonin compared to the ischemic wound group. Vitamin E application also significantly increased OH-proline levels in the ischemic wounds. The antioxidant enzyme activities were not seen to be affected by the treatment procedures used. Conclusion: We concluded that the collagen synthesis decreased together with increased oxidative stress in the induced ischemic wound model; topical vitamin E application could reverse both states and melatonin could not support collagen synthesis although it had an antioxidant effect.