DNA protective and antioxidative effects of melatonin in streptozotocin-induced diabetic rats

Diabetes mellitus is a chronic disease characterized by elevated blood sugar levels. In diabetic patients, oxidative stress induced by the presence of excessive free radicals is closely associated with chronic inflammation, leading to potential tissue damage. Melatonin (MEL) is a compound synthesized by the pineal gland and a scavenger of free radicals. The aim of this study was to research the effects of MEL on oxidative stress and its DNA protective effects in streptozotocin-induced diabetic rats. In total, 32 rats were equally divided into four experimental groups: control, melatonin, diabetic, and diabetic + melatonin. A single dose of streptozotocin (60 mg/kg) was given by intraperitoneal route to induce experimental diabetes. MEL (10 mg/kg daily) was administrated to rats by intraperitoneal route for 6 weeks. Oxidative stress parameters were evaluated in rat liver, kidney, brain, and pancreas tissues. Body weight, plasma glucose, and HbA(1c) levels were studied. DNA damage was analyzed by comet assay in lymphocytes, while % tail DNA and mean tail moment parameters were evaluated. The study results indicate that the intraperitoneal administration of 10 mg/kg MEL over 6 weeks may cause amelioration in oxidative stress parameters against diabetes, leading to beneficial effects based on % tail DNA and mean tail moment parameters in rat lymphocytes.