The effect of melatonin on antioxidant defense indicators in the blood of rats with insulin resistance.

Objective: Aim: To determine the effect of melatonin on the activities of glucose-6-phosphate dehydrogenase, glutathione reductase, glutathione peroxidase and the content of reduced glutathione, glucose and insulin levels in the blood of rats with insulin resistance.

Patients and methods: Materials and Methods: Research performed in compliance with the Rules of the work using experimental animals (1977) and the Council of Europe Convention on the Protection of Vertebrate Animals used in experiments (Strasbourg, 1986). Sexually mature 18-month-old outbred white male rats were divided into groups: 1) control, 2) insulin resistant rats (dexamethasone at a dose of 0.125 mg/kg for 13 days daily), 3) insulin resistant rats ingested with metformin (200 mg/kg) daily, 4) insulin resistant rats were orally administered melatonin at a dose of 10 mg/kg daily. Measurement of fasting glucose content in the blood from the tail vein (One Touch, USA) and insulin in the blood serum (immunochemiluminescent analyzer Snibe Co., Ltd, the Maglumi test kit, China) was performer on the 14th day. Blood was taken to determine the parameters of glutathione system by using standard methods. Statistical processing was performed using the IBM SPSS Statistics 21 program. Differences were considered statistically significant at p≤0.05.

Results: Results: Melatonin ingestion as well as metformin were helpful in normalization of insulin level on the background of glucose level restoration and antioxidant system activation.

Conclusion: Conclusions: We have established the hypoglycemic and antioxidant effects of melatonin on the background of dexamethasone-induced insulin resistance.