Effects of insulin and clonazepam on DNA damage in diabetic rats submitted to the forced swimming test

Diabetes mellitus (DM) is a chronic hyperglycemic state. DM may be associated with moderate cognitive deficits and neurophysiologic/structural changes in the brain (diabetic encephalopathy). Psychiatric manifestations seem to accompany this encephalopathy, since the prevalence of depression in diabetic patients is much higher than in the general population, and clonazepam is being used to treat this complication. The excessive production of oxygen free radicals that may occur in diabetes induces a variety of lesions in macromolecules, including DNA. In this work, we analyzed DNA damage in leukocytes from streptozotocin-induced diabetic rats submitted to the forced swimming test. The DNA damage index was significantly elevated (DI = 61.00 +/- 4.95) in the diabetic group compared to the control group (34.00 +/- 1.26). Significant reductions of the damage index were observed in diabetic animals treated with insulin (45.00 +/- 1.82), clonazepam (52.00 +/- 1.22), or both agents (39.00 +/- 5.83, not significantly different from control levels). Insulin plus clonazepam can protect against DNA damage in stressed diabetic rats. (C) 2010 Elsevier B.V. All rights reserved.