Objective: It\'s known that metabolic and vascular disorders impair functional and structural integrity of brain in diabetic patients. It\'s It is shown that thiamine (TIA) has an important role in neurophysiology. In this study; we aimed to investigate the effect of TIA on the expression of nesfatin in the brain tissues of diabetic rats.

Material and Methods: In this study, adult male Wistar albino rats were used. The experimental animals were divided into 4 groups, containing 6 animals in each group. In the control group; the rats didn\'t receive any drugs during the 6 weeks of the study period. Buffer group was administered phosphate-citrate buffer intraperitoneally (IP). In the DM group; 50 mg/kg single dose streptozotocin (STZ) was administered IP. DM+TIA group received 50 mg/kg single dose of STZ and started 25mg/kg/day of TIA orally after the induction of DM. At the end of the experiment, the rats were decapitated under the anesthesia and the brain tissues were removed. Brain tissues were embedded into paraffin blocks after the routine histological preparations. Avidin-biotin-peroxidase technique was used in determination of nesfatin expression. Histologic score was created in by the assessment of immunohistochemical staining.

Results: The immunoreactivity of nesfatin was found as similar in control and the buffer groups. Nesfatin immunoreactivity was found significantly increased in the DM group compared to the control group. Nesfatin immunoreactivity was found significantly decreased in the DM+TIA group compared to the DM group.

Conclusion: We can conclude that thiamin has protective effects via nesfatin on the brain tissues of diabetic rats..