Effects of noopept on cognitive functions and pubertal process in rats with diabetes

Abstract

Aim: Type 1 diabetes (T1DM) is a common chronic disease in childhood. Increasing insulin resistance in puberty gives rise to higher doses of insulin usage in treatment. Of this reason new approaches in treatment are needed. Noopept researches suggest it to have anti-diabetic properties. We tried to determine the effects of noopept on pubertal diabetes.

Main method: The research was made with 60 prepubertal, 28 day-old, male, Sprague Dawley rats. The rats were divided into randomised 6 groups (n = 10/group). i) Control, ii) Diabetes Control, iii) Noopept Control, iv) Diabetes + Noopept, v) Diabetes + Insulin, vi) Diabetes + Insulin + Noopept. T1DM model was induced by streptozotocin on postnatal 28th day. 0.5 mg/kg noopept and 1 IU insulin were administered intraperitoneally for 14 days. Blood glucose and body weight measurements, puberty follow-up and MWM tests were performed. Hippocampus, hypothalamus and testis were evaluated histologically. Hypothalamic GnRH and kisspeptin were studied immunohistochemically. Serum LH, FSH and insulin, hippocampal homogenate NGF and BDNF levels were determined by ELISA.

Key findings: Delayed puberty was normalized by noopept (p < 0.05). Blood glucose levels were lower in noopept-administered diabetic groups (p < 0.05). Noopept decreased HOMA-IR in insulin administered diabetic group (p < 0.05). Number of degenerated cells in hippocampus and testis were higher in diabetes control group when compared with other groups (p < 0.05). GnRH immunoreactivity in Diabetes + Noopept group was increased when compared to insulin + noopept group (p = 0.018). There was no difference in kisspeptin, serum LH, FSH, hippocampal NGF-BDNF levels and spatial learning assessment among groups (p > 0.05).

Significance: Noopept may have positive effect in treatment of pubertal diabetes.

Keywords: BDNF ELISA rat kits: Elabscience (USA); FSH ELISA rat kits: Elabscience (USA); GnRH antibody: Santa Cruz- USA; Insulin ELISA rat kits: Elabscience (USA); Insulin: Insulin detemir (Levemir Flexpen- Novo Nordisc- Denmark); Kiss1 antibody: Biorbyt, UK; LH ELISA rat kits: Elabscience (USA); NGF ELISA rat kits: Elabscience (USA); Noopept; Noopept: GVS-111, N-phenylacetyl-L-prolyl glycine ethyl ester (Powder City, USA); Pubertal timing; Puberty; Type 1 diabetes.