Rosiglitazone attenuates amyloid beta and glial fibrillary acidic protein in the hippocampus and neuroinflammation associated learning and memory impairments in rats

OBJECTIVE:The aim of the current study was to investigate the beneficial effects of rosiglitazone (Rosi) on amyloid beta(Aβ) and glial fibrillary acidic protein (GFAP) in the hippocampus and neuroinflammation-associated learning and memory impairments in rats. MATERIALS AND METHODS:The rats were grouped and treated as follows: (1) Control in which saline and vehicle were administered instead of LPS and Rosi respectively. (2) Lipopolysaccharide (LPS) group in which LPS was dissolved in saline and injected (1 mg/kg) intraperitoneally. Vehicle was administered instead of Rosi in this group. (3-5) LPS+ Rosi 1, LPS+ Rosi 3, and LPS+ Rosi 5 groups in them 1, 3, or 5 mg/kg of Rosi respectively was administered 30 min before LPS. The treatments were done for two weeks. In the first week, Rosi or its vehicle was injected 30 min before LPS. In the second week, the treatments were the same as the first week and behavioral tests were also carried out in the second week. The hippocampal tissues were finally detached for biochemical assessment. RESULTS:The results showed that Rosi reversed increased levels of Aβ, GFAP, interleukin (IL)- 6, tumor necrosis factor-α (TNF-α), nitric oxide (NO) metabolites, and malondialdehyde (MDA) due to LPS injection. Rosi also reversed attenuating effects of LPS on IL-10 and thiol concentration and activities of catalase (CAT) and superoxide dismutase (SOD). In the Morris water maze test, the LPS group had a longer latency to find the platform while spent a shorter time spent in the target quadrant in the probe trial than the control group. In the passive avoidance test, the animals of the LPS group had a shorter delay to enter the dark chamber than the animals of the control group. Treatment with Rosi reversed these parameters. CONCLUSION:The findings showed Rosi attenuated Aβ, GFAP, and oxidative stress in the hippocampus and neuroinflammation-associated learning and memory impairments in rats.