Comparison of the Neuroprotective Effects of Aspirin, Atorvastatin, Captopril and Metformin in Diabetes Mellitus

Objective: The aim of this study was to investigate the effect of combined intake of a high dose of aspirin, atorvastatin, captopril and metformin on oxidative stress in the brain cortex and hippocampus of streptozotocin (STZ)-induced diabetic rats. Material and methods: Rats were randomly divided into the following 11 groups: control and diabetic (D), as well as 9 groups that were treated with metformin (M, 300 mg/kg) or aspirin (ASA, 120 mg/kg) alone or in different combinations with captopril (C, 50 mg/kg) and/or atorvastatin (AT, 40 mg/kg) as follows: (D + M), (D + ASA), (D + M + ASA), (D + M + C), (D + M + AT), (D + M + C + ASA), (D + M + C + AT), (D + M + AT + ASA) and (D + M + C + AT + ASA). The rats in treatment groups received drugs by gavage daily for six weeks. Serum lipid profile and levels of oxidative markers in the brain cortex and hippocampus tissues were evaluated. Results: The levels of malondialdehyde in the brain cortex and hippocampus in all the treated groups decreased significantly (p < 0.05). There was a significant increase in the total thiol concentration as well as catalase activity in treated rats in (M + AT), (M + C + ASA), (M + C + AT), (M + AT + ASA) and (M + C + AT + ASA) groups in cortex and hippocampus in comparison with the diabetic rats (p < 0.05). Also, the superoxide dismutase activity in all treated rats with medications was significantly increased compared to the diabetic rats (p < 0.05–0.01). Conclusion: Our findings showed that the combined use of high-dose aspirin, metformin, captopril and atorvastatin potentiated their antioxidant effects on the brain, and hence could potentially improve cognitive function with their neuroprotective effects on hippocampus