Melatonin counteracts aluminum-induced affective and cognitive disorders and oxidative damage in male wistar rats

Aluminum (Al) is a potentially toxic element causing many neuropathological and behavioral alterations such as affective and cognitive disorders. Recently, several studies described melatonin (MEL) as an effective antidepressant and anxiolytic substance. This study aimed to assess the effects of MEL and Al combination on affective and cognitive behavior and oxidative stress in male Wistar rats. Animals were injected intraperitoneally with saline (0.9% NaCl), MEL (4 mg/kg), Al (1 mg/kg) or MEL (4 mg/kg) + Al (1 mg/kg) for 8 weeks. After the treatment period, open-field, elevated plus maze, forced swimming test, Y-maze and Morris water maze were used to evaluate anxiety-like, depression-like behaviors, spatial learning, and memory ability. The hippocampus was taken for biochemical examination. The results revealed that MEL and Al combination exerts anxiolytic and antidepressant effects and shows a positive effect on working memory and spatial learning compared to the Al treated groups. Also, biochemical analysis showed that MEL co-administration played a neuroprotective role, increasing superoxide dismutase (SOD) activity and decreasing significantly nitric oxide (NO) and lipid peroxidation (LPO) levels in rat hippocampus in the MEL+Al treated groups. In conclusion, MEL in combination with Al has both anxiolytic and antidepressant effects, improves cognitive behavior and biochemical dysfunction. © 2023, The Author(s), under exclusive licence to Springer Nature Switzerland AG.