The antioxidant and neuroprotective effects of melatonin on glyphosate-based herbicide-induced affective and cognitive impairments in rats

Abstract

Several studies have found that exposure to glyphosate-based herbicides (GBH) can lead to memory impairment and affective disorders. Oxidative stress (OS) is one of the mechanisms that can explain the neurotoxicity of GBH. Consequently, molecules with an antioxidant effect may have neuroprotective potential against GBH-related brain damage. In this work, we aim to evaluate the neuroprotective effect of melatonin (MEL) against affective and cognitive disorders caused by GBH. For this experiment, male Wistar rats received, during the peripubertal period, a daily administration of GBH (75 mg/kg) or GBH + MEL (4 mg/kg). At the end of the treatment, the open field, elevated plus maze, and forced swimming tests were used to explore anxiety levels and depression-like symptoms. While the Y-Maze and Morris Water Maze have been used to detect cognitive deficits, we also measured markers of OS, specifically catalase, nitric oxide, and lipid peroxidation, in the hippocampus and prefrontal cortex. Our results revealed that MEL reduces anxiety and depressive behavior, as well as the cognitive deficits caused by GBH. In addition, co-administration of MEL and GBH induced an improvement in the various markers of OS. The positive action of MEL against OS is therefore one of the mechanisms explaining its neuroprotective power against GBH.