Comparison of the effects of argan and nigella oils on malathion-induced cognitive-behavioral alterations and brain histopathology in male Wistar rats

Abstract

Occupational or environmental exposure to malathion is known to increasingly cause cognitive or psychiatric disorders, since it damages brain tissue through inflammation and oxidative stress processes. Here, we examine the possible neuroprotective effects of some natural products such as argan and nigella oils against malathion-induced cognitive-behavioral deficits and cerebral tissue alterations. Male Wistar rats were used in the present study. The rats were pretreated either with virgin argan oil (2 ml/kg p.o.) or nigella oil (1 ml/kg p.o.) 1 hour before malathion (150 mg/kg p.o.) administration for 28 days. At the end of the experiment, the cognitive-behavioral tests were performed, followed by the biochemical and histological analysis. Our results confirmed significant recognition memory deficits, affective disorders such as anxiety-like behavior in malathion-exposed rats, as well as an increased acetylcholinesterase (AChE) inhibition rate and histological changes in the brain. However, the pretreatment with argan oil significantly reversed the memory and behavioral disorders, and prevented neurodegeneration in the hippocampus and prefrontal cortex (PFC), caused by the malathion. By contrast, nigella oil especially attenuated malathion-induced histopathological effects in the liver. The neuroprotective effects of argan oil against malathion-induced neurotoxicity could be attributed to antioxidant properties of its bioactive compounds such as tocopherol, caffeic acid or oleuropein, whereas nigella oil exerted anti-inflammatory action through its main bioactive component thymoquinone (30-40% approximately).