Protective activity of ethanol Pleurotus ostreatus extract against mercury-induced motor deficits in wistar rats: a neurobehavioural Study

Abstract

Mercury (Hg) is a highly toxic environmental heavy metal known to induce severe neurotoxic effects, particularly impairing motor coordination and neurological function. In Nigeria, mercury exposure from artisanal gold mining has raised significant health concerns. This study investigated the neuroprotective potential of ethanol extract of Pleurotus ostreatus (oyster mushroom) against Hg-induced neurotoxicity in adult Wistar rats. Forty-two adult Wistar rats were randomly assigned to six groups (n = 7). Group A served as control, while Group B received 4 mg/kg HgCl₂. Groups C and D received HgCl₂ plus 250 mg/kg and 500 mg/kg of P. ostreatus extract, respectively. Groups E and F received only P. ostreatus at 250 mg/kg and 500 mg/kg respectively. Treatments were administered orally for 28 days. Neurobehavioral assessments were performed using the Open Field Test (OFT), String Test, Step Test, and Movement Initiation Test. Phytochemical screening of the extract was also conducted using standard protocols. Phytochemical analysis revealed the presence of glycosides, phenols, terpenoids, alkaloids, flavonoids, and tannins. Rats exposed to HgCl₂ showed significant (p < 0.05) neurobehavioral impairments, including reduced latency to grip loss, rearing activity, ambulation, and central square entry, alongside increased initiation time, grooming, immobility, thigmotaxis, sniffing, and crossing behaviors. Co-treatment with P. ostreatus extracts significantly (p < 0.05) reversed these changes, improving motor coordination, exploratory behavior, and neuromuscular strength in a dose-dependent manner. Pleurotus ostreatus extract exhibited significant protective effects against HgCl₂-induced neurotoxicity in rats, likely due to its antioxidant and neuroprotective phytoconstituents. These findings support the therapeutic potential of P. ostreatus as a natural intervention for mercury-induced neurological disorders.