KALU JAMES IKEOGU

This study investigates whether the plant Gongronema latifolium can reduce anxiety (anxiolytic effect) and protect the brain from damage caused by exposure to manganese chloride in laboratory rats.Manganese, although essential in small amounts, becomes toxic when taken in excess. It can accumulate in the brain, leading to oxidative stress, neuronal injury, and behavioral changes such as anxiety and restlessness. Excessive exposure to manganese (Mn) has been associated with neurotoxicity, leading to anxiety-like behaviors due to oxidative stress and neuronal damage. Gongronema latifolium is a medicinal plant commonly used in African traditional medicine for its antioxidant, anti-inflammatory, and protective properties. The research evaluates how effective extracts of this plant are in preventing or reducing anxiety behaviors and brain damage caused by manganese.Wistar rats were exposed to manganese chloride and then treated with different doses of Gongronema latifolium. Their behavior was tested using standard models of anxiety such as the Elevated Plus Maze, Open Field Test, tail suspension test and string test. Brain tissues were later examined for structural and biochemical changes.The study found that Gongronema latifolium reduced anxiety-like behavior, improved antioxidant enzyme levels, and preserved brain structure — showing that it has both anxiolytic and neuroprotective effects. Forty-eight (48) adult Wistar rats of both sexes (n = 8 per group) with an initial mean weight of 100 ± 10 g were randomly divided into six groups. Group A served as the normal control and received distilled water; Group B received manganese chloride (10 mg/kg) to induce anxiety; Groups C and D were treated with manganese chloride plus Gongronema latifolium extract (100 mg/kg and 200 mg/kg, respectively); Group E received Gongronema latifolium (100 mg/kg) as a standard anxiolytic; and Group VI received Gongronema latifolium extract alone (200 mg/kg). Treatments were administered orally for the Gongronema latifolium and intraperitoneally for Manganese chloride for 28 comsecutives days. Neurobehavioral parameters were assessed using the Tail suspension test (TST) ,String Test, Elevated Plus Maze (EPM) and Open Field Test (OFT). Brain tissues were harvested for histological and biochemical analysis.Manganese exposure significantly (p < 0.05) increased anxiety-like behaviors, evidenced by reduced open-arm entries and time in the EPM and decreased central zone exploration in the OFT. Pre-treatment with Gongronema latifolium significantly ameliorated these effects in a dose-dependent manner, comparable to diazepam. In conclusion, Gongronema latifolium demonstrated potent anxiolytic and neuroprotective activities against manganese-induced neurotoxicity through antioxidant and neurorestorative mechanisms. These findings suggest its potential as a natural therapeutic agent for managing anxiety disorders associated with heavy metal neurotoxicity.