U. O. IDEMUDIA

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.

Excessive exposure to Manganese chloride (MnCl2) has been shown to induce neurotoxicity, particularly within the cerebellum, due to oxidative stress and neuronal degeneration. The cerebellum’s high metabolic activity and synaptic density make it especially vulnerable to heavy metal accumulation and oxidative injury.Gongronema latifolium (Utazi leaf), a tropical West African herb rich in flavonoids, saponins, and alkaloids, has demonstrated antioxidant and anti-inflammatory properties in experimental studies. This study was aimed at investigating the neuroprotective effects of aqueous leaf extract of Gongronema latifolium against Manganese chloride induced cerebellar toxicity in adult wistar rats. Forty-eight (48) adult wistar rats were used in this study. They were randomly divided into six groups (n=8) and treated for 28 days as follows: Group A served as control and received 1mL of distilled water, Group B received 10mg/kg of Mncl2, Group C received 100mg/kg of aqueous leaf extract of Gongronema latifolium and 10mg/kg of Mncl2, Group D received 200mg/kg of aqueous leaf extract of Gongronema latifolium and 10mg/kg of Mncl2, Group E received 100mg/kg of aqueous leaf extract of Gongronema latifolium and rats in Group F received 200mg/kg of aqueous leaf extract of Gongronema latifolium. Administration of aqueous leaf extract of Gongronema latifolium was done orally, using an orogastric tube while the administration of Manganese chloride was done via intraperitoneal injection for 28 days respectively. At the end of administration, the neurobehavioral activity was evaluated using the open field and Y-maze tests. The rats were sacrificed by cervical dislocation and the organ (cerebellum) was harvested. This organ was further analyzed for antioxidant enzymes activity, lipid peroxidation and histopathological changes. Graphpad prism softaware was used for all statistical analysis and data was expressed as mean with standard error of mean (SEM). Results obtained showed no significant change (p> 0.05) in the initial body weight and final body weight. A significant decrease (p< 0.05) was observed in the weight change of rats in group B ( 10mg/kg b.wt of Mncl2) when compared to control, however a significant increase was observed in the weight change groups of C and D when compared to B. No significant change (p> 0.05) was observed in the cerebellar and relative cerebellar weight of rats across experimental groups. A significant decrease (p< 0.05) was observed in cerebellar SOD, CAT, GPx AND GSH activity of rats in group B (10mg/kg b.wt. MnCl2)when compared to the control. However, a significant increase (p< 0.05) was observed in cerebellar SOD, CAT, GPx and GSH activity of rats in group C and D when compared to group B. A significant increase (p<0.05) was observed in MDA concentration of rats in group B (10mg/kg b.wt. MncCl2) when compared to control. However, a significant decrease was observed in group C and D when compared to B. Histological anaylsis revealed cerebellar degeneration in rats exposed to Mncl2. However, administration of aqueous leaf extract of Gongronema latifolium mitigated the adverse effects induced by manganese chloride. In conclusion,findings from this study shows that Gongronema latifolium leaf
extract mitigated cerebellar damage caused by MnCl2 exposure.