EVALUATION OF THE PROTECTIVE ACTIVITY OF AQUEOUS PSIDIUM GUAJAVA LEAF EXTRACT

ABSTRACT

Aluminium (Al) is a highly abundant and ubiquitously distributed as an environmental and industrial toxicant. It is contained in many food products, and is implicated in skeletal, haematological, and neurological diseases. Aluminium-induced oxidative damage to DNA has been previously associated with neurodegeneration in different regions of the rat’s brain. The use of exogenous antioxidant to counteract the oxidative damages of aluminium accumulation in the brain has been linked. These natural antioxidants found in medicinal plants have beneficial properties due to the presence of various complex chemical substances for the treatment and prevention of many diseases. Psidium guajava, commonly known as Guava (GV) is highly rich in antioxidants which are helpful in decreasing the incidence of degenerative diseases.

Accordingly, this study was designed to investigate the possible protective effects of Psidium guajava on Aluminium-induced cerebellar toxicity in adult Wistar rats. Adult Wistar rats were weighed and divided into six groups (control and experimental groups). Group A (Control) was administered 1 ml of H₂O/day. Group B (Al) was administered 100 mg/kg body weight (BW) of Aluminium only. Group C (Al + GV1) was administered 100 mg/kg BW of Aluminium and 200mg/kg BW/day of aqueous GV leaf extract. Group D (Al + GV2) was administered 100 mg/kg BW of Al and 400 mg/kg BW of aqueous GV leaf extract. Group E (GV1) was administered 200 mg/kg BW of aqueous GV leaf extract only. Group F (GV2) was administered 400 mg/kg BW of aqueous GV leaf extract only. The administration lasted for 28 days. Rats were fed with standard rat chow and water throughout the entire study period. Animals were weighed every two weeks before commencement and throughout the experiment. At the end of the experiment, neurobehavioral activity (Open field test, Y-Maze test, acute toxicity and NOR test) was evaluated, recorded, and the rats were then sacrificed for sample collection. Following appropriate harvesting of the cerebellum, the antioxidant activity and histological alterations were investigated. Results showed that there was no significant difference in the brain weight and final body weight (FBW) of rats. The neurobehavioural activity showed a significant impairment in the locomotion of rats treated with Aluminium. Conversely, Guava mitigated against the impaired locomotion induced by Aluminium. Results from antioxidant activity showed oxidative stress (low antioxidant activity) in the Al treated groups whereas the Control and GV groups increased significantly in antioxidant activity. In conclusion, the findings showed that GV was not toxic to the rats but protected against Aluminium toxicity. The findings from this study provides the first research evidence on the protective activity of aqueous Psidium guajava leaf extract on aluminium induced cerebellar toxicity in adult Wistar rats.