Aluminium chloride-induced prefrontal cortex toxicity in Wistar rats: evidence from pretreatment with aqueous Psidium guajava leaf extract

Abstract

Aluminium is reported to be a very common element and one of the most abundant metals on Earth. Although aluminium is neurotoxic and linked to several brain disorders, reports indicate that antioxidants from natural sources can neutralise the toxic free radicals generated by aluminium. Consequently, this study evaluated the protective and antioxidative effects of Psidium guajava (GV) aqueous leaf extract on Aluminium-induced prefrontal cortex toxicity. Thirty (30) adult Wistar rats in six (6) groups were used for this experiment (n=5): Group A (control); Group B rats (Al) were given 100 mg/kg body weight (BW) of Aluminium alone; Group C (Al + GV1) rats were given 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 alone and Group F (GV2) was administered 400 mg/kg BW of aqueous GV leaf extract alone. Following the end of administration, neurobehavioral, antioxidant enzymes, and prefrontal cortex histology assessments were done. Findings showed that Group B rats had a significant (p<0.05) decrease in final body and absolute brain weights, and antioxidant enzymes activity when compared to control. Likewise, a significant (p<0.05) decrease was observed in spontaneous alternation in rats treated with Al alone, thus indicating cognitive dysfunction. Conversely, following pretreatment with Psidium guajava, the alterations induced by Al were mitigated. Taken together, Psidium guajava showed a potent capability as a possible neuroprotective agent that can be useful for inhibiting Al-induced neurotoxicity and cognitive dysfunctions. Further investigations and development of this plant could offer a worthwhile substitute to other orthodox drugs currently used in the treatment and/or management of aluminium-related disorders.