Protective Potential of Aqueous Fruit Extract of Azanza Garckeana on Aluminium Chloride-Induced Dentate Gyrus Toxicity in Adult Wistar Rats: a Histological Study

Azanza garckeana, commonly called Goron Tula, is a medicinal plant traditionally used for various therapeutic purposes, including its purported antioxidant and anti-inflammatory properties. Recent studies have begun to explore the phytochemical composition of A. garckeana, revealing the presence of bioactive compounds such as flavonoids and phenolics that may confer neuroprotective effects. Aluminum chloride is known to induce neurotoxicity, leading to cognitive deficits and neuronal damage, which are critical concerns in both clinical and experimental settings. The dentate gyrus, a crucial part of the hippocampus involved in memory and learning, is particularly vulnerable to such toxic insults. The primary aim of this study is to investigate the neuroprotective potential of Aqueous Fruit Extract of Azanza garckeana in mitigating aluminum chloride (AlCl₃)-induced neurotoxicity in the dentate gyrus of adult Wistar rats. The animals for this study were bred at the Animal House, Department of Anatomy, School of Basic Medical Science, College of Medical Science University of Benin, Benin City, Edo State. A dose of 100mg/kg body weight of aluminum chloride and a dose of 500mg/kg body weight and 1000mg/kg body weight Aqueous Fruit Extract of Azanza garckeana were used. A total of thirty (30) adult Wistar rats weighing 160g - 180g were randomly selected into six groups (A, B, C, D, E, F) with each group consisting of five rats. Group A served as the control, Group B was administered 100mg/kg of Alcl2, Group C was administered 100mg/kg of Alcl2 + 500mg/kg of AFEAG, Group D was administered 100mg/kg of Alcl2 + 1000mg/kg of AFEAG, Group E was administered 500mg/kg of AFEAG and Group F was administered 1000mg/kg of AFEAG. The administration was done orally with an orogastric tube for twenty-eight (28) days. The rats were sacrificed after the administration period, and the whole brain was harvested for histological assessments. The histological analysis of the dentate gyrus showed that the control group (A) and the groups treated with the Aqueous Fruit Extract of Azanza garckeana (E and F) had a normal histological appearance, with densely-packed granular cells and rounded pale vesicular nuclei in the granular layer. In contrast, the group treated with aluminum chloride only (B) exhibited several necrotic pyramidal cells with condensed nuclei. The groups treated with aluminum chloride and the low dose (C) or high dose (D) of the Aqueous Fruit Extract of Azanza garckeana showed a significant improvement in the histological appearance of the dentate gyrus, with a reduction in the number of necrotic cells. The findings indicate that Azanza garckeana exhibits strong neuroprotective properties, reducing the deleterious effects of AlCl₃ on the dentate gyrus.