Neurochemistry and Histological Studies of the Prefrontal Cortex of Adult Wistar Rats after the Administration of Ethanolic Leave Extract of Psidium guajava Linn (Myrtaceae)

Abstract

Background: Guava (Psidium Guajava), a large dicotyledonous plant easily identified by its copper-coloured thin smooth bark with greenish colouration underneath is an example of such plant with reportedly wide range of medicinal values. Aims: The study aims to investigate the neurohistological and histochemical effects of graded doses of ethanolic leaf extract of Psidium guajava on the prefrontal cortex of adult Wistar rats. Study Design: This study involved the use of twenty inbred adult male Wistar rats of average weight 200 g which were divided into groups 1– 4. The control rats received 5 ml kg-1 of distilled water, while the treatment groups received oral doses of 100 mg kg-1, 150 mg kg-1, and 200 mg kg-1 body weight of P. guajava for 28 days. Place and Duration of Study: This research was undertaken at the Department of Anatomy, Faculty of Basic Medical Sciences, University of Uyo, Uyo, Nigeria in July 2025. Methodology: Upon complete administration of the extract, ketamine–hydrochloride was used to deeply anesthetize the animals. The brains were then perfused fixed in 10 % buffered formalin. They were processed using hematoxylin and eosin for cellular and neuronal integrity. Representative sections were also used for histochemical analysis using Cresyl Fast Violet staining techniques. Results: Histological observations of the prefrontal cortex showed hypertrophied and vacuolated neuronal cells, decreased cellular population and glia with loss of marginal and adjoining cortical parenchyma including karyorrhectic perikaryons marked with reduced Nissl substance stains and chromatolysis of neuronal cell bodies throughout the six cortical layers Conclusion: Psidium Guajava induced a dose-dependent adverse effects on the neurohistology and histochemical integrity of the prefrontal cortex This may suggest neuronal and biochemical degeneration, thus resulting in impaired prefrontal cortical functions.