Histochemical and Histomorphological Evaluation of Cerebellar Cortical Cells of Adult Wistar Rats Following the Administration of Acanthus montanus Ethanol Leaf Extract

Acanthus montanus is a shrub used in traditional medical practice as a herbal remedy for pains. This study investigated the effect of consuming leaf extract of this plant on neuronal histology and Nissl substance in the cerebellum of adult Wistar rats. Eighteen adult Wistar rats weighing an average of 185 g were randomly divided into three groups of six rats each: A control received appropriate volumes of distilled water, and two test groups administered 200 mg/kg and 500 mg/kg of Acanthus montanus extract. The administration was done with an orogastric tube for 14 consecutive days. After 24 hours of the last administration, animals were anaesthetised with 20 mg/kg ketamine hydrochloride, intraperitoneally, and humanely sacrificed. Their cerebella were dissected out, processed, and stained with haematoxylin and eosin and Cresyl fast violet, as well as neuron-specific enolase immunoreactivity to investigate neuronal integrity. The cells were counted with ImageJ software, and the data was analysed with SPSS version 25.0. In the 200 mg/kg group, cerebellar cortex hyperplasia was observed in the granular layer. In the 500 mg/kg group, hyperplasia was observed in the granular, molecular, and Purkinje layers. Hypertrophy of Purkinje cells was observed in the 200 mg/kg group compared with other groups. Nissl substance increased in the 200 mg/kg group, and positive expression of neuron-specific enolase reactivity was observed in the test groups. In conclusion, these changes in histology and histochemistry suggest that Acanthus montanus extract has a negative effect on cerebellar cytology. As a result, long-term use may not be beneficial.