The Neuroprotective Role of Acorus calamus in Developmental and Histopathological Changes in Autism-Induced Wistar Rats

Introduction Autism spectrum disorder (ASD) is a neurodevelopmental disorder, and a tremendous increase in the incidence of autism poses challenges in identifying the different treatment modalities. Since the defined etiology, pathophysiology, and treatment of autism are unavailable, translational research is being done by creating animal models of autism. This study aimed to assess the effects of Acorus calamus on developmental and histopathological changes in autism-induced Wistar rats. Materials and methods A rat model of autism was created by administering sodium valproate on the 12th day of pregnancy, and rat pups of this group were considered autism-induced. Rat pups of pregnant rats who had received normal saline on the 12th day of pregnancy were considered group I (negative control group). Neural reflexes were assessed in early postnatal days (PND) to confirm the development of autism. Autism-induced rat pups were divided into the following two groups: group II, autism (positive control group), and group III, autism + A. calamus (drug-treated group). On the 21st postnatal day (PND), group III was given an ethanolic extract of A. calamus (200 mg/kg), and group I and group II were given normal saline orally for 15 days. After 15 days of drug exposure, at 36thPND, the rats were sacrificed, and brain tissue was collected for histopathological analysis. Results When compared to the negative control group, autism-induced rat pups showed delayed appearance of neurological reflexes. Neurodegenerative changes were well appreciated in group II (autism-induced rats) than in group III (autism + A. calamus). In the histomorphometric analysis, group II showed a significant reduction in the number of neurons in the frontal cortex and Purkinje cells in the cerebellum. However, when compared to group II, group III (autism treated with A. calamus) did not show significant alteration. Conclusion Valproate exposure at mid-pregnancy creates autism by disturbing neural structures among rat pups. This was clinically represented as the delayed appearance of neural reflexes. Acorus calamus in the early postnatal period protects rat pups’ brain morphology against autism pathology.