Naringin prevents the reduction of the number of neurons and the volume of CA1 in a scopolamine-induced animal model of Alzheimer’s disease (AD): a stereological study

Despite several therapies, the effective treatment of Alzheimer's disease remains a global challenge. Hence, natural products might act as an alternative treatment for Alzheimer's disease. Naringin, a polyphenol, possesses promising potential in the treatment of neurodegenerative disorders. Therefore, we investigated the effect of naringin on scopolamine-induced inhibitory passive avoidance memory impairment, CA1 volume, and neuronal loss by using stereological methods.After the scopolamine intraperitoneal injection, rats were treated with naringin (50, 100, and 200 mg/kg/day) for 14 consecutive days via intraperitoneal injection. The inhibitory passive avoidance test was performed for the memory test. 24 hours after the behavioral test; rats' brains were removed from the skull and fixed with 4% paraformaldehyde. The rats' brains cut and sections coronal, were stained using the cresyl violet staining for neurons. Finally, the changes in the neurons of the hippocampal CA1 area were examined stereologically.We observed that naringin ameliorated significantly inhibitory passive avoidance memory. Scopolamine decreased significantly the volume of the hippocampal CA1 area and naringin injection with doses of 50, 100, and 200 mg/kg, increased the volume of the hippocampal CA1 area. Naringin administration at doses of 50, 100, and 200 mg/kg for 14 consecutive days, increased neuron density and the total number of neurons in the hippocampal CA1 area.We concluded that naringin could be effective in improving scopolamine-induced inhibitory passive avoidance memory deficits and that it appeared to increase the volume and density as well as the total number of neurons in the CA1 area of the Alzheimer's rat hippocampus.