Silibinin Effects on Cognitive Enhancement and Neurotrophic Factor Modulation in an Alzheimer’s Disease Model Induced by Amyloid Beta in Rats

Abstract

Background: Alzheimer's disease (AD) is the most common cause of dementia. Herbal medicines are increasingly recognized as alternative therapies with lower side effects. Objectives: This study aimed to investigate the protective effects of silibinin on cognitive function and the expression of neurotrophic factors in a rat model of AD.Methods: Male Wistar rats (n = 40) were assigned to the sham group, lesion (Aβ1-40 injection), treatment group (Aβ1-40 injection followed by silibinin gavage in doses of 50 and 100 mg/kg), and vehicle group. The cognitive performance of the groups was evaluated using the Morris Water Maze behavioral test. Subsequently, brain tissue homogenates were prepared to measure BDNF and VEGF expression levels using the western blot technique. Also, the brain slices were stained with the Nissl technique and the neurons were counted in the hippocampal regions.Results: The mean number of neurons in the CA1 region in the lesion group was significantly reduced compared to the sham group (P = 0.004), however, treatment with silibinin has significantly increased the number of neurons in this region compared to the lesion group (P = 0.0002). Also, treatment with silibinin led to a significant increase in the levels of neurotrophic VEGF, and BDNF in the treated groups compared to the lesion group (P ≤ 0.05).Conclusion:Findings showed the potential of silibinin in reducing the symptoms associated with Alzheimer's and protecting hippocampal neurons against disease-related damage by increasing the levels of BDNF and VEGF growth factors in the brain.