Evaluation of the Neuroprotective Effect of Silymarin on Acrylamide-Induced Neurotoxicity

Background: Neurotoxicity is one of the most recognized effects of acrylamide (ACR) in humans and animals. Oxidative stress is an important mechanism in ACR-induced neurotoxicity. Objectives: In this research, the effect of silymarin as a potent antioxidant was evaluated against ACR-induced toxicity in both in vitro and in vivo models. Methods: For the in vitro assay, PC12 cells were exposed to different concentrations (2.5 - 100 µM) of silymarin for 24 hours. ACR at a final concentration of 5 mM was added and cell viability was determined using the MTT assay. For the in vivo study, neurotoxicity was induced using intraperitoneal (IP) administration of ACR (50 mg/kg) for 11 days. The effects of different doses of silymarin (40, 80, and 160 mg/kg IP, respectively) were evaluated in ACR-induced neurotoxicity in Wistar rats based on gait scores. Results: Exposure to ACR reduced cell viability in PC12 cells. Pre-treatment of cells with silymarin (100 µM) significantly reduced ACR-induced toxicity. In addition, administration of ACR induced severe toxicity in Wistar rats, while silymarin at a dose of 160 mg/kg could improve the rats’ gait abnormalities. Conclusions: With regard to the potent antioxidant properties of silymarin, the neuroprotective effects of this natural compound suggested in the current study may in part be mediated through inhibition of oxidative stress.