Silymarin protects against acrylamide-induced neurotoxicity via Nrf2 signalling in PC12 cells

• Published in: Food and chemical toxicology 2017-04, Vol.102, p.93-101
• Main Authors: Li, Liang, Sun, Hong-yang, Liu, Wei, Zhao, Hong-yu, Shao, Mei-li
• Format: Article
• Language: English
• Subjects: Acrylamide; Acrylamide - toxicity; Animals; Antioxidant; Gene Expression Regulation - drug effects; Glutamate-Cysteine Ligase - genetics; Glutamate-Cysteine Ligase - metabolism; Glutathione - metabolism; Glutathione Peroxidase - genetics; Glutathione Peroxidase - metabolism; Malondialdehyde - metabolism; Neurotoxicity Syndromes - metabolism; Neurotoxicity Syndromes - prevention & control; NF-E2-Related Factor 2 - genetics; NF-E2-Related Factor 2 - metabolism; Nrf2; Oxidative stress; PC12 Cells - drug effects; PC12 Cells - metabolism; PC12 Cells - pathology; Rats; Reactive Oxygen Species - metabolism; Silymarin; Silymarin - pharmacology
• ISSN: 0278-6915; 1873-6351
• DOI: 10.1016/j.fct.2017.01.021

Silymarin (SM) is a well-known antioxidant, anti-inflammatory and anti-cancer compound extracted from the milk thistle. Here, we investigated the protective effect of SM against acrylamide (AA)-induced neurotoxicity, mainly caused by oxidative stress, via activation of the nuclear transcription factor E2-related factor 2 (Nrf2) signalling pathway in PC12 cells. The MTT reduction assay was used to measure cell viability in various drug-treated groups and demonstrated that SM could increase cell viability in AA-treated PC12 cells. We then measured the reactive oxygen species (ROS) levels by the peroxide-sensitive fluorescent probe DCFH-DA and intracellular glutathione (GSH) and malondialdehyde (MDA) levels by absorption spectrophotometry. Our data revealed that SM could reduce ROS and MDA levels and increase GSH levels in AA-induced PC12 cells. To identify a potential mechanism for SM-induced protection, we measured the mRNA and protein expression levels of Nrf2 and its downstream target antioxidants glutathione peroxidase (Gpx), glutamate cysteine ligase catalytic subunit (GCLC) and glutamate cysteine ligase modifier subunit (GCLM) by quantitative real-time PCR and Western blot, respectively. The results suggested that SM could activate Nrf2 signalling and increase the expression of Nrf2, Gpx, GCLC and GCLM in AA-treated PC12 cells. In conclusion, SM can effectively alleviate AA-induced neurotoxicity in PC12 cells. •Protective effect of silymarin in acrylamide-induced neurotoxicity in vitro.•A way of prevention neurotoxicity of acrylamide, formed during the high-temperature processing of food.•Protective mechanism of silymarin explains involved in Nrf2 signalling and intracellular glutathione metabolism.•Provide insight into the potential silymarin mechanisms involved in neuroprotection.