title: Activation of NRF2/ARE by isosilybin alleviates Aβ25-35-induced oxidative stress injury in HT-22 cells.
abstract: Aβ-mediated oxidative stress damage is considered a direct cause of Alzheimer's disease (AD). Therefore, drugs that have been developed to block oxidative stress are considered effective for AD treatment. Isosilybin is a flavonoid compound extracted from Silybum marianum, and it has been confirmed to have many pharmacological activities. This study aimed to verify that isosilybin could alleviate the Aβ25-35-induced oxidative stress damage in HT-22 hippocampal cells and to investigate the specific targets of isosilybin. A non-toxic dose of isosilybin significantly inhibited the production of reactive oxygen species (ROS), the release of malondialdehyde (MDA) and lactate dehydrogenase (LDH), and the Aβ25-35-stimulated reduction in total antioxidant capacity (T-AOC). Subsequent studies showed that isosilybin significantly increased the protein and mRNA expression of antioxidases, including heme oxygenase-1 (HO-1), glutathione S-transferase (GST), and aldo-keto reductases 1C1 and 1C2 (AKR1C2). Moreover, isosilybin stimulated the activity of an antioxidant-response element (ARE)-driven luciferase reporter gene. Further studies showed that isosilybin induced the expression of NFR-2 in a time- and dose-dependent manner and promoted its translocation to the nucleus. This result indicated that the antioxidant function of isosilybin might be achieved through the activation of NRF2/ARE signalling. Subsequent studies showed that the NRF2-specific agonist t-BHQ effectively inhibited ROS, MDA and LDH release and T-AOC reduction under Aβ25-35 stimulation. In addition, t-BHQ induced the expression of HO-1, GST, and AKR1C2, as well as the activity of ARE luciferase reporter plasmids. NRF2 siRNA blocked the antioxidative stress damage function of isosilybin. Therefore, NRF2 is likely to be a key mediator of isosilybin's anti-Aβ25-35-mediated oxidative stress damage function. Overall, our results confirmed that isosilybin regulates the expression of HO-1, GST, and AKR1C2 through the activation of NRF2/ARE signalling, inhibiting ROS accumulation and ultimately alleviating Aβ25-35-induced oxidative stress damage in HT-22 cells.
authors: Department of Histology and Embryology, Wannan Medical College, Wuhu, China.
authors: Jing
authors: J
authors: Zhou
authors: Department of Histology and Embryology, Wannan Medical College, Wuhu, China.
authors: Gao
authors: G
authors: Chao
authors: Department of Histology and Embryology, Wannan Medical College, Wuhu, China.
authors: YuLei
authors: Y
authors: Li
authors: Department of Histology and Embryology, Wannan Medical College, Wuhu, China.
authors: Min
authors: M
authors: Wu
authors: Department of Histology and Embryology, Wannan Medical College, Wuhu, China. Electronic address: zhongshuzhi2006@sohu.com.
authors: ShuZhi
authors: S
authors: Zhong
authors: Department of Forensic Medicine, Wannan Medical College, Wuhu, China; Anhui Province Key Laboratory of Active Biological Macro-molecules, Wannan Medical College, Wuhu, China. Electronic address: 675733495@qq.com.
authors: ZunYong
authors: Z
authors: Feng
mesh_terms: D016229:Amyloid beta-Peptides / Q000494:pharmacology*; D000818:Animals; D061745:Antioxidant Response Elements / Q000187:drug effects*; D000975:Antioxidants / Q000494:pharmacology*; D002460:Cell Line; D002470:Cell Survival / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000378:metabolism; D007770:L-Lactate Dehydrogenase / Q000378:metabolism; D008315:Malondialdehyde / Q000378:metabolism; D051379:Mice; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D018384:Oxidative Stress / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D012838:Silymarin / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D016229:Amyloid beta-Peptides; D000975:Antioxidants; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D010446:Peptide Fragments; D012838:Silymarin; C074636:amyloid beta-protein (25-35); D008315:Malondialdehyde; C075820:isosilybin; D007770:L-Lactate Dehydrogenase
keywords: HT-22 cell; Isosilybin; Oxidative stress; Reactive oxygen species