title: Rosmarinic acid counteracts activation of hepatic stellate cells via inhibiting the ROS-dependent MMP-2 activity: Involvement of Nrf2 antioxidant system.
abstract: Recently, oxidative stress is involved in hepatofibrogenesis. Matrix metalloproteinase-2 (MMP-2) is required for activation of hepatic stellate cells (HSCs) in response to reactive oxygen species (ROS). This study was designed to explore the hypothesis that the inhibitory effect of rosmarinic acid (RA) on HSCs activation might mainly result from its antioxidant capability by increasing the synthesis of glutathione (GSH) involved in nuclear factor kappa B (NF-κB)-dependent inhibition of MMP-2 activity. Here, we demonstrate that RA reverses activated HSCs to quiescent cells. Concomitantly, RA inhibits MMP-2 activity. RNA interference-imposed knockdown of NF-κB abolished down-regulation of MMP-2 by RA. RA-mediated inactivation of NF-κB could be blocked by the diphenyleneiodonium chloride (DPI; a ROS inhibitor). Conversely, transfection of dominant-negative (DN) mutant of extracellular signal-regulated kinases 2 (ERK2), c-Jun N-terminal kinase 1 (JNK1), or p38α kinase had no such effect. Simultaneously, RA suppresses ROS generation and lipid peroxidation (LPO) whereas increases cellular GSH in HSC-T6 cells. Furthermore, RA significantly increased antioxidant response element (ARE)-mediated luciferase activity, nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and catalytic subunits from glutamate cysteine ligase (GCLc) expression, but not modulatory subunits from GCL (GCLm). RA-mediated up-regulation of GClc is inhibited by the shRNA-induced Nrf2 knockdown. The knocking down of Nrf2 or buthionine sulfoximine (a GCL inhibitor) abolished RA-mediated inhibition of ROS. Collectively, these results provide novel insights into the mechanisms of RA as an antifibrogenic candidate in the prevention and treatment of liver fibrosis.
authors.affiliation: The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China.
authors.forename: Changfang
authors.initials: C
authors.lastname: Lu
authors.affiliation: The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zou
authors.affiliation: The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China.
authors.forename: Yuzhang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: The Institute of Medicine, Qiqihar Medical University, Qiqihar 161006, China. Electronic address: nyc1968@126.com.
authors.forename: Yingcai
authors.initials: Y
authors.lastname: Niu
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000494:pharmacology*; D002461:Cell Line, Transformed; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology; D002934:Cinnamates / Q000494:pharmacology*; D053630:Depsides / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects / Q000502:physiology; D055166:Hepatic Stellate Cells / Q000187:drug effects / Q000378:metabolism*; D020778:Matrix Metalloproteinase 2 / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism*; D051381:Rats; D017382:Reactive Oxygen Species / Q000037:antagonists & inhibitors / Q000378:metabolism*; D000097123:Rosmarinic Acid
chemical_list: D000975:Antioxidants; D002934:Cinnamates; D053630:Depsides; D020778:Matrix Metalloproteinase 2; D051267:NF-E2-Related Factor 2; D017382:Reactive Oxygen Species; D000097123:Rosmarinic Acid
keywords: HSC; Liver fibrosis; MMP-2; Nrf2; Rosmarinic acid