ABSTRACT
Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.
Subject(s)
Alkaloids/toxicity , Antiviral Agents/toxicity , Endoplasmic Reticulum Stress/drug effects , Hepatocytes/drug effects , JNK Mitogen-Activated Protein Kinases/metabolism , Protein Processing, Post-Translational/drug effects , Quinolizines/toxicity , Reactive Oxygen Species/metabolism , Acetylcysteine/pharmacology , Alkaloids/pharmacology , Amino Acid Chloromethyl Ketones/pharmacology , Anthracenes/pharmacology , Antioxidants/pharmacology , Antiviral Agents/pharmacology , Apoptosis/drug effects , Butylamines/pharmacology , Cell Line , Chemical and Drug Induced Liver Injury/etiology , Endoplasmic Reticulum Chaperone BiP , Free Radical Scavengers/pharmacology , Gene Expression Regulation/drug effects , Hepatocytes/enzymology , Humans , Phosphorylation/drug effects , Quinolizines/pharmacologyABSTRACT
OBJECTIVE: To investigate protective effect of glycyrrhizic acid (GA) against lupus nephritis in MRL/lpr mice and explore its underlying mechanisms. METHODS: Forty MRL/lpr mice were randomized equally into blank control group, dexamethasone (1.5 mg/kg) group, GA (20 mg/kg) group, and GA (40 mg/kg) group with corresponding treatments for 7 days, with 10 wild-type mice as the control group. Serum levels of uric acid and creatinine and inflammatory cytokines in the serum and kidney were tested after the treatments using enzyme-linked immunosorbent assays (ELISA). The pathological changes in the kidneys were detected using HE staining, and the protein expressions of NLRP3, ASC, caspase-1, IL-1ß, p-NF-κB, NF-κB, p-IκBα, and IκBα were detected with Western blotting. RESULTS: GA obviously decreased serum levels of uric acid and creatinine, decreased inflammatory cytokines in the serum and kidney, ameliorated renal pathologies and inhibited the expressions of NLRP3, ASC, caspase-1, IL-1ß, p-NF-κB, and p-IκBα proteins in MRL/lpr mice. CONCLUSION: GA has protective effects against lupus nephritis in MRL/lpr mice.
