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AIM: To investigate the anti-fibrotic effect of Panax notoginseng saponins (PNS) in arecoline (ANE)-induced oral submucous fibrosis, and to analyze the effect of PNS on nuclear factor E2-related factor 2(Nrf2)/glutamate-cysteine ligase catalytic subunit (GCLC) signaling pathway. METHODS: CCK-8 assay was used to evaluate the effects of different concentrations of PNS and arecoline on the survival rate of human immortalized keratinocyte cell line HaCaT. The results of CCK-8 were used to select 75 mg/L arecoline, and 25，50 and 100 mg/L PNS as subsequent experimental concentrations. The cells were set as blank control group, model group, and low, medium and high doses (25，50 and 100 mg/L) of PNS groups. The protein and mRNA expressions of collagen type I (COL-I), E-cadherin, Nrf2, GCLC and glutathione reductase (GR) in each group were detected by Western blot and RT-qPCR. Immunofluorescence method was used to detect the entry of Nrf2 into the nucleus. Biochemical kits were used to detect the content of glutathione (GSH), nicotinamide adenine dinucleotide phosphate (NADPH) and malondialdehyde (MDA), and superoxide dismutase (SOD) activity in each group of cells. DCFH-DA fluorescent probe was used to detect the content of intracellular reactive oxygen species (ROS). RESULTS: Compared with the blank control group, the protein and mRNA expression of COL-I in the model group was up-regulated, and the protein and mRNA levels of E-cadherin, Nrf2, GCLC, nuclear Nrf2 and GR were down-regulated. The content of NADPH, MDA and ROS in the cells increased, and the content of GSH and the activity of SOD was significantly reduced. Compared with the model group, the protein and mRNA expression of COL-I was down-regulated, and the protein and mRNA expression of E-cadherin, Nrf2, GCLC, nuclear Nrf2 and GR were up-regulated in PNS 50 and 100 mg/L groups. Compared with the model group，the content of NADPH, MDA and ROS in cells decreased, and the content of GSH and the activity of SOD was significantly enhanced (P<0. 05 or P<0. 01). CONCLUSION:Panax notoginseng saponins have anti-fibrosis effects in HaCaT cells, and their mechanism may be related to the activation of Nrf2/GCLC signaling pathway, thereby resisting oxidative stress and improving oral submucosal fibrosis. [ABSTRACT FROM AUTHOR]