Objective:To observe the influence of ginsenoside Rg1 on transcriptional activation of NF-κB induced by hydrogen peroxide (H_2O_2) in 293T cell,and probe into the antioxidant mechanism of ginsenoside Rg1.Methods:In the experiment,cells was exposed to H_2O_2 after pretreatment with Rg1,cell proliferation and cytotoxicity studies were detected by MTT and Trypan blue.The quantities of generation of intracellular reactive oxygen species (iROS) was analyzed by flow cytometric analysis measured with fluorescent probe 2,7-dichlorofluorescin diacetate (DCFH-DA).NF-κB-responsive element-luciferase reporter gene was transfected and dual-luciferase cis-reporting systems were used to assay the transcriptional activity of NF-κB under the stimulated circumstance of oxidative stress induced by H_2O_2.Results:The results of MTT showed that ginsenoside Rg1 apparently protected the proliferation of 293T cell,which were repressed by H_2O_2 (P＜0.05).The results by trypan blue showed that H_2O_2 stimulated substantial cytotoxicity.This effect was markedly attenuated by treatment with ginsenoside Rg1.Oxidant production,measured as the fluorescence of dichlorofluorescein,was significant increased by 40%-50% through H_2O_2 stimulation.The decrease in iROS generation was significant blocked by 35%-40% through Rg1 and antioxidant.The relative luciferase reporter assay of NF-κB was apparently improved by H_2O_2-induced(P＜0.05),but Ginsenoside Rg1 significantly repressed the relative value of luciferase (P＜0.05).Conclusion:Ginsenoside Rg1 has the obvious protective function from the damage of oxidative stress damage,whose possible mechanism is to eliminate excessive free radicals of the cells effectively,to reduce transcriptional activation of nuclear factor kappa B(NF-κB),and subsequently to suppress the NF-κB circuit activation.

Aim To isolate and characterize the human circulating fibrocytes from human peripheral blood and explore the effects of curcumin on human circulating fi-brocytes.Methods The cells were isolated and puri-fied by density gradient centrifugation,and identified by flow cytometry and immunocytochemistry .Then , CCK-8 and flow cytometry were used to study the effect of curcumin on the proliferation as well as COL I ex-pression of human circulating fibrocytes,respectively. Results After being isolated the cells expressed CD34,CD45 and COLⅠ,among which 79.7% were both CD45 and collagen I positive,typical of human circulating fibrocytes.Curcumin could exert regulatory effects on proliferation of human circulating fibrocytes. Exposure of the cells to curcumin for as short as 24 hours promoted their growth,while prolonged treatment (72 h ) significantly inhibited cell propagation and downregulated the COLⅠ levels,best manifested at a concentration as high as 20 μmol · L-1 .Conclusion The proliferation of cells and COLⅠexpressions can be effectively inhibited by curcumin with the prolonged action period and high concentrations.