Abstract: Objective To observe the effects of dihydroartemisinin（DHA） on the proliferation,differentiation,collagen secretion,inflammatory factors and NF-κB pathway activation of lipopolysaccharide induced cardiac fibroblasts（CFs）,explore the molecular mechanism of DHA inhibiting cardiac fibrosis. Methods The myocardial tissue of SD suckling rats was digested with trypsin to obtain CFs. CFs were arranged into normal group（culture medium）,DHA group（culture medium of 100 ng/mL DHA）,lipopolysaccharide group（50 μg/mL lipopolysaccharide culture medium）,the treatment group（50 μg/mL lipopolysaccharide and 100 ng/mL DHA）.After 48 h incubation of cells in each group,the proliferation of CFS in each group was detected. The ELISA was used to quantify the level of collagen typeⅠ（ColⅠ）,collagen type Ⅲ（Col Ⅲ）,tumor necrosis factor α（TNF-α）,interleukin-6（IL-6） and interleukin-1β（IL-1β） in the culture medium. The immunoblotting was used to evaluate intracellular smooth muscle-a-actin（a-SMA）,nuclear factorκB p65（NF-κBp65）,and phosphorylated nuclear factorκB p65（p-NF-κBp65）. Results The cell proliferation,the content of colⅠ,col Ⅲ,TNF-α,IL-6 and IL-1β in suspension,protein content of a-SMA,NF-κBp65 and p-NF-κBp65 and NF-κBp65/p-NF-κBp65 ratio in intracytoplasmbetween DHA group and normal group had not obviously difference（all P>0.05）. Compared with the normal group,the number of cells in lipopolysaccharide group（0.122 9±0.001 4） increased,and the contents of colⅠ[（0.753 2±0.087 7）ng/L],col Ⅲ[（0.723 3±0.096 8）ng/L],TNF-α[（46.78±3.60）pg/L],IL-6[（30.08±3.93）pg/L] and IL-1β[（12.10±1.55）pg/L] in suspension increased,and the intracytoplasm contents of a-SMA（0.438±0.026）,NF-κBp65（1.221±0.049）,p-NF-κB p65（1.209±0.048） and NF-κBp65/p-NF-κBp65 ratio（0.967±0.046） increased（all P<0.05）. Compared with the lipopolysaccharide group,the number of cells（0.115 6±0.001 2） decreased in treatment group,and the levels of colⅠ[（0.542 4±0.063 6） ng/L],col Ⅲ[（0.502 7±0.057 9）ng/L],TNF-α[（25.32±3.05）pg/L],IL-6[（19.12±3.00）pg/L] and IL-1β[（7.34±0.96）pg/L] decreased in suspension,and the intracytoplasm contents of a-SMA（0.208±0.020）,NF-κBp65（0.528±0.035）,p-NF-κBp65（0.206±0.026） and NF-κBp65/p-NF-κBp65 ratio（0.412±0.025） decreased（all P<0.05）. Conclusion The dihydroartemisinin can inhibit the proliferation,differentiation,secretion of collagen and inflammatory factors of CFS stimulated by lipopolysaccharide,which isclosely related to the effective reduction the activity of of NF-κB pathway.

Key words: Dihydroartemisinin, Lipopolysaccharide, Cardiac fibroblasts, Inflammatory factors, NF-κB pathway