Abstract: To investigate the effect of curcumin on the secretion of IL-6 and TNF-α in THP-1 macrophages stimulated by oxidized lowdensity lipoprotein (ox-LDL) and its related mechanism.THP-1 macrophages,derived from human monocytic leukemia cells，were stimulated by ox-LDL and then treatmented with curcumin,MicroRNA33a (miR33a) inhibitor and ammonium pyrrolidinedithiocarbamate (PDTC).RT-qPCR was applied to test expression of miR33a.Western blot was used to detect the protein expression of NF-κB,IκBα and p-IκBα.The concentration of IL-6,TNF-α in the supernatant was determined by ELISA.Compared with the control group,the expression of miR33a,the protein expression of NF-κB p65,IκBα,p-IκBα/IκBα and the concentration of IL-6 and TNF-α were increased,while the protein expression of IκBα were decreased in ox-LDL group (P＜0.05);Compared with ox-LDL group,the expression of miR33a,NF-κB p65 protein,p-IκBα protein,p-IκBα/IκBα and the concentration of IL-6 and TNF-α were significantly decreased,while the protein expression of IκBα were increased in ox-LDL+curcumin group (P＜0.05).Curcumin may inhibit the secretion of IL-6,TNF-α in THP-1 macrophages stimulated by ox-LDL through down-regulating the NF- κB/miR33a signaling pathway.

Key words: THP-1 macrophages, NF-&kappa, B, miR33a, curcumin, IL-6, TNF-&alpha