Inhibitory Effect Of Curcumin On Inflammatory Responses Induced By Lps In Human Retinal Pigment Epithelial Cells

Objective: To explore the inhibitory effect of curcumin on inflammatory responses induced by lipopolysaccharide(LPS)in retinal pigment epithelial(RPE)cells.Methods: ARPE-19 cells were cultured in vitro.Before stimulated with or without LPS(5?g/mL),ARPE-19 cells were pre-incubated with different concentrations of curcumin(5,10,20,30,40 ?mol/L).The optimum concentration of curcumin was detected by CCK-8 assay.The mRNA level of IL-6 and IL-8 was measured by real-time quantitative polymerase chain reaction(qPCR)and their protein expression was detected by enzyme-linked immunosorbent assay(ELISA).Protein expression levels of I?B-? and p-I?B-? were examined by Western blot.Results: The CCK-8 results showed that the activities of ARPE-19 cells were not affected by different concentrations of curcumin.Curcumin was indicated to be able to protect ARPE-19 cells since pre-treatment with different concentrations of curcumin following by LPS administration.This protection resulted with a maximal protective effect at 20?mol/L.qPCR results indicated that pretreatment of curcumin suppressed the mRNA expression levels of IL-6 and IL-8.ELISA results indicated that pretreatment of curcumin reduced the protein expression levels of IL-6 and IL-8.Western blot results indicated that pre-treatment with curcumin inhibited the phosphorylation of I?B-? mediated by LPS stimulation.Conclusion: Curcumin inhibits the inflammatory responses induced by LPS via suppression NF-?B activity and protects retinal pigment epithelial cells.It may provide more preventive and curative strategy for ocular diseases caused by retinal inflammation.