Anti-inflammatory role of curcumin in Lipopolysaccharide treated A549 cells at global proteome level and on mycobacterial infection

A diet derived agent Curcumin (Diferuloylmethane), demonstrated its clinical application in inflammation, infection and cancer conditions. Nevertheless, its impact on the proteome of epithelial cells of non-small cell lung carcinoma (NSCLC) is yet to be explored. We employed a stable isotope labeling method for cell culture (SILAC) based relative quantitative proteomics and informatics analysis to comprehend global proteome change in A549 cells treated with curcumin and/or Lipopolysaccharide (LPS). Pretreated A549 cells were infected with Mycobacterium tuberculosis H37Rv strain to monitor bacterial load. With exposure to curcumin and LPS, out of the 1492 identified proteins, 305 and 346 proteins showed deregulation respectively. The expression of BID and AIFM1 mitochondrial proteins which play critical role in apoptotic pathway were deregulated in curcumin treated cells. Higher mitochondria intensity was observed in curcumin treated A549 cells than LPS treatment. Simultaneous treatment of curcumin and LPS neutralized the effect of LPS. Curcumin and/or LPS pretreated A549 cells infected with H37Rv, showed successful bacterial internalization. LPS treated A549 cells after infection showed increased bacterial load than curcumin compared to non-treated infected cells. However, simultaneous treatment of curcumin and LPS neutralized the effect of LPS. This study generated molecular evidence to deepen our understanding of the anti-inflammatory role of curcumin and may be useful to identify molecular targets for drug discovery.