Inhibition of Interleukin-6 Expression by Curcumin in Rat Vascular Smooth Muscle Explants In Vitro
Yanti, Stephanie, Yuliani, F.G. Winarno and Maggy T. Suhartono
DOI : 10.3844/ajbbsp.2014.260.266
American Journal of Biochemistry and Biotechnology
Volume 10, Issue 4
In atherosclerotic plaques, infectious agents from microbes may release Lipopolysaccharide (LPS) and heat shock proteins that can stimulate the production of mediators, i.e., pro-inflammatory cytokines, by vascular endothelial cells and Smooth Muscle Cells (SMCs). The elevated level of Interleukin-6 (IL-6) is strongly associated with the development of atherosclerosis. Here, we investigated whether curcumin isolated from the rhizome of Curcuma longa affected the expression of IL-6 at protein and gene levels in rat smooth muscle cells treated with LPS in vitro by conducting ELISA and Reverse Transcriptase-Polymerase Chain Reaction (RT-PCR) assays. LPS at 2 Âµg mL-1 activated the expression of IL-6 protein and mRNA in SMCs. Curcumin (1-15 ÂµM) caused the decreased levels of IL-6 protein and mRNA in the dose-dependent manner in LPS-induced SMCs, indicating its potential antiatherosclerotic effect for cardiovascular risk management. In addition, curcumin also partially blocked the activation of LPS-induced phosphorylation of MAP kinases, i.e., ERK1/2, p38 and JNK, in SMCs, suggesting it may inhibit IL-6 expression via attenuating MAP kinase signaling pathways in LPS-induced SMCs. These data may in part explain the molecular action of antiatherosclerotic effects of curcumin.
© 2014 Yanti, Stephanie, Yuliani, F.G. Winarno and Maggy T. Suhartono. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.