Epigallocatechin-3-gallate inhibits angiotensin II and interleukin-6- induced C-reactive protein production in macrophages

Background: consumption of green tea has been associated with health benefits against multiple diseases including cardiovascular diseases. however,the action mechanisms of green tea and its major ingredient epigallocatechin-3- gallate (egcg) against cardiovascular diseases are still unclear. emerging evidence has suggested a common role for c-reactive protein (crp) in the pathogenesis of inflammation and atherosclerosis. therefore,the effect of egcg on angiotensin ii (ang ii)- and interleukin-6 (il-6)-induced crp production in u937 macrophages and the possible mechanisms were observed. methods: u937 macrophages were cultured,and ang ii and il-6 were used as stimulants for generation of crp. u937 macrophages were preincubated with egcg at 1,3,10μm for 1 h prior to the stimulation. mrna expression and protein level were determined by rt-pcr and elisa,respectively. ros production was observed by a fluorescence microscope. results: pretreatment of macrophages with egcg prior to the stimulation concentration-dependently inhibited ang ii- and il-6- induced expression of crpboth in protein and mrnalevels. meanwhile,egcg reduced ang ii- and il-6-stimulated generation of ros in macrophages. conclusion: egcg is able to inhibit ang ii- and il-6-stimulated crp expression in macrophages to produce an anti-inflammation by interfering with ros generation. the finding is helpful to update understanding of anti-atherosclerotic effects of egcg. copyright © 2012 by institute of pharmacology polish academy of sciences.