EGCG attenuates LPS induced inflammation by target Notch in Caco-2 cell
Previous studies have been reported that the inflammation could be induced by LPS in Caco-2 cell13. But the effect of EGCG in LPS induced Caco-2 cells was still unclear. To evaluate the anti-inflammatory effects of EGCG in LPS induced Caco-2 cells, we perform the experiment as described in methods. The level of TNF-α secretion was increased by LPS treated compared with the normal group (figure 1A). The expression of COX2, which is a kind of inflammation protein, was also added by LPS treatment (figure1B and 1C). The effect of EGCG on inflammation has been reported in some studies, and it also plays an anti-inflammation role in LPS induced Caco-2 cells. The level of TNF-α secretion and COX2 expression were significantly decreased by EGCG add compared with LPS group (figure1A, 1B and 1C). Notch was a novel drug target of EGCG11. To evaluate the mechanism of EGCG anti-inflammation in the intestinal cell, we detected the protein of Notch signaling pathway. The results showed that EGCG could significance decrease the Notch1 expression compared with LPS treatment (figure1D, 1E). Similarly, the expression of Notch2 also decreased by EGCG treatment (figure1D, 1F). The LPS treatment could induce Notch1 activation (figure1D, 1G) and promote the Notch signaling transduction through increased expression of HES-1(figure1D, 1H). But, the expression of Notch1 and Notch2 were decreased by EGCG intervention. The activation of Notch1 (figure1D, 1G) and the downstream signal protein HES-1(figure1D, 1H) were reduced through EGCG treatment. These results reveal a potential mechanism of EGCG anti-inflammation to attenuate colitis by target to Notch pathway.