Anti-inflammatory Effect of (-)-Epigallocatechin-3-O-gallate on Human Umbilical Vein Endothelial Cells Grown on 316L Stainless Steel via STAT3/NF-κB Signaling

Abstract

Stainless steel (316L SS) is commonly used to build coronary artery stents for the treatment of occluded arteries. However, tissues in contact with the stent may develop inflammation that can lead to restenosis. The natural substances derived from normal diet provide a pool of candidates that have potential to treat cardiovascular diseases. (-)-Epigallocatechin-3- O-gallate (EGCG), a polyphenolic flavonoid present in green tea, has antioxidant, antithrombogenic, and anti-inflammatory effects, and may reduce the risk of cardiovascular diseases. This study aimed to investigate whether EGCG has an anti-inflammatory effect on human umbilical vein endothelial cells (HUVECs) attached to the surface of 316L SS. We evaluated cell proliferation using the dimethyl thiazolyl tetrazolium bromide method in HUVECs after treatment with EGCG. Enzyme-linked immunosorbent assay (ELISA) assessed the level of inflammatory cytokines, including interleukin 6 (IL-6) and tumor necrosis factor (TNF) in HUVECs. We further investigated the regulatory mechanisms of the signal transducer and activator of transcription 3 (STAT3)/NF-κB signaling pathway in HUVECs by Western-blot analysis. We found that HUVECs cultured on 316L SS had increased cell proliferation and inflammation, and these can be inhibited by treatment with EGCG. EGCG reduced the secretion of IL-6 and TNF and decreased the expression of STAT3 and NF-κB in HUVECs cultured on 316L SS. Consequently, our study demonstrated that EGCG treatment ameliorates the proliferation of HUVEC when cultured with 316L SS, potentially by modulating the inflammation responses via the STAT3/NF-κB signaling pathways.