Quercetin inhibits TNF-α induced HUVECs apoptosis and inflammation via downregulating NF-kB and AP-1 signaling pathway in vitro

Abstract

Background: Quercetin, a major flavonol, wildly exists in plantage, which has been reported to have an anti-apoptosis and anti-inflammation effects on vascular endothelial cells, but its underlying molecular mechanisms remain unclear. Objective: The aim of this study was to investigate the mechanisms of how quercetin inhibits tumor necrosis factor alpha (TNF-α) induced human umbilical vein endothelial cells (HUVECs) apoptosis and inflammation. Methods and Results: HUVECs were preconditioned with quercetin for 18 hours, and subsequently treated with TNF-α for 6 hours to induce apoptosis. The expression of intercellular cell adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1), E-selectin, β-actin mRNA was then detected by RT-PCR. Flow cytometry was used to estimate the apoptosis rates, and the expression of activator protein 1 (AP-1) and nuclear factor kappa B (NF-κB) was measured by Western blot. TNF-α induced elevated apoptosis rates and upregulation of VCAM-1, ICAM-1, and E-selectin were meaningfully reduced in HUVECs by pretreatment with quercetin. In addition, quercetin also inhibited the activation of AP-1and NF-κB. Conclusion: Results indicate that quercetin could suppress TNF-α induced apoptosis and inflammation by blocking NF-κB and AP-1 signaling pathway in HUVECs, which might be one of the underlying mechanisms in treatment of coronary heart disease.

Macrophages enhance lipopolysaccharide induced apoptosis via Ang1 and NF-κB pathways in human umbilical vein endothelial cells

“…It have been reported that TNF-α can directly induce apoptosis, while other inflammatory factors are reported less. However, in TNF-α induced HUVEC apoptosis, the concertation of TNF-αwas especially high (20 ng/mL to 200 ng/mL) 18 – 20 , while TNF-αconcertation in our studies was much lower (lower than 0.5 ng/mL) 21 . Thus, we speculated that inflammatory factors did not induced apoptosis, and they only played a role in promoting LPS-induced HUVEC apoptosis.…”

ROS Modulating Effects of Lingonberry (Vaccinium vitis-idaea L.) Polyphenols on Obese Adipocyte Hypertrophy and Vascular Endothelial Dysfunction

“…The ACN fraction did not affect ICAM-1 and SELE expression ( Figure 4 B). In TNF-α-induced HUVECs, the upregulated VCAM-1, ICAM-1, and E-selectin were meaningfully reduced by pretreatment with quercetin [ 53 ]. ACNs and hydroxycinnamic acids present in blueberry and cranberry fruits reduced TNF-α-induced upregulation of various inflammatory mediators (IL-8, MCP-1, and ICAM-1) in HUVECs [ 54 ].…”

Effect of red wine or its polyphenols on induced apical periodontitis in rats

“…Even though in the present study no significant reduction in IL-1β and TNF-⍺ levels were associated with red wine consumption or polyphenols therapy, a propensity to a higher inhibition of these cytokines was observed in these two groups. However, numerous studies have confirmed that resveratrol and quercetin can suppresses the release of TNF-⍺ (Chen et al, 2020;Lee & Moon, 2005;Lee et al, 2019;Takada et al, 2004;Wang et al, 2020;Yuan et al, 2018). TNF-α is a proinflammatory cytokine, released by macrophages and has a vital role in periodontitis mediated bone loss by inducing the expression of mediators that amplify or sustain the inflammatory response such as the production of prostaglandins and matrix metalloproteinases (Algate et al, 2016).…”