Inhibitory Effect of Punicalagin on Inflammatory and Angiogenic Activation of Human Umbilical Vein Endothelial Cells.

Wei Liu,Yumeng Yang,Yanghui Ou,Xuemei Zhang,Buling Wu,Xiaohua Wang,Liqi Huang,Mingcheng Huang

doi:10.3389/fphar.2021.727920

Abstract

Punicalagin, a major ellagitannin isolated from pomegranate, is proved to have various pharmacological activities with an undefined therapy mechanism. The objective of this research was to demonstrate the effect of punicalagin on anti-inflammatory and angiogenic activation in human umbilical vein endothelial cells (HUVECs) and their potential mechanisms. Endothelial-leukocyte adhesion assay was applied to evaluate primary cultures of HUVECs activation following tumor necrosis factor alpha (TNF-α) treatment. The endothelial cell proliferation, migration, permeability and tube formation were assessed by EdU assay, wound migration assay, trans-endothelial electrical resistances (TEER) assay, and capillary-like tube formation assay, respectively. In addition, the expression of relevant proteins was assessed using Western blot analysis. We confirmed that punicalagin could reduce the adhesion of human monocyte cells to HUVECs in vitro and in vivo. Further, punicalagin decreased the expression of mRNA and proteins of ICAM-1 and VCAM-1 in HUVECs. Moreover, punicalagin inhibited permeability, proliferation, migration, and tube formation in VEGF-induced HUVECs, suppressed IKK-mediated activation of NF-κB signaling in TNF-α-induced endothelial cells, and inhibited vascular endothelial growth factor receptor 2 (VEGFR2) activation and downstream p-PAK1. Our findings indicated that punicalagin might have a protective effect on HUVECs activation, which suggested that punicalagin functions through an endothelial mediated mechanism for treating various disorders such as, cancer, rheumatoid arthritis, and cardiovascular disease.

Highlights

Vascular endothelium separates blood flow from the surrounding tissues
We found that compared with the control group, punicalagin at low concentrations (12.5, 25 and 50 μM) showed no effects on human umbilical vein endothelial cells (HUVECs)
Adhesion molecules including vascular cell adhesion molecule 1 (VCAM-1), intercellular adhesion molecule 1 (ICAM-1) induce leukocytes adhesion to the endothelial cells (Yang et al, 2016). Quantitative real time polymerase chain reaction (qRT-PCR) was performed to detect the expression of ICAM-1 and VCAM-1 mRNA in the cells, and the supernatant was collected for ELISA

Summary

Introduction

Vascular endothelium separates blood flow from the surrounding tissues. The dysfunction of vascular endothelium is closely correlated with a variety of disorders, including but not least tumor, rheumatoid arthritis, atherosclerosis, sepsis and inflammatory bowel diseases (Pober and Sessa, 2007; Roifman et al, 2009; Khan et al, 2010; Sun et al, 2019). Punicalagin Inhibited Inflammatory and Angiogenicity revealed that punicalagin has significant effects against inflammation, oxidation, cancer, fungi, and bacteria (Xu et al, 2014; Zou et al, 2014; Cao et al, 2015; Kumagai et al, 2015; Xu et al, 2015; Wang et al, 2016). It was found that punicalagin to attenuated the neuroinflammatory response of primary rat microglia activated by lipopolysaccharide (Olajide et al, 2014). These findings indicate the role for punicalagin to regulate inflammatory responses, but its effect on the vascular endothelium remains unknown. This research aimed to investigate the potential role of punicalagin in modulating endothelial permeability, inflammation, angiogenesis, and the related underlying mechanisms

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