Patel R, Kumar S, Varghese JF, Singh N, Singh RP, Yadav UCS. Silymarin prevents endothelial dysfunction by upregulating Erk-5 in oxidized LDL exposed endothelial cells.
Microvasc Res 2024;
153:104667. [PMID:
38307406 DOI:
10.1016/j.mvr.2024.104667]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 01/12/2024] [Accepted: 01/25/2024] [Indexed: 02/04/2024]
Abstract
Extracellular signal-regulated kinase (Erk)-5 is a key mediator of endothelial cell homeostasis, and its inhibition causes loss of critical endothelial markers leading to endothelial dysfunction (ED). Circulating oxidized low-density lipoprotein (oxLDL) has been identified as an underlying cause of ED and atherosclerosis in metabolic disorders. Silymarin (Sym), a flavonolignan, possesses various pharmacological activities however its preventive mechanism in ED warrants further investigation. Here, we have examined the effects of Sym in regulating the expression of Erk-5 and ameliorating ED using in vitro and in vivo models. Primary human umbilical vein endothelial cells (pHUVECs) viability was measured by MTT assay; mRNA and protein expression by RT-qPCR and Western blotting; tube-formation assay was performed to examine endothelialness. In in-vivo experiments, normal chow-fed mice (control) or high-fat diet (HFD)-fed mice were administered Sym or Erk-5 inhibitor (BIX02189) and body weight, blood glucose, plasma-LDL, oxLDL levels, and expression of EC markers in the aorta were examined. Sym (5 μg/ml) maintained the viability and tube-formation ability of oxLDL exposed pHUVECs. Sym increased the expression of Erk-5, vWF, and eNOS and decreased ICAM-1 at transcription and translation levels in oxLDL-exposed pHUVECs. In HFD-fed mice, Sym reduced the body weight, blood glucose, LDL-cholesterol, and oxLDL levels, and increased the levels of vWF and eNOS along with Erk-5 and decreased the level of ICAM-1 in the aorta. These data suggest that Sym could be a potent anti-atherosclerotic agent that could elevate Erk-5 level in the ECs and prevent ED caused by oxidized LDL during HFD-induced obesity in mice.
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