지방세포에서 TLR4/NF-κB/ERK 신호조절을 통한 Aloe-Emodin의 염증 억제 효과

Abstract

Aloe-emodin (AE) is the major bioactive component in aloe and known to exhibit anti-inflammatory activities. However, it has not been elucidated whether its anti-inflammatory potency can contribute to the elimination of obesity. The aim of the current study is to investigate the effect of AE on toll-like receptor 4 (TLR4) pathways in the presence of lipopolysaccharide (LPS) in 3T3-L1 adipocytes. 3T3-L1 adipocytes were treated with AE (0-20 μM) for one hour, followed by LPS treatment for 30 min and then, adipokine mRNA expression levels were measured. Next, TLR4-related molecules were measured in LPS-stimulated 3T3-L1 adipocytes. AE significantly decreased the mRNA expression of the tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), and monocyte chemoattractant protein-1 (MCP-1) in a dose-dependent manner. Moreover, AE suppressed TLR4 mRNA expression. Further study showed that AE could suppress the nuclear factor-κB (NF-κB) and phosphorylation of extracellular receptor-activated kinase (pERK). The results of this study suggest that AE directly inhibits TLR4/NF-κB/ERK signaling pathways and decreases the inflammatory response in adipocytes.