Minor Ginsenoside Rg2 and Rh1 Attenuates LPS-Induced Acute Liver and Kidney Damages via Downregulating Activation of TLR4-STAT1 and Inflammatory Cytokine Production in Macrophages.

Diem Thi Ngoc Huynh,Kyung-Sun Heo,Sohyun Sim,Chang-Seon Myung,Naehwan Baek

doi:10.3390/ijms21186656

Abstract

Ginsenosides have been reported to have various biological effects, such as immune regulation and anticancer activity. In this study, we investigated the anti-inflammatory role of a combination of Rg2 and Rh1, which are minor ginsenosides, in lipopolysaccharide (LPS)-stimulated inflammation. In vitro experiments were performed using the RAW264.7 cell line, and an in vivo model of inflammation was established using LPS-treated ICR mice. We employed Griess assay, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, quantitative reverse transcriptase-polymerase chain reaction, western blotting, immunofluorescence staining, and hematoxylin and eosin staining to evaluate the effect of Rg2 and Rh1. We found that Rg2 and Rh1 significantly decreased LPS-induced major inflammatory mediator production, inducible-nitric oxide synthase expression, and nitric oxide production in macrophages. Moreover, Rg2 and Rh1 combination treatment inhibited the binding of LPS to toll-like receptor 4 (TLR4) on peritoneal macrophages. Therefore, the combination of ginsenoside Rg2 and Rh1 suppressed inflammation by abolishing the binding of LPS to TLR4, thereby inhibiting the TLR4-mediated signaling pathway. The combined ginsenoside synergistically blocked LPS-mediated PKCδ translocation to the plasma membrane, resulting in p38-STAT1 activation and NF-κB translocation. In addition, mRNA levels of pro-inflammatory cytokines, including TNF-α, IL-1β, and IFN-β, were significantly decreased by combined ginsenoside treatment. Notably, the 20 mg/kg ginsenoside treatment significantly reduced LPS-induced acute tissue inflammation levels in vivo, as indicated by the tissue histological damage scores and the levels of biochemical markers for liver and kidney function from mouse serum. These results suggest that the minor ginsenosides Rg2 and Rh1 may play a key role in prevention of LPS-induced acute inflammation and tissue damage.

Highlights

Sepsis, which is a systemic inflammatory response to an infection, leads to organ dysfunction and death [1]
To dete2r. mReisnueltsthe concentration of ginsenosides used in the experiments, we examined the effect of minor gi2n.1s.eEnffeocst iodf tehse GoinnsecneolslidvesiRabg2ilaintyd Ruhs1ionngCe3ll-V(4ia,b5i-lidtyimandetIhnfylalmthmiaatozroylM-2e-dyialt)o-r2P,r5o-dduciptiohnenyltetrazolium bromide (MTT) analysis (Figure 1a)
Since NF-κB is essential for regulation of inflammatory responses, we investigated whether the minor ginsenosides Rg2 and Rh1 suppressed NF-κB (p65) activation and nuclear translocation in LPS-stimulated RAW264.7

Summary

Introduction

Sepsis, which is a systemic inflammatory response to an infection, leads to organ dysfunction and death [1]. The increase in pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 inhibits thrombosis regulation [2]. Acute liver injury and kidney damage are often associated with sepsis, which can be life-threatening [3]. Sepsis often affects the kidneys, resulting in sepsis-associated acute kidney injury that increases the risk of in-hospital death [4]. Lipopolysaccharide (LPS), a major component of the outer membrane of gram-negative bacteria, is one of the factors that trigger systemic inflammatory response [5]. The binding between LPS and TLR4 leads to the activation of the mitogen-activated protein kinase (MAPK) pathway, which includes extracellular signal-regulated kinase (ERK), p38, and c-Jun NH2-terminal kinase (JNK) [8]

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