Hoveniae Semen Seu Fructus Ethanol Extract Exhibits Anti-Inflammatory Activity via MAPK, AP-1, and STAT Signaling Pathways in LPS-Stimulated RAW 264.7 and Mouse Peritoneal Macrophages.

You-Chang Oh,Nam-Hui Yim,Yun Hee Jeong,Won-Kyung Cho,Jin Yeul Ma

doi:10.1155/2019/9184769

You-Chang Oh, Nam-Hui Yim + Show 3 more

Open Access

https://doi.org/10.1155/2019/9184769

Copy DOI

Abstract

Hoveniae semen seu fructus (HSF, fruit and seed of Hovenia dulcis Thunb) is an important traditional herbal medicine and food supplement in East Asia for the treatment of liver diseases, alcohol poisoning, obesity, allergy, and cancer. HSF has also been reported to have anti-inflammatory activity, but the cellular mechanism of action is not fully understood. We assessed the anti-inflammatory properties of an HSF ethanol (HSFE) extract and explored its precise mechanism. The ability of HSFE to suppress inflammatory responses was investigated in a murine macrophage cell line, RAW 264.7, and mouse primary macrophages. Secretions of NO, proinflammatory cytokines, inflammatory factors, and related proteins were measured using the Griess assay, ELISA, Western blot analysis, and real-time PCR, respectively. In addition, the main components of HSFE were analyzed by HPLC, and their anti-inflammatory activity was confirmed. Our results showed that pretreatment of HSFE markedly reduced the expression of NO and iNOS without causing cytotoxicity and significantly attenuated secretion of proinflammatory cytokines, including TNF-α, IL-6, and IL-1β. In addition, HSFE strongly suppressed phosphorylation of MAPK and decreased the activation of AP-1, JAK2/STAT, and NF-κB in LPS-stimulated RAW 264.7 cells in a concentration-dependent manner. Furthermore, HSFE strongly suppressed the inflammatory cytokine levels in mouse peritoneal macrophages. Also, as a result of HPLC analysis, three main components, ampelopsin, taxifolin, and myricetin, were identified in the HSFE extract, and each compound effectively inhibited the secretion of inflammatory mediators induced by LPS. These findings show that HSFE exerts anti-inflammatory effects by suppressing the activation of MAPK, AP-1, JAK2/STAT, and NF-κB signaling pathways in LPS-stimulated macrophages. In addition, the anti-inflammatory efficacy of HSFE appears to be closely related to the action of the three main components. Therefore, HSFE appears to be a promising candidate for the treatment of inflammatory diseases.

Highlights

The inflammatory response in the body is a defense mechanism against potentially harmful stimuli, such as injury, viral or microbial infection, and irritants [1, 2]
We first evaluated the effect of HSF ethanol (HSFE) at ≤50 μg/mL on the viability of macrophages and found that they did not show cytotoxicity, and subsequent experiments were performed at three concentrations
HSFE treatment had a superior inhibitory effect on inducible nitric oxide synthase (iNOS) expression, which demonstrated that the inhibitory effect on nitric oxide (NO) production was related to iNOS inhibition, but HSFE had no inhibitory effect on COX-2 expression

Summary

Introduction

The inflammatory response in the body is a defense mechanism against potentially harmful stimuli, such as injury, viral or microbial infection, and irritants [1, 2]. These inflammatory responses are involved in the activation of immune cells, such as macrophages. LPS, known as endotoxins from the outer membranes of gram-negative bacteria, act on the toll-like receptor 4- (TLR4-) signaling pathway and elicit strong immune responses. The three representative families of MAPK have been identified, including extracellular signal-regulated kinase (ERK), c-Jun NH2-terminal kinase (JNK), and p38, which regulate immune-related cytotoxic mediators

Methods

Results

Conclusion