Alnus Sibirica Extracts Suppress the Expression of Inflammatory Cytokines Induced by Lipopolysaccharides, Tumor Necrosis Factor-α, and Interferon-γ in Human Dermal Fibroblasts.

Jeongyoon Choi,Donghee Lee,Hye Soo Wang,Jae-Hong Ko,Hyemi Bae,Young-Won Kim,Young Wook Choi,Seongtae Kim,Min Won Lee,Hyoweon Bang,Inja Lim,Sunghee Moon,Yelim Seo

doi:10.3390/molecules24162883

Jeongyoon Choi, Donghee Lee + Show 11 more

Open Access

https://doi.org/10.3390/molecules24162883

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Journal: Molecules (Basel, Switzerland)	Publication Date: Aug 8, 2019
Citations: 12	License type: CC BY 4.0

Affiliation: Chung-Ang University

Abstract

The effects of Alnus sibirica (AS) extracts on cytokine expression induced by inflammatory stimulants were examined in human dermal fibroblasts (HDFs) and RAW264.7 cells. The anti-oxidative effect and effect on cell viability of AS extracts were evaluated, and four extracts with the highest anti-oxidative effects were selected. HDFs and RAW264.7 cells were treated with inflammatory stimulants, and the expression of cytokines involved in acute (IL-6 and IL-10) and chronic (IL-18) inflammation, the initiation of the immune response (IL-33), and non-specific immune responses (IL-1β, IL-8, and TNF-α) were determined using a reverse-transcription polymerase chain reaction. LPS increased the expression of all the cytokines, except for IL-18; however, AS extracts, particularly AS2 and AS4, reduced this increase, and TNF-α treatment markedly increased the expression of cytokines related to non-specific immune responses. IFN-γ treatment induced no significant changes, except for increased IL-33 expression in HDFs. AS extracts inhibited the increase in the expression of IL-33 and other cytokines in HDFs. Thus, the exposure of HDFs and RAW264.7 cells to inflammatory stimulants increased the expression of cytokines related to all the inflammatory processes. HDFs are involved not only in simple tissue regeneration but also in inflammatory reactions in the skin. AS2 and AS4 may offer effective therapy for related conditions.

Highlights

Inflammation, the response to stimuli such as infections or noxious substances that induce tissue damage, involves many reactions
The antioxidant capacity of Alnus sibirica (AS) extracts isolated from nine extracts of AS (AS1–AS9) was examined by using the DPPH radical scavenging assay (Figure 2)
Skin inflammation is characterized by the production of cytokines/chemokines and the skin infiltration of immune cells

Summary

Introduction

Inflammation, the response to stimuli such as infections or noxious substances that induce tissue damage, involves many reactions. Cytokines, which are secreted as part of the immune response, are important factors that determine the extent of inflammation. Interleukin (IL)-1β, IL-6, IL-8, IL-10, IL-18, and tumor necrosis factor (TNF)-α are the essential cytokine mediators that connect immune cells and inflammation. Persistent inflammation caused by the excessive production of active cellular substances and pro-inflammatory mediators leads to various types of inflammation [1]. It causes many diseases, including skin inflammation [2], sepsis [3], asthma [4], pulmonary fibrosis [5,6], rheumatoid arthritis [7], and atherosclerosis [8]. An understanding of the relationship between cytokines and inflammation is essential for the appropriate treatment of inflammatory diseases [2,9,10]

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