Faculty of Agriculture, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano, 399-4598, Japan.
Faculty of Agriculture, Shinshu University, 8304 Minamiminowa, Kamiina, Nagano, 399-4598, Japan.
J Ethnopharmacol. 2021 Jul 15;275:114039. doi: 10.1016/j.jep.2021.114039. Epub 2021 Apr 2.
Strawberry geranium (Saxifraga stolonifera [L.] Meeb) has traditionally been used as a drug to treat skin disorders in Japan. However, little is known about its physiological effects on skin keratinocytes.
We investigated the anti-inflammatory effects of a strawberry geranium extract (SGE) on human skin keratinocytes.
The human keratinocyte cell line, HaCaT, was treated with SGE, and then stimulated with tumor necrosis factor (TNF)-α. The expression of 207 genes related to the innate immune system was analyzed using DNA microarrays. The effect of SGE on the target proteins in primary human epidermal keratinocytes was confirmed by quantitative reverse transcription polymerase chain reaction and enzyme-linked immunosorbent assay. The mechanisms of action and active components involved in the suppressive effect of SGE were evaluated by fractionation and a transcription assay.
The microarray analysis revealed that SGE primarily suppressed Toll-like receptor (TLR)2 expression through procyanidin B2 3,3'-di-O-gallate, without TLR2 downregulation, in TNF-α-stimulated HaCaT cells. SGE suppressed TLR2 expression and interleukin (IL)-8 production induced by TLR2 ligands in primary human epidermal keratinocytes and HaCaT cells. Multiple components downregulating TLR2 expression suppressed the Sp1 activity.
We identified a novel physiological function of SGE, which suppresses TLR2 expression and TLR2-mediated inflammation in human skin keratinocytes. This study provides significant insights into the anti-inflammatory effect of SGE in human skin.
草莓老鹳草（Saxifraga stolonifera[L.] Meeb）在日本传统上被用作治疗皮肤疾病的药物。然而，其对皮肤角质形成细胞的生理作用知之甚少。
本研究旨在探讨草莓老鹳草提取物（SGE）对人皮肤角质形成细胞的抗炎作用。
用 SGE 处理人角质形成细胞系 HaCaT 细胞，然后用肿瘤坏死因子（TNF）-α刺激。采用 DNA 微阵列分析 207 个与固有免疫系统相关的基因的表达。通过定量逆转录聚合酶链反应和酶联免疫吸附试验确认 SGE 对原代人表皮角质形成细胞中靶蛋白的作用。通过分级分离和转录测定评估 SGE 抑制作用的作用机制和活性成分。
微阵列分析表明，SGE 通过原花青素 B2 3,3'-二-O-没食子酸酯主要抑制 TLR2 表达，而不通过 TNF-α刺激的 HaCaT 细胞中的 TLR2 下调。SGE 抑制 TLR2 配体诱导的原代人表皮角质形成细胞和 HaCaT 细胞中的 TLR2 表达和白细胞介素（IL）-8 产生。多种下调 TLR2 表达的成分抑制 Sp1 活性。
我们鉴定了 SGE 的一种新的生理功能，即抑制人皮肤角质形成细胞中 TLR2 的表达和 TLR2 介导的炎症。本研究为 SGE 在人皮肤中的抗炎作用提供了重要的见解。
