This study investigated the suppression of photoaging by galacto-oligosaccharide (GOS) ingestion following exposure to ultraviolet (UV) radiation. To investigate its photoprotective effects, GOS along with collagen tripeptide (CTP) as a positive control was orally administered to hairless mice under UVB exposure for 8 weeks. The water holding capacity, transepidermal water loss (TEWL), and wrinkle parameters were measured. Additionally, quantitative reverse-transcription polymerase chain reaction and Western blotting were used to determine mRNA expression and protein levels, respectively. The GOS or CTP orally-administered group showed a decreased water holding capacity and increased TEWL compared to those of the control group, which was exposed to UVB (CON) only. In addition, the wrinkle area and mean wrinkle length in the GOS and CTP groups significantly decreased. Skin aging-related genes, matrix metalloproteinase, had significantly different expression levels in the CTP and GOS groups. Additionally, the tissue inhibitor of metalloproteinases and collagen type I gene expression in the CTP and GOS groups significantly increased. Oral administration of GOS and CTP significantly lowered the tissue cytokine (interleukin-6 and -12, and tumor necrosis factor-α) levels. There was a significant difference in UVB-induced phosphorylation of JNK, p38, and ERK between the GOS group and the CON group. Our findings indicate that GOS intake can suppress skin damage caused by UV light and has a UV photoprotective effect.

中文翻译：

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膳食低聚半乳糖 (GOS) 通过调节 MAPK 信号通路对无毛小鼠产生光保护作用


本研究调查了暴露于紫外线 (UV) 辐射后摄入低聚半乳糖 (GOS) 对光老化的抑制作用。为了研究其光保护作用，将 GOS 与作为阳性对照的胶原三肽 (CTP) 一起口服给无毛小鼠，在 UVB 照射下持续 8 周。测量持水能力、经皮失水量（TEWL）和皱纹参数。此外，定量逆转录聚合酶链反应和蛋白质印迹分别用于测定 mRNA 表达和蛋白质水平。与仅暴露于 UVB (CON) 的对照组相比，GOS 或 CTP 口服组表现出持水能力下降和 TEWL 增加。此外，GOS组和CTP组的皱纹面积和平均皱纹长度显着减少。皮肤衰老相关基因基质金属蛋白酶在CTP组和GOS组中的表达水平存在显着差异。此外，CTP和GOS组中金属蛋白酶组织抑制剂和I型胶原蛋白基因表达显着增加。口服GOS和CTP显着降低组织细胞因子（白细胞介素6和-12，以及肿瘤坏死因子-α）水平。 GOS组和CON组之间UVB诱导的JNK、p38和ERK磷酸化存在显着差异。我们的研究结果表明，摄入GOS可以抑制紫外线引起的皮肤损伤，并具有紫外线防护作用。