Shiratake Sawako, Nakahara Tatsuo, Iwahashi Hiroyasu, Onodera Takefumi, Mizushina Yoshiyuki
Research Center, Maruzen Pharmaceuticals Co., Ltd., Onomichi, Hiroshima 722‑0062, Japan.
Cooperative Research Center of Life Sciences, Kobe Gakuin University, Kobe, Hyogo 650‑8586, Japan.
Mol Med Rep. 2015 Oct;12(4):5857-64. doi: 10.3892/mmr.2015.4156. Epub 2015 Jul 30.
A number of naturally occurring agents are hypothesized to protect against ultraviolet (UV)‑induced skin damage. The present study screened >50 plant extracts for inhibitors of UVB‑induced cytotoxicity, using cultured normal human epidermal keratinocytes (NHEK), and identified that the fruit of rose myrtle (Rhodomyrtus tomentosa) was the most marked inhibitor of cell death. The protective effect of rose myrtle extract and the two key components, piceatannol and piceatannol‑4'‑O‑β‑D‑glucopyranoside, on UVB‑induced damage and inflammation in cultured NHEK was investigated. The 80% ethanol extract from rose myrtle fruit with piceatannol exhibited protection of UVB‑induced cytotoxicity in NHEK; however, piceatannol‑4'‑O‑β‑D‑glucopyranoside exhibited no protection, as determined by a 3‑(4,5‑dimethylthiazol‑2‑yl)‑2,5‑diphenyltetrazolium bromide assay. This extract and piceatannol reduced the production of UVB‑induced cyclobutane pyrimidine dimers and enhanced the cellular enzyme activity of the DNA polymerases in UVB‑irradiated NHEK, suggesting that UVB‑stimulated DNA damage was repaired by the polymerases. In addition, the secretion of prostaglandin E2, which is an inflammatory mediator, was decreased. These results indicated that rose myrtle fruit extract and its key constituent, piceatannol, are potential photoprotective candidates for UV‑induced skin damage.
据推测，许多天然存在的物质可预防紫外线（UV）引起的皮肤损伤。本研究使用培养的正常人表皮角质形成细胞（NHEK），对50多种植物提取物进行了筛选，以寻找对UVB诱导的细胞毒性具有抑制作用的物质，并确定桃金娘（Rhodomyrtus tomentosa）果实是最显著的细胞死亡抑制剂。研究了桃金娘提取物及其两个关键成分，白皮杉醇和白皮杉醇-4'-O-β-D-吡喃葡萄糖苷，对培养的NHEK中UVB诱导的损伤和炎症的保护作用。含有白皮杉醇的桃金娘果实80%乙醇提取物对NHEK中UVB诱导的细胞毒性具有保护作用；然而，通过3-（4,5-二甲基噻唑-2-基）-2,5-二苯基四氮唑溴盐检测法测定，白皮杉醇-4'-O-β-D-吡喃葡萄糖苷没有保护作用。该提取物和白皮杉醇减少了UVB诱导的环丁烷嘧啶二聚体的产生，并增强了UVB照射的NHEK中DNA聚合酶的细胞酶活性，这表明UVB刺激的DNA损伤通过聚合酶得以修复。此外，炎症介质前列腺素E2的分泌减少。这些结果表明，桃金娘果实提取物及其关键成分白皮杉醇是UV诱导皮肤损伤潜在的光保护候选物质。
