title: Rose myrtle (Rhodomyrtus tomentosa) extract and its component, piceatannol, enhance the activity of DNA polymerase and suppress the inflammatory response elicited by UVB‑induced DNA damage in skin cells.
abstract: 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.
authors.affiliation: Research Center, Maruzen Pharmaceuticals Co., Ltd., Onomichi, Hiroshima 722‑0062, Japan.
authors.forename: Sawako
authors.initials: S
authors.lastname: Shiratake
authors.affiliation: Research Center, Maruzen Pharmaceuticals Co., Ltd., Onomichi, Hiroshima 722‑0062, Japan.
authors.forename: Tatsuo
authors.initials: T
authors.lastname: Nakahara
authors.affiliation: Research Center, Maruzen Pharmaceuticals Co., Ltd., Onomichi, Hiroshima 722‑0062, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Iwahashi
authors.affiliation: Cooperative Research Center of Life Sciences, Kobe Gakuin University, Kobe, Hyogo 650‑8586, Japan.
authors.forename: Takefumi
authors.initials: T
authors.lastname: Onodera
authors.affiliation: Cooperative Research Center of Life Sciences, Kobe Gakuin University, Kobe, Hyogo 650‑8586, Japan.
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Mizushina
mesh_terms: D017209:Apoptosis / Q000187:drug effects; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D004249:DNA Damage / Q000187:drug effects* / Q000528:radiation effects*; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism*; D015232:Dinoprostone / Q000378:metabolism; D004789:Enzyme Activation / Q000187:drug effects; D005638:Fruit / Q000737:chemistry; D006801:Humans; D015603:Keratinocytes / Q000187:drug effects* / Q000378:metabolism*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D027826:Rosa / Q000737:chemistry*; D013267:Stilbenes / Q000737:chemistry / Q000494:pharmacology*; D014466:Ultraviolet Rays / Q000009:adverse effects*
chemical_list: D010936:Plant Extracts; D013267:Stilbenes; C041525:3,3',4,5'-tetrahydroxystilbene; D004259:DNA-Directed DNA Polymerase; D015232:Dinoprostone