|摘要: ||紫外線(尤其紫外線A)被認為是誘發皮膚光老化的主要原因。在紫外線照A照射下，促使自由基生成，進而造成胞外基質內膠原蛋白含量的減少。紫外線照A照射會引發皮膚加速老化，外觀上產生皺紋及皮膚鬆弛等現象。之前有釵h研究發現，中國傳統草藥紅景天具有抗缺氧、抗疲勞、抗腫瘤、抗病毒、抗輻射及抗氧化等多種幼纂C然而，目前較少研究對於紅景天在皮膚上的應用，尤其缺乏紅景天對皮膚抗老化弁鄐妞袺鶾篘蝚膍s。因此，本論文研究目的著重於紅景天萃取物是否具有改善因紫外線照射引起的膠原蛋白減少情形，並試圖找出其可能作用機制。將纖維母細胞(Hs68 cells)進行紫外線A照射，以西方墨點法(Western blot analysis)及明膠蛋白酵素電泳法(Gelatin Zymography )來觀察type I procollagen、MMP-1、MMP-2及MMP-9蛋白表現情形，評估紫外線A對其影響；另一部份，將Hs68 cells先經由紅景天甲醇萃取液預培養後，再進行紫外線A(20J/cm2)照射，觀察紅景天萃取液之育預培養對type I procollagen、MMP-1、MMP-2及MMP-9蛋白表現之影響。本實驗研究發現，紫外線A照射Hs68 cells會造成type I procollagen及MMP-1蛋白表現量改變，尤其照射劑量達20 J/cm2時，發現type I procollagen蛋白表現量明顯減少及MMP-1蛋白表現量增加之趨勢。而在經過紅景天甲醇萃取液預培養後，type I procollagen蛋白表現量減少及MMP-1蛋白表現量增加之情形均有顯著改善。然而，MMP-2蛋白活性在本實驗結果都沒有明顯差異，且結果發現觀測不到Hs68 cells有分泌 MMP-9蛋白活性之情形。根據我們實驗結果推論，紅景天甲醇萃取液可能具有改善紫外線A照射所引發type I procollagen蛋白表現量減少及MMP-1蛋白表現量增加之情形，進而維持胞外基質中膠原蛋白之含量，避免皮膚老化現象之生成。因此，我們推論紅景天甲醇萃取液於皮膚抗氧化及抗老化幼臚W深具潛力，值得深入研究。|
Ultraviolet irradiation (especially UVA) is thought to main cause to evoke skin photoageing. UVA irradiation can increase amounts of free radicals and make dermal extracellular matrix alteration; hence it may lead to collagen degeneration. Thereby, UVA can accelerate to display the ageing appearances such as wrinkling and slackening on the skin. The previous studies indicated that the Chinese traditional herbal medicine, rhodiola (Rhodiola rosea L.), had various efficacies on the aspects of anti-hypoxia, anti-fatigue, anti-cancer, anti-bacteria, and anti-irridation. Meanwhile, rhodiola also had great work on anti-oxidation. However, so far, there is less study to investigate the application of rhodiola in the skin field, particularly in evaluation of anti-ageing function. Presently, the purpose of this study is mainly to observe whether the treatment of rhodiola extracts can ameliorate the UVA irradiation-induced collagen decrement, and attempt to find out its probable mechanism. After treatment with or without the rhodiola extracts, expressions of type I procollagen and matrix metalloproteinase (MMP-1, MMP-2, and MMP-9) in human fibroblast cell line (HS68) under UVA irradiation were respectively assessed by using the methods of western blot analysis and gelatin zymography. The studying results find that the UVA irradiation may increase the amounts of free radicals (our previous results). Expressions of type I procollagen are significantly reduced under UVA irradiation with 20 J/cm2, but expressions of MMP-1 are apparently increased. However, those situations of the type I procollagen decrement and the MMP-1 expressions increment can be greatly improved by giving treatment with methanolic rhodiola extracts, but expressions of MMP-2 are uninfluenced (Expressions of MMP-9 are undetectable). Our findings obtain that the rhodiola extracts can ameliorate the UV irradiation-
induced collagen decreases via diminishing the MMP-1 expressions, and thereby lead to increase the collagen expressions. Hence, we speculate that rhodiola may have great potential to further develop and apply on skin anti-oxidation and anti-ageing efficacies.