| 摘要: | 水通道蛋白為一蛋白質家族，功能為細胞膜上的穿膜水通道，能促進水分運輸使其通過細胞膜。在哺乳動物中，目前已發現有十三種水通道蛋白，分別名為 AQP0到AQP12，其中又可再細分為aquaporins、aquaglyceroporins及superaquaporins三個家族，以aquaglyceroporins家族成員AQP3被證實與保濕最為相關。AQP3參與水分及甘油的運輸，其表現程度會受年齡、慢性陽光照射及可能發生於表皮的滲透平衡缺陷之影響。另外，膠原蛋白為皮膚中重要的結構蛋白，皮膚真皮層中的膠原蛋白至少有十型，主要以膠原蛋白第一型及第三型為主。基質金屬蛋白酶 (matrix metalloproteinases, MMPs) 則屬於主要降解細胞外基質中的大分子 (如膠原蛋白) 的內切胜肽酵素家族，在維持細胞外基質上扮演著重要的角色。本研究選用常見於中國與日本中草藥白尾蜈蚣草 (Ajuga decumbens) 之粗萃取物，以不同濃度分別處理人類HaCaT角質層細胞及小鼠3T3纖維母細胞24及48小時，結果顯示：(1) 實驗中所使用的白尾蜈蚣草粗萃取物濃度與處理時間，並不會造成細胞毒性；(2) 以最終濃度 (1~25 g/ml) 處理人類HaCaT角質層細胞24小時，hAQP3 mRNA表現僅有些微增加；5g/ml濃度處理小鼠3T3纖維母細胞 24小時，以及10 g/ml濃度處理48小時，mAQP3 mRNA之表現增加；(3) 經10及25 g/ml的濃度處理小鼠3T3纖維母細胞24小時後，膠原蛋白第一型Col1A1基因表現有顯著增加；以5、10及25 g/ml的濃度處理48小時後，膠原蛋白第三型Col3A1基因表現最為顯著；(4) 以25 g/ml濃度處理小鼠3T3纖維母細胞24小時及10 g/ml濃度處理48小時後，MMP-9 (matrix metalloproteinases 9) 基因表現量有增加的趨勢，MMP-2基因表現則均無顯著變化。我們推論，白尾蜈蚣草萃取之有效成份若運用於訴求保濕功能之化粧品，應具有一定之潛力。
Aquaporins (AQPs) are a family of proteins that facilitate water transport across cell membranes by forming channels. In mammals, there are thirteen AQPs named AQP0 to AQP12, which can be further subdivided into aquaporin, aquaglyceroporin and superaquaporin families. In aquaglyceroporin subfamily, AQP3 is a major protein implicated in skin hydration. AQP3 is a membrane transporter of water and glycerol expressed in plasma membranes in the basal layer keratinocytes of epidermis in normal skin. The expression of AQP3 is strongly affected by age and chronic sun exposure, and a defective osmotic equilibrium could occur in the epidermis. In addition, collagens are structural proteins and the major component of extracellular matrix in skin. There are ten types of collagens in dermis, mainly type I and type III collagens. Matrix metalloproteinases (MMPs) belong to endopeptidase family which functions for the degradation of extracellular matrix. In this study, an ethanolic/water extract of Ajuga decumbens, a naturally occurring herb in China and Japan, was selected as the hydrating agent. We treated human HaCaT keratinocytes and mouse 3T3 fibroblasts with various concentrations of Ajuga decumbens extract. The results indicate that: (1) Ajuga decumbens extract has no cell toxicity in various concentrations and times of treatments; (2) hAQP3 mRNA expression level was slightly increased after 24-hour treatment in HaCaT cells. In 3T3 cells, the level of mAPQ3 mRNA expression was slightly increased by 5g/ml extract after 24-hour treatment, and significantly increased by 10 g/ml extract after 48 hours; (3) After 24 hours of treatment with this extract (10 and 25 g/ml), Col1A1 mRNA was significantly increased, and Col3A1 mRNA was significantly increased by 5, 10 and 25 g/ml after 48-hour treatment in 3T3 cells; (4) after 24 and 48 hours of treatment with this extract (25 and 10 g/ml), MMP-9 mRNA was significantly increased in 3T3 cells. In addition, there was no significant change in MMP-2 mRNA expression level. Therefore, Ajuga decumbens extract should be used as hydrating active ingredients in the application of natural cosmetics. |
