飲食天然物對皮膚美白、保濕、彈性和除皺功效之科學證據分析

台灣醫學美容保養品市場每年以 15% 的速度成長，至 2011 年市場規模成長達 168 億元，美白、保濕功效為消費者欲購買商品的主要和次要需求，皮膚美白的機制可透過抑制酪胺酸酶活性、黑色素生成等達到美白功效；保濕機制可透過減少表皮水分蒸發、鎖住皮膚中的水分等因素達到保濕功效。據經濟部技術處 Industry & Technology Intelligence Service (ITIS) 計畫調查，推估 2013 年台灣保健食品市場需求金額高達約 1,004 億，其中以美容相關保健食品成長趨勢最大，然而保健食品中具有美白、保濕、彈性和除皺功效的成份與科學證據，目前仍過於紊亂且無整合資訊。本研究以資料收集、資訊彙整及文獻分析，將宣稱具有以上功效之成分歸納彙整，並將體內與體外實驗之科學證據統合詳列，以提供研究者一致性之參考資料。根據分析結果顯示，影響黑色素形成的指標蛋白有酪胺酸酶、環磷酸腺苷等約七種蛋白，以體外細胞與體內動物試驗，證實飲食天然物可藉由降低酪胺酸酶活性和蛋白表現量，減少細胞黑色素含量或抑制黑色素細胞生長等，達成美白功效。另外，經由體外細胞測試或體內動物與人體試驗，亦證實飲食天然物能減緩表皮水分流失、提高皮膚彈性、增加保濕相關蛋白表現量和改善皺紋的面積深淺等，也就是具有保濕、維持彈性和除皺功效。總結而言，經由各項科學證據的蒐集與驗證，飲食天然物可抑制黑色素細胞中指標蛋白活性和濃度而減少黑色素形成，達到美白的功效；飲食天然物亦能減少表皮水分流失及增加相關保濕蛋白表現，讓皮膚彈性增加與改善皮膚皺紋形成，而達到美容功效。

關鍵字

美白, 黑色素, 保濕, 彈性, 皺紋, 飲食天然物

並列摘要

Melanogenesis, a cascade of enzymatic and spontaneous reactions, is regulated by several factors to convert tyrosine to melanin pigments. Skin moisturizing is believed that having connection to Aging. In cosmetologic market, the effective anti-melanogenic products and moisturizing products are highly demanded. A large number of dietary extracts or pure compounds have been claimed that possessing melanogenesis-inhibited and moisturizing-increased functions. This study was aimed to collect and summarize the scientific evidence for the effects and underlying mechanisms of dietary compounds on anti-melanogenisis, raising skin moisture, boosting skin elasticity, and ameliorating wrinkle formation. According to the collected literatures, we found that the enzyme activity and expression of tyrosinase, melanoma cell lines from animal (e.g. B16, B16F10, and B16BL6), and human (e.g. A375.S2, and HM3KO) were used as in vitro model; brown guinea pigs was usually used as an in vivo model. The proteins of tyrosinase, melanine, microphthalmia-associated transcription factor (MITF), tyrosinase-related protein-1 & -2 (TRP-1 & -2), cyclic AMP (cAMP), and melanocortin 1 receptor (MC1R) were further used as the regulators and indicators of melanogenesis. The experiments of transepidermal water loss/stratum corneum hydration, elasticity improvement, and skin wrinkle reduction were commonly used the in vivo models of mice (e.g. HR-1 hairless mice, ICR mice) and human. Additionally, the in vitro models of mice dermal fibroblasts and human dermal fibroblasts were employed to test the production of collagen , ceramides , and hyaluronic acid . Accordingly, numerous dietary natural extracts or bioactives were shown to have anti-melanogenic, skin moisturizing, skin elasticity boosting and anti-wrinkle activities by the above-mentioned models and indicators.