臺灣蜂膠美白活性之探討

The Study of Taiwanese Propolis on Skin-Whitening Activity

蜂膠是一種由蜜蜂採集各種植物的嫩芽或樹皮之汁液，再與蜜蜂的唾液酵素、花粉、及蜂蠟等混合所得的膠狀黏性物質，用來塗裝在蜂巢的內壁，可用來防禦外敵、也可對抗微生物感染，避免食物的腐敗。蜂膠具有許多生理活性，包含有抗細菌、抗病毒、抗發炎及及抗腫瘤等。蜂膠中的主成份黃酮類也具有很好的抗氧化能力，可以對抗紫外線，避免皮膚受到傷害，因而被應用在化妝品和保養品上面。但當蜂膠產品塗抹在皮膚上，是否會進入皮膚角質層，而產生美白之效果？因此，本研究想先評估台灣蜂膠的乙醇萃取物及其分層是否能抑制黑色素之生合成。首先先看台灣蜂膠的乙醇萃取物及其分層是否會抑制酪胺酸酶的活性，再以MTT分析其對B16黑色素瘤細胞是否具細胞毒性，並以波長405nm分析其在B16細胞的黑色素含量。結果發現蜂膠的乙醇萃取物及其分層（BG-2及BG-3）可抑制酪胺酸酶活性，但對B16細胞具有細胞毒性，且呈劑量及時間相關性，此細胞毒殺作用可能是因誘導細胞凋亡所致，但詳細機制則需更進一步的研究分析。

Propolis is a hive product that bees manufacture from balsamic resins actively secreted by plants on leaf buds and barks. It possesses several biological activities such as antibacterial, antiviral, antiinflammatory, and antitumor effects. Propolis and its main flavonoids components also show high antioxidant activity. Furthermore, these substances evidence effectiveness as broad spectrum UVB and UVA photoprotection sunscreens. The combination of these characteristics moves up propolis and its main flavonoids components to the class of cosmeceuticals, as possible active ingredient of sunscreen commercial formulations for their protective and preventive properties. However, when the epidermis is exposed to propolis products, the exact mode of melanogenesis is yet to be determined. Therefore, the objective of our study is to investigate the whitening and melanogenesis inhibitory potential of Taiwanese propolis ethanol extract and its fractions at tyrosinase activity assay and melanoma cells. Thus, we first screened the inhibit potential of propolis extract and its fractions on tyrosinase activity. We further determined the cytotoxicity of propolis extract and its fractions in mouse melanoma B16 cells by using tetrazolium salt （MTT）. The effects of propolis extract and its fractions on melanin content in B16 cells were also measured by UV at OD405. The data showed that Taiwanese propolis extract and its fractions （BG-2 and BG-3） inhibited mushroom tyrosinase activity in vitro. They were cytotoxic to B16 cells in a dose-and time-dependent manner and this effect may be from apoptosis induction, but the mechanism is needed further study.