本論文研究目的，在探討具酪胺酸酶抑制活性之植物萃取物於美白化粧品之應用，以中草藥植物：桑 ( Mulberry )、甘草 ( Glycyrrhiza )、
牡丹皮 ( Tree Peony Bark ) 為材料，使用80 % 酒精、水為溶劑，進行微波萃取、減壓濃縮、冷凍乾燥，評估內容有: (一) 探討黑色素生成抑制活性﹔(二) 抗氧化生物活性﹔(三) 細胞存活率試驗評估﹔(四) 探討不同助溶劑之溶解度﹔(五)運用於保養產品應用調製。
在美白生物活性作用方面，結果顯示: ME (桑枝萃取液)、GE (甘草萃取液)、TE (牡丹皮萃取液)皆可對蘑菇酪胺酸酶的活性產生不同程度的抑制，其中以ME萃出物的抑制效果最佳﹔在B-16黑色素瘤細胞上清液之黑色素抑制試驗中ME萃出物的效果亦是較佳。將ME、GE、TE萃取液加入美白化粧水、精華液、乳液保養品配方中，其中以GE配方的蘑菇酪胺酸酶活性抑制較佳﹔在配方中加入4W，結果顯示以GE配方的蘑菇酪胺酸酶活性抑制較佳。
在抗氧化生物活性作用方面，運用清除DPPH自由基能力，結果顯示其中以TE萃出物抑制率較佳﹔運用清除ABTS陽離子自由基能力，結果顯示其中以TE萃出物抑制率較佳﹔其清除DPPH及ABTS自由基皆會隨著萃出物濃度增加而提高抑制率。
在細胞存活率方面，結果顯示: ME、GE、TE萃出物0.1mg/ml，皆有84 % 以上的細胞存活率﹔在0.01 mg/ml，皆有96 %以上的細胞存活率。
運用不同的助溶劑溶解，當助溶劑為Isoceteth-20其溶解力最佳，若與1-3 Bytlene glycol、Propylene glycol搭配使用，則溶解力增加，搭配使用量亦可相對減少。
最後，將ME萃取液加入化粧品配方中，並加入衛生署藥政處規範之部分美白成分調製，經臨床試驗，本論文所討論之精華液配方，對於某些自願者有良好的反應，經自願者連續使用六星期，其美白幼艦i由Lab值顯示，L數值增加達到1.5以上者，結果顯示實驗數據有良好的反應，可提供為良好化粧品原料之商業應用。 The goal of the thesis is to evaluate the application of plant (Chinese medicine plant) extracts with potent tyrosinase inhibition activites on whitening cosmetics. The Mulberry, Glycyrrhiza, and Tree Peony Bark were employed as study materials. The selected plants were extracted by 80 % ethyl alcohols or distilled water by microwave machine, concentrated under a reduced pressure, and then dry by a lyophilizer. The evaluation of the application of herbal extracts on cosmetics includes: (1) suppression activities of melanin synthesis in vitro; (2) anti-oxidation activities; (3)cell survival rate; (4)solubility in cosmetic formula (5)efficacy in skin care products.
In the application on skin whitening, all these plants extracts, ME ( mulberry extract ), GE (Glycyrrhiza extract ), TE (Tree Peony Bark extract ), have the ability to inhibit the mushroom tyrosinase activities. Among them, the ME extract has the best inhibition activities. Similar effects were observed in B-16 melanoma cells. However, when combined with the known whitening ingredients, the GE extract expressed the highest inhibition activities.
In the anti-oxidation activity, TE extract contained a potent activity on the elimination of the DPPH free radical. Similar effect was observed in the TEAC experiment. We further examined the cytotoxicity of the plants extracts. All the materials showed little or none cytotoxicity at the concentration of 0.01 mg/ml.
These extracts have a good solubility in an Isoceteth-20 solution. Although 1-3 butylene glycol and propylene glycol were commonly used solvents, some precipitates were observed in these solutions.
Finally, we added the extracts together with four known whitening ingredients into the skin care formula, and evaluated their effects in vivo. Significant whitening effect was observed in some volunteers by a chromameter.
