| 摘要: | 本研究針對三種柑橘類果皮之酒精萃取物及柑橘類果皮含量最高之酚類化合物：綠原酸(chlorogenic acid)、香豆酸( p-coumaric acid )及抗酪胺酸酶抑制劑之正控制組麴酸(kojic acid)之抗氧化力、抗酪胺酸酶活性及對B16黑色素瘤細胞黑色素生合成抑制作用之探討。於DPPH自由基清除力、TEAC分析、超氧陰離子自由基清除力、還原力及liposome過氧化力等實驗，不同抗氧化分析結果顯示此6組樣本均具有濃度上升抗氧化力亦隨之上升之劑量效應，但卻完全不具有金屬離子螯合力，整體評估其抗氧化力，純物質效用均較果皮萃取物佳，其順序如下: 綠原酸＞香豆酸＞麴酸＞檸檬皮萃取物＞椪柑皮萃取物＞葡萄柚皮萃取物。然而於TEAC分析法卻是麴酸=香豆酸＞綠原酸＞葡萄柚皮萃取物＞檸檬皮萃取物＞椪柑皮萃取物。三種柑橘類果皮之萃取物進行總多酚和總類黃酮含量分析，結果發現均以檸檬皮萃取物含量最高，其含量分別為58.0±0.56及40.5±0.11 mg/g。
以5、10、40和400g/ml濃度進行抗酪胺酸酶活性分析，結果以香豆酸效用最強，麴酸次之，綠原酸、檸檬皮萃取物、葡萄柚皮萃取物之效用依次遞減而椪柑皮萃取物之效用最差。
經評估選擇麴酸及檸檬皮萃取物進行B16黑色素瘤細胞黑色素生合成抑制作用之研究。400g/ml濃度下之麴酸及檸檬皮萃取物均具抑制黑色素生合成作用，其抑制力分別為74.30及21.17%。B16黑色素瘤細胞抗酪胺酸酶活性分析，400g/ml濃度之麴酸有36.32%抑制活性，但檸檬皮萃取物則有促進之效果。於B16黑色素瘤細胞酪胺酸酶基因轉錄表現實驗結果分析，麴酸和檸檬皮萃取物並沒有明顯作用。
本研究發現檸檬皮萃取物，兼具抗氧化力及抗黑色素生成，希望可進一步研究以期代彼等應用於化妝品業或於醫療上可解決色素過度化所引起之皮膚病變。
The study on three kinds of ethanolic extracts from citrus peel, their major constituents: chlorogenic acid, p-coumaric acid and kojic acid positive control for antioxidation, antityrosinase activity and melanogenesis inhibition. It was found that they showed a dose-dependent activity on DPPH, TEAC, superoxide anion assay, reducing power and liposome peroxidation analysis. There were no chelating effect in 6 components. The power of antioxidation by using four different assay methods were in the following order: chlorogenic acid > p-coumaric acid > kojic acid > lemon peel extract > ponkan peel extract > grapefruit peel extract. However, the results were shown that kojic acid is the strongest scavenger for ABTS．+ radical by TEAC assay. In addition, lemon peel extract exhibited the highest levels when comparing three kinds of citrus peel extracts from total phenolic and flavonoid assay, the value of content to be 58.0±0.56 and 40.5±0.11 mg/g, respectively. It was found that antityrosinase activities at the concentration of 5, 10, 40 and 400 g/ml were indicated concentration dependent effect. Chlorogenic acid, kojic acid and lemon peel extract showed higher antityrosinase activity.
Upon evaluation of kojic acid and lemon peel extract on the melanogenesis in the B16 cells, showed marked inhibitory activity with 74.30 and 21.17% reduction, respectively. At a dose of 400 g/ml, kojic acid had 36.32% inhibitory activity for antityrosinase, but lemon peel extract advanced antityrosinase activity. At the same concentration, no significantly inhibited tyrosinase mRNA expression for kojic acid and lemon peel extract, as determined by reverse transcription polymerase chain reaction (RT-PCR).
In this study, it was suggested that lemon peel extract was helpful for cosmetic product and depigmenting agent for hyperpigmentation. |
