本研究評估白英50%乙醇萃取物(50% ethanol extract from Solanum lyratum Thunb., SLEE)對於酪胺酸酶的抑制作用特性。當使用左多巴(L-3,4-dihydroxyphenylalanine, L-dopa)作為蘑菇中酪胺酸酶的受質時,SLEE表現出對於蘑菇酪胺酸酶活性具有抑制效果。SLEE降低Vmax和Km,而且對於蘑菇酪胺酸酶表現出為混合型抑制劑(mixed-type inhibitor)。人類黑色素瘤細胞(Human malignant melanoma A375.S2 cell line)也被用來評估SLEE對於存在黑色素細胞中之酪胺酸酶活性的影響,經由實驗結果得知細胞中酪胺酸酶在受質濃度(L-dopa)0.5、1.0 mg/ml時,SLEE降低黑色素瘤細胞A375.S2酪胺酸酶活性;但在低受質濃度(0.1 mg/ml)情況下則沒有顯著效果。因此,推論白英具有潛力成為酪胺酸酶的抑制劑。
This study aimed to evaluate the inhibition properties of 50% ethanol extract from Solanum lyratum Thunb. (SLEE) toward the activity of tyrosinase. When using L-3,4-dihydroxyphenylalanine (L-dopa) as the substrate for mushroom tyrosinase, SLEE showed inhibitory effect on the activity of mushroom tyrosinase. SLEE decreased the value of Vmax and increased Km, and it behaved as a mixed-type inhibitor toward mushroom tyrosinase. Human malignant melanoma A375.S2 cell line was also used to evaluate the influence of SLEE on tyrosinase activity in the cell. It was found that SLEE reduced the tyrosinase activity in the A375.S2 cells at medium and high enzyme substrate levels (L-dopa, 0.5 and 1.0 mg/ml, respectively), but not at low enzyme substrate level (0.1 mg/ml). It was concluded that SLEE might be a potential inhibitor of tyrosinase.