The invention relates to a use of Hibiscus sabdariffa Linnaes Leaf extracts (HLE) for inhibiting melanin synthesis by applying an effective does of the HLE to skin. The HLE can be used to regulate expression of melanin-related second messenger, genes and proteins and to affect activities of tyrosinases for purpose of inhibiting melanin synthesis. Accordingly, the HLE can be further utilized in manufacturing cosmetic compositions, food additives or pharmaceutical compositions for whitening.本發明係有關於一種洛神葉萃取物用於抑制黑色素生成之用途,其係施予洛神葉萃取物一有效劑量於皮膚,以調節參與黑色素生成路徑相關之第二傳訊者(second messenger)、基因或蛋白質之表現,並進而影響酪胺酸酶活性,達到抑制黑色素生成之用途;藉此,洛神葉萃取物可進一步作為美白之化妝材料組成物、食品添加物或醫藥組成物。
