The present invention relates to a plant extract obtained from the plant leaves of Mulberry. It is extracted from Morus plant leaves, and has an IC 50 value, to inhibit α-glucosidase I, at a concentration of less than 90 μg/ml. The extract preferably comprises 5-40% (w/w) total imino sugars and 20-70% (w/w) total amino acids. The extract is obtained by a three step extraction and purification process and may be used to reduce the production of melanin for the treatment of such ailments or disease caused by pigmentation as freckle, chloasma, striae of pregnancy, senile plaque and melanoma. It can also be used to control blood glucose level.本發明關於一種得自於桑樹葉片的植物萃取物。它萃取自桑屬植物的葉片,且對於抑制α-葡糖苷酶I具有一位在低於90 μg/ml之濃度的IC 50數值。該萃取物較佳為包含5-40%(w/w)之總體亞胺糖以及20-70%(w/w)之總體胺基酸。該萃取物係由三個萃取和純化製程所獲得,且可供用於降低黑色素之生成,以治療色素沈澱所造成的不適或疾病,例如雀斑、黃褐斑、妊娠纹、老人斑和黑色素瘤。它亦可供用於控制血糖位準。
