Effect of Medicinal Herb Prepared through Traditional Antidiabetic Prescription on α-Glucosidase Activity and Evaluation Method for Anti-Melanogenesis Agents Using α-Glucosidase Activity

For the purpose of investigating the in vitro antidiabetic activity of a medicinal herb and herb mixture extracts prepared through traditional antidiabetic prescription, this study examined α-glucosidase inhibitory activity. Tyrosinase, a type Ⅰ membrane glycoprotein, is synthesized and glycosylated in the endoplasmic reticulum (ER) and Golgi. The enzyme is subsequently transported to melanosomes, where it participates in melanogenesis. Previous studies showed that disruption of early ER N-glycan processing by an α-glucosidase inhibitor suppresses tyrosinase enzymatic activity and melanogenesis. According to the results, most oriental medicinal herbal extracts were stronger than acarbose and N-butyldeoxynojirimycin, known as an α-glucosidase inhibitor. Interestingly, ethyl acetate layer of enzyme hydro- lyzed Cheongsimyeonjaeum had an inhibitory effect on melanin synthesis in B16F1 cells, although it did not inhibit tyrosinase activity directly. Together, α-glucosidase inhibition activity could be used to evaluate anti-melanogenesis, although cross-checking with melanin inhibitory assay is recommended.