title: Potent α-glucosidase and protein tyrosine phosphatase 1B inhibitors from Artemisia capillaris.
abstract: As a part of our ongoing effort to identify anti-diabetic constituents from natural sources, we examined the inhibitory activity of the methanol extracts of 12 species of the genus Artemisia, against α-glucosidase and protein tyrosine phosphatase 1B (PTP1B). The methanol extracts of different species exhibited promising α-glucosidase and PTP1B inhibitory activities. Since the methanol extract of Artemisia capillaris exhibited the highest α-glucosidase inhibitory activity together with significant PTP1B inhibitory activity, it was selected for further investigation. Repeated column chromatography based on bioactivity guided fractionation yielded 10 coumarins (esculetin, esculin, scopolin, isoscopolin, daphnetin, umbelliferone, 7-methoxy coumarin, scoparone, scopoletin, 6-methoxy artemicapin C), 8 flavonoids (hyperoside, quercetin, isorhamnetin, cirsilineol, arcapillin, isorhamnetin 3-robinobioside, linarin, isorhamnetin 3-glucoiside), 6 phenolic compounds (1,5-dicaffeoylquinic acid, 3,4-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid, 3,5-dicaffeoylquinic acid methyl ester, 4,5-dicaffeoylquinic acid, 3-caffeoylquinic acid), and one chromone (capillarisin). Among these compounds, esculetin, scopoletin, quercetin, hyperoside, isorhamnetin, 3,5-dicaffeoylquinic acid methyl ester, 3,4-dicaffeoylquinic acid, and 1,5-dicaffeoylquinic acid exhibited potent α-glucosidase inhibitory activity when compared to the positive control acarbose. In addition, esculetin and 6-methoxy artemicapin C displayed PTP1B inhibitory activity. Interestingly, all isolated dicaffeoylquinic acids showed significant PTP1B inhibitory activity. Therefore, the results of the present study clearly demonstrate the potential of the A. capillaris extract to inhibit α-glucosidase and PTP1B. These inhibitory properties can be largely attributed to a combination of different chemical structures, including coumarins, flavonoids, and dicaffeoylquinic acids, which could be further explored to develop therapeutic or preventive agents for the treatment of diabetes.
authors: Department of Food Science and Nutrition, Pukyong National University, Busan, 608-737, Republic of Korea.
authors: Md
authors: M
authors: Nurul Islam
authors: Hyun Ah
authors: HA
authors: Jung
authors: Hee Sook
authors: HS
authors: Sohn
authors: Hye Mi
authors: HM
authors: Kim
authors: Jae Sue
authors: JS
authors: Choi
mesh_terms: D019306:Artemisia / Q000737:chemistry*; D055808:Drug Discovery; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology*; D009682:Magnetic Resonance Spectroscopy; D000432:Methanol / Q000737:chemistry; D015394:Molecular Structure; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1 / Q000037:antagonists & inhibitors*; D013045:Species Specificity; D013329:Structure-Activity Relationship
chemical_list: D004791:Enzyme Inhibitors; D065089:Glycoside Hydrolase Inhibitors; D007004:Hypoglycemic Agents; D054562:Protein Tyrosine Phosphatase, Non-Receptor Type 1; D000432:Methanol