title: In vitro antioxidant, anti-diabetic and antilipemic potentials of quercetagetin extracted from marigold (Tagetes erecta L.) inflorescence residues.
abstract: Quercetagetin, the major flavonoid in marigold (Tagetes erecta L.) inflorescence residues was extracted and purified. The content of quercetagetin after the purification was 89.91 ± 0.26 %. The in vitro antioxidant activity of quercetagetin and its potential in controlling diabetes mellitus and obesity were investigated and compared to quercetin and rutin. The 50 % inhibitory concentration (IC50) values of quercetagetin on scavenging 1, 1-diphenyl-2-picrylhydrazyl (DPPH), 2,2-azinobis-(3-ethylbenzothiazolin-6-sulfonic acid) (ABTS) and hydroxyl radicals were 27.12 ± 1.31 μmol/L, 12.16 ± 0.56 μmol/L and 1833.97 ± 6.66 μmol/L, respectively. The IC50 values of quercetagetin on α-glucosidase, α-amylase and pancreatic lipase were 180.11 ± 3.68 μmol/L, 137.71 ± 3.55 μmol/L and 2327.58 ± 12.37 μmol/L, respectively. These results indicated that quercetagetin exhibited strong in vitro antioxidant, anti-diabetic and antilipemic activities. Lineweaver-Burk plots analysis elucidated that quercetagetin inhibited α-glucosidase and α-amylase non-competitively, while its inhibition against pancreatic lipase was involved in a mixed-type pattern. Moreover, strong correlations were found between ABTS(·+)/DPPH(·) scavenging activities and lipase inhibitory activity (R (2) > 0.90), as well as ·OH scavenging activity and α-amylase inhibitory activity (R (2) = 0.8967).
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Weiyou
authors.initials: W
authors.lastname: Wang
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Honggao
authors.initials: H
authors.lastname: Xu
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Hua
authors.initials: H
authors.lastname: Chen
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Kedong
authors.initials: K
authors.lastname: Tai
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Fuguo
authors.initials: F
authors.lastname: Liu
authors.affiliation: Beijing Advanced Innovation Center for Food Nutrition and Human Health, Beijing Laboratory for Food Quality and Safety, Beijing Key Laboratory of Functional Food From Plant Resources, College of Food Science & Nutritional Engineering, China Agricultural University, Box 112, No.17 Qinghua East Road, Haidian District, Beijing, 100083 China.
authors.forename: Yanxiang
authors.initials: Y
authors.lastname: Gao
keywords: Diabetes mellitus; Enzyme inhibition; Marigold (Tagetes erecta L.) inflorescence residues; Pancreatic lipase; Quercetagetin