title: Inhibitory effects of Citrus flavonoids on starch digestion and antihyperglycemic effects in HepG2 cells.
abstract: Flavonoids are a class of important bioactive natural products and are being extensively used in functional foods. In the present study, the effects of four  Citrus  flavonoids (i.e., hesperidin, naringin, neohesperidin, and nobiletin) on amylase-catalyzed starch digestion, major digestive enzyme activities (e.g., pancreatic α-amylase and α-glucosidase), and glucose use in HepG2 cells were investigated. The results showed that all of the tested  Citrus  flavonoids significantly inhibited amylase-catalyzed starch digestion. Moreover, naringin and neohesperidin mainly inhibited amylose digestion, whereas hesperidin and nobiletin inhibited both amylose and amylopectin digestion. However, these flavonoids showed weak inhibitory activities against digestive enzymes. Furthermore, glucose consumption, glycogen concentration, and glucokinase activity were significantly elevated, and glucose-6-phosphatase activity was markedly decreased by  Citrus  flavonoids. These results demonstrate that  Citrus  flavonoids play important roles in preventing the progression of hyperglycemia, partly by binding to starch, increasing hepatic glycolysis and the glycogen concentration, and lowering hepatic gluconeogenesis. This work suggests that  Citrus  flavonoids might be potentially used for the prevention of postprandial hyperglycemia.
authors.affiliation: State Key Laboratory of Bioreactor Engineering,  East China University of Science and Technology , Shanghai 200237, People's Republic of China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.forename: Ying
authors.initials: Y
authors.lastname: Xu
authors.forename: Yan-Hua
authors.initials: YH
authors.lastname: Lu
mesh_terms: D000687:Amylopectin / Q000737:chemistry / Q000378:metabolism; D000688:Amylose / Q000737:chemistry / Q000378:metabolism; D000818:Animals; D002957:Citrus / Q000737:chemistry*; D004063:Digestion / Q000187:drug effects; D004353:Drug Evaluation, Preclinical / Q000379:methods; D044950:Flavanones / Q000494:pharmacology; D047309:Flavones / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology*; D005941:Glucokinase / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000378:metabolism; D056945:Hep G2 Cells / Q000187:drug effects; D006569:Hesperidin / Q000031:analogs & derivatives / Q000494:pharmacology; D006801:Humans; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D007455:Iodine / Q000737:chemistry / Q000378:metabolism; D008099:Liver / Q000187:drug effects / Q000378:metabolism; D055292:Pancreatic alpha-Amylases / Q000378:metabolism; D013213:Starch / Q000378:metabolism
chemical_list: D044950:Flavanones; D047309:Flavones; D005419:Flavonoids; D007004:Hypoglycemic Agents; D013213:Starch; D006003:Glycogen; D000688:Amylose; D000687:Amylopectin; D007455:Iodine; C008661:nobiletin; D006569:Hesperidin; D005941:Glucokinase; D055292:Pancreatic alpha-Amylases; D005947:Glucose; C005274:naringin; C546526:neohesperidin