title: Hypoglycemic effect of Bumelia sartorum polyphenolic rich extracts.
abstract: Bumelia sartorum (Sapotaceae) is used ethnomedicinally for treatment of several diseases, including diabetes mellitus. The aim of this work was to investigate the hypoglycemic effect of B. sartorum extracts, rich in polyphenolic compounds, and the possible mechanisms of action. Assessment of B. sartorum hypoglycemic activity was performed from the blood glucose level in normoglycemic mice after administration of the extract by oral gavage. The hypothesis that sarco/endoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibition could prolong the increase in cytoplasmic Ca2+ concentration, thus leading to an increase of insulin release was evaluated. The enzyme inhibition was measured by ATP hydrolysis using SERCA1 isolated from rabbit skeletal muscle. The total content of phenolic compounds was determined by the Folin-Ciocalteau method. The ethyl acetate (EtOAc) partition and F5 fraction obtained from B. sartorum, both of them rich in polyphenolics, were shown to have a hypoglycemic effect on normoglycemic mice, more significant than that of the known antidiabetic drug, glibenclamide used as a standard comparable compound. Both samples significantly inhibited SERCA activity. Different extracts of B. sartorum, rich in polyphenolic compounds, were able to reduce blood glucose in normoglycemic mice and inhibit SERCA activity. SERCA inhibition may be one of the possible mechanisms involved in glucose decrease.
authors.affiliation: Biotecnologia Vegetal, Centro de Ciências da Saúde, Cidade Universitária, Universidade Federal do Rio de Janeiro, 21921-590 Rio de Janeiro, RJ, Brazil. hallinyruela@ufrj.br
authors.forename: Halliny S
authors.initials: HS
authors.lastname: Ruela
authors.forename: Katia C C
authors.initials: KC
authors.lastname: Sabino
authors.forename: Ivana C R
authors.initials: IC
authors.lastname: Leal
authors.forename: Ana M
authors.initials: AM
authors.lastname: Landeira-Fernandez
authors.forename: Michelle R A
authors.initials: MR
authors.lastname: de Almeida
authors.forename: Talita S M
authors.initials: TS
authors.lastname: Rocha
authors.forename: Ricardo M
authors.initials: RM
authors.lastname: Kuster
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000032:analysis; D002118:Calcium / Q000378:metabolism; D005260:Female; D007004:Hypoglycemic Agents / Q000494:pharmacology*; D051379:Mice; D010936:Plant Extracts / Q000494:pharmacology*; D059808:Polyphenols / Q000494:pharmacology*; D011817:Rabbits; D029632:Sapotaceae / Q000737:chemistry*; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases / Q000037:antagonists & inhibitors
chemical_list: D001786:Blood Glucose; D007004:Hypoglycemic Agents; D010936:Plant Extracts; D059808:Polyphenols; D053498:Sarcoplasmic Reticulum Calcium-Transporting ATPases; D002118:Calcium