title: Antispasmodic effect of 4'-methylepigallocatechin on guinea pig ileum.
abstract: The antispasmodic effect of 4'-methylepigallocatechin (MEC), which was isolated from Maytenus rigida Mart (Celestraceae), was investigated in vitro in guinea pig intestinal segments. In the isolated ileum, MEC (1 nM-100 μM) did not modify the ileal spontaneous tonus or the electrically elicited contractions. MEC (8 μM) significantly (p<0.01) reduced the submaximal contractions induced by histamine (2 μM), carbachol (100 μM) and BaCl₂ (0.03 M). An additive relaxing action (p<0.001) was observed by co-incubation of verapamil (10 nM) and MEC (8 μM). Although MEC (1 nM-100 μM) did not modify the contractions elicited by 60 mM KCl, it significantly reduced the CaCl₂ contractile response without changing the EC₅₀ (effective concentration of CaCl₂ causing 50% of maximum response). In brief, these results show that MEC has a potent ileal spasmolytic effect and blocks spasms induced by specific and nonspecific stimuli. Importantly, the spasmolytic effects were attained at low concentrations and might be related to the symptomatic relief of abdominal pain that is obtained from the use of the M. rigida stem bark.
authors.affiliation: Physiology Department, Federal University of Sergipe, São Cristóvão, Sergipe, Brazil.
authors.forename: Marcelly Barbosa
authors.initials: MB
authors.lastname: da Rocha
authors.forename: Fábia Valéria Menezes
authors.initials: FV
authors.lastname: Souza
authors.forename: Charlez
authors.initials: C
authors.lastname: dos Santos Estevam
authors.forename: Cosimo
authors.initials: C
authors.lastname: Pizza
authors.forename: Antônio Euzébio Goulart
authors.initials: AE
authors.lastname: Sant'ana
authors.forename: Rosilene Moretti
authors.initials: RM
authors.lastname: Marçal
mesh_terms: D000818:Animals; D017609:Barium Compounds / Q000494:pharmacology; D002122:Calcium Chloride / Q000494:pharmacology; D002217:Carbachol / Q000494:pharmacology; D002392:Catechin / Q000031:analogs & derivatives* / Q000302:isolation & purification / Q000494:pharmacology; D002712:Chlorides / Q000494:pharmacology; D006168:Guinea Pigs; D006632:Histamine / Q000494:pharmacology; D007082:Ileum / Q000187:drug effects*; D029755:Maytenus / Q000737:chemistry*; D009119:Muscle Contraction / Q000187:drug effects*; D009130:Muscle, Smooth / Q000187:drug effects*; D010276:Parasympatholytics / Q000302:isolation & purification / Q000494:pharmacology*; D010936:Plant Extracts / Q000737:chemistry / Q000494:pharmacology*; D011189:Potassium Chloride / Q000494:pharmacology; D014700:Verapamil / Q000494:pharmacology
chemical_list: C577186:4'-methylepigallocatechin; D017609:Barium Compounds; D002712:Chlorides; D010276:Parasympatholytics; D010936:Plant Extracts; C024986:barium chloride; D011189:Potassium Chloride; D006632:Histamine; D002392:Catechin; D002217:Carbachol; D014700:Verapamil; D002122:Calcium Chloride