Atividade gastroprotetora do 2-O-Metil-L-inositol isolado de Magonia Glabrata St. Hill : possíveis mecanismos

• Ano de defesa: 2008
• Autor(a) principal: Olinda, Tiago Moreira de
• Orientador(a): Santos , Flávia Almeida
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Palavras-chave em Português: Mucosa Gástrica; Inositol; Ferimentos e Lesões
• Link de acesso: http://www.repositorio.ufc.br/handle/riufc/2641

2-O-metil-L-inositol as well known as quebrachitol (QCT) isolated from Magonia glabrata St.Hill’s pericarp (Sapindaceae), spread by the popular alias “tingui-de-bola” was evaluated in ethanol and indometacin-induced gastric lesions models in mice. QCT (12,5, 25 and 50 mg/Kg, v.o.) significantly (p < 0,05) reduced gastric lesions induced through administration of ethanol (0,2 mL/animal) in the order of 69, 64 and 53% respectively. QCT (12 and 25mg/Kg, v.o.) also reduced indometacin-induced gastric injuries. The possible mechanism of gastroprotection was accessed through ethanol-induced gastric lesions model in mice and the dose of 25 mg/Kg of QCT was chosen. Pre-treatment of the animals with L-NAME (20 mg/Kg, i.p.), nitric oxide sintase inhibitor, or glibenclamide (5 mg/Kg, i.p.), Potassium ATP-dependent channel blocker (KATP), inhibits QCT’s gastroprotective effect which suggests a participation of NO and activation of KATP on QCT’s gastroprotection. On the same way, QCT’s gastroprotection was abolished when animals were pre-treated with indometacin (10 mg/Kg, v.o.), a non-selective inhibitor of ciclooxigenase, which demonstrates the role of endogen prostaglandins. QCT’s effect was not abolished when animals were pre-treated with capsazepine (5 mg/Kg, i.p.) which indicates that vanilloid receptors TRPV1 are not involved on QCT’s benefic activities. QCT’s gastroprotective activity involves at least in part an antioxidant action, once this drug was capable to reestablish the NP-SH gastric levels which had been depleted after ethanol administration. Nevertheless, QCT did not altered gastric secretion pH when evaluated by pylorus ligature model in rats and also have not altered gastric emptying process in phenol red model in mice. The data shown suggest that QCT promotes gastroprotection against ethanol and indometacin-induced gastric lesion in mice and endogen prostaglandins, nitric oxide and or KATP channels may play a role besides an antioxidant activity.