Mecanismos envolvidos na atividade gastroprotetora do extrato hexânico das folhas de celtis iguanaea (JACQ.) sargent (cannabaceae)

Abstract

Celtis iguanaea, is popularly known as esporão-de-galo, tela, taleira, sarã, gurrupiá and grão-de-galo. It is about 6-9 feet high with rounded crown and long flexible branches armed with thorns. Ethnopharmacological study of this species shows the use of its leaves in the form of tea for treating body aches, chest pain, asthma, colic and indigestion. Previous results from our laboratory have shown gastroprotection and anti-ulcerogenic activities of the aqueous leaf extract and the n-hexane fraction obtained after fractionation of the ethanol leaf extract of esporão-de-galo in different models of gastric ulcers. For this purpose, samples of Celtis iguanaea leaves were collected from Hidrolandia-GO. The voucher specimen was deposited in the Herbarium of UFG (N°. 40110). Male Swiss albino mice, weighing between 35-40 g and frogs (Rana castebiana) of both sexes, weighing between 80-120 g were used. In general test of pharmacological activity, no significant alteration among animals treated orally with EHEG (10, 30, 100, 300 and 1000 mg / kg) or vehicle (2% Tween 80, 10 mL / kg. No evidence of significant effect on CNS and antioxidant activity was recorded with EHEG in vivo and in vitro respectively. On the other hand, EHEG showed anti-ulcerogenic activity in acute ulcers (induced by indomethacin, 75% ethanol and pylorus ligation) and chronic gastric injury induced by acetic acid. The EHEG administered orally increased mucus adhered to the gastric mucosa. Involvement of the α2 receptor in the gastroprotection effect exerted by the EHEG was assessed with the yohimbine (α2 adrenergic receptor antagonist). This compound reduces effect of EHEG. The study of antisecretory activity in isolated frog mucosa in Ussing chamber showed that EHEG reduces basal secretion of gastric acid up to 98.27%, and reduced ACh - stimulated secretion by 39.45%. A similar effect was observed in the pyloric ligation model in rodents, where we observe systemic activity of EHEG. The EHEG also reduced volume, free acidity and total acidity of gastric acid secretion induced by various secretagogues. The results of this study suggest that EHEG has gastroprotective activity by a mechanism that involves in part, anti-ulcerogenic, antisecretory and an increase in mucus production.