Correlação entre a desnutrição proteica e o processo de formação e reparação de ulceras gastricas : efeito protetor/curativo do oleo essencial de Croton cajucara Benth (Euphorbiaceae)

AUTOR(ES)
DATA DE PUBLICAÇÃO

2003

RESUMO

It is known that the protein malnutrition can affect metabolism rates in humans, rodents and other animals. It is generally accepted that peptic ulcers are caused by a failure in the balance between gastric aggressive factors and mucosal defensive factors. Thus, the primary aim of this work was to verify the correlation between protein malnutrition and the gastric ulcer formation in rats fed diets with low (6%) or regular (17%) content of proteins. Croton cajucara Benth (Euphorbiaceae) is a specie widely used in Amazonian folk medicine for the treatment of a wide range of gastrointestinal symptoms. Thus, we also investigated the anti-ulcerogenic action of C. cajucara in the treatment of gastric ulcers in control and protein undernourished rats. It was observed that undernourished animals presented lower number of gastric injuries when compared with control animals in ethanol- and indomethacin-induced acute gastric ulcer. This may have occurred because undernourished animals produced greater amount of mucus and prostaglandin E2 (PGE2) when compared with the values obtained in control animals, even in the absence of the anti-ulcerogenic drugs. Besides, in placebo treated (12% Tween 80) undernourished rats submitted to pylorus ligature, a significant increase in gastric juice volume was observed when compared with control animals. After administration of essential oil from C. cajucara by intra-duodenal route, there was a significant reduction in the total acid content of both animal groups. The gastric juice volume was increased in the control group; however in undernourished rats, the gastric juice volume was higher before and remained high after treatment. In chronic experiments, where the animals were treated for 14 days with vehicle, standard drug (cimetidine) and with Croton cajucara essential oil, undernourished animals showed serious injuries in the gastric mucosa when compared with the gastric lesions of control animals. In acute and chronic ulceration, the essential oil was efficient in both animal groups to prevent and to heal these kinds of injuries. It was observed that C. cajucara essential oil caused citoprotection of the gastric mucosa of control and undernourished rats due to the increase of PGE2 release and gastric mucus content. It was also detected an increase of epidermal growth factor more pronounced in the gastric mucosa of control rats than malnourished rats that probably helped the healing of the gastric lesions. An increase in somatostatin and corticosterone levels and the decrease in gastrin levels were observed in both groups, control and undernourished animals.However, the latter showed high levels of somatostatin and corticosterone hormones and low gastrin levels when compared to control rats. All these factors appear to contribute with the anti-ulcerogenic effect of the essential oil preventing and healing the gastric mucosal damage of both control and undernourished animals. The results of this work confirmed healing effects previously obtained with C. cajucara essential oil in control rats. Additionally, it was possible to demonstrate that undernourished animals showed a resistance of the gastric mucosa against to ulcerogenic agents due to physiological changes found in their organisms

ASSUNTO(S)

estomago - ulcera desnutrição proteica plantas medicinais cicatrização etnofarmacologia rato biologia molecular prostaglandinas

ACESSO AO ARTIGO

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