Résumé
The present study was conducted to evaluate the toxicity of the ethanolic extract of leaves of Parkia platycephala Benth., Fabaceae, on systemic and reproductive parameters. In toxicity on the estrous cycle, four groups of not-pregnant Wistar rats received distilled water and the doses 250, 500 and 1000 mg.kg-1 of plant extract for thirty days, at the end of which they were examined as to the frequency of their phases. The systemic toxicity was assessed through the consumption of water and food and by measuring body mass. After the extract was administered, serum AST, ALT, ALP, bilirubin (total, direct and indirect), urea and creatinine were dosed. The evaluation of the organs (brain, heart, hypophysis, adrenal glands, liver, spleen, uterus and ovaries) in their macroscopic aspects, relative and absolute masses and histological structure showed that the plant extract induced a decrease of water and food consumption and of body mass. It caused an increase in the luteal phase and a decrease in the follicular phase of the estrous cycle and rose serum alkaline phosphatase levels.The data exhibit systemic and reproductive toxicity induced by plant extract in female Wistar rats.
Résumé
Parkia platycephala Benth. (Leguminosae - Mimosoideae), popularly known as "visgueira", fava bean tree or "fava-de-bolota", is widely found in the Northern and Northeastern regions of Brazil. Its pods are used as cattle food supplement in the drought period. Compounds with a gastroprotective activity were obtained from the genus Parkia. Therefore, this study aimed at investigating the gastroprotective effect of the ethanolic extract of Parkia platycephala Benth. leaves (Pp-EtOH), as well as evaluating its possible mechanisms of action in experimental ulcer induction models. Lesions were induced by absolute ethanol, ethanol-HCl, ischemia-reperfusion and indomethacin in rodents. Pp-EtOH showed a protective effect in the lesion models (66, 48 and 52 percent, respectively), but it was not able to protect gastric mucosa against indomethacin-induced lesions. Results show a possible participation of the NO-synthase pathway in the gastroprotection and an antioxidant activity, by the increase of the catalase activity. The participation of prostaglandins and potassium channels sensitive to ATP in the gastroprotective effect of Pp-EtOH seems less likely to occur. More comprehensive studies, therefore, should be carried out to elucidate the antiulcerative effects of this promising natural product against this gastrointestinal disorder.