Toxicological and phytochemical studies of Aspidosperma subincanum Mart. stem bark (Guatambu).

Aspidosperma subincanum Mart. is widely used in Brazilian folk medicine to treat digestive disorders. In this study, acute and subchronic toxicity and cytotoxicity of stem bark ethanolic extract of Aspidosperma subincanum (EEAs) have been evaluated. In addition, phytochemical analysis was performed. The EEAs had low acute toxicity in mice with LD50 =1129 +/- 154mg/kg p.o. and 397 +/- 15 mg/kg i.p. The LC50 was 1340 +/- 428 microg/mL in the brine shrimp assay. There was no relevance of serious changes in behavioral, hematological and biochemical parameters and no deleterious effect on vital organs of rats that resulted after 30 days daily exposure to 5 and 100 mg/kg of EEAs. Phytochemical analysis of stem bark of A. subincanum revealed the presence of indole alkaloids, saponins, terpenoids, steroids and tannins and resulted in the isolation of oleic acid and guatambuine as major constituents. Using the method of the dose by factor approach, the human safe dose was 210 mg/70 kg/day. The EEAs appears to be safe and non-toxic in low doses in rodents and domestic preparations used by population have relatively security.

The acetone soluble fraction from bark extract of Stryphnodendron adstringens (Mart.) coville inhibits gastric acid secretion and experimental gastric ulceration in rats.

The acetone soluble fraction from a crude methanol extract of Stryphnodendron adstringens stem bark (AFSAB) was evaluated in acute (ethanol, indomethacin and hypothermic restraint-stress) and chronic (acetic acid) models of gastric ulceration and on basal and bethanechol-stimulated gastric acid secretion in rats. Rats pretreated orally with AFSAB at doses of 400 and 800 mg/kg showed significant decreases of gastric lesion scores in ethanol (62% and 98%) and hypothermic restraint-stress (89% and 88%) models but exerted no significant influence on indomethacin-induced acute or acetic acid-induced chronic ulceration. In pylorus-ligated rats, AFSAB significantly decreased the basal as well as bethanechol-stimulated gastric secretory volume and the total acidity with an elevated pH value. AFSAB failed to modify the gastric mucus and the gastric wall nonprotein-sulphydryl content. These results point to a possible antisecretory effect of AFSAB which account for the observed antiulcer activity in ethanol and hypothermic restraint-stress induced models of acute gastric ulceration.