[Pharmacologic activity of the aqueous wood extract from Quassia amara (Simarubaceae) on albino rats and mice]. / Actividad farmacológica del extracto acuoso de la madera de Quassia amara (Simarubaceae) en ratas y ratones albinos.

All the assays were done with an aqueous preparation of dry wood from Quassia amara (Simarubaceae). For the hippocratic assay, 12 female SDN rats were used, with an average weight of 144 g and separated in three groups of four individuals each. The dose used were 500 mg/kg and 1,000 mg/kg and the control group received 0.5 ml of distilled water. The extract administration and the observation of the animals were done daily during nine days. Acute toxicity of the preparation was studied with 25 male NGP mice with an average weight of 20.13 g, in groups of five individuals per dose. The oral administration was carry out with the following doses: 250, 500, 750 and 1,000 mg/kg, the control group received 0.5 ml of distilled water. No sign of acute toxicity was observed at any dose. For the toxicity analysis via intraperitoneal injection 15 male NGP mice were assigned to five groups (5 animals each) with doses of 500 and 1,000 mg/kg and a control group with 0.5 ml of distilled water. The group with the dose of 500 mg/kg, presented acute toxicity signs with a 24 hr recovery, and the 1,000 mg/kg dose was lethal to a 100% within 24 hr. The measuring of the peristaltic activity (movement of the intestinal content) were performed on 30 NGP male mice with an average weight of 22 g assigned to three groups of ten individuals each. One dose of 500 mg/kg and 1,000 mg/kg were orally administrated to each experimental group and 0.5 ml of distilled water to the control group. The marker used was activated carbon, orally supplied to every mice 30 min after the administration of the aqueous extract. The animals are decapitated and the measurement of the carbon motion in the small intestine was done after 30 min. Both dose increased the intestinal movement compared to the control group, but only the 1,000 mg/kg dose showed a statistically significant difference (p < or = 0.05).

A bioassay for inhibition of serotonin release from bovine platelets.

A bioassay was developed to study agents capable of inhibiting the release of serotonin from bovine blood platelets. It is a simple, inexpensive, and reproducible high-throughput bioassay suitable for quality control of feverfew, Tanacetum parthenium, a crude drug with proven migraine prophylactic activity that is being considered for governmental registration and regulation. The bioassay, which requires no experimental animals or human subjects, was used to assess the in vitro activity of T. parthenium samples grown from seed obtained from 10 different regions of Europe. The activity was found to vary significantly within and between samples, with no geographical correlation. Serotonin release inhibition was shown to be significantly correlated with the content of the germacranolide sesquiterpene lactone, parthenolide, although other sesquiterpene lactones from this plant and other members of the Asteraceae were also shown to be active. The activities of six other species of Tanacetum, as well as of Artemisia absinthium (wormwood) and Zingiber officinale (ginger), and two commercial drugs for migraine prophylaxis, verapamil hydrochloride and propranolol hydrochloride, were also assessed. The relevance of the bovine platelet serotonin release inhibition bioassay to antimigraine research is discussed.

Effect of ionic charge on detergent-induced hemolysis.

7.0 microM Sodium dodecyl sulfate induces lysis on A Rh(+) red blood cells 1.6 times faster than the cationic analog dodecyl thiouronium chloride at 37 degrees C and pH = 7.30. Hemolysis isotherms show identical values for the Hill cooperativity parameters of the organic surfactants, but different dissociation parameters. The anionic detergent destabilizes red cell membranes more efficiently than the cationic analog, probably due to the predominance of negative charges on the erythrocyte membranes at physiological pH.

Effect of ionic charge on detergent-induced hemolysis.

7.0 microM Sodium dodecyl sulfate induces lysis on A Rh(+) red blood cells 1.6 times faster than the cationic analog dodecyl thiouronium chloride at 37 degrees C and pH = 7.30. Hemolysis isotherms show identical values for the Hill cooperativity parameters of the organic surfactants, but different dissociation parameters. The anionic detergent destabilizes red cell membranes more efficiently than the cationic analog, probably due to the predominance of negative charges on the erythrocyte membranes at physiological pH.

Relationship between the rate of detergent-induced hemolysis and blood type.

The rate of lysis of human erythrocytes induced by the action of 7.0 microM S-Dodecylthiouronium chloride in 0.15 M NaCl was studied at 37 degrees C and pH = 7.2. The Rh-negative cells were hemolyzed approximately twice as fast as the Rh-positive counterparts.

Relationship between the rate of detergent-induced hemolysis and blood type.

The rate of lysis of human erythrocytes induced by the action of 7.0 microM S-Dodecylthiouronium chloride in 0.15 M NaCl was studied at 37 degrees C and pH = 7.2. The Rh-negative cells were hemolyzed approximately twice as fast as the Rh-positive counterparts.

A simple method for the measurement of the hemolytic power of crude snake venoms.

La accion citolitica de sustancias simples y de agentes biologicos complejos puede ser descrita por ecuaciones tipo Hill. Se propone la medicion del poder hemolitico de venenos de serpientes en terminos de la disminucion de la accion litica en una dilucion 1:10. La ventaja de este procedimiento es que el poder citolitico es una funcion de las propriedades bioquimicas del sistema, mas que de la concentracion de los principios activos. Se muestran los poderes hemoliticos de algunos venenos de serpientes sobre eritrocitos humanos O Rh(+)