Study of antinociceptive effect of isolated fractions from Petiveria alliacea L. (tipi) in mice.

The acetate (FA), hexanic (FH), hydroalcoholic (FHA) and precipitated hydroalcoholic (FHAppt) fractions from the root of Petiveria alliacea L. were evaluated for antinociceptive effect using the abdominal constriction induced by acetic acid, hot-plate, formalin tests. The open field and rota rod tests were used to evaluate psychomotor function and myorelaxant activity. The fractions were administered intraperitoneally in mice at doses of 100 and 200 mg/kg. Inhibitions of abdominal constrictions were observed with all doses of the fractions, as compared to control. FH and FHAppt, at both doses, reduced the nociception produced by formalin in the 1st (0-5 min) and 2nd (20-25 min) phases, however FHA (100, 200 mg/kg) and FA 200 mg/kg presented significant inhibition on the 1st and 2nd phases, respectively, of this test. A reduction of the locomotor activity was observed in the open field test with all the fractions. These fractions failed to affect the motor coordination in the rota rod test. Results showed that the different fractions of Petiveria alliacea L. have different antinociceptive potentials as demonstrated in the experimental models of nociception in mice, supporting folk medicine use of this plant.

Effect of anxiolytic, antidepressant, and antipsychotic drugs on cocaine-induced seizures and mortality.

Cocaine abuse may lead to overdose (related to seizures and/or status epilepticus) and to diseases (schizophrenia, depression, and anxiety). This work was designed to study the influence of drugs used to treat psychopathologies associated with cocaine abuse on cocaine-induced seizures and mortality in mice. Fluoxetine (10, 20, 40 mg/kg), imipramine and buspirone (5, 10 mg/kg), pimozide (10, 20 mg/kg), lithium (56.3, 112.5 mg/kg), and naltrexone (25, 50 mg/kg) were administered intraperitoneally, 30 minutes prior to cocaine (90 mg/kg, ip). The animals were observed (30 minutes) to determine: latency to first seizure, number of seizures, and number of deaths after cocaine overdose. Fluoxetine, imipramine, buspirone, and pimozide had pro- or anticonvulsant effects depending on the dose. Smaller doses protected and higher doses increased cocaine-induced seizures and/or mortality. Naltrexone worsened and lithium protected against seizures. Thus, these results suggest that caution should be taken in the selection of pharmacotherapy and dosages for patients with cocaine addiction because of the possibility of potentiating cocaine toxicity.

Insecticidal activity and chemical composition of volatile oils from Hyptis martiusii Benth.

The essential oils from leaves and inflorescences of Hyptis martiusii Benth were analyzed by GC-MS. Twenty-six compounds representing 93.2% of the essential oil of leaves were characterized; Delta-3-carene (22.5%), 1,8-cineole (24.27%), beta-caryophyllene (6.15%), and bicyclogermacrene (6.32%) were found as the major components. In the essential oil of inflorescences 27 compounds representing 87.7% of the oil were identified. The major components were Delta-3-carene (13.5%), alpha-pinene (5.78%), beta-caryophyllene (6.59%), viridiflorene (8.25%), and germacrene B (5.21%). The essential oil of leaves and 1,8-cineole showed pronounced insecticidal effect against Aedes aegypti larvae and Bemisia argentifolii, the vectors of dengue fever and white fly fruit plague, respectively.