Antimitotic action of extracts of Petiveria alliacea on sea urchin egg development

The hydroethanol extract of the roots of Petiveria alliacea L. (Phytolaccaceae) has been investigated previously as an antitumor agent against mouse Ehrlich ascites. The extract and its methanol, butanol and ether fractions exhibited an antimitotic effect on sea urchin egg development. The aqueous fraction did not produce inhibition of cell cleavage. At the first cleavage the inhibition, at the lowest concentration (10 micrograms/ml), produced by the ether fraction was 42 per cent , whereas the inhibition produced by the total extract and by the other fractions was only 5 to 10 per cent showing that the ether fraction was the most active. Even at higher concentrations the butanol and methanol fractions inhibit the cleavage about 30 per cent . At the first cleavage, the ED50 of the hydroethanol extract and of the ether fraction were 45.02 and 12.40 micrograms/ml, respectively. Furthermore, in the second cleavage, the hydroethanol extract was about twice as potent as the methanol or butanol fractions (ED50 of 22.40, 44.80 and 54.10 micrograms/ml, respectively)

Antihistamine activity of Bryophyllum, calycinum

The juice obtained by pressing the leaves of Bryphyllum calycinum (Crassulaceae) exhibited histamine-blocking activity. The juice contains flavonoid compounds, carbohydrates and mineral salts. A flavonoid fraction (fraction B) obtained by partioning the juice between n-butanol and water contained the substance responsible for the antihistamine activity. When assayed on the isolated guinea pig ileum, 50 mg/ml juice and 0.15 mg/ml fraction B produced parallel and concentration-dependent rightward displacement of the concentration-response curve to histamine (EC50 (FL): 1.30 (0.26-5.28) x 10-7 M, 15.80 (5.90 -23.30) x 10-7 M, 12.50 (7.62 -14.90) x 10-7 M, in the absence and presence of 50 mg/ml juice and 12 mg/ml fraction B, respectively) apparently in a competitive manner. The antagonism was specific for histamine, i. e., did not modify the response to acetylcholine, KCl and BaCl2 and was reversible upon washing. Vascular permeability responses of rats to intracutaneous 1.0, 5.0 or 10.0 ug histamine were decreased by about 20-25% in animals pretreated with 4 ml/kg of juice or with 12 mg/kg fraction B. The juice (4 ml/kg) protected guinea pigs from death by asphyxia induced 5 mg histamine and the protection lasted at least at 1 h. However, since the juice was ineffective in protecting the gastric mucosa from histamine-induced ulceration, we conclude that the antihistaminic effect of the juice and fraction B was produced by blockade of H1 and not H2 receptors

Antimicrobial activity pf kaurenoic acid derivatives substituted on carbon-15

The antibacterial and antifungic activities of two kaurenic acids, ent kaurenoic acid and cinnamoylgrandifloric acid isolated from a hexane extract of aerial parts of Mikania laevigata, were investigated and compared with the activities of other kaurenic acid-derivatives substituted on carbon-15. Only acetylgrandifloric acid (en-kaur-16-en-15 alfa-acetyloxy-19-oic) and its epimer xylopic acid (ent-kaur-16-4n-15 beta-acetyloxy-19-oic) displayed significant antibacterial activity at concentrations >=250 microng/ml., the 15 alfa epimer being the most active

In vitro study of the antibiotic activity of diterpenes

The antibiotic activity of 16 diterpenes and of 2 phenanthrehene derivatives of diterpene origin, isolated from Brazilian plants was investigated against bacteria, yeasts, dermatophytes and aflatoxin-producing fung. Eight of the compounds were completely inactive. None showed inhibitory activity against the Gram-negative bacteria assaywed or aginst the Aspergillus species. The phenanthrene derivatives, chemically very simular to phytoalexins isolated from orchids, were especially active

Aspectos basicos das linhagens celulares mais utilizadas. / Culture characteristics of some cell lines

Sao apresentados alguns aspectos basicos das linhagens celulares mais utilizadas nos nossos laboratorios de pesquisas. Quatro linhagens de origem humana e tres linhagens de origem animal sao descritas quanto a sua obtencao, meio de congelamento, meio de cultura, caracteristicas de crescimento e morfologia