Evaluation of analgesic effect of Datura fastuosa leaves and seed extracts.

The aqueous extracts of Datura fastuosa leaves and seeds were evaluated for the analgesic effect on acetic acid-induced writhing and hot plate reaction in mice. According to the results, D. fastuosa leaves and seeds extracts at oral doses of 400 and 800 mg/kg are effective as analgesic. The analgesic activity of leaf extract is reduced by naloxone but not that of seed extract.

Analgesic, antipyretic and anti-inflammatory effects of essential oil of Lippia multiflora.

The essential oil of Lippia multiflora Moldenke (Verbenaceae) produced by conventional hydrodistillation was analyzed and studied for its analgesic, antipyretic and anti-inflammatory activities in rats and mice. At the doses used (2, 4 and 8 ml/kg o.s.) the essential oil of L. multiflora showed significant and dose-dependent analgesic effect on acetic acid-induced writhing in mice. Only the dose of 8 ml/kg of essential oil, antagonized hyperexia induced by brewer's yeast. No effect on granuloma formation was observed.

[Psychopharmacological properties of crude extract and essential oil of Lippia multiflora]. / Propriétés psychopharmacologiques de l'extrait brut et de l'huile essentielle de Lippia multiflora.

Psychopharmacological properties of crude extract and essential oil of Lippia multiflora (Lm), a verbenacea of african traditional pharmacopea were investigated in rat using classical methods. The extract of Lm is constituted by an infusion of dried leaves. The essential oil is obtained by hydrodistillation of the dried leaves of Lm with a yield of 0.6%. A dilution of 1% is realised with distilled water and the dose of 2 ml/kg of this solution was chosen for this study. The wistar rats of both sexes weighting between 150 and 250 g are used. Animal's behaviour is observed macroscopically for 12 hours. The spontaneous motor activity is appreciated by method of Martin et al. slightly modified. The number of squares jumped by animals in a rectangular cage is determined in ten minutes. The traction test which measures the time necessary for restoration of posterior paws of rat on metallic bar and the duration of pentobarbital sleeping are used for evaluation of muscle relaxant and sedative effects, respectively. The effects of the two preparations of Lm on apomorphin stereotypies and hypothermia are used to investigate the eventual neuroleptic or antidepressant activity. Analgesic property is evaluated by using acetic acid method. The results are expressed as mean +/- SEM. Data are analysed by using the Dunnett's test. A probability level of 0.05 or less was considered to be stalistically significant. The two preparations of Lm at the doses used are well tolerated by rats. No macroscopic difference is observed in behavioural of control and treated groups. Crude extract and essential oil:--does not modify a spontaneous motor activity: control: 45.00 +/- 5.63; crude extract of Lm: 31.00 +/- 5.63; essential oil of Lm: 28.00 +/- 7.62; diazepam 4 mg/kg: 23.80 +/- 5.27 (P < 0.05);--caused an increase of the time necessary for the restoration of paws on the metallic bar in the traction test: control 1.20 +/- 0.25 sec; crude extract of Lm 5.60 +/- 0.57 sec (P < 0.01), essential oil of Lm. 3.60 +/- 0.57 sec (P < 0.01) diazepam 3.60 +/- 0.57 sec (P < 0.01). The differences between the results obtained with crude extract, essential oil and diazepam are significant;--caused a reduction of abdominal cramps induced by acetic acid, control: 26.80 +/- 0.41; crude extract of Lm: 17.00 +/- 1.45 (P < 0.01); essential oil of Lm: 9.20 +/- 1.91 (P < 0.01) and acetylsalicylic acid (Aspegic*) 25 mg/kg 5.40 +/- 1.25 (P < 0.01). The differences is significant between essential oil and crude extract (P < 0.05) but no significant difference is observed between essential oil and acetylsalicylate of lysin. No activity of the two preparations is observed on apomorphin stereotypia and hypothermia comparatively with haloperidol 4 mg/kg and clomipramin 16 mg/kg respectively. Those results confirm the tranquillizer and analgesic activities of Lm and reveal that the crude extract would be more muscle relaxant and the essential oil more analgesic.

Purification of cytoplasmic precursors of yeast mitochondrial phenylalanyl-tRNA synthetase subunits.

Two polypeptidic precursors of yeast mitochondrial phenylalanyl-tRNA synthetase subunits were purified from the cytoplasm by immunoprecipitation with an insolubilized glutaraldehyde-treated IgG fraction, followed by two chromatographies on Sephadex G-200 and on DEAE-cellulose. Methionine was found as the N-terminal residue in both precursors, which exhibited N-terminal extensions.

Mitochondrial phenylalanyl t-RNA synthetase from yeast: formation of enzyme-substrate complexes shown by heat or SH reagent inactivation.

The binding of substrates to purified mitochondrial phenylalanyl-tRNA synthetase from yeast was examined using the kinetics of heat or p-hydroxymercurybenzoate inactivation. Individually magnesium chloride and each of the substrates protect the enzyme against thermal denaturation and p-hydroxymercurybenzoate inhibition. No enzyme protection is observed with ATP alone against p-hydroxymercurybenzoate inhibition. The combinations of the various substrates induce a synergistic protection effect. Protection constants of 31 microM and 0.3 microM were found for L-Phe and mt tRNAPhe respectively, from heat inactivation studies. The inhibition of the enzyme activity by p-hydroxymercurybenzoate can be reverted by 2-mercaptoethanol or dithiothreitol.

Biosynthesis and transport of yeast mitochondrial phenylalanyl-tRNA synthetase.

The biosynthesis of yeast mitochondrial Phe-tRNA synthetase is studied in vivo. Antibodies against the enzyme are raised in rabbits. They precipitate two proteins in the post-ribosomal supernatant of the yeast cell homogenate. Immunoprecipitate analysis on SDS - gel electrophoresis shows that the two types of mitochondrial enzyme subunits with molecular weights of 57,000 and 72,000, respectively, are cytoplasmically synthesized as larger, individual precursors. Terminal extensions of the precursors prevent enzyme activity. Mitochondrial membranes linked protease(s) play(s) an active role in maturation.

[Isolation of yeast protoplasts using various preparations of the hepato-pancreatic juice of Helix pomatia]. / Obtention de protoplastes de levure à l'aide de différences préparations de suc hépato-pancréatique d'Helix pomatia.

Conversion of large amounts of Saccharomyces cerevisiae cells to protoplasts is studied using various preparations extracted from Helix pomatia hepato-pancreatic juice. The most favourable yield in two hours incubations (88 per cent) is obtained with 20 ml cytohelicase, a chitinase and glucanase enriched extract, per 400 g of yeast cells, harvested at the end of the logarithmic growth phase and preincubated in presence of 2-mercaptoethanol.