This histamine-like effects of Phallusia nigra extract: evidences for direct activity at H1 receptors

The methanol extract (mol. wt lower than 3,000 Da) of the sea squirt Phallusia nigra has stimulatory activity on guinea-pig ileum preparations. This effect was inhibited by cyproheptadine and mepyramine, but not by atropine. Mepyramine antagonized competitively the extract activity with a pA2 of 10.09 ± 1.12, suggesting a direct activity on H1 histamine receptors. The extract was also assayed on guinea-pig right atria, however, only a mild increase in spontaneous contractions was observed compared to histamine, showing that the extract was a rather poor activator of cardiac H2 receptors. Histamine was not detected upon TLC analysis of the extract by comparison with an authentic standard

Hemograma e hemogasometria de eqüinos submetidos à obstrução experimental de jejuno

Foram utilizados oito eqüinos distribuídos em dois grupos, submetidos ou não à obstrução experimental do jejuno mediante a colocação de um balão intraluminal. Os animais do grupo 1 foram submetidos à enterotomia com colocação do balão sem distensão suficiente para provocar isquemia e os do grupo 2 à isquemia por obstrução do jejuno durante quatro horas. Para determinação do hemograma e da hemogasometria foram obtidas amostras de sangue venoso em quatro momentos: uma hora antes do procedimento cirúrgico (M1), ao final da obstrução/isquemia (M2) e uma hora (M3) e 18 horas (M4) após o início da reperfusão/desobstrução. Não houve diferença entre grupos nas contagens de hemácias, leucócitos totais, neutrófilos bastonetes, neutrófilos segmentados, linfócitos e monócitos, bem como no teor de hemoglobina. Houve diferença no volume globular em M2 e na contagem de eosinófilos em M3. Na hemogasometria, em ambos os grupos, registrou-se diminuição dos teores de sódio, potássio, cálcio ionizado e cloro, da pressão parcial de oxigênio e da saturação de oxiemoglobina. Os resultados indicam que o hemograma, isoladamente, não fornece informações conclusivas, enquanto a hemogasometria possibilita determinar, precocemente, o volume de reposição hidroeletrolítica a ser administrado em eqüino com abdômen agudo decorrente de obstrução de jejuno, auxiliando no tratamento e no melhor prognóstico da afecção intestinal.Eight equines were distributed into two different groups. Those groups were submitted or not to an experimental jejunal obstruction. Animals from group 1 were submitted to an enterotomy with placement of an intraluminal balloon, without enough distention to cause ischemia; animals from group 2 were submitted to ischemia by jejunal obstruction during four hours. In order to determine the hemogram and blood gas analysis, blood samples from peripheral vein were obtained at four moments: one hour before the surgical procedure (M1); at the end of obstruction/ischemia (M2); one hour (M3) and 18 hours (M4) after the beginning of reperfusion/deobstruction. There was no difference among the groups related to the counting of erythrocytes, hemoglobin, total white cells, neutrophils (band), neutrophils (segmented), lymphocytes, and monocytes. There was difference in the globular volume in M2 and in the eosinophils counting in M3. In both groups, the blood gas analysis identified diminished of sodium, potassium, ionized calcium, and chloride amounts, and partial pressure of oxygen and oxihemoglobin saturation. The results indicate that the hemogram alone, do not give conclusive information while the blood gas analysis allows an early determination of the volume of hydroelectrolytic replacement to be given to one equine with acute abdomen due to jejunal obstruction, providing additional support to the treatment and a better prognosis to an intestinal affection.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Antimicrobial activity and chemical analysis of <i>Microlicia hatschbachii</i> Wurdack (Melastomataceae) extract

<div><p>Aerial parts of <i>Microlicia hatschbachii</i> were extracted with hexane, and the extract was evaluated for antimicrobial activity by a broth dilution method. After phytochemical procedures: GC-MS identified aliphatic alkanes, carboxylic acids and methyl esters of long-chain fatty acids; and two diterpenoids [labd-8(17)-en-15-oic acid and labd-8(17),13-dien-15-oic acid] were identified by ¹H and ¹³C NMR. The antimicrobial activity of the hexane extract could be attributed to the presence of labdanes. This identification is the first reported occurrence of labdane diterpenes in the Melastomataceae family.</p></div

Anti-parasitic Guanidine and Pyrimidine Alkaloids from the Marine Sponge Monanchora arbuscula

HPLC-UV-ELSD-MS-guided fractionation of the anti-parasitic extract obtained from the marine sponge Monanchora arbuscula, collected off the southeastern coast of Brazil, led to the isolation of a series of guanidine and pyrimidine alkaloids. The pyrimidines monalidine A (1) and arbusculidine A (7), as well as the guanidine alkaloids batzellamide A (8) and hemibatzelladines 9�11, represent new minor constituents that were identified by analysis of spectroscopic data. The total synthesis of monalidine A confirmed its structure. Arbusculidine A (7), related to the ptilocaulin/mirabilin/netamine family of tricyclic guanidine alkaloids, is the first in this family to possess a benzene ring. Batzellamide A (8) and hemibatzelladines 9�11 represent new carbon skeletons that are related to the batzelladines. Evaluation of the anti-parasitic activity of the major known metabolites, batzelladines D (12), F (13), L (14), and nor-L (15), as well as of synthetic monalidine A (1), against Trypanosoma cruzi and Leishmania infantum is also reported, along with a detailed investigation of parasite cell-death pathways promoted by batzelladine L (14) and norbatzelladine L (15)