The efficacy of 2-nitrovinylfuran derivatives against Leishmania in vitro and in vivo.

Despite recent advances in the treatment of some forms of leishmaniasis, the available drugs are still far from ideal due to inefficacy, parasite resistance, toxicity and cost. The wide-spectrum antimicrobial activity of 2-nitrovinylfuran compounds has been described, as has their activity against Trichomonas vaginalis and other protozoa. Thus, the aim of this study was to test the antileishmanial activities of six 2-nitrovinylfurans in vitro and in a murine model of leishmaniasis. Minimum parasiticide concentration (MPC) and 50% inhibitory concentration (IC50) values for these compounds against the promastigotes of Leishmania amazonensis, Leishmania infantum and Leishmania braziliensis were determined, as were the efficacies of two selected compounds in an experimental model of cutaneous leishmaniasis (CL) caused by L. amazonensis in BALB/c mice. All of the compounds were active against the promastigotes of the three Leishmania species tested. IC50 and MPC values were in the ranges of 0.8-4.7 µM and 1.7-32 µM, respectively. The compounds 2-bromo-5-(2-bromo-2-nitrovinyl)-furan (furvina) and 2-bromo-5-(2-methyl-2-nitrovinyl)-furan (UC245) also reduced lesion growth in vivo at a magnitude comparable to or higher than that achieved by amphotericin B treatment. The results demonstrate the potential of this class of compounds as antileishmanial agents and support the clinical testing of Dermofural(r) (a furvina-containing antifungal ointment) for the treatment of CL.

Cytotoxicity and genotoxicity of endodontic irrigants on human cells / Citotoxicidade e genotoxicidade de irrigantes endodônticos em células humanas

OBJECTIVE: Endodontic irrigants solutions with antibacterial activity have been used in treatment of teeth with infected root canals; however, these solutions can irritate periapical tissues. The aim of this study was to evaluate the cytotoxity and genotoxicity of different endodontic irrigants solutions – sodium hypochlorite (1% and 2%), calcium hydroxide (0.2%), and HCT20 in human KB cells. MATERIAL AND METHOD: Cells were incubated with solutions for 2 and 24 hours. The cell viability was assessed after the trypan blue exclusion and the frequency of cell death mechanism (apoptotic or necrotic) was determined by acridine orange/ethidium bromide fluorescent dyeing test. The genotoxicity effects were assessed by the micronucleus assays. RESULTS AND DISCUSSION: The results showed that Ca(OH)2 alone or in combination with tergentol (HCT20), and NaOCl induced cytotoxicity in KB causing death cells by apoptosis. The micronuclei test showed that KB treated with NaOCl (1%) present an increase in the frequency of micronucleus compared to the control group.

OBJETIVO: Soluções irrigadoras com atividade antibacteriana têm sido usadas no tratamento de dentes com canais radiculares infectados; entretanto, essas soluções podem irritar os tecidos periapicais. O objetivo deste estudo foi avaliar a citotoxicidade e genotoxicidade de diferentes soluções irrigadoras – hipoclorito de sódio (1% e 2%), hidróxidode cálcio (0,2 %) e HCT em células humanas KB. MATERIAL E MÉTODO: As células foram incubadas em soluções por 2 e 24 horas. A viabilidade celular foi determinada após exclusão do tripan blue e a frequência de mecanismo de morte celular (apoptótica ou necrótica) foi determinada pelo teste acridine Orange/ethidium bromide fluorescen dyeing. Os efeitos de genotoxicidade foram determinados pelo ensaio de micronúcleos. RESULTADOS E DISCUSSÃO: Os resultados demonstraram que o Ca(OH2), isoladamente ou em combinação com Tergentol™ (HCT20) e NaOCl, induziram citotoxicidade em KB, causando morte celular por apoptose. O teste de micronúcleos demonstrou que KB tratado codm NaOCl (1%) apresentou aumento na frequência de microdnúcleos quando comparadocom o grupo controle.

Anti-staphylococcal and cytotoxic compounds from Hyptis pectinata.

Bioassay-guided fractionation of a CHCl (3) extract prepared from the Mexican medicinal plant Hyptis pectinata led to the isolation of four pyrones, pectinolides A-C ( 1-3) and H ( 4). Activity was tracked using cultured KB cells. Multidrug-resistant strains of Staphylococcus aureus were sensitive to pectinolide H ( 4; KB > 20 microg/mL) in the concentration range of 32-64 microg/mL. The absolute stereochemistry of this new compound was established as 5 S-[(4 S-acetyloxy)-(1 S-hydroxy)-2 Z-octenyl]-2(5 H)-furanone on the basis of spectral, chiroptical data and chemical correlation with pectinolide A ( 1). Mosher ester derivatives were used with pectinolide B ( 2) for confirmation of the 3'-( S) absolute stereochemistry on the side chain chiral center of pectinolides A-C.

Two unusual acetogenins from the roots of Annona salzmanii.

Two new acetogenins, parisin (1) and salzmanolin (2), were isolated from a MeOH extract of the roots of Annona salzmanii. The structures of 1 and 2 were elucidated by spectroscopic methods including LSI-MS/MS, on both the natural compounds and their acetonide derivatives (1a and 2a). Compounds 1 and 2 showed significant activity against the KB and Vero cell lines.

New bioactive coumarins from Kielmeyera albopunctata.

The CH(2)Cl(2) extract of the stem bark of Kielmeyera albopunctata was subjected to a bioassay-linked LC-MS dereplication procedure using the KB cell line to afford the new coumarins 4-(1-methylpropyl)-5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)chromen-2-one (1), 9-(1-methylpropyl)-4-hydroxy-5-(4-hydroxy-3-methylbutyryl)-2-(1-hydroxy-1-methylethyl)-2,3-dihydrofuro[2,3-f]chromen-7-one (2), and 5,7-dihydroxy-8-(4-hydroxy-3-methylbutyryl)-6-(3-methylbut-2-enyl)-4-phenylchromen-2-one (3). Coumarins 1 and 3 showed moderate cytotoxicity, while 2 was inactive at 20 microg/mL. Compound 1was active in vitro against the trypomastigote form of the parasite Trypanosoma cruzi, killing 80% of the parasites after 24 h contact at 4 degrees C when added at 125 microg/mL to infected murine blood.

Cytotoxic anthraquinone derivatives from Picramnia antidesma.

Activity-guided investigation of crude extracts prepared from the root bark of Picramnia antidesma, a medicinal plant long used for the treatment of malaria in tropical areas of the Americas, when tested on KB cells led to the isolation of a new compound, 10-epi-uveoside, from a cytotoxic fraction containing a rich mixture of anthrone glycosides. The antiplasmodial activity proved to be a result of the high levels of cytotoxicity displayed by the anthraquinone derivatives and therefore infusions from this crude drug lack the selectivity index needed to be an effective antimalarial agent.

Novel bioactive clerodane diterpenoids from the leaves and twigs of Casearia sylvestris.

Fractionation of a methanol extract of the leaves and twigs of Casearia sylvestris, as directed by activity against KB cell cytotoxicity, led to the isolation of three novel clerodane diterpenoids, casearvestrins A-C (1-3). The structures of 1-3 were deduced from one- and two-dimensional NMR experiments, including relative stereochemical assignments based on ROESY correlations and COSY coupling constants. All three compounds displayed promising bioactivity, both in cytotoxicity assays against a panel of tumor cell lines and in antifungal assays via the growth inhibition of Aspergillus niger in a disk diffusion assay.

Indole and beta-carboline alkaloids from Geissospermum sericeum.

The indole alkaloid geissoschizoline (1) and two new derivatives, geissoschizoline N(4)-oxide (2) and 1,2-dehydrogeissoschizoline (3), were obtained from the bark of Geissospermum sericeum together with the beta-carboline alkaloid flavopereirine (4). The in vitro antiplasmodial activity of these compounds was evaluated in chloroquine-resistant (K1) and chloroquine-sensitive (T9-96) Plasmodium falciparum. Their cytotoxicity was determined in a human (KB) cell line.

Cytotoxic and antimicrobial screening of selected terpenoids from Asteraceae species.

Twelve pure compounds originally obtained through a systematic chemotaxonomical study with Mexican plants of the Asteraceae, were subjected to a cytotoxic and in vitro antimicrobial screening. Three different cell lines in culture (KB, KB-VI and P388) were used in the cytotoxicity assay, while antimicrobial activity was tested against Gram-positive and Gram-negative bacteria, as well as Candida albicans. Of the twelve terpenoids tested, only taraxasterol showed antimicrobial activity against Staphylococcus aureus. The significant cytotoxic activity exhibited by five sesquiterpene lactones, and the moderate cytotoxicity of an eudesmane, is discussed.

Effects of Mimosa tenuiflora bark extracts on WI38 and KB human cells in culture.

The effects of three extracts from barks of Mimosa tenuiflora (Willd) Poir, Leguminosae, on the growth rate of two human cell lines were investigated. The plant material was extracted with petroleum ether, ethylacetate and butanol, and the obtained products were evaluated in their ability to modify growth of WI38 normal embryonic fibroblasts, and KB cells from a nasopharyngeal carcinoma in tissue culture conditions. The ethylacetate and butanol extracts produced growth rate inhibition with a different pattern depending on the cell line studied; in contrast, the petroleum ether extract markedly increased proliferation of the same cells in vitro.

Evaluation of the purified fraction of Wilbrandia (c.f.) verticillata for antitumour activity.

Cucurbitacins are known to produce cytotoxic and anticancer activities. Two novel norcucurbitacin glucosides (Wv1 and Wv2) have recently been isolated from a purified fraction obtained from the rhizome of Wilbrandia verticillata. The present study evaluates the cytotoxic and antitumour activities of these norcucurbitacins. We have found a regular cytotoxicity in KB cells (Cy50 = 12 micrograms/ml) as well as a significant inhibition in the Walker 256 carcinosarcoma growth (approximately 75%).

Preparación y toxicidad in vitro de un conjugado entre el factor de crecimiento epidérmico y la adriamicina / Preparation and in vitro toxicity between a conjugate of Epidermal Growth Factor and adriamycine

La principal dificultad de la terapia del cáncer en la actualidad es la utilización de agentes tóxicos cuya actividad antitumoral no es específica. Por tal razón se ha pensado en la unión de agentes tóxicos como toxinas o drogas a factores de crecimiento, hormonas y anticuerpos monoclonales para lograr toxicidad específica sobre las células cancerosas. En este trabajo se presenta la construcción de un conjugado mediante una unión covalente entre el factor de crecimiento epidérmico (EGF) y la adriamicina (ADM). El conjugado retiene la habilidad del EGF de reconocer sus receptores en células de carcinoma mamario, sin perder afinidad y la ADM retiene su toxicidad. La toxicidad del conjugado fue revertida por adición de un exceso de EGF libre y fue dependiente de la cantidad de receptores de EGF presentes en la superficie celular

Estudio farmacológico preclínico de un carbamato con interés oncológico / Preclinical pharmacologic trial of a carbamate of oncologoc interest

El 43GV040 es un producto sintético análogo al dietildetiocarbamato de sodio con perspectiva de uso en la clínica oncológica. Es por ello que se estudiaron sus efectos sobre la línea celular KB así como en algunos modelos in vivo e in vitro en 2 especies de animales (ratas y curiel), sobre el aparato cardiovascular, respiratorio y tracto gastrointestinal. No se observaron efectos directos en ileon y tráquea. A altas concentraciones se encontró un ligero aumento del inotropismo. En el animal intacto, la dosis mayor ensayada produce una ligera disminución de la frecuencia cardíaca y la presión arterial que se recupera. Estos estudios nos señalan la posibilidad de su introducción en el arsenal terapéutico