Staining tumor cells with biotinylated ACL-I, a lectin isolated from the marine sponge, Axinella corrugata.

Axinella corrugata lectin 1 (ACL-1) was purified from aqueous extracts of the marine sponge, Axinella corrugata. ACL-1 strongly agglutinates native rabbit erythrocytes. The hemagglutination is inhibited by N-acetyl derivatives, particularly N, N', N"-triacetylchitotriose, N-acetyl-D-glucosamine, N-acetyl-D-mannosamine and N-acetyl-D-galactosamine. We investigated the capacity of biotinylated ACL-1 to stain several transformed cell lines including breast (T-47D, MCF7), colon (HT-29), lung (H460), ovary (OVCAR-3) and bladder (T24). ACL-I may bind to both monosaccharides and oligosaccharides of tumor cells, N-acetyl-D-galactosamine, and N-acetyl-D- glucosamine glycan types. The lectins are useful, not only as markers and diagnostic parameters, but also for tissue mapping in suspicious neoplasms. In addition, they provide a better understanding of neoplasms at the cytological and molecular levels. Furthermore, the use of potential metastatic markers such as lectins is crucial for developing successful tools for therapy against cancer. We observed that biotinylated ACL-I stains tumor cells and may hold potential as a probe for identifying transformed cells and for studying glycan structures synthesized by such cells.

Screening for cytotoxic activity of extracts and isolated alkaloids from bulbs of Hippeastrum vittatum.

The dichloromethane and n-butanol extracts obtained from fresh bulbs of Hippeastrum vittatum (Amaryllidaceae), collected in Southern Brazil, were evaluated for their cytotoxic activity in vitro against five human cell lines (HT29 colon adenocarcinoma, H460 non-small cell lung carcinoma, RXF393 renal cell carcinoma, MCF7 breast cancer, and OVCAR3 epithelial ovarian cancer), using the sulphorhodamine B assay. Both extracts showed potential antiproliferative activity. From CH(2)Cl(2) fraction, three alkaloids were isolated: lycorine, vittatine and montanine. The two last compounds were submitted to the antiproliferative assay and the highest level of cytotoxicity was found for the alkaloid montanine.

Detecção de atividade lectínica e atividade hemolítica em extratos de esponjas (Porifera) nativas da costa atlântica do Brasil / Detection of lectinic activity and hemolytic activity in extracts of native sponges (Porifera) of atlantic coast of Brazil

Extratos aquosos de vinte espécies de esponjas da costa Atlântica brasileira foram testados para verificação da presença de atividade lectínica e atividade hemolítica. Hemaglutinação para eritrócitos humanos e de distintos animais foi evidenciada em 12 dos 20 extratos testados. Os extratos das espécies Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada e Guitarra sp1. foram os que apresentaram maior atividade hemaglutinante. Dos doze extratos com atividade hemaglutinante dez tiveram a atividade inibida por um ou mais açúcares e/ou glicoproteínas. A lectina do extrato de Chondrilla nucula foi resistente à desnaturação térmica quando aquecida a 100 ºC por 60 minutos. Atividade hemolítica foi encontrada apenas nos extratos de Petromica citrina e Acervochalina sp. As espécies que apresentaram maior potencial para futuros estudos de suas lectinas foram Axinella corrugata, Chondrilla nucula e Chondrosia collectrix, em vista da maior atividade hemaglutinante apresentada por seus extratos, aliada à maior atividade específica.

Aqueous extracts of twenty species of sea sponges of the Brazilian Atlantic coast were tested with the aim of searching the presence of lectinic and hemolytic activity. Hemagglutinating activity for human erythrocytes and for distinct animals were found in 12 of the 20 tested extracts. The extracts of Axinella corrugata, Chondrilla nucula, Chondrosia collectrix, Cinachyrella alloclada and Guitarra sp1. were the ones that presented highest hemagglutinating activity. Ten of the 12 hemagglutinating extracts had the activity inhibited by one or more sugars or glycoproteins. The lectin from Chondrilla nucula was resistant to thermal denaturation when heated up to 100 ºC for 60 minutes. Hemolytic activity was only found in the extracts from Petromica citrina and Acervochalina sp. The species of sea sponges that showed major potential for futures studies of their lectins were Axinella corrugata, Chondrilla nucula and Chondrosia collectrix, due to the highest hemagglutinating activity presented by their extracts, allied to the highest specific activity.

Avaliação da atividade antiviral e determinação do perfil cromatográfico de Hippeastrum glaucescens (Martius) Herbert (Amaryllidaceae) / Evaluation of antiviral activity and determination of the chromatographic profile of Hippeastrum glaucescens (Martius) Herbert (Amaryllidaceae)

Plantas da família Amaryllidaceae são caracterizadas pela presença de alcalóides isoquinolínicos. Desde o primeiro estudo envolvendo alcalóides desta família em 1877, um grande número destas plantas tem sido analisado quimicamente. Estes compostos apresentam uma ampla variedade de atividades biológicas, tais como: antiviral, citotóxica, antitumoral e analgésica. Neste trabalho, foram avaliados o perfil cromatográfico e a potencial atividade antiviral das frações diclorometano A e B, isoladas dos diferentes órgãos vegetais (bulbos, raízes, folhas e flores) de Hippeastrum glaucescens (Martius) Herbert, assim como dos alcalóides licorina, tazetina e pretazetina, previamente isolados desta planta. A extração dos alcalóides de H. glaucescens foi realizada por métodos clássicos, a partir de bulbos, raízes, folhas e flores fornecendo rendimentos totais em alcalóides de 0,53 por cento; 0,81 por cento; 0,29 por cento e 0,12 por cento, respectivamente. Empregando-se cromatografia em camada delgada, verificou-se que os bulbos e as raízes apresentam perfis cromatográficos semelhantes e que os alcalóides licorina, tazetina e pretazetina estão presentes em todas as partes testadas do vegetal. As frações diclorometano A e B, de cada órgão vegetal, e os alcalóides isolados (licorina, tazetina e pretazetina) não inibiram a replicação do herpesvírus simples humano tipo 1 (HSV-1) cepa KOS, quando avaliados através do método de inibição do efeito citopático viral.

Plants of Amaryllidaceae are characterized by isoquinoline alkaloids. Since the first study with Amaryllidaceae alkaloids in 1877, a large number of these plants have been chemically investigated. These compounds have shown a wide range of biological activities such as: antiviral, cytotoxic, antitumoral and analgesic. In this work, the dichloromethane (CH2Cl2) extracts obtained from different parts of the Hippeastrum glaucescens (Martius) Herbert (bulbs, roots, leaves and flowers) and the isolated alkaloids lycorine, tazettine and pretazettine were analyzed by a chromatographic method (TLC) and tested for antiviral activity. The extraction of alkaloids from bulbs, roots, leaves and flowers of H. glaucescens was performed by classic methods and yields 0.53 percent, 0.81 percent, 0.29 percent and 0.12 percent, respectively. Through TLC, bulbs and roots revealed similar chromatographic profiles and lycorine, tazettine and pretazettine were found in all the parts analyzed. The CH2Cl2-A and CH2Cl2-B extracts from each part of the plant and the isolated alkaloids (lycorine, tazettine and pretazettine) did not inhibit the HSV-1 strain KOS replication, when evaluated through the inhibition of cytophatic viral effect.

Childhood lead exposure in Oporto, Portugal.

The study aims were to evaluate childhood lead poisoning in Oporto, Portugal, characterize childhood exposures, find solutions to reduce them, and call the community's attention to the need for preventive measures. Children aged 1-5 years living in Oporto Historical Center, were the target population. Data were gathered by means of a questionnaire and blood lead analyses for 240 children who attended four randomly selected kindergartens. The geometric mean blood lead concentration was 13.9 microg/dl and lead poisoning prevalence (blood lead levels > 10 microg/dL) was 85.8%. Important sources of lead poisoning were father's occupation, mother's smoking habits, and poor hygiene and pica associated with contaminated soils and lead paint. Families were unaware of the problem of lead exposure and its harmful effects. The data indicate that high levels of childhood lead exposures still prevail in Oporto City, an important public health finding that deserves authorities' attention.

Genotoxic effects of structurally related beta-carboline alkaloids.

beta-Carboline alkaloids, found in medicinal plants, tobacco smoke and well-cooked foods, have shown a variety of actions in biological systems related to their interaction with DNA. Therefore, these alkaloids can be considered potentially mutagenic. In this work, the genotoxic, mutagenic, and cytotoxic activities of three aromatic beta-carboline alkaloids (harman, harmine, and harmol) and two dihydro-beta-carboline alkaloids (harmaline and harmalol) were evaluated by means of the Salmonella/microsome assay (Salmonella typhimurium TA98, TA97, TA100, and TA102) and SOS chromotest (Escherichia coli PQ37) with and without metabolic activation. Moreover, harman and harmine were analyzed by the micronucleus assay in vivo. It was shown that genotoxicity was inhibited by the addition of S9 mix for aromatic beta-carbolines harman and harmol in TA97. However, harmine showed signs of mutagenicity only in the presence of S9 mix in TA98 and TA97 frameshift strains. In the SOS chromotest, only harman induced SOS functions in the absence of S9 mix. Dihydro-beta-carbolines were not genotoxic in any of the microorganisms used. The negative responses obtained in the micronucleus assay indicated that harman and harmine were not able to induce chromosomal mutations.

Genotoxic effect of alkaloids

Because of the increase use of alkaloids in general medical practice in recent years, it is of interest to determine genotoxic, mutagenic and recombinogenic response to different groups of alkaloids in prokaryotic and eucaryotic organisms. Reserpine, boldine and chelerythrine did not show genotoxicity response in the SOS-Chromotest whereas skimmianine showed genotixicity in the presence of a metabolic activation mixture. Voacristine isolated fromthe leaves of Ervatamia coronaria shows in vivo cytostatic and mutagenic effects in Saccharomyces cerevisiae hapioids cells. The Rauwolfia alkaloid (reserpine) was not able to induce reverse mutation and recombinational mitotic events (crossing-over and gene conversion) in yeast diploid strain XS2316.

Genotoxic, mutagenic and recombinogenic effects of rauwolfia alkaloids.

In the last decade, the possible correlation between the use of reserpine and rauwolfia drugs as antihypertensive agents and breast cancer incidence has been investigated. For the purpose of evaluating the mutagenic and genotoxic effects of these drugs, reserpine and ajmalicine were studied using the SOS Chromotest and the induction of gene conversion, crossing-over and reverse mutation in the yeast diploid strain XS2316. The results indicated a lack of genotoxic, mutagenic and recombinogenic effects.

The SOS-function-inducing activity of the alkaloids skimmianine and chelerythrine in Escherichia coli

Os alcalóides furoquinoleínico esquimianina e benzofenantridínico celeritrina, extraídos de uma espécie da família Rutaceae foram testados quanto ao aspecto tóxico-genético através do cromoteste-SOS. Nos testes realizados na ausência de metabolizaçäo, ambos alcalóides näo mostraram atividade genotóxica, sendo que a esquimianina apresentou um efeito citotóxico nas concentraçöes mais elevadas. Na presença de mistura de ativaçäo metabólica, a esquimianina mostrou-se genotóxica sendo que este efeito foi mais acentuado quando se empregou fraçäo microssomal induzida com Aroclor 1254 em relaçäo aquela induzida com 3-metilcolantreno