Green does not always mean go: A sulfated galactan from Codium isthmocladum green seaweed reduces melanoma metastasis through direct regulation of malignancy features.

Melanoma is the most lethal form of skin cancer, with a worldwide increase in incidence. Despite the increased overall survival of metastatic melanoma patients given recent advances in targeted and immunotherapy, it still has a poor prognosis and available treatment options carry diverse severe side effects. Polysaccharides from seaweed have been shown to exert antitumor activities. Here we show in vitro and in vivo antitumor activities of a sulfated homogalactan (named 3G4S) from Codium isthmocladum seaweed in the B16-F10 murine melanoma cell line. 3G4S did not induce cytotoxicity or proliferation changes; however, it was able to reduce solid tumor growth and metastasis, while not inducing side effects in mice. B16-F10 cells traits related to the metastatic cascade were also impaired by 3G4S, reducing cell invasion, colony-forming capacity and membrane glycoconjugates. Therefore, 3G4S shows promising antitumor activities without the commonly associated drawbacks of cancer treatments and can be further explored.

Non-Cytotoxic Sulfated Heterorhamnan from Gayralia brasiliensis Green Seaweed Reduces Driver Features of Melanoma Metastatic Progression.

Melanoma is a form of skin cancer with high mortality owing to its fast progression and metastatic capacity. The treatments available nowadays are only palliative in advanced stages of the disease. Thus, alternative therapies for cancer treatment are in demand, and molecules from natural sources, such as polysaccharides, could represent new possible therapeutic approaches. Polysaccharides of freshwater and marine algae with biological activities, such as antitumor properties, are greatly reported in the scientific literature. In the present study, a sulfated heterorhamnan obtained from the green seaweed Gayralia brasiliensis (Gb1 fraction) was chemically characterized and its biological activities in the B16-F10 murine melanoma cell line were evaluated. The Gb1 polysaccharidic fraction tested concentrations presented low or absence of cytotoxicity to B16-F10 cells and neither cell proliferation nor cell cycle were altered. Interestingly, Gb1 treatment decreased B16-F10 cells migration and invasion capabilities and CD44 labeling, showing to be a promising compound for further in vitro and in vivo antitumor studies.

Safe therapeutics of murine melanoma model using a novel antineoplasic, the partially methylated mannogalactan from Pleurotus eryngii.

A heteropolysaccharide was isolated by cold aqueous extraction from edible mushroom Pleurotus eryngii ("King Oyster") basidiocarps and its biological properties were evaluated. Structural assignments were carried out using mono- and bidimensional NMR spectroscopy, monosaccharide composition, and methylation analyses. A mannogalactan having a main chain of (1→6)-linked α-d-galactopyranosyl and 3-O-methyl-α-d-galactopyranosyl residues, both partially substituted at OH-2 by ß-d-Manp (MG-Pe) single-unit was found. Biological effects of mannogalactan from P. eryngii (MG-Pe) were tested against murine melanoma cells. MG-Pe was non-cytotoxic, but reduced in vitro melanoma cells invasion. Also, 50mg/kg MG-Pe administration to melanoma-bearing C57BL/6 mice up to 10days decreased in 60% the tumor volume compared to control. Additionally, no changes were observed when biochemical profile, complete blood cells count (CBC), organs, and body weight were analyzed. Mg-Pe was shown to be a promising anti-melanoma molecule capable of switching melanoma cells to a non-invasive phenotype with no toxicity to melanoma-bearing mice.

Microscopic diagnosis of the leaf and stem of Piper solmsianum C.DC.

Piper solmsianum C.DC., which is popularly known as pariparoba, is a shrub that measures 1-3 m in height and it inhabits areas with wet tropical soils. The objective of this study was to analyze the leaf and stem anatomy using light microscopy, scanning electron micrographs, and energy-dispersive X-ray spectroscopy in order to provide information for species identification. The anatomical profile showed the following main microscopic markers: hypostomatic leaf; hypodermis layer on both sides; pearl glands; biconvex midrib shape; five collateral vascular bundles in open arc with the central bundle larger than the others; circular stem shape; collateral vascular bundles arranged in two rings; sinuous sclerenchymatic sheath in the pith; secretory idioblasts; and starch grains in the mesophyll, in the ground parenchyma of the midrib, petiole, and in the stem; and six morphotypes of calcium oxalate crystals (styloids, cuneiform, tabular crystal rosettes, cuneiform crystal rosettes, elongated square dipyramids, as well as very elongated square dipyramids).

Female Sex Hormones Influence the Febrile Response Induced by Lipopolysaccharide, Cytokines and Prostaglandins but not by Interleukin-1ß in Rats.

There are differences in the immune response, and particularly fever, between males and females. In the present study, we investigated how the febrile responses induced by lipopolysaccharide (LPS) and different endogenous pyrogens were affected by female gonadal hormones. The febrile response to i.p. injection of LPS (50 µg/kg) was 40% lower in female rats compared to male or ovariectomised (OVX) female rats. Accordingly, oestrogen replacement in OVX animals reduced LPS-induced fever. Treatment with the prostaglandin synthesis inhibitor indomethacin (2 mg/kg, i.p. 30 min before) reduced the febrile response induced by LPS in both OVX (88%) and sham-operated (71%) rats. In line with the enhanced fever in OVX rats, there was increased expression of cyclooxygenase-2 (COX-2) in the hypothalamus and elevated levels of prostaglandin E2 (PGE2 ). In addition, OVX rats were hyper-responsive to PGE2 injected i.c.v. By contrast to the enhanced fever in response to LPS and PGE2 , the febrile response induced by i.c.v. injection of interleukin (IL)-1ß was unaffected by ovariectomy, whereas the responses induced by tumour necrosis factor (TNF)-α and macrophage inflammatory protein (MIP)-1α were completely abrogated. These results suggest that the mediators involved in the febrile response in females are similar to males, although the reduction of female hormones may decrease the responsiveness of some mediators such as TNF-α and MIP-1α. Compensatory mechanisms may be activated in females after ovariectomy such as an augmented synthesis of COX-2 and PGE2 .

Análise farmacobotânica de folha e caule de Tanacetum vulgare (L. ) / Pharmacobotanical analysis of leaf and stem of Tanacetum vulgare (L. )

RESUMO Tanacetum vulgare L., conhecida popularmente como catinga-de-mulata, é utilizada na medicina tradicional como vermífugo, digestivo e emenagogo. Objetivou-se analisar a morfoanatomia de folhas e caules dessa espécie medicinal com vistas ao controle da qualidade. Foram utilizadas técnicas usuais de microscopia de luz e eletrônica de varredura. As folhas são compostas, pinatissectas e anfiestomáticas. Tricomas tectores flageliformes simples e glandulares capitados são observados. A nervura central tem formato biconvexo, o pecíolo é côncavo-convexo, a ráque é plano-convexa e o caule é arredondado. Feixes vasculares colaterais, calotas de fibras perivasculares e colênquima lamelar estão presentes na folha e no caule. Os caracteres morfoanatômicos evidenciados contribuem na identificação do táxon e fornecem subsídios farmacobotânicos para o controle da qualidade de drogas vegetais e fitoterápicos.

ABSTRACT Tanacetum vulgare L., popularly known as tansy, is used in traditional medicine as a vermifuge, digestive and emmenagogue. This study aimed to analyze the morphoanatomical leaves and stems of this medicinal plant in order to control the quality. Usual techniques of light and scanning electron microscopy were used. The leaves are composed, pinatissect and amphistomatic. Simple and flagelliform non- glandular trichomes and capitate glandular trichomes are observed. The midrib has biconvex shape, the petiole is concavo-convex, the rachis is plano-convex, and the stem is rounded. Collateral vascular bundles, perivascular fiber caps and laminar collenchyma are encountered in the leaves and stems. Evidenced the morphological and anatomical features contribute to the identification of the taxon and provide pharmacobotanical data for the quality control of herbal drugs.

Baccharis rufescens Spreng. var. tenuifolia (DC. ) Baker: contribuição ao estudo farmacognóstico / Baccharis rufescens Spreng. var. tenuifolia (DC. ) Baker: contribution to the pharmacognostic study

Baccharis rufescens Spreng. var. tenuifolia (DC.) Baker pertence à família Asteraceae e é usada na medicina tradicional como estomáquico e hepatoprotetor. Um estudo fitoquímico mostrou a presença de flavonoides e triterpenos, sendo que os extratos clorofórmico e metanólico de folhas apresentaram-se ativos no bioensaio de toxicidade sobre Artemia salina Leach. Além disso, extratos clorofórmicos evidenciaram a presença de peróxidos, sugerindo sua aplicação no tratamento da malária (Schenkel at al., 2002; Montanher et al., 2002; Moreira et al., 2003). Considerando a importância farmacológica de B. rufescens var. tenuifolia, o presente trabalho objetivou o estudo morfoanatômico e histoquímico do caule e da folha dessa espécie, a fim de fornecer subsídios farmacognósticos para o controle de qualidade. O material botânico foi submetido às técnicas usuais empregadas na microscopia de luz e microscopia eletrônica de varredura. Folha anfiestomática, presença de estômatos anomocíticos, tricomas glandulares capitados bisseriados, tricomas tectores flageliformes simples unisseriados, dutos secretores associados ao floema, calota de fibras perivasculares e cristais de oxalato de cálcio do tipo estiloide e prismático na região medular do caule foram as principais características observadas que auxiliam na identificação do táxon.

Baccharis rufescens Spreng. var. tenuifolia (DC.) Baker belongs to the Asteraceae family. It is used for liver and stomach problems in traditional medicine. Previous phytochemical data reported flavonoid and triterpene contents. Chloroform and methanol extracts of the leaves showed activity in the bioassay of brine shrimp. Chloroform extracts showed the presence of peroxides that can be used to treat malaria (Schenkel et al., 2002; Montanher et al., 2002; Moreira et al., 2003). Considering the pharmacological importance of B. rufescens var. tenuifolia, the purpose of this paper was to perform the anatomical analysis of aerial vegetative parts of Baccharis rufescens var. tenuifolia in order to provide pharmacognostic data for quality control. The plant material was studied by the usual methods of light and scanning electron microscopy. Amphistomatic leaves, anomocytic stomata, biseriate capitate glandular trichomes, uniseriate simple flagelliform non-glandular trichomes, secretory ducts associated to the phloem, perivascular fiber cap, calcium oxalate as prismatic and styloid crystals in the pith of the stem were reported as the mainly anatomical data for B. rufescens var. tenuifolia.Ouvir Ler foneticamente.

SELEÇÃO DE ISOLADOS DE BACILLUS THURINGIENSIS BERLINER PARA TETRANYCHUS URTICAE KOCH

ABSTRACT The two-spotted spider mite is the most important pest to Brazilian crops. The incorrect use of chemical control leads to serious consequences, such as the presence of residues in fruits and the emergence of resistant populations. There is a need for alternative methods for managing the mite, such as biological control, which has been used as a tool in the management of various pests of agricultural importance in the world. Bioassays were carried out to analyze 120 strains of Bacillus thuringiensis Berliner in regard to their pathogenicity to Tetranychus urticae Koch. Suspensions were prepared of the different strains, containing 3 × 108 spores/mL of distilled water, and applied on Jack-bean (Canavalia ensiformes DC) leaf disks. Each strain constituted a treatment, with 8 repetitions, each containing 10 adult Tetranychus urticae females. The tests in laboratory conditions showed that mortality was significantly, ranging from 6.7% (strains LMJ7A) to 54.9% (strains 1077B and 886f).

RESUMO O ácaro rajado é uma das pragas mais importantes em culturas no Brasil. O uso do controle químico de forma descontrolada leva a sérias consequências, como a presença de resíduos em frutos e surgimento de populações resistentes. Faz-se necessário o uso de alternativas de manejo do ácaro, como o controle biológico, que vem sendo utilizado como ferramenta no manejo de di versas pragas de importância agrícola no mundo. Para a realização dos bioensaios, foram avaliadas 120 cepas de Bacillus thuringiensis Berliner quanto à patogenicidade para Tetranychus urticae Koch. Foram preparadas suspensões das diferentes cepas contendo 3 × 108 esporos viáveis/mL de água destilada, aplicadas em discos de folhas de feijão de porco (Canavalia ensiformes DC). Cada cepa constituiu-se em um tratamento, com 8 repetições, cada uma contendo 10 fêmeas adultas do ácaro. Os testes em condições de laboratório mostraram que a mortalidade foi significativa, variando de 6,7% (cepa LMJ7A) a 54,9% (cepas 1077B e 886F).

POTENCIAL DO USO DE FUNGOS ENTOMOPATOGÊNICOS NO CONTROLE DE TETRANYCHUS URTICAE KOCH (ACARI: TETRANYCHIDAE) EM MAMOEIRO: EFEITO DE CULTIVARES SOBRE A PATOGENICIDADE

ABSTRACT Papaya Carica papaya (L.) is affected by various phytosanitary problems, and the mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) is a key pest. The use of entomopathogenic fungi is an alternative to the use of pesticides, lowering the risk of resistance while reducing the the load of toxic substances in the environment. This study was conducted to determine whether the different cultivars of papaya interfere with the pathogenicity of Beauveria bassiana. Metarhizium anisopliae and Lecanicillium longisporum. The bioas say was carried out using adult T. urticae females maintained for at least one generation on leaves of four papaya cultivars (Calimosa, Golden, Sunrise, Tainung 01) or on jack bean leaves (control). Ten females were transferred to Petri dishes with leaf disks of the origin cultivars and jack beans. The mites were then sprayed with a 5 x 107 conidia.mL-1 suspension in a Potter Tower. Conidial suspensions were prepared from the commercial formulations Boveril® B. bassiana, Metarril® M. anisopliae, and Vertirril® L. longisporum. The corrected and confirmed mortalities were evaluated. Differences were observed (Tukey, P 0.05) among the papaya cultivars in terms of the T. urticae pathogenic response. On the 3rd day after spraying (DAS), a better efficiency in mortality percentage was observed for the Vertirril® formulation applied to the Calimosa, Golden and Sunrise cultivars, and for Metarril® applied to the Tainung 01cultivar. On the 5th DAS, the efficiencies among the cultivars were very close.

RESUMO O mamoeiro Carica papaya (L.) é acometido por diversos problemas fitossanitários, sendo o ácaro Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) uma das pragas-chave. A utilização de fungos entomopatogênicos é uma alternativa ao controle por agrotóxicos, reduzindo os riscos de resistência e também a carga de substâncias tóxicas ao ambiente. Este trabalho foi realizado para verificar se as diferentes cultivares de mamoeiro interferem na patogenicidade de Beauveria bassiana, Metarhizium anisopliae e Lecanicillium longisporum. No bioensaio foram utilizadas fêmeas adultas de T. urticae mantidas por pelo menos uma geração sobre folhas de quatro cultivares de mamão, Calimosa, Golden, Sunrise e Tainung 01, e também de uma testemunha de feijão-de-porco. Foram então transferidas dez fêmeas para placas de Petri com discos de folhas das respectivas cultivares de origem e de feijão-de-porco. Em seguida, os ácaros foram pulverizados com suspensões 5 x 107 conídios.mL-1 em Torre de Potter. As suspensões de conídios foram preparadas a partir das formulações comerciais: Boveril® B. bassiana; Metarril® M. anisopliae; Vertirril® L. longisporum. Foi avaliada a mortalidade corrigida e confirmada. Foram observadas diferenças (Tukey, P 0,05) entre as cultivares na resposta patogênica de T. urticae. Para o 3° DAP, uma melhor eficiência em porcentagem de mortalidade foi observada para o formulado Vertirril® aplicado nas cultivares Calimosa, Golden e Sunrise, e para Metarril® na cultivar Tainung 01. Para o 5° DAP, as eficiências entre as cultivares foram muito próximas.

Potencial do uso de fungos entomopatogênicos no controle de Tetranychus urticae Koch (Acari: Tetranychidae) em mamoeiro: efeito de cultivares sobre a patogenicidade / Potential use of entomopathogenic fungi in the control of Tetranychus urticae Koch (Acari: Tetranychidae) in papaya: cultivar effect on patogenicity

O mamoeiro Carica papaya (L.) é acometido por diversos problemas fitossanitários, sendo o ácaro Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) uma das pragas-chave. A utilização de fungos entomopatogênicos é uma alternativa ao controle por agrotóxicos, reduzindo os riscos de resistência e também a carga de substâncias tóxicas ao ambiente. Este trabalho foi realizado para verificar se as diferentes cultivares de mamoeiro interferem na patogenicidade de Beauveria bassiana, Metarhizium anisopliae e Lecanicillium longisporum. No bioensaio foram utilizadas fêmeas adultas de T. urticae mantidas por pelo menos uma geração sobre folhas de quatro cultivares de mamão, Calimosa, Golden, Sunrise e Tainung 01, e também de uma testemunha de feijão-de-porco. Foram então transferidas dez fêmeas para placas de Petri com discos de folhas das respectivas cultivares de origem e de feijão-de-porco. Em seguida, os ácaros foram pulverizados com suspensões 5 x 107 conídios.mL-1 em Torre de Potter. As suspensões de conídios foram preparadas a partir das formulações comerciais: Boveril® B. bassiana; Metarril® M. anisopliae; Vertirril® L. longisporum. Foi avaliada a mortalidade corrigida e confirmada. Foram observadas diferenças (Tukey, P < 0,05) entre as cultivares na resposta patogênica de T. urticae. Para o 3° DAP, uma melhor eficiência em porcentagem de mortalidade foi observada para o formulado Vertirril® aplicado nas cultivares Calimosa, Golden e Sunrise, e para Metarril® na cultivar Tainung 01. Para o 5° DAP, as eficiências entre as cultivares foram muito próximas.

Papaya Carica papaya (L.) is affected by various phytosanitary problems, and the mite Tetranychus urticae (Koch, 1836) (Acari: Tetranychidae) is a key pest. The use of entomopathogenic fungi is an alternative to the use of pesticides, lowering the risk of resistance while reducing the the load of toxic substances in the environment. This study was conducted to determine whether the different cultivars of papaya interfere with the pathogenicity of Beauveria bassiana. Metarhizium anisopliae and Lecanicillium longisporum. The bioas say was carried out using adult T. urticae females maintained for at least one generation on leaves of four papaya cultivars (Calimosa, Golden, Sunrise, Tainung 01) or on jack bean leaves (control). Ten females were transferred to Petri dishes with leaf disks of the origin cultivars and jack beans. The mites were then sprayed with a 5 x 107 conidia.mL-1 suspension in a Potter Tower. Conidial suspensions were prepared from the commercial formulations Boveril® B. bassiana, Metarril® M. anisopliae, and Vertirril® L. longisporum. The corrected and confirmed mortalities were evaluated. Differences were observed (Tukey, P < 0.05) among the papaya cultivars in terms of the T. urticae pathogenic response. On the 3rd day after spraying (DAS), a better efficiency in mortality percentage was observed for the Vertirril® formulation applied to the Calimosa, Golden and Sunrise cultivars, and for Metarril® applied to the Tainung 01cultivar. On the 5th DAS, the efficiencies among the cultivars were very close.

Seleção de isolados de Bacillus thuringiensis Berliner para Tetranychus urticae Koch / Screening of Bacillus thuringiensis Berliner against Tetranychus urticae Koch

O ácaro rajado é uma das pragas mais importantes em culturas no Brasil. O uso do controle químico de forma descontrolada leva a sérias consequências, como a presença de resíduos em frutos e surgimento de populações resistentes. Faz-se necessário o uso de alternativas de manejo do ácaro, como o controle biológico, que vem sendo utilizado como ferramenta no manejo de di versas pragas de importância agrícola no mundo. Para a realização dos bioensaios, foram avaliadas 120 cepas de Bacillus thuringiensis Berliner quanto à patogenicidade para Tetranychus urticae Koch. Foram preparadas suspensões das diferentes cepas contendo 3 × 108 esporos viáveis/mL de água destilada, aplicadas em discos de folhas de feijão de porco (Canavalia ensiformes DC). Cada cepa constituiu-se em um tratamento, com 8 repetições, cada uma contendo 10 fêmeas adultas do ácaro. Os testes em condições de laboratório mostraram que a mortalidade foi significativa, variando de 6,7% (cepa LMJ7A) a 54,9% (cepas 1077B e 886F).

The two-spotted spider mite is the most important pest to Brazilian crops. The incorrect use of chemical control leads to serious consequences, such as the presence of residues in fruits and the emergence of resistant populations. There is a need for alternative methods for managing the mite, such as biological control, which has been used as a tool in the management of various pests of agricultural importance in the world. Bioassays were carried out to analyze 120 strains of Bacillus thuringiensis Berliner in regard to their pathogenicity to Tetranychus urticae Koch. Suspensions were prepared of the different strains, containing 3 × 108 spores/mL of distilled water, and applied on Jack-bean (Canavalia ensiformes DC) leaf disks. Each strain constituted a treatment, with 8 repetitions, each containing 10 adult Tetranychus urticae females. The tests in laboratory conditions showed that mortality was significantly, ranging from 6.7% (strains LMJ7A) to 54.9% (strains 1077B and 886f).

Desempenho de trichogramma spp. (hymenoptera: trichogrammatidae) em ovos de diaphania hyalinata (l.) (lepidoptera: pyralidae) tratados com metarhizium anisopliae e beauveria bassiana

ABSTRACT Diaphania hyalinata (L., 1758) is one of the most important pests of the Cucurbitacae, and biological control is an alternative method to replace chemicals. Compatibility between biological control agents was evaluated measuring the performance of females of Trichogramma atopovirilia and Trichogramma pretiosum in eggs of Diaphania hyalinata treated with the entomopathogenic fungi Metarhizim anisopliae and Beauveria bassiana. Twenty eggs of D. hyalinata were immersed in a suspension of Metarri®, Boveril® and distilled water (control) and offered daily for the parasitism for 24 hours until the death of the parasitoids. Evaluation was made of the daily, accumulated and total parasitism, number of parasitized eggs, viability, sex ratio and longevity. The formulations of M. anisopliae and B. bassiana did not affect the reproductive characteristics and survival of the two species of Trichogramma, and T. pretiosumshowed higher parasitism thanT. atopovirilia in eggs of D. hyalinata. The results obtained in this work showed that it is possible to integrate the use ofT. atopoviriliaand theentomopathogenic fungi M. anisopliae and B. bassiana in cucurbit IPM systems.

RESUMO Diaphania hyalinata (L., 1758) é uma das principais pragas de Cucurbitacea e ênfase tem sido dada ao controle biológico desta praga em substituição ao controle químico. A compatibilidade de agentes de controle biológico foi avaliada pelo desempenho de fêmeas de Trichogramma atopovirilia Oatman & Platner, 1983 e Trichogramma pretiosum Riley, 1879 em ovos de D. hyalinata pulverizados com os fungos entomopatogênicos Metarhizium anisopliae (Metsh.) Sorok, 1883 e Beauveria bassiana (Balls.) Vuill. Vinte ovos de D. hyalinata foram imersos em suspensão de Metarril®, Boveril® e água destilada (testemunha) e oferecidos diariamente para o parasitismo por 24h até a morte dos parasitoides. Foram avaliados o parasitismo diário, acumulado e total, número de ovos parasitados, viabilidade, razão sexual e longevidade. Os fungos entomopatogênicos M. anisopliae e B. bassiana não afetaram as características reprodutivas e de sobrevivência das duas espécies do gênero Trichogramma, sendo que T. pretiosum apresentou maior parasitismo que T. atopovirilia em ovos de D. hyalinata. Os resultados obtidos neste trabalho mostram que é possível a integração de T. atopovirilia e os fungos entomopatogênicos M. anisopliae e B. bassiana em programas de manejo integrado de pragas de cucurbitáceas.

Cell death and DNA damage in peritoneal macrophages of mice (Mus musculus) exposed to inorganic lead.

Lead is a heavy metal of considerable environmental and occupational concern and there is growing evidence that it is toxic to the human immune system. In this regard, this study examined the effect of lead (Pb) exposure to peritoneal macrophages (Mvarphis) of mice (Mus musculus) cultivated in DMEM medium supplemented with fetal bovine serum, in order to investigate cell damage related to cell death. Cells were exposed to two concentrations of inorganic lead [Pb(II)] for 4, 24 and 72h. Cell viability declined during the treatment, with responses including cell death, cellular damage and DNA damage. Cell death images were found in treated cells with an increase in Bax expression, but the inorganic lead failed to induce the loss of membrane asymmetry (Annexin V conjugates), suggesting that cell death was mainly due to necrosis induction. The effects of Pb(II) on the mechanisms of cell death is not completely understood, but the immunosuppression due to DNA damage and Mvarphis death is discussed here. We have previously shown the effect of inorganic lead in mitochondria and phagocytosis in Mvarphis, suggesting here a pathway for the effect of the metal on mechanisms of cell death, also discussing its effects on the immune system.

Cytotoxic effect of a new 1,3,4-thiadiazolium mesoionic compound (MI-D) on cell lines of human melanoma.

The structural characteristics of mesoionic compounds, which contain distinct regions of positive and negative charges associated with a poly-heteroatomic system, enable them to cross cellular membranes and interact strongly with biomolecules. Potential biological applications have been described for mesoionic compounds. 1,3,4-Thiadiazolium mesoionic compound (MI-D), a new mesoionic compound, has been demonstrated to be extremely cytotoxic to B16-F10 murine melanoma cells when compared to fotemustine and dacarbazine, drugs of reference in melanoma treatment protocols, describing inhibition of tumours grown in vitro and in vivo. We now evaluate the effects of mesoionic compound MI-D on different human melanoma cell lines. The drug decreased the viability and proliferation of MEL-85, SK-MEL, A2058 and MEWO cell lines in vitro, showing a considerable cytotoxic activity on these human cells. Adhesion of MEL-85 cells was evaluated in the presence of the drug using different extracellular matrix (ECM) constituents. MI-D decreased MEL-85 adhesion to laminin, fibronectin and matrigel. The morphology and actin cytoskeleton organisation of MEL-85 cells were also modified on MI-D treatment. These results on human melanoma cell lines indicate that MI-D is a very encouraging drug against melanoma, a tumour that is extremely resistant to chemotherapy.

Heparan sulfate and control of cell division: adhesion and proliferation of mutant CHO-745 cells lacking xylosyl transferase

We have examined the role of cell surface glycosaminoglycans in cell division: adhesion and proliferation of Chinese hamster ovary (CHO) cells. We used both wild-type (CHO-K1) cells and a mutant (CHO-745) which is deficient in the synthesis of proteoglycans due to lack of activity of xylosyl transferase. Using different amounts of wild-type and mutant cells, little adhesion was observed in the presence of laminin and type I collagen. However, when fibronectin or vitronectin was used as substrate, there was an enhancement in the adhesion of wild-type and mutant cells. Only CHO-K1 cells showed a time-dependent adhesion on type IV collagen. These results suggest that the two cell lines present different adhesive profiles. Several lines of experimental evidence suggest that heparan sulfate proteoglycans play a role in cell adhesion as positive modulators of cell proliferation and as key participants in the process of cell division. Proliferation and cell cycle assays clearly demonstrate that a decrease in the amount of glycosaminoglycans does not inhibit the proliferation of mutant CHO-745 cells when compared to the wild type CHO-K1, in agreement with the findings that both CHO-K1 and CHO-745 cells take 8 h to enter the S phase

Heparan sulfate and control of cell division: adhesion and proliferation of mutant CHO-745 cells lacking xylosyl transferase.

We have examined the role of cell surface glycosaminoglycans in cell division: adhesion and proliferation of Chinese hamster ovary (CHO) cells. We used both wild-type (CHO-K1) cells and a mutant (CHO-745) which is deficient in the synthesis of proteoglycans due to lack of activity of xylosyl transferase. Using different amounts of wild-type and mutant cells, little adhesion was observed in the presence of laminin and type I collagen. However, when fibronectin or vitronectin was used as substrate, there was an enhancement in the adhesion of wild-type and mutant cells. Only CHO-K1 cells showed a time-dependent adhesion on type IV collagen. These results suggest that the two cell lines present different adhesive profiles. Several lines of experimental evidence suggest that heparan sulfate proteoglycans play a role in cell adhesion as positive modulators of cell proliferation and as key participants in the process of cell division. Proliferation and cell cycle assays clearly demonstrate that a decrease in the amount of glycosaminoglycans does not inhibit the proliferation of mutant CHO-745 cells when compared to the wild type CHO-K1, in agreement with the findings that both CHO-K1 and CHO-745 cells take 8 h to enter the S phase.

In vivo and in vitro cytotoxicity of brown spider venom for blood vessel endothelial cells.

The effect of brown spider (Loxosceles intermedia) venom on endothelial cells was investigated in vivo and in vitro. Morphological and ultrastructural observations by light microscopy and transmission electron microscopy showed that the venom acts in vivo upon vessel endothelial cells of rabbits that were intradermally injected, evoking vessel instability, cytoplasmic endothelial cell vacuolization, and blebs. Likewise, treatment of rabbit endothelial cells in culture with the venom led to loss of adhesion of the cells to the substrate. Endothelial cells in culture were metabolically radiolabeled with sodium [35S]-sulfate and the sulfated compounds (proteoglycans and sulfated proteins) from medium, cell surface, and extracellular matrix (ECM) were analyzed. Agarose gel electrophoresis and SDS-PAGE showed that the venom is active on the ECM and on cell surface proteoglycans, shedding these molecules into the culture medium. In addition, when purified heparan sulfate proteoglycan (HSPG) and purified laminin-entactin (LN/ET) complex were incubated with the venom we observed a partial degradation of the protein core of HSPG as well as the hydrolysis of entactin. The above results suggest that the L. intermedia venom has a deleterious effect on the endothelium of vessels both in vivo and in culture, removing important constituents such as HSPG and entactin that are involved in the adhesion of endothelial cells and of subendothelial ECM organization.

A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins

Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). The effect of this polymer on adhesion properties with specific extracellular matrix components was studied using several matrix proteins as substrates for cell attachment. Treatment with the polymer inhibited the adhesion of fibronectin to both CHO-K1 (2 x 10(5))()and CHO-745 (2 x 10(5) and 5 x 10(5)) cells. No effect was detected with laminin, using the two cell types. On the other hand, adhesion to vitronectin was inhibited in CHO-K1 cells and adhesion to type I collagen was inhibited in CHO-745 cells. In spite of this inhibition, the fucan did not affect either cell proliferation or cell cycle. These results demonstrate that this polymer is a new anti-adhesive compound with potential pharmacological applications

A fucan from the brown seaweed Spatoglossum schröederi inhibits Chinese hamster ovary cell adhesion to several extracellular matrix proteins.

Fucans, a family of sulfated polysaccharides present in brown seaweed, have several biological activities. Their use as drugs would offer the advantage of no potential risk of contamination with viruses or particles such as prions. A fucan prepared from Spatoglossum schröederi was tested as a possible inhibitor of cell-matrix interactions using wild-type Chinese hamster ovary cells (CHO-K1) and the mutant type deficient in xylosyltransferase (CHO-745). The effect of this polymer on adhesion properties with specific extracellular matrix components was studied using several matrix proteins as substrates for cell attachment. Treatment with the polymer inhibited the adhesion of fibronectin to both CHO-K1 (2 x 10(5)) and CHO-745 (2 x 10(5) and 5 x 10(5)) cells. No effect was detected with laminin, using the two cell types. On the other hand, adhesion to vitronectin was inhibited in CHO-K1 cells and adhesion to type I collagen was inhibited in CHO-745 cells. In spite of this inhibition, the fucan did not affect either cell proliferation or cell cycle. These results demonstrate that this polymer is a new anti-adhesive compound with potential pharmacological applications.

Structural and ultrastructural description of the venom gland of Loxosceles intermedia (brown spider).

The brown spider, genus Loxosceles, is becoming of great medical importance, with envenomation (Loxoscelism) occurring throughout the world. The biological activities of the brown spider venom usually include dermonecrotic lesions at the bite site accompanied by hemolytic and haemorrhagic effects and also by renal failure. The objective of the present study was to describe the histology of the venom gland of L. intermedia using glands from adult spiders which were investigated by light microscopy, using immunohistochemical and staining methods, by transmission electron microscopy, and by scanning electron microscopy. The organization of the venom gland of Loxosceles intermedia follows the general architecture of spiders' venom glands. Using light microscopy and transmission electron microscopy we observed that the venom glands of L. intermedia present two layers of striated muscle fibers, an external layer and an internal layer in touch with an extracellular matrix which is a basement membrane structure and a fibrillar collagen matrix separating the muscular region from epithelial cells of the venom gland. Muscle cells are multinucleated, with nuclei peripherally placed and their cytoplasm rich in sarcoplasmic reticulum, myofibrills and continuous Z lines. By using scanning electron microscopy we can detect muscular cells from external layer as branching cells. Epithelial cells have their cytosol extremely rich in rough endoplasmic reticulum, mitochondria collection, Golgi apparatus, interdigitating membranes and secretory vesicles that ultimately accumulate the venom, a complex protein mixture.