Actinobacteria from Antarctica as a source for anticancer discovery.

Although many advances have been achieved to treat aggressive tumours, cancer remains a leading cause of death and a public health problem worldwide. Among the main approaches for the discovery of new bioactive agents, the prospect of microbial secondary metabolites represents an effective source for the development of drug leads. In this study, we investigated the actinobacterial diversity associated with an endemic Antarctic species, Deschampsia antarctica, by integrated culture-dependent and culture-independent methods and acknowledged this niche as a reservoir of bioactive strains for the production of antitumour compounds. The 16S rRNA-based analysis showed the predominance of the Actinomycetales order, a well-known group of bioactive metabolite producers belonging to the Actinobacteria phylum. Cultivation techniques were applied, and 72 psychrotolerant Actinobacteria strains belonging to the genera Actinoplanes, Arthrobacter, Kribbella, Mycobacterium, Nocardia, Pilimelia, Pseudarthrobacter, Rhodococcus, Streptacidiphilus, Streptomyces and Tsukamurella were identified. The secondary metabolites were screened, and 17 isolates were identified as promising antitumour compound producers. However, the bio-guided assay showed a pronounced antiproliferative activity for the crude extracts of Streptomyces sp. CMAA 1527 and Streptomyces sp. CMAA 1653. The TGI and LC50 values revealed the potential of these natural products to control the proliferation of breast (MCF-7), glioblastoma (U251), lung/non-small (NCI-H460) and kidney (786-0) human cancer cell lines. Cinerubin B and actinomycin V were the predominant compounds identified in Streptomyces sp. CMAA 1527 and Streptomyces sp. CMAA 1653, respectively. Our results suggest that the rhizosphere of D. antarctica represents a prominent reservoir of bioactive actinobacteria strains and reveals it as an important environment for potential antitumour agents.

Agaricus blazei Bioactive Compounds and their Effects on Human Health: Benefits and Controversies.

BACKGROUND: The mushroom Agaricus blazei has evoked considerable scientific and practical interest in several fields, especially those linked to its medicinal properties. This review aims to summarize and evaluate the past decade findings related to nutritional and therapeutic uses of A. blazei, with especial emphasis on the most recent discoveries regarding its chemical composition and clinical investigations. METHODS: The specialized literature was searched for basic and clinical studies. The main isolated and identified compounds or fractions are described and confronted with their corresponding bioactivities. RESULTS: Basic research of high quality using ex vivo and in vivo conditions are quite abundant in the specialized literature, but ony 17 clinical studies and two case reports were found. A great number of active molecules have been identified, and they can be divided into three categories, (1) hydrophilic small molecules (e.g., phenolics), (2) lipophilic or partially lipophilic small molecules (e.g., agarol) (3) and macromolecules (e.g., ß-glucans). At least the following bioactivities can be considered as being supported by experimental evidence: antioxidant activity (in aging or disease), immunomodulation and cell signaling, anti-inflammatory activity, antiparasitic actions, antimicrobial activity, anticancer effects and tumor growth inhibiting effects, antimutagenic activity, hepatoprotection against chemical or viral infection and antidiabetic activity. CONCLUSION: The amount and quality of the evidence that has been accumulating during the last decade strongly speaks in favor of the health benefits of the ingestion of A.blazei or derived products. However, there are many uncertainties and limitations when attempts are made to extrapolate or to demonstrate their biological effects in the human organism in health or disease. Clearly, more clinical trials, using reliable statistical methods and standardized preparations are needed to establish the efficacy of A. blazei as a therapeutic agent.

Extraction and purification of high-value metabolites from microalgae: essential lipids, astaxanthin and phycobiliproteins.

The marked trend and consumers growing interest in natural and healthy products have forced researches and industry to develop novel products with functional ingredients. Microalgae have been recognized as source of functional ingredients with positive health effects since these microorganisms produce polyunsaturated fatty acids, polysaccharides, natural pigments, essential minerals, vitamins, enzymes and bioactive peptides. For this reason, the manuscript reviews two of the main high-value metabolites which can be obtained from microalgae: pigments and essential lipids. Therefore, the extraction and purification methods for polyunsaturated fatty acids, astaxanthin, phycoerythrin and phycocyanin are described. Also, the effect that environmental growth conditions have in the production of these metabolites is described. This review summarizes the existing methods to extract and purify such metabolites in order to develop a feasible and sustainable algae industry.

Glycolipids from seaweeds and their potential biotechnological applications.

Marine macroalgae, or seaweeds, are a formidable source of natural compounds with diverse biological activities. In the last five decades it has been estimated that more than 3000 natural compounds were discovered from these organisms. The great majority of the published works have focused on terpenoids. In comparison, glycolipids are a neglected class of macroalgal secondary metabolites therefore remaining as a largely unknown reservoir of molecular diversity. Nevertheless, the interest regarding these compounds has been growing fast in the last decades as activities of ecological or pharmaceutical interest have been highlighted. This paper will review recent work regarding isolation and structural characterization of glycolipids from seaweeds and their prospective biological activities.

Factors affecting Anastrepha fraterculus female receptivity modulation by accessory gland products.

In the context of the sterile insect technique (SIT), mass-rearing and male irradiation are imperative. Post-teneral treatments such as the addition of protein in adult's male diet and male hormonal treatment are used to improve sexual performance and to accelerate sexual maturation. In this work we investigated the effect of male accessory glands products (AGPs) on female receptivity of the South American fruit fly Anastrepha fraterculus (Wiedemann), and the effect of strain rearing history, male irradiation, male diet and hormonal treatment on AGPs. Injections of aqueous extracts of male accessory glands into the abdomen of females reduced their receptivity. The AGPs from laboratory males were more effective in inhibiting female receptivity, compared to AGPs from wild males, irrespective of females' origin. The AGPs from fertile males were more effective than AGPs from sterile males. The AGPs from protein-fed males were more effective than AGPs from sugar-fed males. Finally, the AGPs of males treated with juvenile hormone were less effective in inhibiting female receptivity than AGPs of untreated males. We conclude that inhibition of sexual receptivity of A. fraterculus mated females is mediated by products in male accessory gland's and the way that these products act vary widely according to the effect of extrinsic factors. We discuss the results in the perspective of the SIT application for A. fraterculus.

The effect of royal sun agaricus, Agaricus brasiliensis S. Wasser et al., extract on methyl methanesulfonate caused genotoxicity in Drosophila melanogaster.

The effect of culinary-medicinal Royal Sun Agaricus (Agaricus brasiliensis) hot water extract on methyl methane sulfonate (MMS) induced mutagenicity/genotoxity in Drosophila melanogaster was studied using a quick and broadly applicable in vivo assay, i.e., the wing somatic mutation and recombination test. We used 2nd instar larvae, trans-heterozygous for the third chromosome recessive markers, i.e., multiple wing hairs (mvh) and flare-3 [flr (3)], and fed them for 24 h with the aqueous extract of A. brasiliensis. For antigenotoxicity studies a 24-h pretreatment with the extract was done, followed by a 48-h treatment of the then 3rd instar larvae with MMS. The frequency of mutations of the wing blade changes (i.e., of the number of wing spots of different sizes) induced in somatic cells was determined as a parameter of genetic changes of the wing imaginal discs. The results showed that A. brasiliensis extract did not cause any genotoxic or mutagenic effects. No antigenotoxic and/or protective effect against the induction of mutations by MMS was observed. Instead, a possible enhanced mitotic recombination frequency by MMS was seen after pretreatment of the larvae with A. brasiliensis extract. Possible mechanisms of action are discussed.

Estudo químico biomonitorado de duas espécies vegetais buscando o isolamento e a identificação de substâncias leishmanicidas e tóxicas para células tumorais

Duas espécies vegetais foram objeto de estudo para esta dissertação: Pittosporum undulatum Vent. (Pittosporaceae) e Piptadenia adiantoides (Spreng.) J.F. Macbr. (Fabaceae). Elas foram selecionadas a partir da triagem realizada durante um projeto multidisciplinar envolvendo o LQPN e grupos do IRR e da UFMG. Os extratos etanólicos dos frutos de P. undulatum e do caule de P. adiantoides demonstraram citotoxicidade para uma ou mais linhagens de células tumorais humanas (MCF-7, UACC-62 e TK-10). Da primeira foi obtida uma fração rica em saponinas que mostrou elevada atividade citotóxica, com CI50 (concentração capaz de inibir em 50% a proliferação celular) de 1,7 μg/mL, um valor menor do que o encontrado por Oliveira e colaboradores (2006) para a droga controle etoposídeo (12μg/mL). A fração rica em saponinas foi hidrolisada em meio ácido e o fracionamento da mistura reacional forneceu uma fração composta de duas sapogeninas triterpênicas. A análise dos dados de RMN de 1H e 13C e dos dados de IES-EM permitiram a elucidação da estrutura dessas sapogeninas como sendo o (3 Beta, 15 Alfa, 16 Alfa, 21 Beta, 22 Alfa)-21-(acetiloxi)-3, 15, 16, 28-tetraidroxiolean-12-en-22-il 2-metilbutanoato e o (3 Beta, 15 Alfa, 16 Alfa, 21 Beta, 22 Alfa)-21-(acetiloxi)-3,15,16,28-tetraidroxiolean-12-en-22-il 3-metillbut-2-enoato. Esta é a primeira vez que são descritas sapogeninas derivadas de R1-barrigenol esterificadas em C-21 e C-22 para a espécie P. undulatum.

Da segunda espécie vegetal, a fração dicloromêtanica (AFD), obtida por partição do extrato etanólico do caule, demonstrou atividade citostática para células MCF-7 inibindo em 100% a proliferação celular quando testada a 20 μg/mL. AFD foi fracionada empregando-se diversas técnicas cromatográficas resultando em frações ricas flavonóides que mostraram atividade citotóxica para as três linhagens de células tumorais. A fração MeOH:H2O obtida da partição do extrato foi fracionada e forneceu a rutina (quercetina-3-O-[O-Alfa-L-ramnopiranosil(1->6)- Beta-D-glicopiranosídeo). Esta é a primeira vez que esta espécie é investigada quimicamente e quanto à sua atividade biológica

Plant endophytes as a platform for discovery-based undergraduate science education.

Project ownership is an essential but sometimes overlooked ingredient for a successful undergraduate research experience. We have embarked on an experiment in undergraduate education that targets isolation of microbes from rainforest plants and characterization of natural products as objectives for discovery-based undergraduate research.

A blood plasma inhibitor is responsible for circadian changes in rat renal Na,K-ATPase activity.

Rhythmic changes in activity following a circadian schedule have been described for several enzymes. The possibility of circadian changes in Na,K-ATPase activity was studied in homogenates of rat kidney cortex cells. Male Sprague-Dawley rats were kept on a schedule of 12h light (06:00-18:00 h) and 12 h darkness (18:00-06:00 h) for 2 weeks. At the end of the conditioning period, one rat was killed every 2 h, until completion of a 24 h cycle. Outermost kidney cortex slices were prepared, homogenized and assayed for Na,K-ATPase activity. The whole procedure was repeated six times. Na,K-ATPase activity shows an important oscillation (2 cycles/24 h). Peak activities were detected at 09:00 and 21:00 h, whereas the lowest activities were detected at 15:00 and 01:00-03:00 h. The highest activity was 40+/-3 nmoles Pi mg protein(-1)min(-1) (09:00 h), and the lowest was 79+/-3 nmoles Pi mg protein(-1)min(-1) (15:00 h). The amount of the Na+-stimulated phosphorylated intermediate is the same for the 09:00 h and 15:00 h homogenates. Preincubation of 09:00 h kidney cortex homogenates with blood plasma drawn from rats at either 03:00 h or 15:00 h, significantly inhibited their Na,K-ATPase activity. This inhibition was not seen when the preincubation was carried out with either 09:00 h or 21:00 h blood plasma. The striking oscillation (2 cycles/24 h) of the Na,K-ATPase activity of rat kidney cortex cells is ascribed to the presence of an endogenous inhibitor in blood plasma.

Paesslerins A and B: novel tricyclic sesquiterpenoids from the soft coral Alcyonium paessleri.

[structure: see text] In the course of our search of new bioactive metabolites from marine invertebrates, paesslerins A and B, sesquiterpenoids with an unprecedented tricyclic skeleton, were isolated from the subAntarctic soft coral Alcyonium paessleri collected at a depth of 200 m near the South Georgia islands, and their structures were elucidated by spectroscopic techniques. These compounds show moderate cytotoxicity in preliminary assays.

Invertebrate compounds acting on the hemostatic mechanism.

Physiological secretions from some invertebrates have toxic effects on mammalian blood coagulation and fibrinolytic systems. Some of these effects occur because the substances contained in the secretions resemble the components of the hemostatic system. Some of the substances have been characterized, and have been found to have similar molecular weights or sequences, which may indicate a common ancestry. The components can be divided into five groups: antithrombic agents (group I); inhibitors and activators of the prothrombinase complex (group II); substances that affect platelet function (group III); substances that affect the fibrinolytic mechanism (group IV); and a group of miscellaneous agents whose activities are difficult to group together (group V). In group I special mention of the antithrombin agents in Hirudo medicinalis should be made. In group II, the agents affecting the prothrombinase complex are antistasin from Haementeria officinalis, ghilanten from Haementeria Ghiliani and the tick anticoagulant protein from Ornithodoros moubata, a factor V activator/inhibitor from Lonomia achelous and factor II and factor X activators from L. achelous and Lonomia obliqua. Examples of factors which affect platelet function (group III) are glossina from the black fly Glossina morsitans, calin from H. medicinalis, decorsin (a desintegrin) from Macrobdella decorsa, and FAGA from Stichopus japonicus selenka. The first three of these are inhibitors of platelet aggregation, and the last is an inducer. The plasminogen activators (group IV) from the L. achelous caterpillar and Eutriatoma maculata trigger the fibrinolytic system, whereas hementin from H. officinalis and hementerin from Haementeria depressa are directly fibrinolytic. The last group of substances (group V) include those with factor-XIIa-like activity from D. farinae, kallikrein-like activity and a factor XIII degrading enzyme from L. achelous, destabilase from H. medicinalis and prolixin S (nitroforin 2, or anti-factor-IXa) from Rhodnius prolixus. Some of these components have been well characterized, cloned and prepared in recombinant form, and seem to be very promising from the therapeutic point of view.

Estudio retrospectivo multicentrico del asma bronquial en la infancia / Multicentric retrospective study of bronquial asthma in infants

Trabajo Retropectivos multicentrico. Fueron estudiados un total de 2.544 pacientes atendidos en los 4 hospitales mas grandes de Santa cruz de la Sierra en 1992. Encontrandose 1.267 pacientes en consulta externa y 1.140 en emergencia. La proporcion de consultas por asma Bronquial en estos Hospitales fue de 2.34 por ciento con un indice de internacion de 5.77 por ciento (147 pacientes internados). Se encontro una leve predominancia del sexo masculino 58.8por ciento sobre el femenino (41.2 por ciento). El grupo etereo mas acometido fueron los mayores de 5 anos. En mas de 60 por ciento de los pacientes internados los principales sintomas fueron Disnea. Sibilancia, Tos y Tiraje. La droga mas utilizada fue la Aminofilina en 93.2 por ciento, seguida de los B2 adrenergicos en 76.9 y los corticoides en 59.2. La mortlidad fue del 1.2 por ciento. La gran mayoria de los pacientes recibio alta con un tiempo medio de internacion de 2,86 dias. Conclusiones que el Asma Bronquial prevalente en Santa Cruz de la Sierra con indice de Internacion y de mortalidad bajos indicando que la mayoria de los ninos responden adecuadamente al tratamiento de la crisis asmatica.

[Characterization of a substance which protects Klebsiella pneumoniae from the bactericidal effect of normal human serum]. / Caracterización de una sustancia que protege a Klebsiella pneumoniae del efecto bactericida del suero humano normal.

Chemical composition of a substance produced by Klebsiella pneumoniae which is accumulated in chemically defined medium was determined. This substance (the protective factor) protects the bacterium from being killed by normal human serum. Protective factor was treated with DNase, lysozyme and an alkaline protease. The two former enzymes did not affect the protective factor. On the other hand, when alkaline protease was used, the protective activity was totally lost. Results showed that the protective factor is a protein.

The effects produced by acidified serum upon adipocytic conversion in 3T3-F442A cells.

The acidified fetal bovine serum (FBS) produces a factor which inhibits the adipose differentiation of murine fibroblasts 3T3-F442A. In this work, we studied if the inhibitory factor (IF) has any effect on the proliferation of 3T3-F442A cells. Our data showed an increment in the number of cells cultured in the presence of IF. We do not know how the IF maintains the cell proliferation. Furthermore, we investigated if IF acts on the resting state (Go) of the 3T3-F442A. We found that the IF prevented the adipose differentiation in the state (Go), this data suggests that the 3T3-F442A in this state (Go) were not yet compromised to difference to adipocytes. We also showed that bovine serum (BS) had an inhibitory activity too, but this was lower than FBS. This report suggests that the IF may play a role during the development of the adipose tissue.

[Substance produced by Klebsiella pneumoniae with protects it from the bactericidal effect of normal human serum]. / Substancia producida por Klebsiella pneumoniae que la protege del efecto bactericida del suero humano normal.

A Klebsiella pneumoniae culture in Fouad's chemically defined medium, which was grown from 18 to 24 hours at 37 degrees C was prepared. Bacterial cells were eliminated by centrifugation and the supernatant was sterilized by Millipore membrane filtration. A protective activity against normal human serum bactericidal effect on K. pneumoniae K-9 and K-13 was ascribed to sterile filtrate. The protective filtrate seems to be a high molecular weight substance.

Increase of biosynthesis and degradation of collagen in normal lungs induced by soluble factors obtained from experimental pulmonary silicosis.

We have studied the effects of soluble factors obtained from rat lungs with experimentally-induced pulmonary fibrosis of 2 months duration on the in vitro rates of biosynthesis and degradation of collagen in normal rat lung preparations. Factors soluble in phosphate-buffered saline were prepared from the minced lungs of normal controls and of silicotic animals. The in vitro rate of collagen biosynthesis of normal rat lung explants was measured as the rate of incorporation of radioactive proline into total and collagenous protein. The in vitro rate of collagen degradation in normal rat lung homogenates was measured as the rate of release of hydroxyproline-containing materials of less than 100,000 daltons to the supernatant. Our results suggest that in this experimental model of pulmonary fibrosis there are soluble factors that stimulate both collagen biosynthesis and collagen degradation in in vitro preparations of normal rat lung.