Role of the consumption of fucoidans and beta-glucans on human health: an update of the literature / Rol del consumo de fucoidanos y betaglucanos en la salud humana: artículo de actualización

ABSTRACT Bioactive compounds are substances present in low doses in foods mostly from the plant kingdom. Their consumption can influence physiological or cellular processes and has a beneficial effect on health. Fucoidans and beta-glucans are bioactive compounds that share the characteristic of being carbohydrates of the polysaccharide type, specifically of the soluble fiber kind. These compounds can be found in foods available in Chile and part of the Chilean diet; foods include, brown algae and some cereals. The concentration of these compounds in foods is variable, and depends on factors like season, cultivation, germination, and method of preparation and conservation. The current literature shows the potential beneficial effects of fucoidan and beta-glucans compounds in human health, which include: anticoagulant, immuno-modulator and antidiabetic and immunomodulating. The effects depend, among other factors, on their bioavailability and molecular weight. The objective of this review was to describe the potential beneficial effects of these bioactive compounds, analyze their characteristics and properties, and provide consumption recommendations that may lead to achieving the expected beneficial effects. To that end, relevant and recent scientific literature was analyzed.

RESUMEN Los compuestos bioactivos corresponden a aquellos elementos presentes en los alimentos, que influyen en procesos fisiológicos o celulares, cuyo consumo produce un efecto beneficioso para la salud, encontrándose en alimentos principalmente del reino vegetal y cuyas concentraciones en los alimentos son en mínimas dosis. Los fucoidanos y los beta-glucanos, son compuestos bioactivos que comparten la característica de ser un carbohidrato, de tipo polisacárido, específicamente fibra de tipo soluble, encontrándose presente en alimentos disponibles en nuestro país y que son parte de nuestra dieta, como las algas pardas y algunos cereales. La concentración de estos compuestos en los alimentos, es fluctuante y depende de factores como la estacionalidad, cultivo, germinación, método de preparación y conservación. En la bibliografía actual, se evidencian los potenciales efectos beneficiosos de fucanos y beta-glucanos para la salud humana como anticoagulante, antidiabético e inmunomodulador, la intensidad de estos efectos dependen de su biodisponibilidad y del peso molecular. El objetivo de esta revisión fué profundizar respecto a los potenciales efectos beneficiosos de estos compuestos bioactivos, analizar sus características, propiedades, además de relacionar una recomendación de consumo que permita alcanzar los efectos beneficiosos esperados. Para ello se analizó la bibliografía científica atingente, relevante y reciente.

Cloning and expression of Brucella cyclic beta-1, 2 glucan transporter gene [cgt]

Brucellosis is an important cosmopolitan infection disease caused by organisms belonging to the genus Brucella. The cgt gene [cyclic beta-1, 2 glucan transporter gene] is a virulent factor in Brucella genus. The present study was conducted with the aim of cloning and expression of Brucella cgt gene. Brucella melitensis cgt gene was amplified from extracted chromosomal DNA by PCR, then PCR product was cloned into pTZ57R and subcloned into pGEMEX-1 expression vector, then expressed in JM109 E. coli strain. Recombinant protein was confirmed by western blot analysis using patient's serum. The PCR product was cloned in pTZ57R plasmid via T/A cloning method. Recombinant plasmid was digested by Band HI and SacI restriction enzymes, the released band was purified and subcloned into pGEMEX-1 expression vector. Then, sample cells were lysed using lyses buffer and sonicated, then electrophoresed on SDS-PAGE. Protein bands were transferred on nitrocellulose membrane and reacted by patient's serum and detected by FIRP conjugated-anti human antibody. We cloned and expressed Brucella abortus cyclic beta-1, 2-glucan transporter gene [cgt] which is an important agent in brucellosis. Using cgt gene mutant may be an effective way for inhibiting or decreasing the pathogenicity of bacteria

Solubilization of water-insoluble beta-glucan isolated from Ganoderma lucidum.

The fungal beta-D-glucan is a biological response modifier (BRM), but a major obstacle to the clinical utilization of beta-glucan BRMs is thei relative lack of solubility in aqueous media. Water insoluble fungal glucans extracted by alkali from the mycelia of Ganoderma lucidum were sulfated to yield their corresponding water-soluble derivatives. Insoluble glucan is dissolved in methyl sulfoxide and urea, and is partially sulfated with sulfuric acid. The sulfated glucan (SGL) yield prepared from insoluble glucan (IGL) was 85%, the sulfation degree of SGL was about 14.9%, and the solubility of SGL was above 95% in water. The monosugar SGL content was 34.9% alpha-glucose and 35.9% beta-glucose. The mean molecular weight (MW) of SGL was shown as a single peak on Sepharose CL-4B column chromatography, and their MW was approximately 9.3 kDa. The 13C NMR spectrum analysis shows that SGL has a high similarity with the beta-(1-->3)-linked triple-helical control.

Isolation of 4-aminopyridine resistant mutants affecting alkali-insoluble glucan content of cell walls in Saccharomyces cerevisiae.

Saccharomyces cerevisiae cells when grown on synthetic medium plates containing 10 mM of 4-aminopyridine (4-AP) undergo cell lysis. Using an ethylmethane sulfonate mutagenesis (EMS) screen, 4-AP resistant mutants (apr) were isolated which could grow on inhibitory concentration of 4-AP. Eighty mutants were obtained that were recessive, monogenic and formed two complementation groups. To identify genes, whose products might be interacting with the apr loci, extragenic suppressors were isolated, which reverted 4-AP resistance phenotype of apr mutants. The suppressors, when genetically characterized, were found to be recessive and represented two loci with overlapping functions. Representative alleles from apr mutants were analyzed for cell wall composition. They were found to have a higher amount of alkali-insoluble glucan signifying the role of alkali-insoluble glucan in cell wall maintenance.