Ana Villares

Flavonoids as anti-inflammatory agents: implications in cancer and cardiovascular disease.

Chronic inflammation is being shown to be increasingly involved in the onset and development of several pathological disturbances such as arteriosclerosis, obesity, diabetes, neurodegenerative diseases and even cancer. Treatment for chronic inflammatory disorders has not been solved, and there is an urgent need to find new and safe anti-inflammatory compounds. Flavonoids belong to a group of natural substances occurring normally in the diet that exhibit a variety of beneficial effects on health. The anti-inflammatory properties of flavonoids have been studied recently, in order to establish and characterize their potential utility as therapeutic agents in the treatment of inflammatory diseases. Several mechanisms of action have been proposed to explain in vivo flavonoid anti-inflammatory actions, such as antioxidant activity, inhibition of eicosanoid generating enzymes or the modulation of the production of proinflammatory molecules. Recent studies have also shown that some flavonoids are modulators of proinflammatory gene expression, thus leading to the attenuation of the inflammatory response. However, much work remains to be done in order to achieve definitive conclusions about their potential usefulness. This review summarizes the known mechanisms involved in the anti-inflammatory activity of flavonoids and the implications of these effects on the protection against cancer and cardiovascular disease.

Edible mushrooms: Role in the prevention of cardiovascular diseases

Edible mushrooms are a valuable source of nutrients and bioactive compounds in addition to a growing appeal for humans by their flavors and culinary features. Recently, they have become increasingly attractive as functional foods for their potential beneficial effects on human health. Hence, food industry is especially interested in cultivated and wild edible mushrooms. Cardiovascular diseases are one of the most prevalent causes of morbidity and mortality in the Western world. Several investigations have shown the influence of mushrooms intake on some metabolic markers (total, LDL, HDL cholesterol, fasting triacylglycerol, homocysteine, blood pressure, homeostatic function and oxidative and inflammatory damage), which potentially may reduce the risk of suffering cardiovascular diseases. Relevant nutritional aspects of mushrooms include a high fiber supply, a low fat content with low trans isomers of unsaturated fatty acids and a low concentration of sodium as well as the occurrence of components such as eritadenine, phenolic compounds, sterols (such as ergosterol), chitosan, triterpenes, etc., which are considered as important responsible agents for some hitherto healthy properties. The aims of this review are to report putative positive effects of mushrooms consumption on cardiovascular diseases risk markers and to identify some putative bioactive compounds involved in these effects.

Novel isolation of water-soluble polysaccharides from the fruiting bodies of Pleurotus ostreatus mushrooms

Novel water-soluble polysaccharides have been isolated from the fruiting bodies of the edible mushroom Pleurotus ostreatus. Three polysaccharide fractions were obtained by ethanol precipitation from cold water, hot water and hot aqueous NaOH extracts. The fractions were purified by size exclusion chromatography showing a unique carbohydrate occurring in each fraction: PC from the cold fraction, PH from the hot fraction and PB from the hot aqueous NaOH fraction. The analysis of the methylated alditol acetates and the NMR studies revealed that all the polysaccharides displayed a linear backbone. PC was formed by α-(1→3),(1→6)-linked galactopyranosyl residues whereas PH and PB consisted of glucose-linked units. PH was exclusively composed of glucopyranosyl units bound by α-(1→4) linkages whereas PB was a β-linked glucan showing (1→3) and (1→6) glycosidic bonds. The analysis of molecular arrangement by complexation with Congo red showed that only the β-linked polysaccharide (PB) displayed a triple helix conformation.

In vitro anti-inflammatory activity of phenolic rich extracts from white and red common beans.

According to epidemiological evidence, diets rich in fruits and vegetables can reduce the incidence of several chronic diseases that share an inflammatory component. These protective effects are attributed, in part, to the occurrence of different antioxidant components, mainly phenolic compounds. Our aim was to characterise phenolic composition, and to determine antioxidant and anti-inflammatory activities of phenolic rich extracts obtained from two kinds of common beans, white kidney beans (WKB) and round purple beans (RPB). Phenolic acids were the predominant component in WKB extracts, whereas RPB extracts presented higher concentrations of phenolic compounds, mainly catechin derivatives, proanthocyanidins and catechin glucoside. In addition, RPB extracts showed higher antioxidant capacity and higher anti-inflammatory activity by the reduction of NO production and cytokine mRNA expression of LPS stimulated macrophages. These results suggest that common bean extracts may be used as a source of anti-inflammatory agents as well as a dietary complement for health promotion.

Storage temperature and UV-irradiation influence on the ergosterol content in edible mushrooms.

Ergosterol (5,7,22-ergostatrien-3β-ol) and ergosteryl derivatives from different genera of edible mushrooms were separated and quantified by an isocratic reversed-phase high performance liquid chromatography (HPLC) method. The technique allowed a rapid separation of free ergosterol and two ergosteryl derivatives occurring in mushrooms. The ergosterol content varied considerably depending on the fungus. Thus, the species Agaricus bisporus and Hygrophorus marzuolus presented high quantities of ergosterol (6.4-6.8 mg/g, dry matter) followed by Pleurotus ostreatus, Calocybe gambosa, Lentinus edodes, and Boletus edulis (3.3-4.0mg/g). In contrast, other species, such as Cantharellus cibarius, Lactarius deliciosus and Craterellus cornucopioides, contained significantly lower ergosterol amounts (0.2-0.4 mg/g). Two ergosteryl derivatives were found in mushrooms and also the content depended on the fungus. The stability of ergosterol, in terms of the formation of ergosterol peroxide, was evaluated under different storage temperatures and UV radiation. The lower the temperature (-20°C) and the radiation time (10 min), the lower ergosterol oxidation was observed.

Mushrooms as a Source of Anti-Inflammatory Agents

Inflammation is nowadays well known to be involved in the development of several chronic diseases such as arteriosclerosis, obesity, diabetes, neurodegenerative diseases, and cancer. Treatment for chronic inflammatory disorders has not been solved yet, and there is an urgent need to find new and safe anti-inflammatory preventive and therapeutic compounds. Medicinal mushrooms have been traditionally used in Asian countries to manage and treat different diseases. On the other hand, edible mushrooms have recently attracted much interest as a functional food because of their antimutagenic, anti-tumoral, anti-viral, anti-thrombotic, hypocholesterolemic, hypolipidemic, and anti-oxidant properties. Among all of these healthy properties, special attention was paid to the immunomodulatory activity of some fungal compounds such as polysaccharides, mainly β-glucans. Recently, some studies have demonstrated that both whole mushrooms and extracts may show anti-inflammatory activity due to the presence of bioactive compounds. This review summarizes the most recent studies investigating immunomodulatory and especially, anti-inflammatory properties of both medicinal and edible mushrooms, the compounds putatively implicated and the mechanisms that were already established.

Polysaccharides from the edible mushroom Calocybe gambosa: structure and chain conformation of a (1→4),(1→6)-linked glucan.

Three polysaccharides were isolated from the fruiting bodies of the mushroom Calocybe gambosa by cold water (PS-Cg fC), hot water (PS-Cg fH), and hot aqueous NaOH (PS-Cg fB) extractions. The size exclusion chromatograms presented in all cases a single peak showing a molecular weight of 145kDa. On the basis of acid hydrolysis, methylation analysis, and NMR analysis, the structure of the three polysaccharides appeared to be equivalent. The three carbohydrates were composed of glucose and the methylation analysis showed that the units were (1→4),(1→6)-linked with a degree of branching (DB) of 4%. NMR experiments showed that the three fractions contained the same polysaccharide. (1)H NMR spectroscopy revealed that the linkages were β-type in all cases. The complexation with Congo red demonstrated that the polysaccharides displayed a triple-strand helical conformation. The polysaccharides were composed of a repeating unit with a structure as below: [structure: see text].

Comparison of different types of stationary phases for the analysis of soy isoflavones by HPLC

Nowadays, there are new technologies in high-performance liquid chromatography columns available enabling faster and more efficient separations. In this work, we compared three different types of columns for the analysis of main soy isoflavones. The evaluated columns were a conventional reverse phase particle column, a fused-core particle column, and a monolithic column. The comparison was in terms of chromatographic parameters such as resolution, asymmetry, number of theoretical plates, variability of retention time, and peak width. The lower column pressure was provided by the monolithic column, although lower chromatographic performance was achieved. Conventional and fused-core particle columns presented similar pressure. Results also indicate that direct transfer between particle and monolithic columns is not possible requiring adjustment of conditions and a different method optimization strategy. The best chromatographic performance and separation speed were observed for the fused-core particle column. Also, the effect of sample solvent on the separation and peak shape was evaluated and indicated that monolithic column is the most affected especially when using higher concentrations of acetonitrile or ethanol. Sample solvent that showed the lowest effect on the chromatographic performance of the columns was methanol. Overall evaluation of methanol and acetonitrile as mobile phase for the separation of isoflavones indicated higher chromatographic performance of acetonitrile, although methanol may be an attractive alternative. Using acetonitrile as mobile phase resulted in faster, higher resolution, narrower, and more symmetric peaks than methanol with all columns. It also generated the lower column pressure and flatter pressure profile due to mobile phase changes, and therefore, it presents a higher potential to be explored for the development of faster separation methods.

Structural Characterization of Water-Soluble Polysaccharides from the Fruiting Bodies of Lentinus edodes Mushrooms

Water-soluble polysaccharides have been extracted from the fruiting bodies of Lentinus edodes mushrooms. Three carbohydrate fractions (cold water, hot water and hot aqueous NaOH) from the mushrooms were separated by ethanol precipitation. Size exclusion chromatography revealed the presence of a unique polysaccharide in each fraction. Cold water fraction polysaccharide (PLeC) was composed of glucose and galactose bound by (1→3) and (1→4) linkages with a high degree of branching at O-3 and O-4 of galactose residues. Hot water fraction polysaccharide (PLeH) showed (1→4),(1→6)-linked glucopyranosyl residues with branches at O-4 and O-6. Differently, hot aqueous NaOH fraction (PLeB) consisted of a (1→3),(1→6)-linked glucan branched at O-3 and O-6. NMR studies revealed that the polysaccharides PLeC and PLeH displayed both α and β configurations whereas PLeB presented β anomeric configuration. The analysis of molecular arrangement by complexation with Congo red showed that the three polysaccharides (PLeC, PLeH and PLeB) displayed a triple helix conformation.

Use of Modified Atmosphere Packaging to Preserve Mushroom Quality during Storage

Mushrooms have attracted much attention due to their excellent nutritional and sensory properties. However, they are highly perishable and rapidly lose their organoleptic characteristics. Many methods have been employed for mushroom storage, such as packaging, blanching, canning, or freeze drying. Among them, modified atmosphere packaging (MAP) has been widely employed for preserving fresh mushrooms. MAP provides an affordable packaging system that partly avoids enzymatic browning, fermentation and other biochemical processes by maintaining a controlled gas atmosphere. Several factors, including optimum CO2 and O2 partial pressures, permeability, package material, thickness, or product weight, must be considered in order to design a suitable modified atmosphere package for mushrooms. Thus, different strategies are available to preserve mushroom quality after harvest. The article presents some promising patents on use of modified atmosphere packaging to preserve mushroom quality during storage.