Aneli M. Barbosa-Dekker

Effect of natural polymers on the survival of Lactobacillus casei encapsulated in alginate microspheres

Abstract Linseed and okra mucilages, the fungal exopolysaccharide botryosphaeran, and commercial fructo-oligosaccharides (FOS) were used to microencapsulate Lactobacillus casei LC-01 and L. casei BGP 93 in sodium alginate microspheres by the extrusion technique in calcium chloride. The addition of carbohydrate biopolymers from linseed, okra and the fungal exocellular (1 → 3)(1 → 6)-β-D-glucan, named botryosphaeran provided higher encapsulation efficiency (EE) (>93% and >86%) for L. casei LC 01 and L. casei BGP 93, respectively. The use of linseed, okra and botryosphaeran improved the stability of probiotics encapsulated in the microspheres during the storage period over 15 d at 5 °C when compared to microspheres formulated with sodium alginate alone as the main encapsulating agent (p ≤ 0.05). In in vitro gastrointestinal simulation tests, the use of FOS combined with linseed mucilage was shown to be more effective in protecting L. casei cells LC-01 and L. casei BGP 93.

Botryosphaeran reduces obesity, hepatic steatosis, dyslipidaemia, insulin resistance and glucose intolerance in diet-induced obese rats

Aims: Obesity is associated with comorbidities such as diabetes and hepatic steatosis. &bgr;‐Glucans have been described as effective in treating conditions including dyslipidaemia and diabetes. Thus, the objective of this study was to evaluate the effects of botryosphaeran [(1 → 3)(1 → 6)‐&bgr;‐D‐glucan] on obesity and its comorbidities, and understand its mechanism of action. Main methods: Obesity was induced in adult male Wistar rats by ingestion of a high‐fat diet and water with sucrose (300 g/L) for 8 weeks. Control rats received standard diet. After six weeks, treatment commenced with botryosphaeran (12 mg/kg.b.w., via gavage, 15 days), respective controls received water. Rats were divided into 3 groups: control (C), obese (O), and obese + botryosphaeran (OB). In the 8th week, obesity was characterized. Feed‐intake, glucose and lipid profiles, glucose tolerance, and concentrations of glycogen and lipids in liver were analyzed. Protein expression was determined by Western blotting. Key findings: Obese rats showed significant increases in weight gain and adipose tissue, presented glucose intolerance, dyslipidaemia, and hepatic steatosis. Botryosphaeran significantly reduced feed intake, weight gain, periepididymal and mesenteric fat, and improved glucose tolerance. Botryosphaeran also reduced triglyceride and VLDL, and increased HDL levels. Furthermore, botryosphaeran increased glycogen and reduced total lipids, triglycerides and cholesterol in liver, and increased AMP‐activated protein kinase(AMPK) activity and Forkhead transcription factor 3a(FOXO3a) protein expression in adipose tissue. Significance: This study demonstrated that botryosphaeran was effective in reducing obesity, hepatic steatosis, dyslipidaemia insulin resistance and glucose intolerance in diet‐induced obese rats, and these effects were, at least in part, associated with reduced feed intake, and AMPK and FOXO3a activities.

Blueberry and honey vinegar: successive batch production, antioxidant potential and antimicrobial ability

Gourmet vinegars are versatile culinary ingredients that have aroused the interest of consumers not only for their unusual taste, but also for their health benefits. In this work, blueberry and honey wine was first obtained using a bench-scale bioreactor. This wine had high concentrations of phenolic compounds (706.18 mg GAE/mL) and appreciable free radical scavenging ability against DPPH (161.42 μmol trolox equivalent/100 mL) and ABTS•+ (356.41 μmol trolox equivalent/100 mL), as well as ferric-ion reducing antioxidant capacity (1419.86 μmol FeSO4/100 mL). In sequence, vinegar was produced from the wine in wooden barrels using successive acetification cycles. The average acetic acid concentration found in the vinegars was 4.4 g/100 mL, and the average acetic acid yield and volumetric productivity were 52.69% and 0.38 g/(L.h), respectively. Appreciable polyphenolic compounds (681.87 to 847.98 μg GAE/mL) and anthocyanin (12.8 to 15.39 mg/L) contents were found and high antioxidant activity. In addition, the vinegars demonstrated antimicrobial ability against Bacillus subtilis and Salmonella enterica Typhimurium.

Structure and Biological Functions of d-Glucans and Their Applications

Abstract Glucans are natural macromolecules obtained from the cell wall of yeast and cereals or as an extracellular metabolite from filamentous fungi and bacteria. Glucans have wide commercial applications in the chemical and pharmaceutical sectors because of their biomedical and technological properties. They constitute the group of biomacromolecules with demonstrated activity in stimulating the immune system and have potential in treating human disease conditions. Such biomacromolecules display anticoagulant, antithrombotic, antioxidant, and antiinflammatory activities, and they have been effective in lowering blood cholesterol levels, in reducing the risk of cardiovascular problems, and in treating various illnesses such as cancer, diabetes, and microbial infections. The chemical and conformational structure of glucans has a close relationship with biological and biomedical activities. The biological response depends on the number of units, degree of polymerization, frequency of branching, type of connections, and chain length, which corresponds to primary structure. Furthermore, there exist a considerable number of studies that described the importance of the three-dimensional conformation of the molecule on its biological properties. In this review, we show the latest advances and citations regarding the relationship between the chemical and conformational structure of glucans on antioxidant activity, immune response, antiproliferative, and hypocholesterolemic activities, as well as in the control of obesity and other benefits in human health.

In vitro protective effects of botryosphaeran, a (1 → 3;1 → 6)-β-d-glucan, against mutagens in normal and tumor rodent cells

Botryosphaeran (BOT) is an exocellular β-d-glucan (carbohydrate biopolymer) of the (1→3;1→6)-linked type produced by Botryosphaeria rhodina MAMB-05. The cytotoxic, mutagenic, genotoxic, and protective effects of this substance were evaluated in Chinese hamster lung fibroblasts (V79) and rat hepatocarcinoma cells (HTC) by the micronucleus test (MN) and the comet assay. BOT was not genotoxic in either cell line; it decreased the clastogenic effects of doxorubicin, H2O2, and benzo[a]pyrene. These results indicate that BOT may have potential as a therapeutic agent.

Sulfonation of (1→6)-β-D-Glucan (Lasiodiplodan) and Its Antioxidant and Antimicrobial Potential

The objective of this study was to investigate the sulfonation of (1→6)-β-D-glucan (lasiodiplodan) as a potentiating mechanism for biological functionalities. Lasiodiplodan was sulfonated by the chlorosulfonic acid-pyridine method. The modified exopolysaccharide was characterized by FT-IR and C NMR spectroscopy, X-ray diffraction and SEM. Antioxidant activity was assessed by the methods of H2O2 and OH radical removal and reducing power. Antimicrobial potential was evaluated by the broth-microdilution method. Sulfonation resulted in a derivative with DS of 0.24. FT-IR analysis indicated the introduction of sulfonyl groups in the macromolecule structure through specific bands in the regions of 1,240 cm and 810 cm. C NMR analysis suggested that sulfonation occurred at carbon 2 of the glucose residue. Sulfonation led to morphological changes in the structure of the biopolymer resulting in a heterogeneous structure with the presence of fibrils. Derivatization promoted an increase in the antioxidant ability of the macromolecule, with a high OH removal potential (74.32%). Bacteriostatic activity against E. coli (Escherichia coli) and S. enterica (Salmonella enterica) typhimurium and fungicidal activity against C. albicans (Candida albicans) and C. tropicalis (Candida tropicalis) were found in the sulfonated sample. Sulfonation potentiated the antioxidant and antimicrobial activities of the biomacromolecule, suggesting that it is a potentiating mechanism of biological functions.