Isomelezitose Overproduction by Alginate-Entrapped Recombinant E. coli Cells and In Vitro Evaluation of Its Potential Prebiotic Effect.

In this work, the trisaccharide isomelezitose was overproduced from sucrose using a biocatalyst based on immobilized Escherichia coli cells harbouring the α-glucosidase from the yeast Metschnikowia reukaufii, the best native producer of this sugar described to date. The overall process for isomelezitose production and purification was performed in three simple steps: (i) oligosaccharides synthesis by alginate-entrapped E. coli; (ii) elimination of monosaccharides (glucose and fructose) using alginate-entrapped Komagataella phaffii cells; and (iii) semi-preparative high performance liquid chromatography under isocratic conditions. As result, approximately 2.15 g of isomelezitose (purity exceeding 95%) was obtained from 15 g of sucrose. The potential prebiotic effect of this sugar on probiotic bacteria (Lactobacillus casei, Lactobacillus rhamnosus and Enterococcus faecium) was analysed using in vitro assays for the first time. The growth of all probiotic bacteria cultures supplemented with isomelezitose was significantly improved and was similar to that of cultures supplemented with a commercial mixture of fructo-oligosaccharides. In addition, when isomelezitose was added to the bacteria cultures, the production of organic acids (mainly butyrate) was significantly promoted. Therefore, these results confirm that isomelezitose is a potential novel prebiotic that could be included in healthier foodstuffs designed for human gastrointestinal balance maintenance.

Proanthocyanidins Limit Adipose Accrual Induced by a Cafeteria Diet, Several Weeks after the End of the Treatment.

A dose of proanthocyanidins with satiating properties proved to be able to limit body weight increase several weeks after administration under exposure to a cafeteria diet. Here we describe some of the molecular targets and the duration of the effects. We treated rats with 500 mg grape seed proanthocyanidin extract (GSPE)/kg BW for ten days. Seven or seventeen weeks after the last GSPE dose, while animals were on a cafeteria diet, we used reverse transcriptase-polymerase chain reaction (RT-PCR) to measure the mRNA of the key energy metabolism enzymes from the liver, adipose depots and muscle. We found that a reduction in the expression of adipose Lpl might explain the lower amount of adipose tissue in rats seven weeks after the last GSPE dose. The liver showed increased expression of Cpt1a and Hmgs2 together with a reduction in Fasn and Dgat2. In addition, muscle showed a higher fatty oxidation (Oxct1 and Cpt1b mRNA). However, after seventeen weeks, there was a completely different gene expression pattern. At the conclusion of the study, seven weeks after the last GSPE administration there was a limitation in adipose accrual that might be mediated by an inhibition of the gene expression of the adipose tissue Lpl. Concomitantly there was an increase in fatty acid oxidation in liver and muscle.

Resveratrol Supplementation in Schizophrenia Patients: A Randomized Clinical Trial Evaluating Serum Glucose and Cardiovascular Risk Factors.

BACKGROUND: Patients with schizophrenia (SZ) are generally overweight or obese and have several metabolic disorders. Additionally, such patients have a lower life expectancy and the main cause of their increased mortality is cardiovascular disease (CVD). The objective of this study was to determine the efficacy of resveratrol supplementation on serum glucose and CVD risk factors in individuals with SZ. METHODS AND RESULTS: This is a four-week randomized, double-blind controlled trial (registration No.: NCT 02062190) in which 19 men with a diagnosis of SZ, aged 18 to 65, were assigned to either a resveratrol supplement group (200 mg/day) or a placebo group (200 mg/day). In short, we did not observe significant changes after resveratrol supplementation. In the placebo group, we found a significant increase in total cholesterol levels (p = 0.024) and in LDL-cholesterol (p = 0.002), as well as a decrease in body fat percentage (p = 0.038). The placebo group also showed an increase in triglycerides (9.19%) and a reduction in HDL-cholesterol (4.88%). In the resveratrol group, triglycerides decreased (7.64%). CONCLUSION: In summary, oral resveratrol in reasonably low dosages (200 mg daily) brought no differences to body weight, waist circumference, glucose, and total cholesterol. It was possible to note that the lipid profile in the placebo group worsened and, although no significant differences were found, we can assume that resveratrol might prevent lipid profile damage and that the intervention affected the lipoprotein metabolism at various levels.

Potassium phosphite primes defense responses in potato against Phytophthora infestans.

Although phosphite is widely used to protect plants from pathogenic oomycetes on a wide range of horticultural crops, the molecular mechanisms behind phosphite induced resistance are poorly understood. The aim of this work was to assess the effects of potassium phosphite (KPhi) on potato plant defense responses to infection with Phytophtora infestans (Pi). Pathogen development was severely restricted and there was also an important decrease in lesion size in infected KPhi-treated leaves. We demonstrated that KPhi primed hydrogen peroxide and superoxide anion production in potato leaves at 12 h post-inoculation with Pi. Moreover, the KPhi-treated leaves showed an increased and earlier callose deposition as compared with water-treated plants, beginning 48 h after inoculation. In contrast, callose deposition was not detected in water-treated leaves until 72 h after inoculation. In addition, we carried out RNA gel blot analysis of genes implicated in the responses mediated by salicylic (SA) and jasmonic acid (JA). To this end, we examined the temporal expression pattern of StNPR1 and StWRKY1, two transcription factors related to SA pathway, and StPR1 and StIPII, marker genes related to SA and JA pathways, respectively. The expression of StNPR1 and StWRKY1 was enhanced in response to KPhi treatment. In contrast, StIPII was down regulated in both KPhi- and water-treated leaves, until 48 h after infection with Pi, suggesting that the regulation of this gene could be independent of the KPhi treatment. Our results indicate that KPhi primes the plant for an earlier and more intense response to infection and that SA would mediate this response.