Preparation of a new resource food-arabinogalactan and its protective effect against enterotoxicity in IEC-6 cells by inhibiting endoplasmic reticulum stress

Plant polysaccharides can be used as bioactive natural polymers that provide health benefits, however high molecular weight neutral polysaccharides have not shown good bioactivity. In this study, high molecular weight neutral arabinogalactan was isolated and structurally characterized to investigate it antioxidant activity against IEC-6 cells. In this study, a neutral polysaccharide (AG-40-I-II) was obtained from the roots of Larix gmelinii (Rupr.) Kuzen. and purified using ethanol fractional precipitation and purification on a DEAE-52 cellulose column and a Superose 12 gel filtration column. The structural characteristics of AG-40-I-II was detected by chemical and spectroscopic methods. The results showed that the average molecular weight of AG-40-I-II was 18.6 kDa, the main chain was composed of →4)-β-D-Gal-(1, → 4, 6)-β-D-Gal-(1 and →4)-β- D-Glc-(1, the side chain is composed of T-β-L-Araf(1 → 6). The effect of AG-40-I-II on H2O2-induced IEC-6 cell injury was determined by MTT method. Besides, AG-40-I-II could reduce the level of MDA and increase SOD activity on IEC-6 cells, which could significantly inhibit the production of ROS. Importantly, AG-40-I-II inhibited the splicing of XBP1 by IRE1α through the ERS pathway and reduced the cell apoptosis induced by H2O2. In summary, the results of this study indicate that AG-40-I-II, as a natural source of plant polysaccharides, has good antioxidant activity, and is expected to become a safe plant source of natural antioxidants, which has great potential in biomedicine potential.

Selenium deficiency induced apoptosis via mitochondrial pathway caused by Oxidative Stress in porcine gastric tissues

Selenium (Se) is an essential nutrient for the body, which can ensure GSH-Px activity and has antioxidant effect. Se deficiency may lead to apoptosis in various tissues and organs in animals. Pigs as major livestock in the farming industry, Se deficiency can cause various types of diseases such as white muscle disease, and mulberry heart disease.The aim of this experiment was to investigate the effect and mechanism of Se deficiency on apoptosis in porcine gastric tissue. Forty weaned piglets were randomly divided into Se deficiency group and control group, and fed with low Se diet and normal diet for six weeks respectively. The histochemical characteristics, antioxidant indexes, apoptotic genes and apoptotic protein expression of gastric cells in Se-deficient piglets were detected. The results of antioxidant index, TUNEL, RT-PCR and Western blot showed that Se deficiency decreased the activities of CAT, SOD and GSH-Px, increased the apoptotic rate of porcine gastric tissue, increased the expression of Bax and Caspase-3, and decreased the expression of Bcl-2. The results demonstrated that Se deficiency could induce apoptosis in porcine gastric tissue cells through oxidative stress-induced mitochondrial pathway. The stomach was a key target of Se deficiency and may play a key role in the response to Se deficiency. Our study may provide new ideas for the prevention and treatment of swine gastric diseases caused by Se deficiency and is beneficial to the development of pig farming industry.

Salvianolic acid B attenuates oxidative stress-induced injuries in enterocytes by activating Akt/GSK3β signaling and preserving mitochondrial function

The cellular and tissue damage induced by oxidative stress (OS) contribute to a variety of human diseases, which include gastrointestinal diseases. Salvianolic acid B (Sal B), which is a natural polyphenolic acid in Salvia miltiorrhiza, exhibits prominent antioxidant properties. However, its precise function and molecular mechanisms in protecting normal intestine epithelium from OS-induced damage are still poorly defined. In this study, we tried to clarify this relationship. Here, we found Sal B addiction in the rat intestinal epithelial cell, IEC-6, prevented H₂O₂-induced cell viability decrease and apoptosis induction, ameliorated H₂O₂-induced intestinal epithelial barrier dysfunction and mitochondrial dysfunction, and suppressed H₂O₂-induced production of ROS to varying degrees, ranging from 10% to 30%. Moreover, by employing an ischemia reperfusion model of rats, we also discovered that Sal B treatment reversed ischemia and a reperfusion-caused decrease in villus height and crypt depth, decreased proliferation of enterocytes, and increased the apoptotic index in the jejunum and ileum. Mechanistically, Sal B treatment up-regulated the phosphorylated level of Akt and GSK3β in enterocytes in vitro and in vivo, and PI3K inhibitor LY294002 treatment abrogated the protective effects of Sal B. Meanwhile, the inactivation of GSK3β reversed the oxidative stress-induced apoptosis and mitochondrial dysfunction in IEC-6 cells. Together, our results demonstrated that the damage of intestinal epithelial cells in in vitro and in vivo models were both attenuated by Sal B treatment, and such antioxidant activity might very possibly be attributed to the activation of Akt/GSK3β signaling.

Ratiometric nanoprobe for circulating tumor cell detection and intracellular hydrogen peroxide evaluation in colorectal cancer patients

The application of intensity-based H₂O₂-responsive fluorescence nanoprobe for circulating tumor cell detection was limited by the complex background and the nanoprobe uptake in each CTC. In this context, we developed a ratiometric fluorescence nanoprobe, on which a H₂O₂-responsive subunit and a stable subunit grafted working as a H₂O₂ detector and a reference, respectively. When responding to intracellular H₂O₂, the reference fluorescence (580 nm) maintained as a correction background while the detector fluorescence (450 nm) was turned on to conduct CTC enumeration and intracellular H₂O₂ evaluation. Two normal cells and three colon cancer cells were examined to evaluate their endogenous H₂O₂ with the ratiometric nanoprobe by flow cytometry and confocal laser scanning microscopy. CTC sample from colorectal cancer patients was used to validate the performance of the nanoprobe for CTC enumeration and H₂O₂ evaluation. The results indicated that not only CTC could be effectively identified based on the "turn on" fluorescence, but also the viability of the identified CTCs could be assessed with the intensity of the reference fluorescence to avoid the false-positive number. Moreover, the clinical results demonstrated that the viability CTC count combined with intracellular H₂O₂ content (described as I₄₅₀/₅₈₀)were related to the tumor TNM stage, which might provide significant guidance for clinical treatments.

Overtime expression of plasma membrane and mitochondrial function markers associated with cell death in human spermatozoa exposed to nonphysiological levels of reactive oxygen species

In many cell types, the potential of reactive oxygen species to induce death processes has been largely demonstrated. Studies in spermatozoa have associated the imbalance of reactive oxygen species and phosphatidylserine externalisation as an apoptosis marker. However, the lack of consensus about time effect in the joint expression of these and other death markers has made it difficult to understand the set of mechanisms influenced beyond the concentration effect of reactive oxygen species to stimulate cell death. Here, the plasma membrane permeability and integrity, phosphatidylserine externalisation and mitochondrial membrane potential were jointly evaluated as death markers in human spermatozoa stimulated with H₂ O₂ . The results showed a profound and sustained effect of dissipation in the mitochondrial membrane potential and an increased phosphatidylserine externalisation in human spermatozoa exposed to 3 mmol^-1 of H₂ O₂ at 30 min. This was followed by an increased membrane permeability after 45 min. The last observed event was the loss of cell membrane integrity at 60 min. In conclusion, mitochondria are rapidly affected in human spermatozoa exposed to reactive oxygen species, with the barely detectable mitochondrial membrane potential coexisting with the high phosphatidylserine externalisation in cells with normal membrane permeability.

The Effects of Two Different Burn Dressings on Serum Oxidative Stress Indicators in Children with Partial Burn

In this study, we evaluated and compared the effect of treatment with a hydrofiber dressing with silver (HFAg) and a polylactic membrane (PLM) on systemic oxidative stress in systemic inflammatory reaction in thermal burn injuries in children. A prospective randomized and matched pairing study of 20 to 50% of TBSA was performed from children equal to both sexes affected by thermal injuries. The control group was included in normal children of both sexes. Serum malondialdehyde (MDA), total antioxidant capacity (TAC), total oxidant capacity (TOC), and glutathione (GSH) levels were analyzed and the results were analyzed statistically. In this study, it was found that PLM treatment increased TAC and GSH levels in burn patients significantly more than the other group. With the use of PLM, TOC decreased to normal level from day 3. In the HFAg group, TAC and GSH levels began to increase on the seventh day. On the first day of the burn, the TOC level started to increase. This increase continued on days 7 and 14. The TOC level began to fall on the 21st day. The increase in TAC was higher in the PLM group. In the PLM group, TOC fell faster. As a result, we think that different burn dressings can have different systemic effects. We can speculate that PLM has an antioxidant effect in the burn tissue due to high lactate content. Therefore, PLM may have decreased serum oxidative stress indicators more effectively than HFAg.

Comparative genome analysis reveals key genetic factors associated with probiotic property in Enterococcus faecium strains

BACKGROUND

Enterococcus faecium though commensal in the human gut, few strains provide a beneficial effect to humans as probiotics while few are responsible for the nosocomial infection. Comparative genomics of E. faecium can decipher the genomic differences responsible for probiotic, pathogenic and non-pathogenic properties. In this study, we compared E. faecium strain 17OM39 with a marketed probiotic, non-pathogenic non-probiotic (NPNP) and pathogenic strains.

RESULTS

E. faecium 17OM39 was found to be closely related with marketed probiotic strain T110 based on core genome analysis. Strain 17OM39 was devoid of known vancomycin, tetracycline resistance and functional virulence genes. Moreover, E. faecium 17OM39 genome was found to be more stable due to the absence of frequently found transposable elements. Genes imparting beneficial functional properties were observed to be present in marketed probiotic T110 and 17OM39 strains. Genes associated with colonization and survival within gastrointestinal tract was also detected across all the strains.

CONCLUSIONS

Beyond shared genetic features; this study particularly identified genes that are responsible for imparting probiotic, non-pathogenic and pathogenic features to the strains of E. faecium. Higher genomic stability, absence of known virulence factors and antibiotic resistance genes and close genomic relatedness with marketed probiotics makes E. faecium 17OM39 a potential probiotic candidate. The work presented here demonstrates that comparative genome analyses can be applied to large numbers of genomes, to find potential probiotic candidates.