Zwitterion modified chitosan as a high-performance corrosion inhibitor for mild steel in hydrochloric acid solution.

Herein, a novel chitosan Schiff base (CS-FGA) as a sustainable corrosion inhibitor has been successfully synthesized via a simple amidation reaction by using an imidazolium zwitterion and chitosan (CS). The corrosion inhibition property of CS-FGA for mild steel (MS) in a 1.0 M HCl solution was studied by various electrochemical tests and physical characterization methods. The findings indicate that the maximum inhibition efficiency of CS-FGA as a mixed-type inhibitor for MS in 1.0 M HCl solution with 400 mg L-1 reaches 97.6 %, much much higher than the CS and the recently reported chitosan-based inhibitors. Scanning electron microscopy (SEM), atomic force microscopy (AFM), and water contact angle (WCA) results reveal that the CS-FGA molecules firmly adsorb on the MS surface to form a protective layer. The adsorption of CS-FGA on the MS surface belongs to the Langmuir adsorption isotherm containing both the physisorption and chemisorption. According to the X-ray photoelectron spectroscopy (XPS) and UV-vis spectrum, FeN bonds presented on the MS surface further prove the chemisorption between CS-FGA and Fe to generate the stable protective layer. Additionally, theoretical calculations from quantum chemical calculation (DFT) and molecular simulations (MD) were performed to reveal the inhibition mechanism of CS-FGA.

Corrosion inhibition activity of a natural polysaccharide from Dysosma versipellis using tailor-made deep eutectic solvents.

In this work, a total of 18 types of choline chloride, betaine, and L-proline-based deep eutectic solvents (DESs) were synthesized to determine the extraction yield of a natural polysaccharide (PSA) from Dysosma versipellis using an ultrasound-assisted extraction method. Results indicate that the choline-oxalic acid-based DES has the best extraction yield for PSA due to the proper physical-chemical properties between PSA and DES. To evaluate the optimal extraction conditions, a response surface methodology was carried out. Under the optimal conditions, the extraction yield of PSA reaches 10.37 % (± 0.03 %), higher than the conventional extraction methods. Findings from FT-IR and NMR suggest that the extracted PSA belongs to a neutral polysaccharide with (1 â†’ 6)-linked α-d-glucopyranose in the main chain. Interestingly, results from various electrochemical measurements show the extracted PSA exhibits excellent corrosion inhibition performance for mild steel (MS) in a 0.5 M HCl solution, with 90.8 % of maximum corrosion inhibition efficiency at 210 mg L-1. SEM and XPS measurements reveal the formation of a protective layer on the MS surface. The adsorption behaviour of extracted PSA well obeys the Langmuir adsorption isotherm containing the chemisorption and physisorption. Additionally, theoretical calculations validate the experimental findings.

Natural chitosan-based carbon dots as an eco-friendly and effective corrosion inhibitor for mild steel in HCl solution.

Polysaccharide chitosan and L-histidine were applied to synthesize chitosan-based carbon dots (CA-CDs) by a simple laser ablation method. After characterization of the CA-CDs by FT-IR, UV-vis, Raman, XRD, TEM, and XPS, the CA-CDs were introduced as an eco-friendly and high-performance corrosion inhibitor for mild steel (MS) in 1.0 M HCl solution. The inhibition action and mechanism of CA-CDs were determined by weight loss and electrochemical measurements, in combination with SEM, AFM, and XPS. The results show that CA-CDs as mixed-type inhibitors could effectively weaken the corrosion of MS in 1.0 M HCl solution, and their maximum inhibition efficiency reaches 97.4 % at 40 mg L-1. The adsorption behavior of CA-CDs well obeys the Langmuir adsorption isotherm containing both chemisorption and physisorption. The chemisorption mainly results from the multiple adsorption sites in the CA-CDs, and the physical adsorption is due to the blocking and barrier effect of CA-CD nanoparticles. Both adsorption behaviors were proposed to elucidate the corrosion inhibition mechanism of CA-CDs.

Dopamine modified natural glucomannan as a highly efficient inhibitor for mild steel: Experimental and theoretical methods.

In this work, Glucomannan was modified with dopamine to synthesize a new polysaccharide Schiff base (GAD). After confirmation of GAD by NMR and FT-IR spectroscopic methods, it was introduced as a sustainable corrosion inhibitor with excellent anti-corrosion action for mild steel in 0.5 M hydrochloric acid (HCl) solution. Employing electrochemical test, morphology measurement, and theoretical analysis, the anticorrosion performance of GAD on mild steel in 0.5 M HCl solution is determined. Maximum efficiency of GAD for suppressing the corrosion rate of mild steel at 0.12 g L-1 reaches 99.0 %. After immersion in HCl solution for 24 h, the results from scanning electron microscopy indicate that GAD is firmly attached to the mild steel surface by making a protective layer. According to the X-ray photoelectron spectroscopy (XPS), FeN bonds existed on the steel surface indicate the presence of chemisorption between GAD and Fe to form stable complexes attracted to the active position on the mild steel. The effects of Schiff base groups on the corrosion inhibition efficiencies were also investigated. Moreover, the inhibition mechanism of GAD was further illustrated by the free Gibbs energy, quantum chemical calculation and molecular dynamics simulation.

Validation of the Asia-Pacific colorectal screening score and its modified versions in predicting colorectal advanced neoplasia in Chinese population.

BACKGROUND: Colorectal cancer is one of the most common cancers in the world. Several studies suggest using the Asia-Pacific colorectal screening (APCS) score and its modified versions to select high-risk populations for early colonoscopy, but external validation remains rare, and which score should be selected for CRC screening in China is unclear. Validation of multiple scores in the same population might help to choose the best performing score. METHODS: We conducted a cross-sectional study under the framework of Cancer Screening Program in Urban China, data from asymptomatic colorectal cancer screening in Xuzhou was used to validate the APCS score, the colorectal neoplasia predict (CNP) score, the Korean colorectal screening (KCS) score, the Modified APCS score and the 8-point risk score in predicting colorectal advanced neoplasia (CAN). RESULTS: 1804 subjects were included in the analysis and 112 CAN (6.21%) was detected. In each score, the detection rate of CAN was higher in the high-risk group than in the non-high-risk group (P < 0.05), and the RR (95%C.I.) ranged 2.20 (1.50-3.22) [8-point risk] to 4.00 (2.41-6.65) [Modified APCS]. The c-statistics (95%C.I.) of the scoring systems ranged from 0.58 (0.53-0.62) [8-point risk] to 0.65 (0.61-0.69) [KCS]. The sensitivity (95%C.I.) of these systems ranged from 31.25 (22.83-40.70) [8-point risk] to 84.82 (76.81-90.90) [Modified APCS], while the specificity (95%C.I.) ranged from 43.50 (41.12-45.90) [Modified APCS] to 83.81 (81.96-85.53) [8-point risk]. Using the APCS scoring system as a comparator, the net reclassification improvement (NRI) of each modified version ranged from - 10.34% (95%C.I.: - 22.63 to 1.95%) [8-point risk] to 4.79% (95%C.I.: - 1.50% to 11.08) [KCS]. The colonoscopy resource load (95%C.I.) ranged from 9 [1-3] [8-point risk] to 11 [3-5] [APCS and Modified APCS]. CONCLUSIONS: The APCS score and its modified versions have certain ability to predict the risk of advanced neoplasia and reduce the resource load. The modified APCS score and the KCS score seemed the preferable systems to classify high risk subjects based on its high RR, sensitivity and predictive ability in the selected population. Future research could focus on adding risk factors or combining with laboratory test results to improve the predictive power of the scoring system.

Simultaneous detection of multiple phenolic compounds in fish by gas chromatography-mass spectrometry following a modified QuEChERS cleanup.

Phenolic compounds can cause health problems in humans through the food chain. Considering that fish play an important role in human diets, we established a rapid, simple and high-throughput method for the determination of 18 phenolic compounds in fish based on a modified QuEChERS sample preparation method combined with GC-MS. The average recovery of the 18 phenolic compounds was 81.3-116% at 3 spiked levels, and the relative standard deviations, RSDr and RSDwR, were in the range of 1.1-11.3% and 1.5-12.2%, respectively. The limit of detection was 2.0-10.1 µg/kg. Satisfactory linear relationships (R2 > 0.998) were observed for the phenolic compounds in their corresponding concentration ranges. Moreover, the established method exhibited a high sensitivity, good stability, and reliability. The development of this method has an important theoretical and practical significance for establishing standards and to control the residue levels of phenolic compounds in fish.

Synthesis of Rice Husk-Based MCM-41 for Removal of Aflatoxin B1 from Peanut Oil.

Edible oils, especially peanut oil, usually contain aflatoxin B1 (AFB1) at extremely high concentrations. This study focused on the synthesis of rice husk-based mesoporous silica (MCM-41) for the removal of AFB1 from peanut oil. MCM-41 was characterized by X-ray diffraction, N2 physisorption, and transmission electron microscope. MCM-41 was shown to have ordered channels with high specific surface area (1246 m2/g), pore volume (1.75 cm3/g), and pore diameter (3.11 nm). Under the optimal concentration of 1.0 mg/mL of the adsorbent dose, the adsorption behavior of MCM-41, natural montmorillonite (MONT), and commercial activated carbon (CA) for AFB1 were compared. The adsorption of AFB1 in peanut oil onto the three adsorbents was slower compared to that of AFB1 in an aqueous solution. In addition, the pseudo-second-order kinetic model better fit the adsorption kinetics of AFB1, while the adsorption mechanism followed the Langmuir adsorption isotherm on the three adsorbents. The calculated maximum adsorbed amounts of AFB1 on MONT, MCM-41, and CA were 199.41, 215.93, and 248.93 ng/mg, respectively. These results suggested that MCM-41 without modification could meet market demand and could be considered a good candidate for the removal of AFB1 from peanut oil. This study provides insights that could prove to be of economic and practical value.

Effects of Five Different Lactic Acid Bacteria on Bioactive Components and Volatile Compounds of Oat.

In this research, oats were fermented with Lactobacillus plantarum, Lactobacillus acidophilus, Lactobacillus casei, Lactobacillus bulgaricus and Streptococcus thermophilus for 48 h at 37 °C. The purpose of this work was to compare the growth capacities of the five lactic acid bacteria (LAB) in the oat matrix and the effects of fermentation on the contents of the bioactive components of oat, such as ß-glucan, polyphenols, flavonoids and volatile compounds at different time (0, 4, 8, 12, 24, 36 and 48 h). After 48 h of fermentation, the number of living L. acidophilus in oat reached 7.05 × 109 cfu/mL, much higher than that of other strains. S. thermophilus retained the greatest ß-glucan content, and L. casei had increased total polyphenol and total flavonoid contents. The proportion of free and bound polyphenols and flavonoids in all samples was changed by microbial action, indicating that forms of polyphenols and flavonoids can be transformed during the fermentation process, and the changes varied with different strains. The samples with L. plantarum, L. acidophilus, and L. casei fermentation contained more alcohols, whereas those with S. thermophilus and L. bulgaricus fermentation had more aldehydes, which revealed that the composition of volatile components was related to strains. The results indicate that oat substrate is a good medium for LAB growth. This study provides a reference for the use of different strains to achieve different fermentation purposes and a theoretical basis for the further processing of oat and fermented oat beverages.

Precise diagnosis of three top cancers using dbGaP data.

The challenge of decoding information about complex diseases hidden in huge number of single nucleotide polymorphism (SNP) genotypes is undertaken based on five dbGaP studies. Current genome-wide association studies have successfully identified many high-risk SNPs associated with diseases, but precise diagnostic models for complex diseases by these or more other SNP genotypes are still unavailable in the literature. We report that lung cancer, breast cancer and prostate cancer as the first three top cancers worldwide can be predicted precisely via 240-370 SNPs with accuracy up to 99% according to leave-one-out and 10-fold cross-validation. Our findings (1) confirm an early guess of Dr. Mitchell H. Gail that about 300 SNPs are needed to improve risk forecasts for breast cancer, (2) reveal an incredible fact that SNP genotypes may contain almost all information that one wants to know, and (3) show a hopeful possibility that complex diseases can be precisely diagnosed by means of SNP genotypes without using phenotypical features. In short words, information hidden in SNP genotypes can be extracted in efficient ways to make precise diagnoses for complex diseases.

Preservation of hydrogen peroxide-induced oxidative damage in HepG-2 cells by rice protein hydrolysates pretreated with electron beams.

In this paper, electron beam irradiated rice protein hydrolysates (ERPHs) were assessed for their ability to prevent hydrogen peroxide-induced oxidative stress in human HepG-2 cells. The related mechanism was also studied by analyzing the structural changes. Cytotoxicity experiments showed that rice protein hydrolysates pretreated with electron beam irradiation (EBI) were not toxic to cells if appropriate concentrations were applied. Cell viability markedly increased when the cells were treated with ERPHs before H2O2 induction. Furthermore, the ERPHs effectively suppressed H2O2-induced ROS production and lipid peroxidation and increased the protein expression levels of the intracellular antioxidant enzymes SOD, GSH-Px and CAT in H2O2-stressed HepG-2 cells. Consequently, the loss of mitochondrial membrane potential and cell apoptosis was alleviated. Circular dichroism analysis showed that pretreatment of rice protein with EBI significantly changed the secondary structure (the conversion of α-helices to random coils), which is beneficial to the improvement of its antioxidative activity. ERPHs exhibited stronger antioxidative effects than those without irradiation, possibly because of the difference in molecular weight distribution and amino acid composition. These findings indicate an efficient way to produce peptides with better antioxidant activity.

Absorption Rates and Mechanisms of Avenanthramides in a Caco-2 Cell Model and Their Antioxidant Activity during Absorption.

Avenanthramides (AVNs) are a unique kind of polyphenols that were only detected in the oats and have been demonstrated to exhibit strong antioxidant activities but low bioavailability. The purpose of the present research was to evaluate the absorption rates and mechanisms of AVNs (AVN 2c, AVN 2f, and AVN 2p) using a human colon adenocarcinoma cell line (Caco-2) cell model and clarify the influence of the absorption process on the antioxidant capacities of AVNs. Furthermore, the absorption rates and antioxidant activities of ferulic acid and caffeic acid were compared with those of AVNs. Results showed that the apparent absorption rates (Papp) of AVN 2c, AVN 2f, and AVN 2p were 0.65 ± 0.05 × 10-6, 1.18 ± 0.16 × 10-6, and 1.44 ± 0.09 × 10-6 cm/s, respectively, which were significantly lower than those of caffeic acid (3.76 ± 0.31 × 10-6 cm/s) and ferulic acid (1.69 ± 0.13 × 10-5 cm/s). Moreover, the metabolites (caffeic acid, ferulic acid, and AVN 2f) of AVNs after absorption were detected and quantified by high-performance liquid chromatography-mass spectrometry. Before absorption, although the antioxidant capacities of AVNs were significantly stronger than those of ferulic acid and caffeic acid, there was an opposite result after absorption. In addition, AVNs transported the Caco-2 monolayer by paracellular diffusion and were affected by monoamine oxidase and efflux transporters (P-gp, MRP2) during absorption. The co-administration of quercetin could significantly improve the absorption rates of AVNs.

Effect of high energy electron beam on proteolysis and antioxidant activity of rice proteins.

This research focused on the effects of electron beam irradiation (EBI) on the hydrolysis and antioxidant activity of rice proteins (RPs). The RPs were treated with 0, 5, 10, 20 and 30 kGy doses of EBI. The results showed that EBI pretreatment improved significantly (P < 0.05) the degree of hydrolysis, increasing the DH value by more than 15.09% at a dose of 30 kGy. In addition, radical scavenging results showed that EBI treatment had effects on antioxidant activity and could increase the DPPH and ABTS+ radical scavenging activity of rice protein hydrolysates (RPHs) by 32.06% and 79.11%, respectively (30 kGy). The CAA test also confirmed that EBI pretreatment could effectively improve the ability of RPHs to remove intracellular free radicals. Scanning electron microscopy indicated that EBI treatment destroyed microstructures and resulted in cracks and fragments of RPs. Circular dichroism analysis showed that EBI affected the secondary structure of RPs by destroying the α-helix structure. Changes in the UV visible spectra indicated unfolding of RPs by EBI. Amino acid and molecular weight distribution analysis revealed that EBI pretreatment could increase the ratio of antioxidant-related amino acids and produce smaller peptides. Therefore, EBI pretreatment is an efficient method to promote protein proteolysis due to its effect on the molecular conformation as well as on protein microstructure. Moreover, EBI treatment applied before enzymatic hydrolysis has the potential to prepare hydrolysates with high bioactivity.

Diagnostic Accuracy Of Fecal Occult Blood Tests For Detecting Proximal Versus Distal Colorectal Neoplasia: A Systematic Review And Meta-Analysis.

OBJECTIVE: We conducted a systematic review and meta-analysis aimed at evaluating the differences of diagnostic performance of fecal occult blood tests (FOBTs) in detecting advanced colorectal neoplasms located in the proximal versus distal colorectum. METHODS: PubMed, Embase, Cochrane Library, and Web of Science were searched for eligible articles published before August 17, 2018. Two independent reviewers conducted study assessment and data extraction. Diagnosis-related indicators of FOBT for detecting proximal and distal colorectal neoplasms were summarized, and further stratified by the type of FOBT (guaiac-based FOBT (gFOBT) and immunochemical FOBT (iFOBT)). Pooled sensitivities and specificities were calculated using a random effect model. Summary receiver operating characteristic curves were plotted and area under the curves were calculated. RESULTS: Overall, 31 studies meeting the inclusion criteria were included in this review. For gFOBT, we found no site-specific difference (proximally vs distally located) of pooled sensitivities observed in the colorectal cancer (CRC), advanced adenomas, and advanced neoplasms groups. As for iFOBT, pooled sensitivities for detecting CRC located in the distal colon/rectum were comparable with that in the proximal colon (proximal vs distal, 0.67, 95% CI 0.62-0.72 vs 0.72, 95% CI 0.68-0.75), while higher pooled sensitivities for detecting advanced adenomas and advanced neoplasms located in the distal colon/rectum than for detecting those in the proximal colon were observed for iFOBT with the values of 0.24 (95% CI 0.22-0.25) vs 0.32 (95% CI 0.30-0.34) and 0.25 (95% CI 0.23-0.28) vs 0.38 (95% CI 0.36-0.40), respectively. Summary receiver operating characteristic curve analyses showed similar patterns for both types of FOBT regarding the diagnostic accuracy for detecting colorectal neoplasms according to the anatomical sites of the colorectum. CONCLUSION: iFOBT had higher sensitivity for detecting advanced adenomas and advanced neoplasia located in the distal colon/rectum than that for those in the proximal colon.

Effects of Milk Proteins on the Bioaccessibility and Antioxidant Activity of Oat Phenolics During In Vitro Digestion.

This study investigated the effects of milk solution or milk proteins (casein and whey protein) on the bioaccessibility and antioxidant activity of oat phenolics during in vitro gastric and pancreatic digestion. During digestion, most of oat phenolics were partially degraded by alkaline pH of pancreatic fluid (pH 7.5). For phenolic acids, both milk solution and milk protein only had a slight influence on their bioaccessibility, while exhibited a significant effect on antioxidant activity of oat phenolic extracts and bioaccessibility of avenanthramides (AVs), a kind of bioactive phenols exclusively found in oats. The antioxidant activity and bioaccessibility of AVs were decreased by adding milk and casein, while significantly improved when mixed with milk whey protein. Remarkably, the bioaccessibility of AV 2c, which had the highest antioxidant activity among all phenolic compounds detected in oats, increased above 360% after intestinal digestion by mixing with whey protein. This result suggested the possibility of protecting AVs against digestive alteration and oxidation by milk whey protein. PRACTICAL APPLICATION: In recent years, oats are often consumed with milk under different conditions of preparation, and there have been many oat milk products manufactured by food companies all over the world. The results of this paper showed that the adding of milk may reduce the absorption and antioxidant activity of phenolic compounds from oat. However, the antioxidant activity and bioaccessibility of oat phenolics were significantly increased when mixed with milk whey protein, suggesting that oats could be consumed with milk whey protein to improve their functional properties.

Phenolic contents, cellular antioxidant activity and antiproliferative capacity of different varieties of oats.

The objectives of this research were to determine the phenolic contents, oxygen radical absorbance capacities (ORAC), cellular antioxidant activities (CAA), and antiproliferative capacities of nine oat varieties and four brans in China. Of all varieties, Longyan 3 and Beiyan 1 exhibited the highest total avenanthramides (146.94±7.31 and 120.95±6.66µg/g, respectively) and ORAC values (21.03±0.56 and 21.18±1.45µM Trolox/g, respectively), while Shaotong exhibited the highest total phenolic acids (143.52±9.42µg/g) and CAA values (33.38±1.74µM quercetin/100g). The EC50 of antiproliferative capacities ranged from 167.31±6.42 to 233.42±21.31mg/mL, with the lowest in Beixiao 8 while the highest in Jinyan 8. ORAC values correlated with avenanthramides while CAA values correlated with phenolic acids. Moreover, phenolic contents, antioxidant properties, and antiproliferative capacities of oat brans was higher than that of corresponding whole oats in most cases.

Isolation of a novel calcium-binding peptide from wheat germ protein hydrolysates and the prediction for its mechanism of combination.

To isolate a novel peptide with specific calcium-binding capacity, wheat germ protein was hydrolyzed. The hydrolysates were purified using ultrafiltration, anion-exchange chromatography, gel filtration chromatography, and reversed-phase high performance liquid chromatography. The amino acid sequence of the purified peptide was determined and confirmed to be FVDVT (Phe-Val-Asp-Val-Thr). The calcium-binding capacity of FVDVT reached 89.94±0.75%, increased by 86.37% compared to the hydrolysates. The chelating mechanism between FVDVT and calcium was further investigated by Ultraviolet-Visible absorption spectroscopy, Fourier transform infrared spectroscopy, X-ray diffraction, and 1H nuclear magnetic resonances spectroscopy. The results indicated that the oxygen atoms of the carboxy group and the nitrogen atoms of the amido group provided major binding sites. In addition, aspartic acid and threonine show considerable capacity for incorporating with calcium by donating electron pairs. This study provides a feasible approach to isolate calcium-binding peptides and to clarify the possible binding mechanism of calcium and peptide.

In vivo toxicity assessment of deoxynivalenol-contaminated wheat after ozone degradation.

The effect of ozone on deoxynivalenol (DON) detoxification was investigated. Ozone treatment could significantly reduce the levels of DON in wheat; 53% of DON in wheat was decomposed with 90 mg l-1 of ozone at a flow rate of 15 l min-1 for 4 h. The safety of DON-contaminated wheats (DCWs) untreated/treated by ozone was also evaluated. Institute of Cancer Research (ICR) mice were divided into a standard diet group and five experimental diet groups for a 51-day orally administration experiment. In the experiment, no remarkable changes in the general appearance of the mice were observed, and all the mice survived until the scheduled necropsy. The results of sub-chronic toxicity indicated that mice fed on DCWs alone had significantly decreased in body weight gain, thymus and spleen weights, ratios of liver, thymus and spleen to body weight, blood indices (red blood cell, haemoglobin, white blood cell), and pro-inflammatory cytokines (interleukin-6 (IL-6), tumour necrosis factor alpha (TNF-α)), while showing a significant increase in alanine aminotransferase, aspartate aminotransferase, blood creatinine and blood urea nitrogen levels. Histopathological examination indicate that DON elicited some degree of toxicity on the liver, kidney and thymus tissue. Mice fed on DCWs treated by ozone mitigated the adverse effects compared with mice fed on DCWs. All the results suggested that the deleterious effects of DON could be highly reduced by ozone, and ozone itself shows minor toxic effects on animals in this process.

Antitumor activities and immunomodulatory of rice bran polysaccharides and its sulfates in vitro.

Polysaccharides purified from rice bran show antitumor activity against tumor cells, yet the mechanism of this action remains poorly understood. To address this issue, our study evaluated the effect of rice bran polysaccharides on mouse melanoma cell line B16, and Raw264.7 macrophages. Rice bran polysaccharides (RBP) failed to inhibit B16 cell growth in vitro. However, Raw264.7 macrophages treated by RBP enhancement of cytotoxic effects. The cytotoxicity was confirmed by the stimulation of nitric oxide (NO) production and tumor necrosis factor-α (TNF-α) secretion on Raw264.7 macrophages in a dose-dependent manner. RBP2, a fraction of RBP, notably enhanced the inhibition of B16 cells and boosted the immunepotentiation effect compared with RBP. To further enhance the inhibition of B16 cell growth, sulfated polysaccharides (SRBP) was derived using the chlorosulfonic acid-pyridine method. SRBP2 was found to suppress B16 cell growth, reduce B16 cell survival and stimulate NO and TNF-α production. However, SRBP2 displayed a cytotoxic effect on Raw264.7 macrophages. These results suggest that the antitumor activity of RBP and RBP2 is mediated mainly through the activation of macrophages. SRBP2 exerts its antitumor activity by inducing apoptosis in tumor cells and the secretion of NO and TNF-α.

Protective effects of rice dreg protein hydrolysates against hydrogen peroxide-induced oxidative stress in HepG-2 cells.

In this paper, the effects of rice dreg protein hydrolysates (RDPHs) obtained by various proteases on hydrogen peroxide-induced oxidative stress in HepG-2 cells were investigated. Cell cytotoxicity was evaluated through the aspects of cell viability, ROS level, antioxidant enzyme activity, and production of malondialdehyde (MDA). Cell apoptosis was assessed by flow cytometry. Molecular weight distribution was analyzed by gel permeation chromatography, and amino acid composition was measured using an automatic amino acid analyzer. The survival of cells and the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were significantly increased through the pre-incubation of HepG-2 cells with RDPHs before H2O2 exposure. Additionally, these pretreatments also resulted in a reduction in ROS and MDA levels. As a result, apoptosis and loss of mitochondrial membrane potential of the HepG-2 cells were alleviated. Furthermore, the protective effects of protein hydrolysates obtained by various proteases were noticeably distinct, in which RDPHs prepared by alkaline protease showed higher antioxidant activities. The difference in the protective effects might be attributed to the specific peptide or amino acid composition. Therefore, enzymatic hydrolysis with different enzymes studied here could attenuate H2O2-induced cell damage, and the type of protease greatly influenced the anti-oxidative activity. Particularly, optimum use of Alcalase could produce peptides with higher antioxidant activity.

Characterization of selenium-enriched mycelia of Catathelasma ventricosum and their antihyperglycemic and antioxidant properties.

This is the first report concerning the selenium enrichment of Catathelasma ventricosum mycelia. The selenium-containing proteins present in selenium-enriched mycelia (Se-MC) were identified using size-exclusion chromatography-inductively coupled plasma-mass spectrometry (SEC-ICP-MS). The selenium-containing amino acids liberated by hydrolysis of these proteins were identified using anion exchange-ICP-MS. Se-MC was found to contain selenoproteins with molecular weights ranging from 1.7 to 60.5 kDa. The main selenium-containing amino acids within them were selenomethionine and selenocysteine. Furthermore, Se-MC possessed excellent antihyperglycemic and antioxidant properties. Se-MC normalized biochemical parameters like insulin level, blood glucose level, body weight, and antioxidant enzyme activity in streptozocin-induced diabetic mice. It also inhibited the α-amylase and α-glucosidase activities present in in vitro gastric and intestinal models. In conclusion, Se-MC has the potential to serve as a dietary supplement of selenium, an antioxidant, or an ingredient for the formulation of nutraceuticals.