Identification of Corn Peptides with Alcohol Dehydrogenase Activating Activity Absorbed by Caco-2 Cell Monolayers.

Alcohol dehydrogenase (ADH) plays a pivotal role in constraining alcohol metabolism. Assessing the ADH-activating activity in vitro can provide insight into the capacity to accelerate ethanol metabolism in vivo. In this study, ADH-activating peptides were prepared from corn protein meal (CGM) using enzymatic hydrolysis, and these peptides were subsequently identified following simulated gastrointestinal digestion and their absorption through the Caco-2 cell monolayer membrane. The current investigation revealed that corn protein hydrolysate hydrolyzed using alcalase exhibited the highest ADH activation capability, maintaining an ADH activation rate of 52.93 ± 2.07% following simulated gastrointestinal digestion in vitro. After absorption through the Caco-2 cell monolayer membrane, ADH-activating peptides were identified. Among them, SSNCQPF, TGCPVLQ, and QPQQPW were validated to possess strong ADH activation activity, with EC50 values of 1.35 ± 0.22 mM, 2.26 ± 0.16 mM, and 2.73 ± 0.13 mM, respectively. Molecular Docking revealed that the activation of ADH occurred via the formation of a stable complex between the peptide and the active center of ADH by hydrogen bonds and hydrophobic interactions. The results of this study also suggest that corn protein hydrolysate could be a novel functional dietary element that helps protects the liver from damage caused by alcohol and aids in alcohol metabolism.

Purification, identification and molecular docking of dual-functional peptides derived from corn protein hydrolysates with antioxidant and antiadhesive activity against Helicobacter pylori.

BACKGROUND: More than 50% of the world's population is infected with Helicobacter pylori, which is classified as a group I carcinogen by the World Health Organization (WHO). RESULTS: Corn protein dual-functional peptides were identified and functionally analyzed in vitro and in silico. Two novel dual-functional peptides were identified as Cys-Gln-Asp-Val-Pro-Leu-Leu (CQDVPLL, CQ7) and Thr-Ile-Phe-Pro-Gln-Cys (TIFPQC, TI6) using nanoscale liquid chromatography coupled to tandem mass spectrometry (nano-LC-MS/MS). The antiadhesive effects against H. pylori of CQ7 and TI6 were 45.17 ± 2.41% and 48.62 ± 1.84% at 4 mg mL-1 , respectively. In silico prediction showed that CQ7 and TI6 had good physicochemical properties. Molecular docking demonstrated that CQ7 and TI6 could bind to the adhesins BabA and SabA by hydrophobic interactions and hydrogen bonds, preventing H. pylori infection. Moreover, CQ7 showed strong antioxidant activity due to its unique amino acid composition. CONCLUSION: The present study demonstrated that the identified peptides, CQ7 and TI6, possess antioxidant and antiadhesive effects, preventing H. pylori infection and alleviating oxidative injury to the gastric mucosa. © 2023 Society of Chemical Industry.

The investigation of reducing PAHs emission from coal pyrolysis by gaseous catalytic cracking.

The catalytic cracking method of PAHs for the pyrolysis gaseous products is proposed to control their pollution to the environment. In this study, the Py-GC-MS is used to investigate in situ the catalytic effect of CaO and Fe2O3 on the 16 PAHs from Pingshuo coal pyrolysis under different catalytic temperatures and catalyst particle sizes. The results demonstrate that Fe2O3 is effective than that of CaO for catalytic cracking of 16 PAHs and that their catalytic temperature corresponding to the maximum PAHs cracking rates is different. The PAHs cracking rate is up to 60.59% for Fe2O3 at 600°C and is 52.88% at 700°C for CaO. The catalytic temperature and particle size of the catalysts have a significant effect on PAHs cracking rate and CaO will lose the capability of decreasing 16 PAHs when the temperature is higher than 900°C. The possible cracking process of 16 PAHs is deduced by elaborately analyzing the cracking effect of the two catalysts on 16 different species of PAHs.

Four novel anti-adhesive activity peptides against Helicobacter pylori derived from rice bran protein: release, identification and anti-adhesive mechanisms elucidation.

H. pylori is a highly pathogenic and prevalent pathogen that is a class I carcinogen. More than 50% of the world's population is infected with H. pylori. An anti-adhesive strategy is an effective way to antagonize H. pylori infection, which does not cause H. pylori resistance and is safer compared to antibiotic therapy. In the present study, to obtain rice bran protein-derived anti-adhesive activity peptides against H. pylori, an efficient enzymatic hydrolysis system was established, and it was found that rice bran protein hydrolysate prepared under specific conditions possessed anti-adhesive activity against H. pylori. The anti-adhesive activity of rice bran protein hydrolysate (RPH) was 43.74 ± 1.12% (4 mg mL-1), and gastric digestion (RPHA) had no significant effect on its activity. Hydrophobic amino acids and aromatic amino acids were important for its anti-adhesive activity. Further, 284 peptide sequences with potential anti-adhesive activity were isolated and identified from RPHA. Combined with molecular docking results, four novel anti-adhesive activity peptides were finally screened, namely LS5 (LSFRL), SN8 (SNTPGMVY), VV7 (VVNFGNL) and PV9 (PVLWGVPKG). Among them, PV9 showed the highest anti-adhesive activity of 59.64 ± 2.00% (4 mg mL-1). These four peptides could bind H. pylori adhesins BabA and SabA, occupying the binding sites of cell receptors and acting as anti-adhesion agents. In conclusion, four rice bran protein-derived anti-adhesive activity peptides against H. pylori can be used for the development of novel functional foods antagonizing H. pylori infection.

Preparation of Corn Peptides with Anti-Adhesive Activity and Its Functionality to Alleviate Gastric Injury Induced by Helicobacter pylori Infection In Vivo.

More than 50% of the world population is infected with Helicobacter pylori (H. pylori), which is classified as group I carcinogen by the WHO. H. pylori surface adhesins specifically recognize gastric mucosal epithelial cells' (GES-1 cells) receptor to complete the adhesion. Blocking the adhesion with an anti-adhesion compound is an effective way to prevent H. pylori infection. The present study found that corn protein hydrolysate, hydrolyzed by Neutral, effectively alleviated gastric injury induced by H. pylori infection through anti-adhesive and anti-inflammatory effects in vitro and in vivo. The hydrolysate inhibited H. pylori adhesion to GES-1 cells significantly, and its anti-adhesive activity was 50.44 ± 0.27% at 4 mg/mL, which indicated that the hydrolysate possessed a similar structure to the GES-1 cells' receptor, and exhibited anti-adhesive activity in binding to H. pylori. In vivo, compared with the H. pylori infection model group, the medium and high dose of the hydrolysate (400-600 mg/kg·bw) significantly decreased (p < 0.05) the amount of H. pylori colonization, pro-inflammatory cytokines (IL-6, IL-1ß, TNF-α and MPO), chemokines (KC and MCP-1) as well as key metabolites of NF-κB signaling pathway levels (TLR4, MyD88 and NF-κB), and it increased antioxidant enzyme contents (SOD and GSH-Px) and the mitigation of H. pylori-induced pathological changes in the gastric mucosa. Taken together, these results indicated that the hydrolysate intervention can prevent H. pylori-induced gastric injury by anti-adhesive activity and inhibiting the NF-κB signaling pathway's induction of inflammation. Hence, the corn protein hydrolysate might act as a potential anti-adhesive agent to prevent H. pylori infection.

[The protective function and mechanism of notoginsenoside Rb1 against hypoxia hypercapnia-induced pulmonary vasoconstriction].

OBJECTIVE: To explore the protective function and mechanism of notoginsenoside Rb1 against hypoxia hypercapnia-induced pulmonary vasoconstriction (HHPV). METHODS: The pulmonary artery smooth muscle cells of healthy male SD rats were primarily cultured and the second to the fifth subcultured cells were incubated with 8, 40, and 100 mg/L notoginsenoside Rb1 respectively under the hypoxia-hypercapnia condition (1% O2 and 6% CO2). The cells were harvested for 24 h. The phosphated extracellular signal-regulated kinase (p-ERK) protein expression of the cells was detected by Western blot. The mRNA expressions of ERK1 and ERK2 were detected using half quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The expression of p-ERK protein, the mRNA expressions of ERK1 and ERK2 were weakly positive in the control group. Their expressions in the hypoxia-hypercapnia group were obviously enhanced (P < 0.01). After intervention of Rb1 at different concentrations, their expressions were obviously lowered (P < 0.05, P < 0.01) in a dose-dependent manner. The optimal effects were obtained at the dose of 100 mg/L. The expression of p-ERK protein was significantly positively correlated with mRNA expressions of ERK1 and ERK2 in notoginsenoside Rbl-treated groups (r = 0.500, P < 0.01; r = 0.977, P < 0.01). CONCLUSIONS: ERK1/2 pathway might play a role in the rat HHPV. Notoginsenoside Rb, could alleviate HHPV by inhibiting the ERK1/2 pathway.

Exploring Potential Mechanisms of Fludioxonil Resistance in Fusarium oxysporum f. sp. melonis.

Melon Fusarium wilt (MFW), which is caused by Fusarium oxysporum f. sp. melonis (FOM), is a soil-borne disease that commonly impacts melon cultivation worldwide. In the absence of any disease-resistant melon cultivars, the control of MFW relies heavily on the application of chemical fungicides. Fludioxonil, a phenylpyrrole fungicide, has been shown to have broad-spectrum activity against many crop pathogens. Sensitivity analysis experiments suggest that fludioxonil has a strong inhibitory effect on the mycelial growth of FOM isolates. Five fludioxonil-resistant FOM mutants were successfully generated by repeated exposure to fludioxonil under laboratory conditions. Although the mutants exhibited significantly reduced mycelial growth in the presence of the fungicide, there initially appeared to be little fitness cost, with no significant difference (p < 0.05) in the growth rates of the mutants and wild-type isolates. However, further investigation revealed that the sporulation of the fludioxonil-resistant mutants was affected, and mutants exhibited significantly (p < 0.05) reduced growth rates in response to KCl, NaCl, glucose, and mannitol. Meanwhile, molecular analysis of the mutants strongly suggested that the observed fludioxonil resistance was related to changes in the sequence and expression of the FoOs1 gene. In addition, the current study found no evidence of cross-resistance between fludioxonil and any of the other fungicides tested. These results indicate that fludioxonil has great potential as an alternative method of control for FOM in melon crops.

A novel serine protease with anticoagulant and fibrinolytic activities from the fruiting bodies of mushroom Agrocybe aegerita.

A novel fibrinolytic enzyme, ACase was isolated from fruiting bodies of a mushroom, Agrocybe aegerita. ACase was purified by using ammonium sulfate precipitation, gel filtration, ion exchange and hydrophobic chromatographies to 237.12 fold with a specific activity of 1716.77 U/mg. ACase was found to be a heterodimer with molecular mass of 31.4 and 21.2 kDa by SDS-PAGE and appeared as a single band on Native-PAGE and fibrin-zymogram. The N-terminal sequence of the two subunits of ACase was AIVTQTNAPWGL (subunit 1) and SNADGNGHGTHV (subunit 2). ACase had maximal activity at 47 °C and pH 7.6. It's activity was improved by Cu2+, Na+, Fe3+, Zn2+, Ba2+, K+ and Mn2+, but inhibited by Fe2+, Mg2+ and Ca2+. PMSF, SBTI, aprotinine and Lys inhibited the enzyme activity, which suggested that ACase was a serine protease. ACase could degrade all three chains (α, ß and γ) of fibrinogen. Moreover, the enzyme acted as both, a plasmin-like fibrinolytic enzyme and a plasminogen activator. It could hydrolyze human thrombin slightly, which indicated that the ACase could inhibit the activity of thrombin and acted as an anticoagulant to prevent thrombosis. Based on these results, ACase might act as a therapeutic agent for treating thrombosis, or as a functional food. Further investigation of the enzyme is underway.

Blockchain-Based Reversible Data Hiding for Securing Medical Images.

Medical images carry a lot of important information for making a medical diagnosis. Since the medical images need to be communicated frequently to allow timely and accurate diagnosis, it has become a target for malicious attacks. Hence, medical images are protected through encryption algorithms. Recently, reversible data hiding on the encrypted images (RDHEI) schemes are employed to embed private information into the medical images. This allows effective and secure communication, wherein the privately embedded information (e.g., medical records and personal information) is very useful to the medical diagnosis. However, existing RDHEI schemes still suffer from low embedding capacity, which limits their applicability. Besides, such solution still lacks a good mechanism to ensure its integrity and traceability. To resolve these issues, a novel approach based on image block-wise encryption and histogram shifting is proposed to provide more embedding capacity in the encrypted images. The embedding rate is over 0.8 bpp for typical medical images. On top of that, a blockchain-based system for RDHEI is proposed to resolve the traceability. The private information is stored on the blockchain together with the hash value of the original medical image. This allows traceability of all the medical images communicated over the proposed blockchain network.

Enhanced Properties and Lactose Hydrolysis Efficiencies of Food-Grade ß-Galactosidases Immobilized on Various Supports: a Comparative Approach.

In this study, a fungal and two yeast ß-galactosidases were immobilized using alginate and chitosan. The biochemical parameters and lactose hydrolysis abilities of immobilized enzymes were analyzed. The pH optima of immobilized fungal ß-galactosidases shifted to more acidic pH compared to free enzyme. Remarkably, the optimal temperature of chitosan-entrapped yeast enzyme, Maxilact, increased to 60 °C, which is significantly higher than that of the free Maxilact (40 °C) and other immobilized forms. Chitosan-immobilized A. oryzae ß-galactosidase showed improved lactose hydrolysis (95.7%) from milk, compared to the free enzyme (82.7%) in 12 h. Chitosan-immobilized Maxilact was the most efficient in lactose removal from milk (100% lactose hydrolysis in 2 h). The immobilized lactases displayed excellent reusability, and chitosan-immobilized Maxilact hydrolyzed > 95% lactose in milk after five reuses. Compared to free enzymes, the immobilized enzymes are more suitable for cost-effective industrial production of low-lactose milk due to improved thermal activity, lactose hydrolysis efficiencies, and reusability.

Increased MALAT1 expression contributes to cisplatin resistance in non-small cell lung cancer.

Cisplatin-based chemotherapy is commonly used for the clinical treatment of patients with non-small cell lung cancer (NSCLC). However, the anti-tumor efficacy of cisplatin is limited by poor clinical response and the development of chemoresistance. At present, the underlying mechanism for cisplatin resistance remains unclear. In the present study, it was identified that metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA that has been demonstrated to function as an oncogene, was increased in tumor tissues from patients with cisplatin-resistant NSCLC. In addition, the MALAT1 level was increased in A549rCDDP cells compared with the parental A549 cells. Silencing of MALAT1 sensitized A549rCDDP cells to cisplatin treatment, while overexpression of MALAT1 in A549 cells decreased their sensitivity towards cisplatin. Through analysis of the gene expression in patient samples, a decrease in miR-145 and an increase in Kruppel-like factor 4 (KLF4) in tumor tissues compared with adjacent normal tissues was observed. A negative association between MALAT1 and miR-145 was also identified in A549 cells and A549rCDDP cells. Furthermore, reverse transcription quantitative polymerase chain reaction and western blotting identified that KLF4 was positively and negatively regulated by MALAT1 and miR-145, respectively. The direct regulatory association between MALAT1 and miR-145 and the target gene KLF4 was additionally confirmed using a luciferase reporter assay. Knockdown of MALAT1 reversed cisplatin resistance in A549rCDDP cells. Taken together, these data indicated that MALAT1 decreased the sensitivity of NSCLC to cisplatin via the regulation of miR-145 and KLF4.

[The effects of ERK1/2 pathway on the expression of calcium activated chloride channel in hypoxia in PASMCs rat model].

OBJECTIVE: To investigate the expression of mRNA and protein of Calcium activated chloride channel (CLCA2) in hypoxic pulmonary artery smooth muscle cell (PASMCs) of rat and it's relationship with ERK1/2 signal pathway. METHODS: PASMCs were randomly divided into 5 groups including normal group(N group), hypoxia group(H group), DMSO group(D group), U0126 group (U group) and Staurosporine aglycone group(SA group). The protein expression of CLCA2 in PASMCs was detected by Western blot.The mRNA expression of CLCA2 was detected by half quantitative reverse transcription polymerase chain reaction (RT-PCR). RESULTS: The mRNA and protein expressions of CLCA2 in H group were significantly higher than N group (P<0.01). Comparing with D group,the mRNA and protein expressions of CLCA2 were significantly increased in U group (P<0.01),the mRNA expression of CLCA2 in SA group was obviously decreased (P<0.01) with slightly decreasing of its protein expression. CONCLUSIONS: Hypoxia promotes the expressions of mRNA and protein of CLCA2 in rat PASMCs. The ERK1/2 pathway activator Staurosporine aglycone reduces the mRNA and protein expression of CLCA2 in rats PASMCs and the ERK1/2 pathway inhibitor U0126 induces the upregulation of the mRNA and protein expressiosn of CLCA2 in rats PASMCs.

[Effect of notoginsenoside Rg1 on p38MAPK expression of pulmonary arterial smooth muscle cells exposed to hypoxia hypercapnia].

OBJECTIVE: To study the effect of Notoginsenoside Rgl on p38 mitogen activated protein kinase (p38MAPK) expression in pulmonary artery smooth muscle cells (PASMCs) cultured in hypoxia hypercapnia. METHODS: SD rat PASMCs was primary cultured, the cells of passage 2- 5 were divided into six groups: normoxic group (N group), hypoxia hypercapnia group (H group), dimethyl sulfoxide (DMSO) control group (HD group), Rg1 treated group (Rg low dose, Rg middle dose and Rg high dose group). Western blot was used to detect the expression of p-p38MAPK protein, and RT-PCR to determine the expression of p38MAPK mRNA. RESULTS: Western blot and RT-PCR analysis indicated that the expression of p-p38MAPK protein and p-p38MAPK mRNA were significantly higher in HD group than those in N group (P < 0.01). Whereas, in Rg1 treated groups, the level of p-p38MAPK markedly decreased (P < 0.01) in dose-dependent manner. CONCLUSION: Notoginsenoside Rg1 has protective effects on PASMCs under hypoxia hypercapnia condition, which may be related to inhibiting expression of p38MAPK.