OBJECTIVE

The aim of this study was to investigate the protective effects of Lactobacillus brevis BIOTECH 1766 against oxidative damage in the brain, liver, and kidneys induced by aluminum (Al) poisoning in ICR mice.

Twenty mice were divided into four groups (n = 5): (I) control, (II) Al, (III) citric acid (CA), and (IV) L. brevis BIOTECH 1766 group. A 14-day treatment period was implemented, wherein groups I and II received sterile water, while groups III and IV received 10 mg/kg bw of CA and 1 x 109 cfu/kg bw of L. brevis BIOTECH 1766, respectively. On day 15, all except the control group received a single oral dose of 1438 mg/kg bw of AlCl3. 6H2O. After 24 h, mice were euthanized to collect the brain, liver, and kidneys for the oxidative stress marker analyses and histopathological examination.

Acute intoxication of Al led to a significant increase in tissue malondialdehyde (MDA) and a significant decrease in the tissue's reduced glutathione (GSH), catalase (CAT), and superoxide dismutase (SOD). Mice pretreated with CA or L. brevis BIOTECH 1766 have markedly reduced CAT activity in the liver, and SOD in all three organs. Extensive organ injuries were also prevented by CA and L. brevis BIOTECH 1766 pretreatment, with the latter providing better protection against liver damage.

The findings showed that L. brevis BIOTECH 1766 provides a protective effect against acute Al poisoning in mice by ameliorating oxidative damage in the brain, liver, and kidneys.

OBJECTIVE: In this study, the combined effect of two stressors, namely, electromagnetic fields (EMFs) from mobile phones and fructose consumption, on hypothalamic and hepatic master metabolic regulators of the AMPK/SIRT1-UCP2/FOXO1 pathway were elucidated to delineate the underlying molecular mechanisms of insulin resistance. METHODS: Weaned Wistar rats (28 days old) were divided into 4 groups: Normal, Exposure Only (ExpO), Fructose Only (FruO), and Exposure and Fructose (EF). Each group was provided standard laboratory chow ad libitum for 8 weeks . Additionally, the control groups, namely, the Normal and FruO groups, had unrestricted access to drinking water and fructose solution (15%), respectively. Furthermore, the respective treatment groups, namely, the ExpO and EF groups, received EMF exposure (1,760 MHz, 2 h/day x 8 weeks). In early adulthood, mitochondrial function, insulin receptor signaling, and oxidative stress signals in hypothalamic and hepatic tissues were assessed using western blotting and biochemical analysis. RESULT: In the hypothalamic tissue of EF, SIRT1, FOXO 1, p-PI3K, p-AKT, Complex III, UCP2, MnSOD, and catalase expressions and OXPHOS and GSH activities were significantly decreased ( P < 0.05) compared to the Normal, ExpO, and FruO groups. In hepatic tissue of EF, the p-AMPKα, SIRT1, FOXO1, IRS1, p-PI3K, Complex I, II, III, IV, V, UCP2, and MnSOD expressions and the activity of OXPHOS, SOD, catalase, and GSH were significantly reduced compared to the Normal group ( P < 0.05). CONCLUSION The findings suggest that the combination of EMF exposure and fructose consumption during childhood and adolescence in Wistar rats disrupts the closely interlinked and multi-regulated crosstalk of insulin receptor signals, mitochondrial OXPHOS, and the antioxidant defense system in the hypothalamus and liver.
Humans ; Rats ; Animals ; Adult ; Rats, Wistar ; Fructose/metabolism* ; Catalase ; Receptor, Insulin/metabolism* ; AMP-Activated Protein Kinases/metabolism* ; Electromagnetic Fields/adverse effects* ; Sirtuin 1/metabolism* ; Cell Phone ; Phosphatidylinositol 3-Kinases/metabolism* ; Forkhead Box Protein O1/metabolism* ; Uncoupling Protein 2

OBJECTIVE: To explore the protective effect and underlying mechanism of Lycium barbarum polysaccharides (LBP) in a non-alcoholic fatty liver disease (NAFLD) cell model. METHODS: Normal human hepatocyte LO2 cells were treated with 1 mmol/L free fatty acids (FFA) mixture for 24 h to induce NAFLD cell model. Cells were divided into 5 groups, including control, model, low-, medium- and high dose LBP (30,100 and 300 µg/mL) groups. The monosaccharide components of LBP were analyzed with high performance liquid chromatography. Effects of LBP on cell viability and intracellular lipid accumulation were assessed by cell counting Kit-8 assay and oil red O staining, respectively. Triglyceride (TG), alanine aminotransferase (ALT), aspartate aminotransferase (AST), adenosine triphosphate (ATP) and oxidative stress indicators were evaluated. Energy balance and mitochondrial biogenesis related mRNA and proteins were determined by quantitative real-time polymerase chain reaction and Western blot, respectively. RESULTS: Heteropolysaccharides with mannose and glucose are the main components of LBP. LBP treatment significantly decreased intracellular lipid accumulation as well as TG, ALT, AST and malondialdehyde levels (P<0.05 or P<0.01), increased the levels of superoxide dismutase, phospholipid hydroperoxide glutathione peroxidase, catalase, and ATP in NAFLD cell model (P<0.05). Meanwhile, the expression of uncoupling protein 2 was down-regulated and peroxisome proliferator-activated receptor gamma coactivator-1α/nuclear respiratory factor 1/mitochondrial transcription factor A pathway was up-regulated (P<0.05). CONCLUSION LBP promotes mitochondrial biogenesis and improves energy balance in NAFLD cell model.
Humans ; Non-alcoholic Fatty Liver Disease/drug therapy* ; Lycium/metabolism* ; Catalase/metabolism* ; Organelle Biogenesis ; Alanine Transaminase ; Uncoupling Protein 2 ; Fatty Acids, Nonesterified ; Mannose ; Nuclear Respiratory Factor 1/metabolism* ; PPAR gamma/metabolism* ; Phospholipid Hydroperoxide Glutathione Peroxidase ; Drugs, Chinese Herbal/pharmacology* ; Malondialdehyde/metabolism* ; Superoxide Dismutase/metabolism* ; Polysaccharides/pharmacology* ; Triglycerides ; RNA, Messenger ; Aspartate Aminotransferases ; Glucose ; Adenosine Triphosphate

Catalase is widely used in the food, medical, and textile industries. It possesses exceptional properties including high catalytic efficiency, high specificity, and environmental friendliness. Free catalase cannot be recycled and reused in industry, resulting in a costly industrial biotransformation process if catalase is used as a core ingredient. Developing a simple, mild, cost-effective, and environmentally friendly approach to immobilize catalase is anticipated to improve its utilization efficiency and enzymatic performance. In this study, the catalase KatA derived from Bacillus subtilis 168 was expressed in Escherichia coli. Following separation and purification, the purified enzyme was prepared as an immobilized enzyme in the form of enzyme-inorganic hybrid nanoflowers, and the enzymatic properties were investigated. The results indicated that the purified KatA was obtained through a three-step procedure that included ethanol precipitation, DEAE anion exchange chromatography, and hydrophobic chromatography. Then, by optimizing the process parameters, a novel KatA/Ca₃(PO₄)₂ hybrid nanoflower was developed. The optimum reaction temperature of the free KatA was determined to be 35 ℃, the optimum reaction temperature of KatA/Ca₃(PO₄)₂ hybrid nanoflowers was 30-35 ℃, and the optimum reaction pH of both was 11.0. The free KatA and KatA/Ca₃(PO₄)₂ hybrid nanoflowers exhibited excellent stability at pH 4.0-11.0 and 25-50 ℃. The KatA/Ca₃(PO₄)₂ hybrid nanoflowers demonstrated increased storage stability than that of the free KatA, maintaining 82% of the original enzymatic activity after 14 d of storage at 4 ℃, whereas the free KatA has only 50% of the original enzymatic activity. In addition, after 5 catalytic reactions, the nanoflower still maintained 55% of its initial enzymatic activity, indicating that it has good operational stability. The K_m of the free KatA to the substrate hydrogen peroxide was (8.80±0.42) mmol/L, and the k_cat/K_m was (13 151.53± 299.19) L/(mmol·s). The K_m of the KatA/Ca₃(PO₄)₂ hybrid nanoflowers was (32.75±2.96) mmol/L, and the k_cat/K_m was (4 550.67±107.51) L/(mmol·s). Compared to the free KatA, the affinity of KatA/Ca₃(PO₄)₂ hybrid nanoflowers to the substrate hydrogen peroxide was decreased, and the catalytic efficiency was also decreased. In summary, this study developed KatA/Ca₃(PO₄)₂ hybrid nanoflowers using Ca²⁺ as a self-assembly inducer, which enhanced the enzymatic properties and will facilitate the environmentally friendly preparation and widespread application of immobilized catalase.
Catalase ; Nanostructures/chemistry* ; Hydrogen Peroxide/metabolism* ; Enzymes, Immobilized/chemistry* ; Catalysis

OBJECTIVE: To observe the effect of astaxanthin (ASTA) on the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) in suspended leukocyte-depleted red blood cells stored for transfusion. METHODS: The suspended leukocyte-depleted red blood cells were randomly divided into group A, B, C and D. The ASTA was added into preservation solution of suspended leukocyte-depleted red blood cells of group B, C and D with the final concentration 5, 10 and 20 μmol/L, respectively, while DMSO was added into cells of group A in the same volume. After 7, 14, 28 and 42 days of storage, the reactive oxygen species (ROS) content in red blood cells was detected by fluorescence microplate reader, malondialdehyde (MDA) content was detected by thiobarbituric acid (TBA) method, activity of SOD was detected by xanthine oxidase method, the activity of CAT was detected by visible light method, and activity of GSH-Px was detected by colorimetry. RESULTS: After 7, 14, 28 and 42 days of storage, the contents of ROS and MDA in suspended red blood cells of group B, C and D were significantly lower(P<0.05), while the activities of SOD and GSH-Px were higher than those of group A(P<0.05); and CAT activity in cells treated by ASTA was significantly higher at 28 and 42 days of storage in comparison with that of group A(P<0.05). There were positive correlations between the ROS, MDA content in suspended red blood cells of group A, B, C, D and storage time(P<0.01), while negative correlation between SOD, CAT, GSH-Px activity and storage time(P<0.01). CONCLUSION ASTA can decrease the oxidative stress level and peroxide damage degree by increasing the antioxidant enzyme activities in suspended leukocyte-depleted red blood cells during storage.
Antioxidants ; Catalase/metabolism* ; Erythrocytes ; Leukocytes ; Oxidative Stress ; Superoxide Dismutase/metabolism* ; Xanthophylls

Six month old Cinnamomum cassia seedlings were used to simulate drought stress with polyethylene glycol(PEG 6000). The physiological indicators(osmotic substances, antioxidant enzymes, etc.) and chemical components of seedlings under different drought levels and the correlation between the two were studied. The results showed that the chlorophyll content and relative water content decreased gradually with the increase of PGE 6000(0, 5%, 10%, 15%) concentration and time(3, 5, 7 d), while the soluble protein content, soluble sugar content and catalase(CAT) activity increased, but the rising rate slowed down with the time. The activities of peroxidase(POD), superoxide dismutase(SOD), malondialdehyde(MDA) and proline content increased at first and then decreased. The content of coumarin, cinnamaldehyde, cinnamic acid and dimethoxycinnamaldehyde decreased, while the content of cinnamyl alcohol continued to increase.Under drought stress, the fluorescence signals of reactive oxygen species and no contents in roots of C. cassia seedlings were significantly stronger than those of the control.Further correlation analysis showed that coumarin content, di-methoxycinnamaldehyde content and osmoregulation substance content were significantly negatively correlated(P<0.05), cinnamic acid content was significantly negatively correlated with POD and SOD activities(P<0.01).It was found that C. cassia seedlings showed a certain degree of drought tolerance under short-term or mild drought stress, but if the drought exceeded a certain degree, the physiological metabolism of the seedlings would be unbalanced.
Catalase ; Cinnamomum aromaticum ; Droughts ; Malondialdehyde ; Seedlings ; Stress, Physiological ; Superoxide Dismutase

Objective: To evaluate multidrug resistant loop-mediated isothermal amplification (MDR-LAMP) assay for the early diagnosis of multidrug-resistant tuberculosis and to compare the mutation patterns associated with the Methods: MDR-LAMP assay was evaluated using 100 Results: The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of MDR-LAMP were 85.5%, 93.6%, 96.7%, and 74.4% for the detection of resistance to isoniazid and rifampicin, respectively, and 80.5%, 92.3%, 98.6%, and 41.4% for the detection of Conclusion MDR-LAMP is a rapid and accessible assay for the laboratory identification of rifampicin and isoniazid resistance of
Antitubercular Agents ; Bacterial Proteins/genetics* ; Catalase/genetics* ; DNA, Bacterial/analysis* ; DNA-Directed RNA Polymerases/genetics* ; Drug Resistance, Multiple, Bacterial/genetics* ; Isoniazid ; Molecular Diagnostic Techniques/methods* ; Mutation ; Mycobacterium tuberculosis/isolation & purification* ; Nucleic Acid Amplification Techniques/methods* ; Oxidoreductases/genetics* ; Phenotype ; Rifampin ; Whole Genome Sequencing

Some enzymes belonging to the multicopper oxidase (MCO) family can degrade the hazardous biogenic amine (BA) present in food. However, the oxidation of MCO in the process of degrading BAs may reduce its activity and stability, resulting in decreased catalytic efficiency. In this work, an MCO from Lactobacillus fermentum (MCOF) was fused with a Bacillus subtilis catalase (CAT) using different strategies and the fusion enzymes were respectively expressed in Escherichia coli BL21(DE3). The tolerance of eight fused MCOFs to H2O2 increased by 51%-68%, and the stability of CAT&MCOF increased by 17%, compared to the wild type MCOF. Using 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid (ABTS) as a substrate, the substrate affinity (Km), the catalytic efficiency (kcat/Km) and the molar specific activity of CAT&MCOF increased by 1.0-fold, 1.7-fold and 1.2-fold than those of MCOF, respectively. The stability of CAT&MCOF under acidic conditions (pH 2.5-4.5) and moderate temperatures (35-55 °C) also improved. Moreover, the degradation rates of putrescine, cadaverine and histamine catalyzed by CAT&MCOF reached 31.7%, 36.0% and 57.8%, respectively, which increased by 132.5%, 45.7% and 38.9% compared to that of MCOF. The improvement on the stability and catalytic efficiency of MCOF by fusion expression with CAT provides a good example for improving the applicability of enzymes through molecular modifications.
Biogenic Amines ; Cadaverine ; Catalase/genetics* ; Escherichia coli/genetics* ; Hydrogen Peroxide

Seed vigor is a key factor affecting seed quality. The mechanical drying process exerts a significant influence on rice seed vigor. The initial moisture content (IMC) and drying temperature are considered the main factors affecting rice seed vigor through mechanical drying. This study aimed to determine the optimum drying temperature for rice seeds according to the IMC, and elucidate the mechanisms mediating the effects of drying temperature and IMC on seed vigor. Rice seeds with three different IMCs (20%, 25%, and 30%) were dried to the target moisture content (14%) at four different drying temperatures. The results showed that the drying temperature and IMC had significant effects on the drying performance and vigor of the rice seeds. The upper limits of drying temperature for rice seeds with 20%, 25%, and 30% IMCs were 45, 42, and 38 °C, respectively. The drying rate and seed temperature increased significantly with increasing drying temperature. The drying temperature, drying rate, and seed temperature showed extremely significant negative correlations with germination energy (GE), germination rate, germination index (GI), and vigor index (VI). A high IMC and drying temperature probably induced a massive accumulation of hydrogen peroxide (H₂O₂) and superoxide anions in the seeds, enhanced superoxide dismutase (SOD) and catalase (CAT) activity, and increased the abscisic acid (ABA) content. In the early stage of seed germination, the IMC and drying temperature regulated seed germination through the metabolism of H₂O₂, gibberellin acid (GA), ABA, and α-amylase. These results indicate that the metabolism of reactive oxygen species (ROS), antioxidant enzymes, GA, ABA, and α-amylase might be involved in the mediation of the effects of drying temperature on seed vigor. The results of this study provide a theoretical basis and technical guidance for the mechanical drying of rice seeds.
Abscisic Acid/metabolism* ; Antioxidants/pharmacology* ; Catalase/metabolism* ; Gene Expression Regulation, Plant/drug effects* ; Germination ; Gibberellins/metabolism* ; Hydrogen Peroxide/chemistry* ; Malondialdehyde/chemistry* ; Oryza/metabolism* ; Oxygen/chemistry* ; Plant Proteins/genetics* ; Reactive Oxygen Species ; Seeds/metabolism* ; Superoxide Dismutase/metabolism* ; Superoxides/chemistry* ; Temperature ; Weather ; alpha-Amylases/metabolism*

Hydrogen sulfide is well-known to exhibit anti-inflammatory and cytoprotective activities, and also has protective effects in the liver. This study aimed to examine the protective effect of hydrogen sulfide in rats with hepatic encephalopathy, which was induced by mild bile duct ligation. In this rat model, bile ducts were mildly ligated for 26 days. Rats were treated for the final 5 days with sodium hydrosulfide (NaHS). NaHS (25 µmol/kg), 0.5% sodium carboxymethyl cellulose, or silymarin (100 mg/kg) was administered intraperitoneally once per day for 5 consecutive days. Mild bile duct ligation caused hepatotoxicity and inflammation in rats. Intraperitoneal NaHS administration reduced levels of aspartate aminotransferase and alanine aminotransferase, which are indicators of liver disease, compared to levels in the control mild bile duct ligation group. Levels of ammonia, a major causative factor of hepatic encephalopathy, were also significantly decreased. Malondialdehyde, myeloperoxidase, catalase, and tumor necrosis factor-α levels were measured to confirm antioxidative and anti-inflammatory effects. N-Methyl-D-aspartic acid (NMDA) receptors with neurotoxic activity were assessed for subunit NMDA receptor subtype 2B. Based on these data, NaHS is suggested to exhibit hepatoprotective effects and guard against neurotoxicity through antioxidant and anti-inflammatory actions.
Alanine Transaminase ; Ammonia ; Animals ; Aspartate Aminotransferases ; Bile Ducts ; Carboxymethylcellulose Sodium ; Catalase ; Hepatic Encephalopathy ; Hydrogen Sulfide ; Inflammation ; Ligation ; Liver ; Liver Diseases ; Malondialdehyde ; Models, Animal ; N-Methylaspartate ; Necrosis ; Peroxidase ; Rats ; Silymarin ; Sodium