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

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 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

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

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*

The increasing demand of Chinese materia medica could not be supplied by wild resource, and the cultivated medicinal materials become popular, which led to decreased quality of many medicinal materials due to the difference of the circumstance between the wild and the cultivated. How to improve quality becomes key points of Chinese medicine resource. The leaves of Scutellaria baicalensis were sprayed with H₂O₂, the activities of superoxide dismutase (SOD) and catalase (CAT) changed little, but there had been a marked decrease of peroxidase (POD) and ascorbic oxidase (APX), which showed that the antioxidase system declined. Meanwhile, H₂O₂, as enhanced the expression of phenylalnine ammonialyase (PAL) and β-glucuronidase (GUS) as well as activity of PAL, promoted the biosynthesis and biotransformation of flavonoids. At the day 2 after treated, H₂O₂ of 0.004 μmol·L⁻¹ the contents of the baicalin and the wogonoside decreased slightly, but the contents of the baicalein and the wogonin increased significantly, the baicalein from 0.094% to 0.324%, the wogonin from 0.060% to 0.110%, i. e. increased 246% and 83.3%, respectively.
Ascorbate Oxidase ; metabolism ; Catalase ; metabolism ; Drugs, Chinese Herbal ; chemistry ; Flavanones ; analysis ; Flavonoids ; analysis ; Glucosides ; analysis ; Glucuronidase ; metabolism ; Hydrogen Peroxide ; Peroxidase ; metabolism ; Phenylalanine Ammonia-Lyase ; metabolism ; Scutellaria baicalensis ; metabolism ; Secondary Metabolism ; Superoxide Dismutase ; metabolism

The aims of the present study were to evaluate the effects of puerarin on angiotensin II-induced cardiac fibroblast proliferation and to explore the molecular mechanisms of action. Considering the role of HO in nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activation, we hypothesized that modulating catalase activity would be a potential target in regulating the redox-sensitive pathways. Our results showed that the activation of Rac1 was dependent on the levels of intracellular HO. Puerarin blocked the phosphorylation of extracellular regulated protein kinases (ERK)1/2, abolished activator protein (AP)-1 binding activity, and eventually attenuated cardiac fibroblast proliferation through the inhibition of HO-dependent Rac1 activation. Further studies revealed that angiotensin II treatment resulted in decreased catalase protein expression and enzyme activity, which was disrupted by puerarin via the upregulation of catalase protein expression at the transcriptional level and the prolonged protein degradation. These findings indicated that the anti-proliferation mechanism of puerarin was mainly through blocking angiontensin II-triggered downregulation of catalase expression and HO-dependent Rac1 activation.
Angiotensin II ; pharmacology ; Angiotensin II Type 1 Receptor Blockers ; pharmacology ; Animals ; Animals, Newborn ; Catalase ; genetics ; metabolism ; Cell Proliferation ; drug effects ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; antagonists & inhibitors ; metabolism ; Fibroblasts ; Gene Expression Regulation ; drug effects ; Heart ; drug effects ; Hydrogen Peroxide ; metabolism ; pharmacology ; Isoflavones ; pharmacology ; Mice ; Myocardium ; cytology ; enzymology ; metabolism ; NADPH Oxidases ; antagonists & inhibitors ; metabolism ; Neuropeptides ; metabolism ; Signal Transduction ; drug effects ; Transcription Factor AP-1 ; antagonists & inhibitors ; metabolism ; Transcriptional Activation ; drug effects ; rac1 GTP-Binding Protein ; metabolism

The aging process induces a plethora of changes in the body including alterations in hormonal regulation and metabolism in various organs including the heart. Aging is associated with marked increase in the vulnerability of the heart to ischemia-reperfusion injury. Furthermore, it significantly hampers the development of adaptive response to various forms of conditioning stimuli (pre/post/remote conditioning). Aging significantly impairs the activation of signaling pathways that mediate preconditioning-induced cardioprotection. It possibly impairs the uptake and release of adenosine, decreases the number of adenosine transporter sites and down-regulates the transcription of adenosine receptors in the myocardium to attenuate adenosine-mediated cardioprotection. Furthermore, aging decreases the expression of peroxisome proliferator-activated receptor gamma co-activator 1-alpha (PGC-1α) and subsequent transcription of catalase enzyme which subsequently increases the oxidative stress and decreases the responsiveness to preconditioning stimuli in the senescent diabetic hearts. In addition, in the aged rat hearts, the conditioning stimulus fails to phosphorylate Akt kinase that is required for mediating cardioprotective signaling in the heart. Moreover, aging increases the concentration of Na⁺ and K⁺, connexin expression and caveolin abundance in the myocardium and increases the susceptibility to ischemia-reperfusion injury. In addition, aging also reduces the responsiveness to conditioning stimuli possibly due to reduced kinase signaling and reduced STAT-3 phosphorylation. However, aging is associated with an increase in MKP-1 phosphorylation, which dephosphorylates (deactivates) mitogen activated protein kinase that is involved in cardioprotective signaling. The present review describes aging as one of the major confounding factors in attenuating remote ischemic preconditioning-induced cardioprotection along with the possible mechanisms.
Adenosine ; Aging* ; Animals ; Catalase ; Heart ; Metabolism ; Myocardium ; Negotiating ; Oxidative Stress ; Phosphorylation ; Phosphotransferases ; PPAR gamma ; Protein Kinases ; Rats ; Receptors, Purinergic P1 ; Reperfusion Injury

To explore the protective effect of rosiglitazone (RGZ) on hepatic ischemia reperfusion injury (HIRI) and the underlying mechanisms.
 Methods: A rat model of ischemia-reperfusion injury was established by clamping the left and middle lobe of liver with noninvasive vascular clamp. A total of 30 Sprague-Dawley rats were randomly divided into a sham group, an HIRI group, and a RGZ group (10 rats in each group). Two hours after reperfusion, serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, lactate dehydrogenase (LDH) level, malondialdehyde (MDA) content and catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities were examined. HE staining was used to observe liver pathological morphology. The liver peroxisome proliferators-activated receptor γ (PPAR-γ), p-PPAR-γ, nuclear factor related factor 2 (Nrf-2), antioxidant response element (ARE), heme oxygenase 1 (HO-1) and quinone oxidoreductase-1 (NQO-1) were detected by Western blot.
 Results: Compared with the HIRI group, the levels of ALT, AST, LDH and MDA in the RGZ group were significantly decreased (all P<0.05), while the levels of Nrf-2, ARE, HO-1 and NQO-1 in the RGZ group were significantly increased. The hepatic swelling, necrosis and pathological damage were decreased (all P<0.05). In addition, there was no difference in the level of PPAR-γ between the 2 groups (P>0.05).
 Conclusion: PPAR-γ agonist RGZ can attenuate HIRI, which may be related to activating Nrf2/ARE signaling pathway and enhancement of antioxidant ability.
Alanine Transaminase ; blood ; Animals ; Aspartate Aminotransferases ; blood ; Catalase ; blood ; Disease Models, Animal ; Glutathione Peroxidase ; blood ; L-Lactate Dehydrogenase ; blood ; Ligation ; Liver ; blood supply ; metabolism ; Malondialdehyde ; blood ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Reperfusion Injury ; blood ; etiology ; prevention & control ; Rosiglitazone ; Superoxide Dismutase ; blood ; Thiazolidinediones ; therapeutic use

The well-known detrimental effects of cadmium (Cd) on plants are chloroplast destruction, photosynthetic pigment inhibition, imbalance of essential plant nutrients, and membrane damage. Jasmonic acid (JA) is an alleviator against different stresses such as salinity and drought. However, the functional attributes of JA in plants such as the interactive effects of JA application and Cd on rapeseed in response to heavy metal stress remain unclear. JA at 50 µmol/L was observed in literature to have senescence effects in plants. In the present study, 25 µmol/L JA is observed to be a "stress ameliorating molecule" by improving the tolerance of rapeseed plants to Cd toxicity. JA reduces the Cd uptake in the leaves, thereby reducing membrane damage and malondialdehyde content and increasing the essential nutrient uptake. Furthermore, JA shields the chloroplast against the damaging effects of Cd, thereby increasing gas exchange and photosynthetic pigments. Moreover, JA modulates the antioxidant enzyme activity to strengthen the internal defense system. Our results demonstrate the function of JA in alleviating Cd toxicity and its underlying mechanism. Moreover, JA attenuates the damage of Cd to plants. This study enriches our knowledge regarding the use of and protection provided by JA in Cd stress.
Brassica napus/metabolism* ; Cadmium/toxicity* ; Catalase/metabolism* ; Cyclopentanes/pharmacology* ; Oxylipins/pharmacology* ; Photosynthesis ; Plant Leaves/metabolism* ; Superoxide Dismutase/metabolism*