Malate Dehydrogenase Activity Research Articles

Evaluating the effects of metal ions on malate dehydrogenase enzyme activity in Watermelon.

Malate Dehydrogenase (MDH) is an essential enzyme in the cellular respiration pathway known as the Tricarboxylic Acid Cycle. Using NAD+ or NADP+ as a cofactor, MDH catalyzes the reversible conversion of oxaloacetate to malate. It can be found in plants, bacteria, and animals. However, some metal ions, such as Cu2+, Zn2+, and Pb2+, can decrease MDH activity. In this study, the recombinant MDH protein (His-MDH) of watermelon was purified and quality tested by SDS-PAGE. The average protein concentrations of elution, cell lysate, and wash were 0.37 mg/mL, 2.23 mg/mL, and 0.24 mg/mL, respectively. According to SDS-PAGE, the size of the purified protein was approximately 37 kD, suggesting the purification of the correct protein. The enzyme activity of the MDH protein will be tested in the presence of metal ions such as MgSO4, NiSO4, ZnSO4, CuSO4, and PdCl2, which have been shown to inhibit dehydrogenase enzymes. Our results provide valuable insight on how different metal ions present in the environment can affect the cell respiration of organisms by affecting the malate dehydrogenase enzyme. Further studies on the roles of metal ions in the TCA cycle and related metabolism, as well as the mechanisms by which metal ions inhibit enzyme activity, will be beneficial in understanding ways to improve soil conditions for higher crop production and for the understanding of evolutionary processes.

Performance of crustacean and insect meal based diets on the growth and digestive enzyme profile of pearlspot Etroplus suratensis (Bloch, 1790)

A feeding trial of 75 days was conducted in tanks to study the performance of shrimphead meal (SM), crab shell meal (CM) and silkworm pupae meal (SWP) on the growth anddigestive enzyme profile of pearlspot, Etroplus suratensis. Four iso-nitrogenous diets with31.5% crude protein replacing 50% fishmeal (FM) in the diets were formulated viz., SM (T1),CM (T2), SWP (T3) and a control (C). Pearlspot advanced fry, 2 cm in length and 1.1 g inweight, was stocked at 60 nos per tank. After 75 days of the experiment, feed conversionratio (FCR), feed efficiency ratio (FER) and protein efficiency ratio (PER) were observed to besignificantly better (p<0.05) in all treatment groups (T1, T2 and T3) than in control (C). T2 (CM)fed fishes exhibited a maximum specific growth rate (SGR) of 3.25±0.09, and significantlyhigher (p<0.05) weight gain (11.54±0.78 g) than T1, T3 and control. In enzyme assays, T2 (CM) fedfishes exhibited significantly higher (p<0.05) protease activity than other treatments.Lipase activity was significantly higher (p<0.05) in T3. However, there was no significantdifference with control diet-fed fishes. Significantly higher (p<0.05) activities of amylase,malate dehydrogenase (MDH) and lactase dehydrogenase (LDH) were observed in all thetreatments compared with control. The outcomes of the present study indicate that crabmeal (31.5% CP) could be effectively utilised as a 50% replacement for fishmeal in the dietof E. suratensis advanced fry for higher yields. Keywords:Crab meal, Enzyme activity, Growth, Shrimp meal,Silkworm pupae meal

Activity-based protein profiling technology reveals malate dehydrogenase as the target protein of cinnamaldehyde against Aspergillus niger

Cinnamaldehyde displays strong antifungal activity against fungi such as Aspergillus niger, but its precise molecular mechanisms of antifungal action remain inadequately understood. In this investigation, we applied chemoproteomics and bioinformatic analysis to unveil the target proteins of cinnamaldehyde in Aspergillus niger cells. Additionally, our study encompassed the examination of cinnamaldehyde's effects on cell membranes, mitochondrial malate dehydrogenase activity, and intracellular ATP levels in Aspergillus niger cells. Our findings suggest that malate dehydrogenase could potentially serve as an inhibitory target of cinnamaldehyde in Aspergillus niger cells. By disrupting the activity of malate dehydrogenase, cinnamaldehyde interferes with the mitochondrial tricarboxylic acid (TCA) cycle, leading to a significant decrease in intracellular ATP levels. Following treatment with cinnamaldehyde at a concentration of 1 MIC, the inhibition rate of MDH activity was 74.90 %, accompanied by an 84.5 % decrease in intracellular ATP content. Furthermore, cinnamaldehyde disrupts cell membrane integrity, resulting in the release of cellular contents and subsequent cell demise. This study endeavors to unveil the molecular-level antifungal mechanism of cinnamaldehyde via a chemoproteomics approach, thereby offering valuable insights for further development and utilization of cinnamaldehyde in preventing and mitigating food spoilage.

Toxic Trio: Zinc, Copper, and Mercury's Effects on Earthworm Enzymes

The impact of heavy metal exposure on earthworm enzyme activities, specifically lactate dehydrogenase (LDH), succinate dehydrogenase (SDH), malate dehydrogenase (MDH), glutamate dehydrogenase (GDH), xanthine oxidase (XOD), lipid peroxidation, superoxide dismutase (SOD), catalase, and glutathione-S-transferase (GST), was investigated in Perionyx excavatus. In control earthworms, LDH activities were 0.120 µmoles/mg protein/hour in the skin, 0.087 µmoles/mg protein/hour in the ovary, 0.062 µmoles/mg protein/hour in the testis, and 0.096 µmoles/mg protein/hour in the intestine. Exposure to mercuric chloride, copper sulfate, and zinc sulfate resulted in significant decreases in LDH activities by 10% to 19.35%, 4.16% to 22.58%, and 5.74% to 15%, respectively. Similarly, SDH activities declined by 10% to 23% with mercuric chloride, 6.89% to 17.91% with copper sulfate, and 4.13% to 16.66% with zinc sulfate treatments. MDH activities also decreased dramatically across all organs, with statistically significant reductions. GDH activities showed varied responses, while XOD activities uniformly decreased. Lipid peroxidation increased significantly after heavy metal exposure. SOD activities increased with mercuric chloride and copper sulfate, while catalase activities decreased with all three treatments. GST activities were significantly reduced by all treatments, particularly by mercuric chloride and copper sulfate. These findings underscore the substantial impact of heavy metal exposure on earthworm enzyme activities, suggesting potential cellular stress and metabolic disturbances.

Disturbances in mitochondrial bioenergetics and control quality and unbalanced redox homeostasis in the liver of a mouse model of mucopolysaccharidosis type II.

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a lysosomal storage disease caused by mutations in the gene encoding the enzyme iduronate 2-sulfatase (IDS) and biochemically characterized by the accumulation of glycosaminoglycans (GAGs) in different tissues. It is a multisystemic disorder that presents liver abnormalities, the pathophysiology of which is not yet established. In the present study, we evaluated bioenergetics, redox homeostasis, and mitochondrial dynamics in the liver of 6-month-old MPS II mice (IDS-). Our findings show a decrease in the activity of α-ketoglutarate dehydrogenase and an increase in the activities of succinate dehydrogenase and malate dehydrogenase. The activity of mitochondrial complex I was also increased whereas the other complex activities were not affected. In contrast, mitochondrial respiration, membrane potential, ATP production, and calcium retention capacity were not altered. Furthermore, malondialdehyde levels and 2',7'-dichlorofluorescein oxidation were increased in the liver of MPS II mice, indicating lipid peroxidation and increased ROS levels, respectively. Sulfhydryl and reduced glutathione levels, as well as glutathione S-transferase, glutathione peroxidase (GPx), superoxide dismutase, and catalase activities were also increased. Finally, the levels of proteins involved in mitochondrial mass and dynamics were decreased in knockout mice liver. Taken together, these data suggest that alterations in energy metabolism, redox homeostasis, and mitochondrial dynamics can be involved in the pathophysiology of liver abnormalities observed in MPS II.

Enhancing l-Malic Acid Production in Aspergillus niger via Natural Activation of sthA Gene Expression.

The efficient production of l-malic acid using Aspergillus niger requires overcoming challenges in synthesis efficiency and excessive byproduct buildup. This study addresses these hurdles, improving the activity of NADH-dependent malate dehydrogenase (Mdh) in the early stages of the fermentation process. By employing a constitutive promoter to express the Escherichia coli sthA responsible for the transfer of reducing equivalents between NAD(H) and NADP(H) in A. niger, the l-malic acid production was significantly elevated. However, this resulted in conidiation defects of A. niger, limiting industrial viability. To mitigate this, we discovered and utilized the PmfsA promoter, enabling the specific expression of sthA during the fermentation stage. This conditional expression strain showed similar phenotypes to its parent strain while exhibiting exceptional performance in a 5 L fermenter. Notably, it achieved a 65.5% increase in productivity, reduced fermentation cycle by 1.5 days, and lowered succinic acid by 76.2%. This work marks a promising advancement in industrial l-malic acid synthesis via biological fermentation, showcasing the potential of synthetic biology in A. niger for broader applications.

Antibacterial Mechanism, Control Efficiency, and Nontarget Toxicity Evaluation of Actinomycin X2 against Xanthomonas citri Subsp. citri.

The present study investigated the antibacterial mechanism, control efficiency, and nontarget toxicity of actinomycin X2 (Act-X2) against Xanthomonas citri subsp. citri (Xcc) for the first time. Act-X2 almost completely inhibited the proliferation of Xcc in the growth curve assay at a concentration of 0.25 MIC (minimum inhibitory concentration, MIC = 31.25 μg/mL). This inhibitory effect was achieved by increasing the production of reactive oxygen species (ROS), blocking the formation of biofilms, obstructing the synthesis of intracellular proteins, and decreasing the enzymatic activities of malate dehydrogenase (MDH) and succinate dehydrogenase (SDH) of Xcc. Molecular docking and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) analysis results indicated that Act-X2 steadily bonded to the RNA polymerase, ribosome, malate dehydrogenase, and succinate dehydrogenase to inhibit their activities, thus drastically reducing the expression levels of related genes. Act-X2 showed far more effectiveness than the commercially available pesticide Cu2(OH)3Cl in the prevention and therapy of citrus canker disease. Furthermore, the nontarget toxicity evaluation demonstrated that Act-X2 was not phytotoxic to citrus trees and exhibited minimal toxicity to earthworms in both contact and soil toxic assays. This study suggests that Act-X2 has the potential as an effective and environmentally friendly antibacterial agent.

Dietary papaya peel extract ameliorates the crowding stress, enhances growth and immunity in Labeo rohita fingerlings.

This study was designed to determine the effects of papaya peel extract (PPE) supplementation on the growth and immunophysiological responses of rohu fingerlings at different stocking densities. In this study, three isonitrogenous (307.2-309.8gkg-1 protein) and isocaloric diets (16.10-16.16MJ digestible energy kg-1) were prepared using three different inclusion levels (0, 5, and 10gkg-1) of PPE. Four hundred and five rohu fingerlings (mean weight: 4.24g ± 0.12) were randomly distributed into nine treatment groups in triplicates viz. low (10nos 75 L-1 or ≈ 0.565kg/m3), medium (15nos 75 L-1 or ≈ 0.848kg/m3), and high (20nos 75 L-1 or ≈ 1.13kg/m3) following a completely randomized design. The study found that increasing stocking density negatively affected fish growth indices, such as weight gain percentage (WG%), feed efficiency ratio (FER), specific growth rate (SGR) and survival. In contrast, dietary PPE supplementation improved growth indices and survival (p < 0.05). We also observed that aminotransferase, lactate (LDH), and malate dehydrogenase (MDH) activity increased with stocking density, whereas 5 and 10gkg-1 PPE supplementation reduced LDH and MDH activity (p < 0.05). PPE supplementation positively affected serum indices, decreased glucose levels, and increased respiratory burst activity (p < 0.05). Interferon-gamma (IFN-γ) expression was highest in the low- and medium-stocking density groups fed with 5gkg-1 PPE, which also increased total immunoglobulin and myeloperoxidase activity while decreasing malondialdehyde concentration (p < 0.05). The results revealed that 5gkg-1 dietary PPE supplementation could be used as a growth promoter and immunostimulant to improve immuno-physiological responses at low and medium stocking densities.

Antifungal activity and potential mechanism of action of Huangqin decoction against Trichophyton rubrum.

Introduction. Trichophyton rubrum is a major causative agent of superficial dermatomycoses such as onychomycosis and tinea pedis. Huangqin decoction (HQD), as a classical traditional Chinese medicine formula, was found to inhibit the growth of common clinical dermatophytes such as T. rubrum in our previous drug susceptibility experiments.Hypothesis/Gap Statement. The antifungal activity and potential mechanism of HQD against T. rubrum have not yet been investigated.Aim. The aim of this study was to investigate the antifungal activity and explore the potential mechanism of action of HQD against T. rubrum.Methodology. The present study was performed to evaluate the antifungal activity of HQD against T. rubrum by determination of minimal inhibitory concentrations (MICs), minimal fungicidal concentrations (MFCs), mycelial growth, biomass, spore germination and structural damage, and explore its preliminary anti-dermatophyte mechanisms by sorbitol and ergosterol assay, HPLC-based ergosterol test, enzyme-linked immunosorbent assay and mitochondrial enzyme activity test.Results. HQD was able to inhibit the growth of T. rubrum significantly, with an MIC of 3.125 mg ml-1 and an MFC of 12.5 mg ml-1. It also significantly inhibited the hyphal growth, conidia germination and biomass growth of T. rubrum in a dose-dependent manner, and induced structural damage in different degrees for T. rubrum cells. HQD showed no effect on cell wall integrity, but was able to damage the cell membrane of T. rubrum by interfering with ergosterol biosynthesis, involving the reduction of squalene epoxidase (SE) and sterol 14α-demethylase P450 (CYP51) activities, and also affect the malate dehydrogenase (MDH), succinate dehydrogenase (SDH) and ATPase activities of mitochondria.Conclusion. These results revealed that HQD had significant anti-dermatophyte activity, which was associated with destroying the cell membrane and affecting the enzyme activities of mitochondria.

Effects of bleaching on oxygen dynamics and energy metabolism of two Caribbean coral species

As mass coral bleaching events become more frequent, it is increasingly important to elucidate the factors underlying coral susceptibility and survival. We measured photosynthesis, respiration, and O2 concentration at the coral tissue surface, Symbiodiniaceae genotypes, and energy metabolic enzyme activities in Agaricia agaricites and Orbicella franksi throughout experimentally-induced thermal bleaching (+3 °C). A. agaricites colonies started to bleach two days into the thermal treatment and were fully bleached between Days 19–31. In contrast, O. franksi colonies only started to bleach on Day 12 and five colonies fully bleached between Days 24–38 while the remining three colonies took up 55 days. Both species experienced decreased photosynthesis and respiration rates as bleaching progressed. As a result, daytime O2 concentration at the coral surface shifted from hyperoxia in unbleached corals to normoxia in partially bleached corals, and to near hypoxia in fully bleached corals. Additionally, nighttime tissue surface O2 concentration shifted from hypoxia to normoxia, likely resulting from decreased symbiotic algae density, respiration, and photosynthates that fuel coral aerobic respiration. Genetic profiling of internal transcribed spacer 2 (ITS2) revealed differences in Symbiodiniaceae clade proportions between control and bleached colonies. Activity levels of energy metabolic enzymes did not significantly vary between control and bleached A. agaricites, but malate dehydrogenase and strombine dehydrogenase activities were significantly higher in bleached O. franksi colonies compared to controls. These differences were driven by the three O. franksi colonies that took the longest to bleach and contained >98 % Durusdinium sp. D1. The shifts in O2 dynamics within the microhabitat of bleached corals may have important implications for the metabolism of the coral holobiont while the changes in Symbiodiniaceae ITS2 profile and the upregulation of energy metabolic enzymes identify a potential factor contributing to bleaching dynamics.

Effects of Aerobic Treadmill Training on Oxidative Stress Parameters, Metabolic Enzymes, and Histomorphometric Changes in Colon of Rats with Experimentally Induced Hyperhomocysteinemia.

The aim of this study was to investigate the effects of aerobic treadmill training regimen of four weeks duration on oxidative stress parameters, metabolic enzymes, and histomorphometric changes in the colon of hyperhomocysteinemic rats. Male Wistar albino rats were divided into four groups (n = 10, per group): C, 0.9% NaCl 0.2 mL/day subcutaneous injection (s.c.) 2x/day; H, homocysteine 0.45 µmol/g b.w./day s.c. 2x/day; CPA, saline (0.9% NaCl 0.2 mL/day s.c. 2x/day) and an aerobic treadmill training program; and HPA, homocysteine (0.45 µmol/g b.w./day s.c. 2x/day) and an aerobic treadmill training program. The HPA group had an increased level of malondialdehyde (5.568 ± 0.872 μmol/mg protein, p = 0.0128 vs. CPA (3.080 ± 0.887 μmol/mg protein)), catalase activity (3.195 ± 0.533 U/mg protein, p < 0.0001 vs. C (1.467 ± 0.501 U/mg protein), p = 0.0012 vs. H (1.955 ± 0.293 U/mg protein), and p = 0.0003 vs. CPA (1.789 ± 0.256 U/mg protein)), and total superoxide dismutase activity (9.857 ± 1.566 U/mg protein, p < 0.0001 vs. C (6.738 ± 0.339 U/mg protein), p < 0.0001 vs. H (6.015 ± 0.424 U/mg protein), and p < 0.0001 vs. CPA (5.172 ± 0.284 U/mg protein)) were detected in the rat colon. In the HPA group, higher activities of lactate dehydrogenase (2.675 ± 1.364 mU/mg protein) were detected in comparison to the CPA group (1.198 ± 0.217 mU/mg protein, p = 0.0234) and higher activities of malate dehydrogenase (9.962 (5.752-10.220) mU/mg protein) were detected in comparison to the CPA group (4.727 (4.562-5.299) mU/mg protein, p = 0.0385). Subchronic treadmill training in the rats with hyperhomocysteinemia triggers the colon tissue antioxidant response (by increasing the activities of superoxide dismutase and catalase) and elicits an increase in metabolic enzyme activities (lactate dehydrogenase and malate dehydrogenase). This study offers a comprehensive assessment of the effects of aerobic exercise on colonic tissues in a rat model of hyperhomocysteinemia, evaluating a range of biological indicators including antioxidant enzyme activity, metabolic enzyme activity, and morphometric parameters, which suggested that exercise may confer protective effects at both the physiological and morphological levels.

Dietary short-term supplementation of grape seed proanthocyanidin extract improves pork quality and promotes skeletal muscle fiber type conversion in finishing pigs

Plant extracts are commonly used as feed additives to improve pork quality. However, due to their high cost, shortening the duration of supplement use can help reduce production costs. In this study, we aimed to investigate the effects of grape seed proanthocyanidin extract (GSPE) on meat quality and muscle fiber characteristics of finishing pigs during the late stage of fattening, which was 30 days in our experimental design. The results indicated that short-term dietary supplementation of GSPE significantly reduced backfat thickness, but increased loin eye area and improved meat color and tenderness. Moreover, GSPE increased slow myosin heavy chain (MyHC) expression and malate dehydrogenase (MDH) activity, while decreasing fast MyHC expression and lactate dehydrogenase (LDH) activity in the Longissimus thoracis (LT) muscle. Additionally, GSPE increased the expression of Sirt1 and PGC-1α proteins in the LT muscle of finishing pigs and upregulated AMP-activated protein kinase α 1 (AMPKα1), AMPKα2, nuclear respiratory factor 1 (NRF1), and calcium/calmodulin-dependent protein kinase kinase β (CaMKKβ) mRNA expression levels. These findings suggest that even during the late stage of fattening, GSPE treatment can regulate skeletal muscle fiber type transformation through the AMPK signaling pathway, thereby affecting the muscle quality of finishing pigs. Therefore, by incorporating GSPE into the diet of pigs during the late stage of fattening, producers can enhance pork quality while reducing production costs.

Genome-wide characterization of soybean malate dehydrogenase genes reveals a positive role of GmMDH2 in salt stress response

Malate dehydrogenase (MDH) is a widely expressed enzyme that plays a key role in plant growth, development, and the stress response. However, information on MDH genes in the soybean genome is limited. Seventeen members of the soybean MDH family were identified by genome-wide analysis, and the presence of conserved protein motifs was analyzed. The genes were divided into five clusters according to their phylogenetic relationships. The intracellular localizations of six GmMDHs were determined by confocal microscopy on Arabidopsis mesophyll protoplasts. Transcripts of GmMDHs were significantly increased by abiotic stress (drought, salt, and alkalinity) and hormone treatments, as shown by analysis of cis-regulatory elements and quantitative real-time polymerase chain reaction (qRT-PCR). GmMDHs displayed unique expression patterns in diverse soybean tissues. It is noteworthy that under salt stress, the expression levels of a chloroplast isoform (GmMDH2) were unusually high, presumably indicating a critical role in soybean responses to salinity. Expression of GmMDH2 in Escherichia coli showed that the recombinant enzyme had NADP-dependent MDH activity. The redox states of the nicotinamide adenine dinucleotide phosphate (NADPH) pool and antioxidant activities were shown to be modulated by GmMDH2 gene overexpression, which in turn reduced reactive oxygen species (ROS) formation in transgenic soybean, significantly enhancing the salt stress resistance. Gene-based association analysis showed that variations in GmMDH2 were strongly linked to seedling salt tolerance. A polymorphism possibly associated with salt tolerance was discovered in the promoter region of GmMDH2. These findings not only improve our understanding of the stress response mechanism by identifying and characterizing the MDH gene family throughout the soybean genome but it also identified a potential candidate gene for the future enchancement of salt tolerance in the soybean.

Effect of flavanone rich lemon peel extract on feed intake and growth of Labeo rohita (Hamilton, 1822) fingerlings reared at low temperature recirculatory aquaculture system

An 8-week experiment was conducted to study the effect of dietary lemon peel extract on feed intake and growth of Labeo rohita (rohu) fingerlings reared at low temperature (18 ± 1 °C). As a preliminary study, the antioxidant activity of lemon peel extract from water and ethanol was performed using DPPH, TPC, and FRAP assays, and found that the antioxidant activity in all three assays was higher for ethanol extract (25 mg L−1). Five isonitrogenous (300.0 g kg-1) and isocaloric (16.10 MJ kg−1) practical diets with varying levels of ethanol lemon peel extract viz, control (0.0 g kg−1 lemon peel extract), LPE2.5 (2.5 g kg−1 lemon peel extract), LPE5.0 (5.0 g kg−1 lemon peel extract), LPE10 (10.0 g kg−1 lemon peel extract), LPE20 (20.0 g kg−1 lemon peel extract) were prepared. The average initial body weight of the experimental animal was 10.30 ± 0.5 g, and the experiment was conducted in a low temperature (18 ± 1 °C) recirculatory aquaculture system (RAS) with a flow rate of 1.5 L min−1. The results showed that dietary lemon peel extract (LPE) supplementation increased the feed intake and growth performance in rohu fingerlings (p < 0.05). Fish fed with 5.0 g kg−1 LPE exhibited the best growth rates, thermal growth coefficient (TGC), and feed conversion (p < 0.05); however, TGC was similar in LPE5.0 and LPE10 fed groups (p > 0.05). Protease and aminotransferase enzyme activities positively correlated with growth rates (p < 0.05). Dietary LPE supplementation significantly augmented the hepatic malate dehydrogenase, citrate synthase, superoxide dismutase, and catalase activities (p < 0.05). From these results, it can be concluded that dietary supplementation of lemon peel extract at 5–10 g kg−1 level had positive effects on feed intake and metabolic activities of rohu reared at low temperature.

Pathophysiological mechanisms of adaptation of muscle tissue of descendants of irradiated animals to altering influence of ionizing radiation

Biochemical processes occurring in a living organism take part in the development of radiation-induced structural disorders, realizing primary damage. As a result, morphological manifestations of radiation damage are preceded by chemical shifts determining them. In the descendants of animals irradiated in different doses, a decrease in physical performance is observed, which is due to a violation of the efficiency of the use of the unique biosubstrate of muscle tissue - creatinephosphate, a change in the ratio of the activity of aerobic and anaerobic metabolism, and processes of trans-deamination of amino acids. The purpose of the work is to investigate the the mechanisms of disruption of metabolic processes in the muscle tissue of the descendants of irradiated animals. It was concluded that, unlike skeletal muscle, the activity of the tricarboxylic acid cycle, in particular the NAD-dependent malate dehydrogenase, in the myocardium is quite significant both in the cytoplasm and in the mitochondria of the tissue, as evidenced by the higher level of tricarboxylic acid cycle metabolites acids - malic and oxaloacetic, as well as the activity of NADP-dependent malate dehydrogenase, which performs a connecting role between glycolysis and the cycle of tricarboxylic acids in providing them with metabolites and transferring protons from NADH+H+ to NADP. The author revealed that myocardium is characterized by a larger pool of adenyl nucleotides due to ATP. Tha data obrtained shiowed hyperglycemia which is observed in the blood of the descendants of irradiated animals. Gluconeogenesis is enhanced in the liver of the descendants of irradiated animals and this explains the hyperglycemia and accumulation of glycogen in the liver. At the same time, the penetration of glucose into muscle cells is weakened, which is associated with a decrease in their glycogen content, and this can be explained by the decrease in adaptation to physical exertion in the descendants of irradiated animals. The author made a cionclusion that the pathophysiological mechanisms of radiation-induced energy supply restructuring are aimed at short-term processes of strengthening the supply of energy to vital organs and systems for destroyed biochemical, physiological, functional and regulatory processes restoration and sanogenetic mechanisms activation.

Co-Inoculation with Bradyrhizobium and Humic Substances Combined with Herbaspirillum seropedicae Promotes Soybean Vegetative Growth and Nodulation

The effect of humic substances (HSs) in combination with or without plant-growth-promoting bacteria on soybean vegetative growth and root nodulation was examined in this study. Seeds were inoculated with Bradyrhizobium japonicum SEMIA 5079 in the presence of HSs from leonardite and Herbaspirillum seropedicae HRC54. Additional HSs and H. seropedicae application at the substrate surface was conducted at the V3 stage. The experiment was carried out in a greenhouse using pots filled with a top layer of an Oxisol soil, and plants were harvested at the R1 stage. The HS and H. seropedicae treatments significantly promoted plant shoot and root growth. The number and weight of soybean nodules were higher in the treated plants when compared to a control. The plant nodulation process was affected by the treatments that included activities of malate dehydrogenase (MDH), nitrate reductase (NR) and plasma membrane H+-ATPase (MHA). At low concentrations, the HSs and H. seropedicae increased the nodule quantity, size and weight, favoring plant growth. Combining humic substances and plant-growth-promoting bacteria (PGPB) could be a promising approach to promoting soybean nodulation and increasing crop production.

Effects of caloric restriction and ketogenic diet on renal fibrosis after ischemia/reperfusion injury

The beneficial effects of caloric restriction (CR) and a ketogenic diet (KD) have been previously shown when performed prior to kidney injury. We investigated the effects of CR and KD on fibrosis development after unilateral kidney ischemia/reperfusion (UIR). Post-treatment with CR significantly (p < 0.05) affected blood glucose (2-fold decrease), ketone bodies (3-fold increase), lactate (1.5-fold decrease), and lipids (1.4-fold decrease). In the kidney, CR improved succinate dehydrogenase and malate dehydrogenase activity by 2-fold each, but worsened fibrosis progression. Similar results were shown for the KD, which restored the post-UIR impaired activities of succinate dehydrogenase, malate dehydrogenase, and α-ketoglutarate dehydrogenase (which was decreased 2-fold) but had no effect on fibrosis progression. Thus, our study shows that the use of CR or KD after UIR did not reduce the development of fibrosis, as shown by hydroxyproline content, western-blotting, and RT-PCR, whereas it caused significant metabolic changes in kidney tissue after UIR.

Comparative metabolomics analysis investigating the impact of melatonin-enriched diet on energy metabolism in the crayfish, Cherax destructor.

Melatonin is a multifunctional bioactive molecule present in almost all organisms and has been gradually used in the aquaculture industry in recent years. Energy metabolism is an essential process for individuals to maintain their life activities; however, the process through which melatonin regulates energy metabolism in aquatic animals remains unclear. The present study aimed to conduct a comprehensive analysis of the regulatory mechanism of melatonin for energy metabolism in Cherax destructor by combining metabolomics analysis with the detection of the key substance content, enzymatic activity, and gene expression levels in the energy metabolism process after culturing with dietary melatonin supplementation for 8weeks. Our results showed that dietary melatonin increased the content of glycogen, triglycerides, and free fatty acids; decreased lactate levels; and promoted the enzymatic activity of pyruvate kinase (PK), malate dehydrogenase (MDH), and acetyl-CoA carboxylase. The results of gene expression analysis showed that dietary melatonin also increased the expression levels of hexokinase, PK, MDH, lactate dehydrogenase, lipase, and fatty acid synthase genes. The results of metabolomics analysis showed that differentially expressed metabolites were significantly enriched in lysine degradation and glycerophospholipid metabolism. In conclusion, our study demonstrates that dietary melatonin increased oxidative phosphorylation, improved glucose utilization, and promoted storage of glycogen and lipids in C. destructor. These lipids are used not only for energy storage but also to maintain the structure and function of cell membranes. Our results further add to the understanding of the mechanisms of energy regulation by melatonin in crustaceans.

Phenyllactic acid maintains the storage quality of ‘Zaosu’ pears by regulating respiration and energy metabolism

Respiration and energy metabolism are intricately linked to the quality and senescence of fruit after harvest. This investigation was carried out to examine alternations in quality parameters, respiration, and energy metabolism of ‘Zaosu’ pears subsequent to phenyllactic acid immersion. Results demonstrated that phenyllactic acid treatment led to a reduction in L* , a* , b* values, ΔE, and mass loss. Additionally, it maintained ascorbic acid, reducing sugar, soluble sugar, soluble solids, and chlorophyll contents; delayed the decrease in flesh firmness and titratable acidity of pears. The activities and gene expressions of glucose-6-phosphate dehydrogenase, glucose phosphate isomerase, hexokinase, nicotinamide adenine dinucleotide kinase, cytochrome C oxidase, and succinate dehydrogenasepears in pears were enhanced by phenyllactic acid. Moreover, phenyllactic acid promoted PbPK, PbAOX, PbH+-ATPase, and PbCa2+-ATPase expressions, while inhibiting malate dehydrogenase activity and the expressions of PbPFK and PbMDH in pears. Phenyllactic acid also led to a decrease in the levels of nicotinamide adenine dinucleotide hydrogen and nicotinamide adenine dinucleotide, while causing an increase in the levels of nicotinamide adenine dinucleotide phosphate hydrogen and nicotinamide adenine dinucleotide phosphate within the fruit. Collectively, postharvest phenyllactic acid treatment can effectively preserve the storage quality of ‘Zaosu’ pears by regulating the activity and gene expression of the key enzymes involved in respiration and energy metabolism.

Dietary Taurine Supplementation Improves the Meat Quality, Muscle Fiber Type, and Mitochondrial Function of Finishing Pigs.

This study investigated the effects of dietary supplementation with taurine (TAU) on the meat quality, muscle fiber type, and mitochondrial function of finishing pigs. The results demonstrated that TAU significantly increased the a* value while decreasing b*45min, L*24h, and drip loss24h and drip loss48h in the longissimus dorsi (LD) muscle. Dietary supplemented with TAU reduced the content of lactate and the glycolytic potential (GP) in the LD muscle. Dietary supplemented with TAU enhanced the oxidative fiber-related gene expression as well as increased succinic dehydrogenase and malate dehydrogenase activities while reducing lactate dehydrogenase activity. Furthermore, dietary supplementation with TAU increased the contents of mtDNA and ATP and mitochondrial function-related gene expression. Moreover, TAU enhanced the mRNA expressions of calcineurin (CaN) and nuclear factor of activated T cells c1 (NFATc1) and protein expressions of CNA and NFATc1. The results indicate that dietary TAU supplementation improves meat quality and mitochondrial biogenesis and function and promotes muscle fiber-type conversion from the glycolytic fiber to the oxidative fiber via the CaN/NFATc1 pathway.