Antioxidase System Research Articles

Inhibition of nitrogen assimilation promotes carbon-based secondary metabolism in callus of Cyclocarya paliurus

The biosynthesis and accumulation of secondary metabolites are critical important to quality formation of medicinal plants, which are usually give way to primary processes and growth. Here, methionine sulfoximine (MSO) was used to inhibit the nitrogen assimilation in callus of Cyclocarya paliurus. The newly assimilated nitrogen characterized by 15N atom percentage excess, and the levels of amino acid and protein were reduced. The other primary processes such as carbohydrate metabolism and lipid metabolism were also repressed. In addition, the expression of the growth-related target of rapamycin (TOR) signaling was repressed, indicating nitrogen assimilation inhibition led to a systematic down-regulated primary metabolisms and resulted in a disruption of growth. In contrast, the biosynthesis of flavonoids and triterpenoids, antioxidase system, and the SnRK2-mediated abscisic acid (ABA) and jasmonic acid (JA) signaling were induced, which can improve plant stress resistance and defense. Nitrogen assimilation inhibition led to the carbon metabolic flux redirection from primary processes to secondary pathways, and facilitated the biosynthesis of flavonoids and triterpenoids in calluses of C. paliurus. Our results provide a comprehensive understanding of metabolic flux redirection between primary and secondary metabolic pathways and a potential means to improve the quality of medicinal plants.

Breeding of a thermostable xylanase-producing strain of Myceliophthora thermophila by atmospheric room temperature plasma (ARTP) mutagenesis.

Introduction: Hemicellulose is an important component in lignocellulose materials, which is second only to cellulose, accounting for 15%-35% of the dry weight of plants. In the current situation of energy shortage, making full use of lignocellulose materials to produce fuel ethanol has become an important way to solve the energy problem. Xylanase plays a crucial role in the utilization of hemicellulose. It is a necessary means to reduce the cost of hemicellulose utilization by improving the activity of xylanase. Moreover, most naturally xylanases are mesophilic enzymes, which limits their industrial application. Methods:In this study, Myceliophthora thermophila was used to produce xylanases and a thermostable mutant M 2103 was obtained by atmospheric room temperature plasma (ARTP) mutagenesis. The research work started with exploring the effects of ARTP mutagenesis on the antioxidase system [superoxide dismutase (SOD), catalase (CAT), peroxidase (POD), polyphenol oxidase (PPO), and antioxidant capacity (AOC)] of M. thermophile, and found that superoxide dismutase activity increased by 221.13%, and polyphenol oxidase activity increased by 486.04% as compared with the original strain when the implantation time was 300s. So as to determine the conditions for subsequent mutagenesis. Results and Discussion:For the mutant M 2103, the reaction temperature for xylanase production remained stable in the range of 70°C-85°C. Its optimum temperature was 75°C, which was 15°C higher than that of the original strain. And its xylanase activity increased by 21.71% as compared with the original strain. M 2103 displayed a significantly higher relative xylanase activity than the original strain in the acidic (pH 4.0-7.0) range, and the xylanase activity was relatively stable in the pH range of 6.0-8.5. These results provide an alternative biocatalyst for the production of xylooligosaccharide, and a potential usage of ARTP in the mutagenesis of thermostable mutant.

Fermented Cerasus humilis fruits protect against high-fat diet induced hyperlipidemia which is associated with alteration of gut microbiota.

Hyperlipidemia is regarded as a public health matter, and its effective prevention and treatment are urgently required. However, the treatment of hyperlipidemia is still relatively scarce. Fermented Cerasus humilis fruit (FCHF) had higher total flavonoid, total phenolic, procyanidin, and organic and free amino acid content, and lower total sugar content, than non-fermented C.humilis fruit (NFCHF). Both FCHF and NFCHF treatment significantly prevent putting on weight. Furthermore, FCHF administration ameliorated hyperlipidemia and cholesterol over-accumulation. In addition, FCHF administration activated the antioxidase system and decreased the malondialdehyde content to relieve oxidative stress, and showed more efficaciously than NFCHF administration. FCHF treatments significantly reverse the fat deposition in high-fat diet rat liver. FCHF supplementation can relieve the dysbacteriosis induced by hyperlipidemia, and regulate the composition of rat gut microbiota by increasing the abundance of Prevotella and norank_f_Muribaculaceae. Lactobacillus plantarum and Saccharomyces cerevisiae fermentation enhanced the antihyperlipidemic property of C. humilis fruits by promoting gut microbiota regulation. © 2022 Society of Chemical Industry.

Synthesis of Abscisic Acid in Neopyropia yezoensis and Its Regulation of Antioxidase Genes Expressions Under Hypersaline Stress.

Abscisic acid (ABA) is regarded as crucial for plant adaptation to water-limited conditions and it functions evolutionarily conserved. Thus, insights into the synthesis of ABA and its regulation on downstream stress-responsive genes in Neopyropia yezoensis, a typical Archaeplastida distributed in intertidal zone, will improve the knowledge about how ABA signaling evolved in plants. Here, the variations in ABA contents, antioxidant enzyme activities and expression of the target genes were determined under the presence of exogenous ABA and two specific inhibitors of the ABA precursor synthesis. ABA content was down-regulated under the treatments of each or the combination of the two inhibitors. Antioxidant enzyme activities like SOD, CAT and APX were decreased slightly with inhibitors, but up-regulated when the addition of exogenous ABA. The quantitative assays using real-time PCR (qRT-PCR) results were consistent with the enzyme activities. All the results suggested that ABA can also alleviate oxidative stress in N. yezoensis as it in terrestrial plant. Combined with the transcriptome assay, it was hypothesized that ABA is synthesized in N. yezoensis via a pathway that is similar to the carotenoid pathway in higher plants, and both the MVA and that the MEP pathways for isoprenyl pyrophosphate (IPP) synthesis likely exist simultaneously. The ABA signaling pathway in N. yezoensis was also analyzed from an evolutionary standpoint and it was illustrated that the emergence of the ABA signaling pathway in this alga is an ancestral one. In addition, the presence of the ABRE motif in the promoter region of antioxidase genes suggested that the antioxidase system is regulated by the ABA signaling pathway.

Use of integrated biomarker response for evaluating antioxidant stress and DNA damage of earthworms (Eisenia fetida) in decabromodiphenyl ethane-contaminated soil

Decabromodiphenyl ethane (DBDPE) is a new and popular type of brominated flame retardant (BFR) with high bromine content, strong thermal stability, and ultraviolet resistance. To evaluated the potential toxicity of this new BFR to soil ecosystem, different concentrations of DBDPE were used to observe effects on earthworms (Eisenia fetida) in artificial soil. The reactive oxygen species (ROS) contents, activities of antioxidase system and detoxify enzyme, levels of malondialdehyde (MDA), as well as DNA damage in earthworms were measured after exposure to 0, 2.5, 5, 10, and 20 mg/kg DBDPE in artificial soil for 7, 14, 21, and 28 days. The results showed that ROS and MDA content significantly increased for all treatments from days 7–21, followed by a decrease. Throughout the experimental period, SOD, POD, and CAT activities increased. The GST activity was stimulated significantly from days 14–28. Besides, the olive tail moment (OTM) value in all treated groups was significantly higher than that in the control and exhibited a concentration-related and exposure time-related response. This is the first study evaluating the biological toxicity of BFR at different concentrations using an integrated biomarker response index. Our results show that DBDPE has biochemical toxicity on earthworms, which sheds some light on the potential risks of DBDPE in the soil environment and provides a basis for the monitoring and diagnosis of soils contaminated with DBDPE.

Ammonium nutrition mitigates cadmium toxicity in rice (Oryza sativa L.) through improving antioxidase system and the glutathione-ascorbate cycle efficiency.

Nitrogen (N) forms not only affect cadmium (Cd) accumulation in plants, but also affect plant resistance to Cd toxicity. However, few researches have been reported underlying the mechanism of the relationship between nitrogen forms and plant resistance under Cd exposure. Here, we explored the mechanism on how different NO3-/NH4+ ratios affect antioxidase system and the glutathione-ascorbate cycle under five different ratios of NO3-/NH4+ (1:0, 2:1, 1:1, 1:2, 0:1) and three dosages of Cd exposure (0, 1, 5μmolL-1 Cd) in rice (Oryza sativa L.). The results showed that high NO3- and high Cd exposure both significantly inhibited tissue growth of rice plants, and this inhibiting trend was mitigated with increasing NH4+ ratios as proved by the increased biomass and the decreased concentrations of malonaldehyde (MDA) and hydrogen peroxide (H2O2), as well as the levels of Cd contents in rice tissues. Additionally, high NH4+ ratios elevated the SOD activities in rice tissues, especially at high Cd treatment. However, other two antioxidases (CAT and APX) were insensitive to changes of NO3-/NH4+ ratios (except the full NO3-). Furthermore, high NH4+ ratios induced increasing of the efficiency of glutathione-ascorbate cycle (GSH-AsA) under two levels of Cd exposure, as evidenced by increasing concentrations of GSH and AsA and the activities of GR and DHAR in rice tissues. Overall, these results revealed that ammonium nutrition caused an enhancement resistance to Cd stress in rice plants was responsible for increasing of partial antioxidase system and the efficiencies of GSH-AsA cycle.

Main Allelochemicals from the Rhizosphere Soil of Saussurea lappa (Decne.) Sch. Bip. and Their Effects on Plants' Antioxidase Systems.

Allelochemicals are the media of allelopathy and form the chemical bases of plant-environment interactions. To determine true allelochemicals and their autotoxic effects, seven compounds were isolated and identified from in-situ sampled rhizosphere soil of cultivated Saussurea lappa. Of these; costunolide (2), dehydrocostus lactone (3) and scopoletin (4) showed significant inhibition on seedling growth in a concentration-dependent manner. Detection and observation demonstrated that the antioxidase system was found to be affected by these chemicals, resulting in the accumulation of ROS and membrane damage. To investigate their release ways, the compounds were traced back and volumes quantified in rhizosphere soil and plant tissues. This work made clear the chemical bases and their physiological effects on the plants. These chemicals were found to be the secondary metabolites of the plants and included in the rhizosphere soil. The findings identified a potential pathway of plant-plant interactions, which provided theoretical basis to overcoming replanting problems. This research was also useful for exploring ecological effects of allelochemicals in green agriculture.

Molybdenum Sulfide Induce Growth Enhancement Effect of Rice ( Oryza sativa L.) through Regulating the Synthesis of Chlorophyll and the Expression of Aquaporin Gene.

Molybdenum sulfide (MoS2) has been applied widely in industrial and environmental application, leading to increasing release into environment. So far, no studies have been investigated with regard to the potential effect of MoS2 on plants. Herein, we studied the impact of MoS2 on the growth, chlorophyll content, lipid peroxidation, antioxidase system, and aquaporins of rice for the first time. Results showed that MoS2 did not significantly affect the germination of rice seeds, malonaldehyde (MDA) content, and the antioxidant enzyme activity. While the length and biomass of rice root and shoot, chlorophyll content index (CCI), and expression of aquaporin genes were significantly increased. Based on these results, we concluded that MoS2 promoted rice growth through (i) the promotion of nitrogen source assimilation, (ii) the enhancement of photosynthesis, enzymatic-related biochemical reactions, and metabolic processes, subsequently, (iii) the acceleration of cell division and expansion, furthermore (iv) no abiotic stress and favorable condition of antioxidant enzyme system. These results provided an important insight into the further application of MoS2 on agriculture and environment.

Exogenous H₂O₂ regulated secondary metabolism of Scutellaria baicalensis and enhanced drug quality

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.

Interactions between salicylic acid and antioxidant enzymes tilting the balance of H2O2 from photorespiration in non-target crops under halosulfuron-methyl stress

Halosulfuron-methyl (HSM) is a safe, selective and effective sulfonylurea herbicide (SU) for the control of sedge and broadleaf weeds in sugarcane, corn, tomato, and other crops. The primary site of action is acetolactate synthase (ALS), a key enzyme of branched chain amino acids (BCAAs) synthesis. In addition to ALS inhibition, BCAAs deficiencies and oxidative damage may be involved in toxic effects of SUs. However, secondary targets of HSM relevant to plant physiological responses are unclear. In the present study, comparative growth inhibition and peroxidization injury between sensitive and tolerance crops were observed at biochemical and physiological levels suggesting involvement of H2O2, ethylene, salicylic acid (SA) in the oxidative stress responses to HSM. HSM caused accumulation of H2O2, stimulated photorespiration and consequent accumulation of SA that worsened the peroxidization injury to the sensitive C3 plant soybean (Glycine max). The growth inhibition at low concentrations of HSM could be lessened by supplementary BCAAs, reactive oxygen species scavengers or ethylene inducers, whereas the oxidation damage at high concentrations of HSM could not be reversed and ultimately lead to plant death. H2O2 at a low level stimulated the antioxidase system including glutathione S-transferase activities in the HSM-tolerant C4 maize (Zea mays), which contributes to HSM tolerance. H2O2 plays an important role on HSM stress responses in both HSM-sensitive and HSM-tolerant soybean and maize.

The bisphenol A-enhanced activity of thyroid carcinoma cell line B-CPAP is inhibited by Icarrin

Objective: To investigate the effect of icariin (ICA) on the bisphenol A (BPA)-enhanced proliferation function of thyroid carcinoma cell B-CPAP and underlying mechanism. Methods: The proliferation of Gastric B-CPAP cell line was evaluated by cell counting kit-8 (CCK-8). Apoptosis and ROS expression in B-CPAP cells were detected by flow cytometry. The expression of superoxide dismutase (SOD) and malondialdehyde (MDA) in B-CPAP cells were measured by individual assay kits. The expressions of Bcl-2 and γ-HA2X were detected by Western blot. SPSS 18.0 software was used to analyze the data. Results: B-CPAP cell activity was promoted by treatment with 3×10(-7)mol/L BPA for 48 h, with significant difference in absorbance between BPA and control groups (1.089±0.053 vs 0.935±0.010, P<0.05). The cell activities of BPA+ ICA(25), BPA+ ICA(50), BPA+ ICA(100) and BPA+ ICA(200) groups was 0.780±0.036, 1.007±0.050, 0.958±0.033 and 0.625±0.064, respectively (all P<0.01). The proliferation of B-CPAP cells treated with BPA for 72 hours showed a similar trend to 48 hours. There was no significant difference between all treatment groups in 24 hours. The apoptosis rate was (19.272±0.186)% in BPA-treated cells, and was (22.412±0.238)% in control cells (P<0.05). The apoptosis rates of BPA+ ICA(50) and BPA+ ICA(200) groups were (23.688±0.412)% and (30.270±0.696)%, respectively (P<0.01). The intracellular accumulation of ROS in BPA, BPA+ ICA(50), and BPA+ ICA(200) groups were 806±21, 1 772±37, 2 041±16, respectively (P<0.01). The expressions of anti-apoptotic protein Bcl-2 in control, BPA, BPA+ ICA(50), BPA+ ICA(200) groups were 7 120±151, 9 801±286, 5 902±171 and 4 203±216, respectively (P<0.01). Conclusion: BPA can promote the proliferation of thyroid carcinoma B-CPAP cells and decrease the apoptosis of cells, and this effect can be inhibited by ICA. The possible mechanism is to induce high expression of intracellular ROS and inhibit the expression of antioxidase system, leading to cell oxidative damage, thereby inducing apoptosis.

A polysaccharide isolated from Cynomorium songaricum Rupr. protects PC12 cells against H2O2-induced injury

As a great deal of interest is developed to study novel bioactive components with health benefit effects from natural resources, in this paper, a rat pheochromocytoma line 12 (PC12) cell is built to observe the protective effect of a Cynomorium songaricum Rupr. polysaccharide (CSP) against H2O2-induced oxidative stress. Fluorescence microscope, flow cytometry and micro-plate reader are used to assess cell viability and apoptosis. And the levels of reactive oxygen species (ROS), 8-hydroxy-2′-deoxyguanosine (8-OH-dG), malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and lactate dehydrogenase (LDH) are evaluated. The results show that, the CSP can significantly protect PC12 cells against H2O2-induced oxidative stress, increase the intracellular antioxidase system load and inhibit H2O2-induced apoptosis by scavenging of ROS, regulating cell cycle, preventing DNA damage and protecting the cell membrane. This research would be benefit for preventing and curing the oxidation-related diseases in polysaccharide study.

Neuroprotection by Polynitrogen Manganese Complexes: Regulation of Reactive Oxygen Species-Related Pathways.

Cell death in the central nervous system causes neurologic diseases, in which reactive oxygen species (ROS) play a critical role by either inducing cellular oxidative stress or by increasing the cell tolerance against insult. Neurologic diseases may potentially be treated by regulating ROS levels in a certain range with small molecules. We studied preconditioning with two polynitrogen manganese complexes (1 and 2) to regulate intracellular ROS levels in the protection of both the differentiated rat pheochromocytoma cell line (PC12 cells) and neurons against H2O2-induced apoptosis. Pre-treatment with the two complexes attenuated the cell apoptosis caused by H2O2. And the ROS-related neuroprotective mechanisms were explored. Both complexes activate the hypoxia inducible factor-related pathways and increase the cell adaptation to oxidative stress. Pre-treatment with complex 1 eliminated intracellular ROS, which also activated antioxidase system, while short-term incubation of complex 2, generated low levels of ROS leading to cell survival.

Effect of Cadmium on Antioxidase System in Process of Maize Germination

Effect of Cadmium on Antioxidase System in Process of Maize Germination

Study on the Ammonia Tolerance Threshold ofOttelia acuminata(Gagnep.) Dandy Seedling

As a typical representative plant of Erhai Lake in Yunnan Province, Ottelia acuminata (Gagnep.) Dandy has an important ecological status. Erhai Lakeside has characteristics of a low-polluted water that contains major polluted sources, such as ammonia. A simulated experi-ment based on these characteristics was per-formed in 2013 to determine the ammonia toler-ance threshold of macrophyte seedlings through the analysis of antioxidase system indices and malondialdehyde. The tolerance threshold of the seedlings was given as the symbol Nmtor. The re-sults showed that in a blank substrate simulated experiment, the ammonia tolerance threshold of the seedling is 0.5<Nmtor≤4.0 mg l−1, which is al-most the same as that of Hydrilla varticillata (an anti-pollution macrophyte). The seedling can en-dure ammonia pollution, which means the spe-cies is not an "absolute clear-water macrophyte" and its cause of extinction is comprehensive. In the blank substrate, ammonia tolerance thresh-olds of stems, leaves, and roots of the seedlings are 0.5<Nmtor≤4.0 mg l−1 and 0.5≤Nmtor≤4.0 mg l−\ respectively. The stems, leaves, and roots of Ottelia acuminata (Gagnep.)Dandy seedlings have almost the same ammonia tolerance thresholds.

Hydrophobicity of whey protein hydrolysates enhances the protective effect against oxidative damage on PC 12 cells.

The relationship between hydrophobicity and the protective effect of whey protein hydrolysates (WPHs) against oxidative stress was studied. Whey protein was first hydrolysed by pepsin and trypsin to obtain WPHs. After absorbed by macroporous adsorption resin DA201-C, three fractions named as M20, M40, and M60 were eluted by various concentrations of ethanol. The hydrophobicity showed a trend of increase from M20 to M60. Antioxidant ability test in vitro indicated that all the three components of WPHs displayed reasonably good antioxidant ability. Moreover, with the increase of hydrophobicity, antioxidant ability of WPHs improved significantly. Then rat pheochromocytoma line 12 (PC12) cells oxidative model was built to evaluate the suppression of oxidative stress of three components on PC12 cells induced by H2O2. Morphological alterations, cell viability, apoptosis rate, and intracellular antioxidase system tests all indicated that WPHs exert significant protection on PC cells against H2O2-induced damage. Among them, M60 had the highest protective effect by increasing 19·3% cell survival and reducing 28·6% cell apoptosis. These results suggested hydrophobicity of WPHs was contributing to the antioxidant ability and the protective effect against oxidative damage.

Aerobic interval training protects against myocardial infarction‐induced oxidative injury by enhancing antioxidase system and mitochondrial biosynthesis

1. Aerobic interval training (AIT) exerts beneficial effects on cardiovascular disease. However, its cardioprotective mechanisms are not fully understood. The aim of the present study was to evaluate AIT-mediated anti-oxidation by focusing on anti-oxidase and mitochondrial biogenesis in rats after myocardial infarction (MI). 2. Sprague-Dawley rats were divided into three groups: (i) a sham-operated control (CON); (ii) an MI group; and (iii) an MI + AIT group. Myocardial microstructure and function, markers of oxidative stress, mitochondrial anti-oxidase, Phase II enzymes and mitochondrial biogenesis were assessed. In addition, levels of nuclear factor-erythroid 2-related factor (Nrf2) and phosphorylated (p-) AMP-activated protein kinase (AMPK) were determined. The anti-oxidative gene sirtuin 3 (SIRT3) and the prosurvival phosphatidylinositol-3 kinase (PI3-K)-protein kinase B (Akt) signalling cascade were also evaluated. 3. Compared with CON, there was noticeable microstructure injury, cardiac dysfunction and oxidative damage in rats after MI. In addition, decreased mitochondrial anti-oxidase content, Phase II enzyme (except heme oxygenase-1) expression and mitochondrial biogenesis were observed in the post-MI rats as well as reduced protein levels of the regulators Nrf2 and p-AMPK and suppression of SIRT3 levels and PI3-K/Akt signalling. These detrimental modifications were considerably ameliorated by AIT, as evidenced by increases in anti-oxidase, mitochondrial biogenesis, Nrf2 and AMPK phosphorylation, as well as SIRT3 upregulation and PI3-K/Akt signalling activation. Moreover, PI3-K inhibitor-LY294002 (20 mg/kg) treatment partly attenuated AIT-elicited increases in Nrf2 levels and AMPK phosphorylation. 4. Based on these results, we conclude that AIT effectively alleviates MI-induced oxidative injury, which may be closely correlated with activation of the anti-oxidase system and mitochondrial biosynthesis. Increased SIRT3 expression and activation of PI3-K/Akt signalling may play key roles in AIT-mediated anti-oxidation. These results open up new avenues for exercise intervention therapies for MI patients.

Toxic effects of Triclosan on the detoxification system and breeding of Daphnia magna

The toxic effects of different concentrations of Triclosan (TCS) (1-128 μg/L) on Daphnia magna (D. magna) were investigated by acute (48 h) and chronic (21-day) toxicity tests. The response of antioxidase system and Phase I metabolism process of D. magna exposed to TCS were investigated by measuring a series of biomarkers including glutathione S-transferase (GST), catalase (CAT), superoxide dismutase (SOD), malondialdehyde (MDA), 7-ethoxyresorufin O-deethylase (EROD), Erythromycin N-demethylase (ERND) and Aminopyrine N-demethylase (APND). The 48 h LC50 of TCS was 330 μg/L for D. magna. In the chronic test, total number of neonates per female, body length and the intrinsic rate of natural increase (r) of D. magna increased at the low exposure concentrations (1-16 μg/L) and decreased at the high concentrations (64-128 μg/L), while the total number of molting per adult decreased continually. The GST and CAT activities showed no significant increase in all treatments, and SOD activities were induced after 24-h exposure and inhibited after 48-h exposure at 4-128 μg/L of concentrations. The MDA content increased after 6-h exposure but decreased after 48-h exposure at 4-128 μg/L. EROD activities initially increased after 6-h exposure, but decreased after 24 and 48-h exposure, ERND and APND activities showed a similar temporal pattern among different treatments groups. SOD, MDA and APND were sensitive to TCS, thus they are suitable as potential biomarkers for the exposure to TCS.

GW24-e3722 Ebselen protected myocardium from overtraining-induced oxidative damage in rats

ObjectivesGeneration of large amount of ROS is considered to be a causative factor of structure damage or apoptotic in the myocardium and to be involved in the progress of exercise...

Reactive oxygen system plays an important role in shrimp Litopenaeus vannamei defense against ­Vibrio parahaemolyticus and WSSV infection

The present study investigated the in vivo hemocytic and hepatopancreatic response to Vibrio parahaemolyticus and white spot syndrome virus (WSSV) injection in shrimp Litopenaeus vannamei. The proliferation of bacteria and virus in shrimp, animal mortality, total hemocyte counts (THCs), phenoloxidase (PO) activity, respiratory burst, and gene expression of immune factors associated with immune recognition (lectin), prophenoloxidase (proPO) activation, and the anti-microorganism (lysozyme) and active oxygen defense response (including respiratory burst, cytosolic manganese superoxide dismutase [C-MnSOD], and catalase [CAT]) were quantified. Shrimp death rate increased significantly and was time-dependent after V. parahaemolyticus or WSSV injection. The production of superoxide anion, and the gene expression including lectin in hemocytes, proPO in the hepatopancreas, lysozyme, C-MnSOD and CAT could be induced by injection with V parahaemolyticus and WSSV. The highest value of lysozyme was in the hemocytes with 66.59 times (at 3 h) greater expression than in the control group after WSSV injection and 3.69 times (24 h) greater than in the control group after V parahaemolyticus injection. In the hepatopancreas, CAT expression showed a significant increase, with up to 16 times greater expression than in the control group at 6 h postinjection with WSSV and 7.02 times greater expression than in the control group at 48 h postinjection with V parahaemolyticus (p < 0.05). However, significant decreases in PO activity and proPO transcripts in hemocytes and lectin transcripts in the hepatopancreas were detected after V parahaemolyticus and WSSV injection (p < 0.05). The results suggest that lysozyme, the antioxidase system, and reactive oxygen species might play a crucial role in shrimp defense against bacterial and viral infection.