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1.
J Environ Sci (China) ; 85: 147-155, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471021

RESUMO

Polymer hydrogel-based materials have been shown to act as novel Fenton catalysts for water treatment, but the rational design of hydrogel-based catalysts with good stability has been a great challenge. To increase the stability and activity of polymer-based Fenton catalysts, uniform urchin-like α-Fe2O3 was grown in situ in a PVA carrier matrix here. PVA molecules promoted the growth of urchin-like α-Fe2O3, and then the PVA hydrogel acted as a barrier and carrier to reduce agglomeration. Through coordination by hydroxyl groups, PVA had good combination with Fe ions and α-Fe2O3. The formation of Fe-O-C bonds between iron oxides and polymers was reported for the first time, enhancing the material stability during catalysis. Under higher PVA concentrations, the resulting composite hydrogel could generate more ˙OH due to the increase in the number of active sites because of the hairy urchin-like structure. In tetracycline degradation through a heterogeneous Fenton reaction, the resulting material had good catalytic activity from pH 2 to pH 10 with low iron leaching, good reusability and remained at a level of nearly 90% after five consecutive cycles. Density functional theory calculations were used to further prove the mechanism of structural change of the iron oxides. The HOMO and LUMO energies of the iron oxides changed from 5.428 and 4.899 eV to 5.926 and 5.310 eV, indicating that the presence of PVA could influence the charge of the iron atom. The results provide new insights into the preparation of polymer hydrogel-based heterogeneous Fenton catalysts with enhanced stability for water treatment.


Assuntos
Hidrogéis/química , Poluentes Químicos da Água/química , Purificação da Água/métodos , Compostos Férricos , Peróxido de Hidrogênio/química , Polímeros
2.
J Environ Sci (China) ; 85: 189-199, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31471026

RESUMO

Membrane fouling is an obstacle impeding the wide applications of ceramic membranes and organics are responsible for most of the membrane fouling issues in wastewater treatment. In this study, Fenton cleaning strategy was firstly proposed to clean ceramic membrane fouling in wastewater treatment. Fe2+ efficiently catalyzed fouling cleaning with H2O2 (1.5%) to recover the filterability of ceramic membrane. The maximum ∆TMP recovery (over 99%) was achieved at an optimal Fe2+ dosage of 124 mg/L after 6 hr of immersion cleaning. The total residual membrane fouling resistance decreased gradually from this optimum value as the Fe2+ dosage increased above 124 mg/L. The residual hydraulically reversible fouling resistance accounted for most of the membrane fouling and was basically removed (≤3.0 × 109 m-1) when Fe2+ dosages higher than 124 mg/L were used. The foulants responsible for the formation of a residual hydraulically reversible fouling layer (DOC (dissolved organic carbon), proteins, polysaccharides, EEM (fluorescence excitation-emission matrix spectra), SS (suspended solids), and VSS (volatile suspended solids)) were gradually removed as the Fe2+ dosage increased. These residual organic foulants were degraded from biopolymers (10-200 kDa) to low molecular weight substances (0.1-1 kDa), and the particle size of these residual foulants decreased significantly as a result. The strong oxidation power of hydrogen peroxide/hydroxy radicals towards organic foulants was enhanced by Fe2+. Fe2+ played a significant role in the removal of hydraulically reversible fouling and irreversible fouling from the ceramic membrane. However, Fe2+ (≥124 mg/L) increased the likelihood of forming secondary iron-organics aggregates.


Assuntos
Membranas Artificiais , Eliminação de Resíduos Líquidos/métodos , Biopolímeros , Cerâmica , Peróxido de Hidrogênio , Águas Residuárias
3.
Bioresour Technol ; 293: 122072, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31484102

RESUMO

Based on the multi-functional magnetic sludge-derived biochar (MSBC), an innovative integrated process-coupling accumulation by adsorbing, degradation by microwave (MW)-induced catalytic oxidation in the presence of H2O2 and the regeneration of adsorbent simultaneously, was proposed. In this study, bisphenol S (4,4'-sulfonyldiphenol) was chosen as the pollutant model, its behaviors and related mechanism of BPS and MSBC in MW + H2O2 system were investigated. The BPS effective degradation on MSBC was proved by decoupling the adsorption and degradation with solvent extraction. OH and h+ play vital roles based on the scavenger tests. The synergistic effects of hot-spot of microwave irradiation, activation of H2O2, and charge transfer-induced doping effects of MSBC were attributed to the reactions. This work proves the feasibility in economics and energy-save treatment approach for low concentration organic pollutants in water.


Assuntos
Peróxido de Hidrogênio , Esgotos , Carvão Vegetal , Micro-Ondas , Fenóis , Regeneração , Sulfonas
4.
Bioresour Technol ; 293: 122013, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31494434

RESUMO

Here, we show the utility of a cyanobacterial biomass for overproduction and easy downstream processing of the thermostable protein KatB (a Mn-catalase). The nitrogen-fixing blue-green alga, Anabaena, was bioengineered to overexpress the KatB protein (An-KatB). Interestingly, pure An-KatB could be isolated from Anabaena by a simple physical process, obviating the need of expensive resins or chromatographic steps. An-KatB was an efficient H2O2-detoxifying protein that retained all the properties of Mn-catalases. Surprisingly, the purified An-KatB showed improved characteristics than the corresponding KatB (Ec-KatB) protein purified after over-expression in E. coli. An-KatB was unaffected by exposure to high temperature (85 °C), whereas a commercially procured heme-catalase showed an appreciable drop in activity beyond 50 °C. These data convincingly demonstrate the utility of Anabaena as a competent microbial bioresource for overproduction of proteins and further highlight the advantage of An-KatB over heme-catalases in bioprocesses where H2O2 is to be decomposed at elevated temperatures.


Assuntos
Cianobactérias , Escherichia coli , Biomassa , Catalase , Peróxido de Hidrogênio
5.
Bioresour Technol ; 292: 122077, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31477347

RESUMO

In this work, alkaline hydrogen peroxide (AHP) solution with 1 wt% H2O2 was electrogenerated by oxygen reduction with a current efficiency of 75.2% in a home-made gas diffusion electrode-based electrochemical cell and used for rice straw pretreatment (0.1 g H2O2/g rice straw, 10% (w/v) biomass loading, 55 °C, 2 h). Results showed that the AHP pretreatment removed 97.56% of the initial lignin, 85.75% of the initial hemicellulose, and only 0.56% of the initial cellulose, and the specific surface area and porosity of the AHP pretreated rice straw (AHP-RS) were greatly increased. Saccharification results showed that after 48 h of enzymatic hydrolysis AHP-RS achieved a 3.2-fold increase in reducing sugar concentration compared to the untreated rice straw (5.81 and 1.81 g L-1), highlighting the potential use of this AHP solution for lignocellulose pretreatment.


Assuntos
Celulase , Oryza , Celulose , Peróxido de Hidrogênio , Hidrólise , Lignina
6.
Pestic Biochem Physiol ; 159: 118-126, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31400773

RESUMO

In the plant-insect arms race, plants synthesize toxic compounds to defend against herbivorous insects, whereas insects employ cytochrome P450 monooxygenases (P450s) to detoxify these phytotoxins. As ubiquitous environmental contaminants, heavy metals can be easily absorbed by plants and further accumulated in herbivorous insects through the food chains, resulting in tangible consequences for plant-insect interactions. However, whether heavy metals can influence P450 activities and thereby cause further effects on larval tolerance to phytotoxins remains unknown. In this study, we shown that prior exposure to copper (Cu) enhanced larval tolerance to xanthotoxin in Spodoptera litura, a major polyphagous pest of agriculture. P450 activities were induced in larvae exposed to Cu or xanthotoxin, and a midgut specific expressed P450 gene, CYP6B50 was cross-induced after exposure to these two toxic xenobiotics. Knocking down CYP6B50 by RNA interference (RNAi) rendered the larvae more sensitive to xanthotoxin. As defense against oxidative stress following metal exposure has been demonstrated to affect insecticide resistance, the reactive oxygen species (ROS) generation and antioxidant enzyme activities were assessed. Cu exposure caused the accumulation of hydrogen peroxide (H2O2) and enhanced the activities of superoxide dismutase (SOD) and peroxidase (POD) in larval midgut. In addition, two antioxidant response elements (AREs) were identified from the CYP6B50 promoter, indicating that Cu-induced CYP6B50 expression may be related to the ROS burst. Application of ROS scavenger N-acetylcysteine (NAC) effectively suppressed CYP6B50 expression, inhibited P450 activities and impaired larval tolerance to xanthotoxin that had been induced by Cu. These results indicate that the increase in CYP6B50 expression regulated by Cu-induced H2O2 generation contributed to the enhancement of larval tolerance to xanthotoxin in S. litura. Ingestion of heavy metals from their host plants can inadvertently boost the counter-defense system of herbivorous insects to protect themselves against plant defensive toxins.


Assuntos
Cobre/farmacologia , Peróxido de Hidrogênio/metabolismo , Metoxaleno/farmacologia , Spodoptera/efeitos dos fármacos , Spodoptera/metabolismo , Animais , Elementos de Resposta Antioxidante/genética , Elementos de Resposta Antioxidante/fisiologia , Sistema Enzimático do Citocromo P-450/metabolismo , Peroxidase/genética , Peroxidase/metabolismo , Interferência de RNA , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo
7.
J Appl Oral Sci ; 27: e20180453, 2019 Aug 12.
Artigo em Inglês | MEDLINE | ID: mdl-31411261

RESUMO

OBJECTIVE: This study was designed for the chemical activation of a 35% hydrogen peroxide (H2O2) bleaching gel to increase its whitening effectiveness and reduce its toxicity. METHODOLOGY: First, the bleaching gel - associated or not with ferrous sulfate (FS), manganese chloride (MC), peroxidase (PR), or catalase (CT) - was applied (3x 15 min) to enamel/dentin discs adapted to artificial pulp chambers. Then, odontoblast-like MDPC-23 cells were exposed for 1 h to the extracts (culture medium + components released from the product), for the assessment of viability (MTT assay) and oxidative stress (H2DCFDA). Residual H2O2 and bleaching effectiveness (DE) were also evaluated. Data were analyzed with one-way ANOVA complemented with Tukey's test (n=8. p<0.05). RESULTS: All chemically activated groups minimized MDPC-23 oxidative stress generation; however, significantly higher cell viability was detected for MC, PR, and CT than for plain 35% H2O2 gel. Nevertheless, FS, MC, PR, and CT reduced the amount of residual H2O2 and increased bleaching effectiveness. CONCLUSION: Chemical activation of 35% H2O2 gel with MC, PR, and CT minimized residual H2O2 and pulp cell toxicity; but PR duplicated the whitening potential of the bleaching gel after a single 45-minute session.


Assuntos
Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/toxicidade , Clareadores Dentários/química , Clareadores Dentários/toxicidade , Clareamento Dental/métodos , Análise de Variância , Catalase/química , Sobrevivência Celular , Células Cultivadas , Cloretos/química , Cor , Polpa Dentária/química , Polpa Dentária/diagnóstico por imagem , Dentina/química , Dentina/efeitos dos fármacos , Compostos Ferrosos/química , Compostos de Manganês/química , Odontoblastos/efeitos dos fármacos , Peroxidase/química , Valores de Referência , Reprodutibilidade dos Testes , Estatísticas não Paramétricas , Fatores de Tempo
8.
Dokl Biochem Biophys ; 486(1): 197-200, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31367820

RESUMO

The oxidative modification of human hemoglobin (Hb) treated with hydrogen peroxide was investigated. Using the mass spectrometry method, the oxidized amino acid residues of the hemoglobin molecule were detected: αTrp14, αTyr24, αArg31, αMet32, αTyr42, αHis45, αHis72, αMet76, αPro77, αLys90, αCys104, αTyr140, ßHis2, ßTrp15, ßTrp37, ßMet55, ßCys93, ßCys112, ßTyr130, ßLys144, and ßHis146. The antioxidant potential of the Hb molecule in the intracellular space and in the blood plasma is discussed.


Assuntos
Hemoglobinas/metabolismo , Peróxido de Hidrogênio/farmacologia , Humanos , Oxirredução/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos
9.
Microbiol Res ; 227: 126297, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31421711

RESUMO

Many plant growth promoting rhizobacteria such as Bacillus velezensis GJ11 can produce acetoin to trigger induced systemic resistance (ISR) in plants. For improving acetoin production, the mutant strains were respectively constructed by knockout of the gene of bdh (2,3-butanediol dehydrogenase) and gdh (glycerol dehydrogenase) in GJ11, but only GJ11Δbdh produced a high level of acetoin triggering strong ISR against Pseudomonas syringae infection in plants. GJ11Δbdh could induce H2O2 accumulation in plants by producing a high level of acetoin. H2O2 was necessary for triggering ISR against the pathogen infection because after scavenging H2O2 with ascorbic acid or catalase, the inhibition role to pathogen infection induced by acetoin almost disappeared in plants. Further investigation found the plants treated with GJ11Δbdh in an obvious "priming" state, in which the mild immune response was observed such as a slight increase of H2O2 production, callose deposition, and enzymes activity related with defence response (e.g. POD, PAL and PPO). The plants in "priming" could rapidly respond to the pathogen infection accompanying with a significant increase of H2O2 production, callose deposition, and enzymes activity. Collectively, this study provides new insight into the role of acetoin as a strong elicitor of defense response, and ascribes a new approach to construct the mutant strains with high production of acetoin for triggering stronger ISR against pathogens infection in plants.


Assuntos
Acetoína/metabolismo , Arabidopsis/genética , Bacillus/genética , Bacillus/metabolismo , Resistência à Doença/genética , Imunidade Vegetal/genética , Oxirredutases do Álcool/genética , Arabidopsis/imunologia , Arabidopsis/microbiologia , Ácido Ascórbico/metabolismo , Catalase/metabolismo , Resistência à Doença/fisiologia , Perfilação da Expressão Gênica , Regulação da Expressão Gênica de Plantas , Técnicas de Inativação de Genes , Genes de Plantas/genética , Peróxido de Hidrogênio/metabolismo , Doenças das Plantas/imunologia , Doenças das Plantas/microbiologia , Imunidade Vegetal/fisiologia , Pseudomonas syringae/patogenicidade , Desidrogenase do Álcool de Açúcar/genética
10.
Adv Exp Med Biol ; 1155: 567-581, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468432

RESUMO

Here, we investigated the hepatoprotective effect of a hot water extract from Loliolus beka gray meat (LBMH) containing plentiful taurine in H2O2-induced oxidative stress in hepatocytes. LBMH potently scavenged the 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) radicals and exhibited the good reducing power and the oxygen radical absorbance capacity (ORAC) value. Also, LBMH improved the cell viability against H2O2-induced hepatic damage in cultured hepatocytes by reducing intracellular reactive oxygen species (ROS) production. In addition, LBMH inhibited apoptosis via a reduction in sub-G1 cell population, as well as inhibition of apoptotic body formation from H2O2-induced oxidative damage in hepatocytes. Moreover, LBMH regulated the expression levels of Bax, a pro-apoptotic molecule and Bcl-2, an anti-apoptotic molecule in H2O2-treated hepatocytes. Additionally, pre-treatment with LBMH increased the expression of heme oxygenase 1 (HO-1), which is a hepatoprotective enzyme, by activating the nuclear factor erythroid 2-related factor 2 (Nrf2) in H2O2-treated hepatocytes. Taken together, LBMH may be useful as a food ingredient for treatment of liver disease by regulating the Nrf2/HO-1 signal pathway.


Assuntos
Antioxidantes , Extratos Celulares/farmacologia , Decapodiformes/química , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo , Taurina/farmacologia , Animais , Células Cultivadas , Heme Oxigenase-1/metabolismo , Hepatócitos/citologia , Humanos , Peróxido de Hidrogênio , Carne , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo
11.
Adv Exp Med Biol ; 1155: 583-596, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468433

RESUMO

In this study, we evaluated the protective effects of an aqueous extract from Batillus cornutus meat (BM) against cellular oxidative damage caused by hydrogen peroxide (H2O2) in human hepatocyte, Chang cells. First, we prepared an aqueous extract of BM meat (BMW) showing the highest taurine content among free amino acid contents. BMW led to high antioxidant activity showing 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, good reducing power and an oxygen radical absorbance capacity (ORAC) value. Also, BMW improved cell viability that was diminished by H2O2 exposure, as it reduced the generation of intracellular reactive oxygen species (ROS) in Chang cells. In addition, BMW up-regulated the production of antioxidant enzymes, such as catalase and superoxide dismutase (SOD), compared to H2O2-treated Chang cells lacking BMW. Moreover, BMW induced the expressions of nuclear Nrf2 and cytosolic HO-1 in H2O2-treated Chang cells. Interestingly, the treatment of ZnPP, HO-1 inhibitor, abolished the improvement in cell viability and intracellular ROS generation mediated by BMW treatment. In conclusion, this study suggests that BMW protects hepatocytes against H2O2-mediated cellular oxidative damage via up-regulation of the Nrf2/HO-1 signal pathway.


Assuntos
Extratos Celulares/farmacologia , Gastrópodes/química , Heme Oxigenase-1/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Transdução de Sinais , Taurina/farmacologia , Animais , Células Cultivadas , Humanos , Peróxido de Hidrogênio , Carne , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima
12.
Adv Exp Med Biol ; 1155: 597-610, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468434

RESUMO

Octopus ocellatus meat (OM) is well known as a plentiful protein source. In this study, we evaluated the hepatoprotective effect of an aqueous extract of OM (OMA) against H2O2-triggered oxidative stress in human hepatocytes. First of all, taurine rich OMA showed a good ORAC value and reducing power and it was similar with that of ascorbic acid, which is known as a strong antioxidant. Also, OMA significantly improved H2O2-decreased cell viability by reducing the generation of intracellular reactive oxygen species (ROS) in hepatocytes. Interestingly, the stimulation of H2O2-induced the formations of apoptotic bodies and sub-G1 DNA content, whereas they were inhibited by the treatment with OMA. Furthermore, OMA regulated the protein expression levels of apoptotic molecules, such as Bax and Bcl-2. Taken together, this study suggests that OMA, which contains an abundant amount of taurine, protects hepatocytes from H2O2-triggered oxidative stress and might be a functional food material with hepatoprotective effects.


Assuntos
Extratos Celulares/farmacologia , Hepatócitos/efeitos dos fármacos , Octopodiformes/química , Estresse Oxidativo , Animais , Apoptose , Células Cultivadas , Hepatócitos/citologia , Humanos , Peróxido de Hidrogênio/efeitos adversos , Carne , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Proteína X Associada a bcl-2/metabolismo
13.
Adv Exp Med Biol ; 1155: 643-659, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468437

RESUMO

Batillus cornutus (B. cornutus) is one of the gastropoda, which are distributed along the coast of China, Japan and South Korea and northeast area. In this study, we first identified the antioxidant effects of a B. cornutus meat (BM) enzymatic hydrolysate in H2O2-treated Vero cells. First of all, we prepared an Alcalase hydrolysate from BM (BMA) and revealed a high taurine content. Also, taurine rich BMA dose-dependently increased 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, reducing power and the higher oxygen radical absorbance capacity (ORAC) value. In addition, BMA significantly increased the cell viability via the down-regulation of intracellular reactive oxygen species (ROS) production, as well as the decreased formation of apoptotic bodies and sub-G1 DNA population in H2O2-treated Vero cells. Furthermore, BMA increased the expression of the anti-apoptotic molecule, Bcl-2, and decreased the expressions of Bax, p53 and cleaved PARP, all of which are pro-apoptotic molecules, in H2O2-treated Vero cells. Based on these results, this study suggests that BMA may be used as a potential protector on damage caused by oxidative stress.


Assuntos
Antioxidantes/farmacologia , Gastrópodes/química , Estresse Oxidativo , Hidrolisados de Proteína/farmacologia , Animais , Cercopithecus aethiops , Peróxido de Hidrogênio , Carne , Espécies Reativas de Oxigênio/metabolismo , Subtilisinas , Células Vero
14.
Adv Exp Med Biol ; 1155: 661-674, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468438

RESUMO

In the present study, we investigated the antioxidant activity of an aqueous extract from Atrina pectinate meat (APW) against H2O2-induced oxidative stress in a human hepatocyte. The extraction yield of APW was 30.01 ± 0.83% and which contained the highest taurine content among free amino acid contents. APW led to the high antioxidant activity showing 2,2-azino-bis(3-ethylbenzthiazoline)-6-sulfonic acid (ABTS) radical scavenging activity, good reducing power and oxygen radical absorbance capacity (ORAC) value. Also, the results showed that APW improved the cell viability decreased by H2O2 stimulation as well as the reduction of intracellular reactive oxygen species (ROS) generation in hepatocytes. Additionally, APW up-regulated the production of antioxidant mechanisms related enzymes such as catalase and superoxide dismutase (SOD), compared to the only H2O2-treated hepatocytes. Moreover, APW increased the expressions of nuclear Nrf2 and cytosolic HO-1 in H2O2-treated hepatocytes. Interestingly, the treatment of ZnPP, a HO-1 inhibitor abolished the cell viability and intracellular ROS generation induced by APW treatment. In conclusion, this study suggests that APW protects H2O2 induced oxidative stress via up-regulating of Nrf2/HO-1 signal pathway in hepatocytes.


Assuntos
Antioxidantes/farmacologia , Bivalves/química , Extratos Celulares/farmacologia , Hepatócitos/efeitos dos fármacos , Estresse Oxidativo , Animais , Heme Oxigenase-1/metabolismo , Humanos , Peróxido de Hidrogênio , Carne , Fator 2 Relacionado a NF-E2/metabolismo , Espécies Reativas de Oxigênio/metabolismo
15.
Adv Exp Med Biol ; 1155: 691-703, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468440

RESUMO

In this study, we investigated the hepatoprotective activity of the water extract derived from Octopus vulgaris meat (OM). First of all, a water extract prepared from OM (OMW) showed the high extraction yield (48.22%) and the highest taurine content (39.84%) in free amino acids. OMW exhibited the high value of reducing power, ABTS and hydrogen peroxide radical scavenging activities in dose-dependent manner. The taurine-rich OMW also led to the reduced intracellular reactive oxygen species (ROS) generation with the increased cell survival in H2O2-treated Chang liver cells. In addition, OMW decreased the apoptotic phenomenon, including the formations of apoptotic bodies and sub-G1 DNA contents by regulating the protein expressions of apoptosis-related molecules such as Bcl-2 and Bax. From these results, this study indicated the taurine-rich OMW protected hepatocytes against oxidative stress. These findings suggest that OWM may be a novel potential antioxidant resource.


Assuntos
Extratos Celulares/farmacologia , Hepatócitos/citologia , Octopodiformes/química , Estresse Oxidativo , Taurina/farmacologia , Animais , Antioxidantes/farmacologia , Linhagem Celular , Humanos , Peróxido de Hidrogênio , Carne , Espécies Reativas de Oxigênio , Água
16.
Adv Exp Med Biol ; 1155: 705-715, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31468441

RESUMO

Blood vessels become less flexible with senescence; arteries narrow and become less flexible, disturbing blood circulation in aging and other vascular diseases. Mechanistically, vascular senescence plays an important role in the pathogenesis of normal aging and age-related vascular diseases. Vascular senescence also causes vascular dysfunction, resulting in damage to the vessel wall. Vascular aging involves the senescence of endothelial cells. Hydrogen peroxide is widely used to achieve oxidative stress-induced premature senescence. Here, we investigated the protective effects of a hot water extract of Loliolus beka meat (LBM) against H2O2-exposed HUVECs, a human umbilical vein endothelial cells line. The hot water extract of LBM protected cells against H2O2-induced cytotoxicity while reducing the expression of senescence markers, including ß-galactosidase, p53, and p21. In addition, the hot water extract of LBM protected against H2O2-induced DNA damage. These findings suggest that the hot water extract of LBM protects HUVECs from H2O2-induced senescence by preventing cellular damage. LBM serve as a supplement or natural food with benefits against vascular disease.


Assuntos
Extratos Celulares/farmacologia , Decapodiformes/química , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Estresse Oxidativo , Animais , Células Cultivadas , Senescência Celular , Humanos , Peróxido de Hidrogênio , Carne
17.
BMC Plant Biol ; 19(1): 345, 2019 Aug 07.
Artigo em Inglês | MEDLINE | ID: mdl-31390991

RESUMO

BACKGROUND: Aquaporin (AQP) proteins comprise a group of membrane intrinsic proteins (MIPs) that are responsible for transporting water and other small molecules, which is crucial for plant survival under stress conditions including salt stress. Despite the vital role of AQPs, little is known about them in cucumber (Cucumis sativus L.). RESULTS: In this study, we identified 39 aquaporin-encoding genes in cucumber that were separated by phylogenetic analysis into five sub-families (PIP, TIP, NIP, SIP, and XIP). Their substrate specificity was then assessed based on key amino acid residues such as the aromatic/Arginine (ar/R) selectivity filter, Froger's positions, and specificity-determining positions. The putative cis-regulatory motifs available in the promoter region of each AQP gene were analyzed and results revealed that their promoter regions contain many abiotic related cis-regulatory elements. Furthermore, analysis of previously released RNA-seq data revealed tissue- and treatment-specific expression patterns of cucumber AQP genes (CsAQPs). Three aquaporins (CsTIP1;1, CsPIP2;4, and CsPIP1;2) were the most transcript abundance genes, with CsTIP1;1 showing the highest expression levels among all aquaporins. Subcellular localization analysis in Nicotiana benthamiana epidermal cells revealed the diverse and broad array of sub-cellular localizations of CsAQPs. We then performed RNA-seq to identify the expression pattern of CsAQPs under salt stress and found a general decreased expression level of root CsAQPs. Moreover, qRT-PCR revealed rapid changes in the expression levels of CsAQPs in response to diverse abiotic stresses including salt, polyethylene glycol (PEG)-6000, heat, and chilling stresses. Additionally, transient expression of AQPs in N. benthamiana increased leaf water loss rate, suggesting their potential roles in the regulation of plant water status under stress conditions. CONCLUSIONS: Our results indicated that CsAQPs play important roles in response to salt stress. The genome-wide identification and primary function characterization of cucumber aquaporins provides insight to elucidate the complexity of the AQP gene family and their biological functions in cucumber.


Assuntos
Aquaporinas/fisiologia , Cucumis sativus/genética , Proteínas de Plantas/fisiologia , Aquaporinas/genética , Aquaporinas/metabolismo , Cucumis sativus/metabolismo , Expressão Gênica , Regulação da Expressão Gênica de Plantas , Genoma de Planta , Peróxido de Hidrogênio/metabolismo , Filogenia , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Estresse Fisiológico/genética , Transcriptoma , Água/metabolismo
18.
Exp Parasitol ; 205: 107748, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31442453

RESUMO

Trypanosoma cruzi (the causative agent of Chagas disease) presents a complex life cycle that involves adaptations in vertebrate and invertebrate hosts. As a protozoan parasite of hematophagous insects and mammalian hosts, T. cruzi is exposed to reactive oxygen species (ROS). To investigate the functionality of T. cruzi tartrate-resistant acid phosphatase type 5 (TcACP5), we cloned, superexpressed and purified the enzyme. Purified TcACP5 exhibited a Vmax and apparent Km for pNPP hydrolysis of 7.7 ±â€¯0.2 nmol pNP × µg-1 × h-1 and 169.3 ±â€¯22.6 µM, respectively. The pH dependence was characterized by sharp maximal activity at pH 5.0, and inhibition assays demonstrated its sensitivity to acid phosphatase inhibitors. Similar activities were obtained with saturating concentrations of P-Ser and P-Thr as substrates. The enzyme metabolizes hydrogen peroxide (H2O2) in vitro, and parasites superexpressing this enzyme were more resistant to oxidative stress promoted by H2O2. Taken together, these results suggest that TcACP5 plays a central role in phosphoryl transfer and redox reactions.


Assuntos
Peróxido de Hidrogênio/farmacologia , Estresse Oxidativo/fisiologia , Fosfatase Ácida Resistente a Tartarato/metabolismo , Trypanosoma cruzi/enzimologia , Sequência de Aminoácidos , Imunofluorescência , Regulação Enzimológica da Expressão Gênica , Peróxido de Hidrogênio/metabolismo , Concentração de Íons de Hidrogênio , Microscopia Confocal , Oxirredução , Especificidade por Substrato , Fosfatase Ácida Resistente a Tartarato/antagonistas & inibidores , Fosfatase Ácida Resistente a Tartarato/química , Transfecção , Trypanosoma cruzi/efeitos dos fármacos
19.
Plant Mol Biol ; 101(3): 315-323, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31392474

RESUMO

KEY MESSAGE: Pre-treatment of soybean seedlings with 200 µM salicylic acid before fungal inoculation significantly alleviated disease resistance in soybean seedlings against Fusarium solani infection. Sudden death syndrome of soybean is largely caused by Fusarium solani (F. solani). Salicylic acid (SA) has been reported to induce resistance in plants against many pathogens. However, the effect of exogenous SA application on F. solani infection of soybean is less reported. This study investigated the effect of foliar application of SA on soybean seedlings before F. solani infection. Seedlings were sprayed with 200 µM SA and inoculated with F. solani after 24 h of last SA application. After 3 days post-inoculation, seedlings treated with 200 µM SA showed significantly fewer disease symptoms with increased endogenous SA level, SA marker genes expression and antioxidant activities in the SA-treated seedlings more than the untreated control seedlings. Furthermore, the decrease in hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels was observed in the SA-treated plants as compared to the untreated plants. Analysis of the effect of SA application on F. solani showed that the mycelia growth of F. solani was not affected by SA treatment. Further investigation in this study revealed a decreased in F. solani biomass content in the SA treated seedlings. Results from the present study show that pre-treatment of 200 µM SA can induce resistance of soybean seedlings against F. solani infection.


Assuntos
Resistência à Doença/efeitos dos fármacos , Fusarium/patogenicidade , Doenças das Plantas/microbiologia , Ácido Salicílico/farmacologia , Soja/microbiologia , Regulação da Expressão Gênica de Plantas , Peróxido de Hidrogênio/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/microbiologia , Plântula/efeitos dos fármacos , Plântula/microbiologia , Soja/efeitos dos fármacos
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