RESUMO
Bryostatin-1 (Bry-1) has been proven to be effective and safe in clinical trials of a variety of immune-related diseases. However, little is known about its effect on Crohn's disease (CD). We aimed to investigate the impact of Bry-1 on CD-like colitis and determine the mechanism underlying this effect. In the present study, 15-week-old male Il-10-/- mice with spontaneous colitis were divided into positive control and Bry-1-treated (Bry-1, 30 µg/kg every other day, injected intraperitoneally for 4 weeks) groups. Age-matched, male wild-type (WT) mice were used as a negative control. The effects of Bry-1 on colitis, intestinal barrier function and T cell responses as well as the potential regulatory mechanisms were evaluated. We found that the systemic delivery of Bry-1 significantly ameliorated colitis in Il-10-/- mice, as demonstrated by decreases in the disease activity index (DAI), inflammatory score and proinflammatory mediator levels. The protective effects of Bry-1 on CD-like colitis included the maintenance of intestinal barrier integrity and the helper T cell (Th)/regulatory T cell (Treg) balance. These effects of Bry-1 may act in part through nuclear factor erythroid 2-related factor 2 (Nrf2) signalling activation and STAT3/4 signalling inhibition. The protective effect of Bry-1 on CD-like colitis suggests Bry-1 has therapeutic potential in human CD, particularly given the established clinical safety of Bry-1.
Assuntos
Briostatinas/uso terapêutico , Colite/tratamento farmacológico , Colite/imunologia , Interleucina-10/deficiência , Intestinos/imunologia , Intestinos/patologia , Animais , Apoptose/efeitos dos fármacos , Briostatinas/farmacologia , Colite/patologia , Regulação para Baixo/efeitos dos fármacos , Células Epiteliais/metabolismo , Interleucina-10/metabolismo , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , Permeabilidade , Transdução de Sinais/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th17/efeitos dos fármacos , Células Th17/imunologia , Proteínas de Junções Íntimas/metabolismo , Junções Íntimas/efeitos dos fármacos , Junções Íntimas/metabolismo , Junções Íntimas/ultraestruturaRESUMO
Roxarsone (ROX), an organoarsenic feed additive, occurs as itself and its metabolites including As(V), As(III), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in animal manure. Animal manure improves soil biological property, whereas As compounds impact microorganisms. The integral influence of animal manure bearing ROX metabolites on soil biological quality is not clear yet. Herein, the effect of four chicken manures excreted by chickens fed with four diets containing 0, 40, 80 and 120â¯mg ROX kg-1, on soil biological attributes. ROX addition in chicken diets increased total As and ROX metabolites in manures, but decreased manure total N, ammonium and nitrate. The elevated ROX metabolites in manures increased soil total As, As species and total N, and increased first and then decreased soil nitrate and nitrite, but did not affect soil ammonium in manure-applied soils. The promoting role of both soil As(III) and ammonium on soil microbial biomass carbon and nitrogen, respiration and saccharase activity, were exceeded or balanced by the inhibiting effect of soil nitrate. The suppression of soil catalase activity by soil As(V) was surpassed by the enhancement caused by soil nitrate and nitrite. Soil urease, acid phosphatase and polyphenol oxidase activities were not suitable bioindicators in the four manure-amended soils. Soil DMA did not affect soil biological properties, and MMA was not detectable in all manure-amended soils. The above highlights the complexity of joint influence of soil As and N on biological attributes. Totally, when ROX is used at allowable dose in chicken diet, soil biological quality would be suppressed in manure-amended soil.
Assuntos
Esterco/análise , Roxarsona/análise , Poluentes do Solo/análise , Solo/química , Animais , Arsênio/análise , Arsenicais/análise , Biomassa , Ácido Cacodílico/análise , Carbono/análise , Galinhas , Dieta/veterinária , Nitrogênio/análise , Microbiologia do SoloRESUMO
Roxarsone (ROX), an organoarsenic feed additive, and its metabolites, can be present in animal manure used to fertilize rice. Rice is prone to absorb arsenic, and is subject to straighthead disorder, which reduces rice yield and is linked with organic arsenic compounds. This study aims to elucidate how soil property affect arsenic accumulation in rice plants fertilized with chicken manure containing ROX metabolites. Manures of chickens fed without or with ROX, designated as control manure and ROX treated manure (ROXCM), respectively, were applied in eight paddy soils of different origins, to investigate the assimilation of arsenic species in rice plants. The results show that inorganic arsenic (arsenate and arsenite), monomethylarsonic acid and dimethylarsinic acid (DMA) were detected in all brown rice and husk, trace tetramethylarsonium and trimethylarsine oxide were occasionally found in these both parts, whereas all these arsenic species were determined in straw, irrespective of manure type. ROXCM application specifically and significantly increased brown rice DMA (Pâ¯=â¯0.002), which remarkably enhanced the risk of straighthead disease in rice. Although soil total As impacted grain biomass, soil free-iron oxides and pH dominated arsenic accumulation by rice plants. The significantly increased grain DMA suggests manure bearing ROX metabolites is not suitable to be used in soils with abundant free-iron oxides and/or high pH, if straighthead disorder is to be avoided in rice.
Assuntos
Oryza/metabolismo , Roxarsona/metabolismo , Poluentes do Solo/metabolismo , Solo/química , Animais , Biomassa , Galinhas/metabolismo , Grão Comestível/crescimento & desenvolvimento , Grão Comestível/metabolismo , Esterco/análise , Oryza/crescimento & desenvolvimentoRESUMO
Bacillus velezensis is well known as a plant growth-promoting rhizobacteria (PGPR) and biocontrol agent. Nevertheless, there are very few reports on the study of B. velezensis on tomato early blight, especially the biocontrol effects among different inoculation concentrations. In this study, an IAA-producing strain, Bacillus velezensis YXDHD1-7 was isolated from the tomato rhizosphere soil, which had the strongest inhibitory effect against Alternaria solani. Inoculation with bacterial suspensions of this strain promoted the growth of tomato seedlings effectively. Furthermore, inoculations at 106, 107, and 108 cfu/mL resulted in control efficacies of 100%, 83.15%, and 69.90%, respectively. Genome sequencing showed that it possesses 22 gene clusters associated with the synthesis of antimicrobial metabolites and genes that are involved in the production of IAA. Furthermore, it may be able to produce spermidine and volatile compounds that also enhance plant growth and defense responses. Our results suggest that strain YXDHD1-7 prevents early blight disease by promoting growth and enhancing the defense enzyme activities in tomato plants. This strain is a promising candidate for an excellent microbial inoculant that can be used to enhance tomato production.
RESUMO
Pseudomonas chengduensis is a new species of Pseudomonas discovered in 2014, and currently, there is a scarcity of research on this bacterium. The P. chengduensis strain WD211 was isolated from a fish pond. This study investigated the purification capability and environmental adaptability of strain WD211 in wastewater and described the basic features and functional genes of its complete genome. According to the results, the sewage treated with strain WD211 showed a decrease in concentration of 18.12% in total nitrogen, 89.39% in NH4+, 62.16% in NO3-, 79.97% in total phosphorus, and 71.41% in COD after 24 h. Strain WD211 is able to survive in a pH range of 6-11. It shows resistance to 7% sodium chloride and different types of antibiotics. Genomic analysis showed that strain WD211 may remove nitrogen and phosphorus through the metabolic pathway of nitrogen assimilation and phosphorus accumulation, and that it can promote organic decomposition through oxygenase. Strain WD211 possesses genes for producing betaine, trehalose, and sodium ion transport, which provide it with salt tolerance. It also has genes for antibiotic efflux and multiple oxidases, which give it antibiotic resistance. This study contributes to the understanding of the sewage treatment ability and potential applications of P. chengduensis.
Assuntos
Pseudomonas , Esgotos , Animais , Esgotos/microbiologia , Pseudomonas/genética , Pseudomonas/metabolismo , Aquicultura , Antibacterianos/metabolismo , Nitrogênio/metabolismo , Fósforo/metabolismoRESUMO
Paenibacillus mucilaginosus has widely been reported as a plant growth-promoting rhizobacteria (PGPR). However, the important genomic insights into plant growth promotion in this species remain undescribed. In this study, the genome of P. mucilaginosus G78 was sequenced using Illumina NovaSeq PE150. It contains 8,576,872 bp with a GC content of 58.5%, and was taxonomically characterized. Additionally, a total of 7337 genes with 143 tRNAs, 41 rRNAs, and 5 ncRNAs were identified. This strain can prohibit the growth of the plant pathogen, but also has the capability to form biofilm, solubilize phosphate, and produce IAA. Twenty-six gene clusters encoding secondary metabolites were identified, and the genotypic characterization indirectly proved its resistant ability to ampicillin, bacitracin, polymyxin and chloramphenicol. The putative exopolysaccharide biosynthesis and biofilm formation gene clusters were explored. According to the genetic features, the potential monosaccharides of its exopolysaccharides for P. mucilaginosus G78 may include glucose, mannose, galactose, fucose, that can probably be acetylated and pyruvated. Conservation of the pelADEFG compared with other 40 Paenibacillus species suggests that Pel may be specific biofilm matrix component in P. mucilaginosus. Several genes relevant to plant growth-promoting traits, i.e., IAA production and phosphate solubilization are well conserved compared with other 40 other Paenibacillus strains. The current study can benefit for understanding the plant growth-promoting traits of P. mucilaginosus as well as its potential application in agriculture as PGPR.
Assuntos
Paenibacillus , Paenibacillus/genética , Desenvolvimento Vegetal , Genômica , FosfatosRESUMO
Tomato cultivars with contrasting resistance to pathogens regulate root exudates differentially in response to Ralstonia solanacearum attacks. However, strategies using innate root exudates against infection remain unknown. This study analyzed the innate root exudates of two tomato cultivars and their functions in regulating R. solanacearum infection. The innate root exudates differed between the two cultivars. Astaxanthin released from resistant plants inhibited colonization by R. solanacearum but promoted motility, while neferine released from susceptible plants suppressed motility and colonization. The secretion of astaxanthin in resistant tomatoes promoted the growth of biocontrol fungi in soil and reduced the abundance of pathogenic fungi. Neferine secreted by the susceptible cultivar inhibited the relative abundance of the bacterial-biocontrol-related Bacillus genus, indirectly reducing the soil's immune capacity. This study revealed contrasting strategies using root exudates in resistant and susceptible tomato cultivars to cope with R. solanacearum infection, providing a basis for breeding disease-resistant cultivars.
Assuntos
Ralstonia solanacearum , Solanum lycopersicum , Capacidades de Enfrentamento , Melhoramento Vegetal , Solo , Doenças das Plantas/microbiologiaRESUMO
Roxarsone (ROX) is widely used as a feed additive in intensive animal production. While an animal is fed with ROX, the As compounds in the manure primarily occur as ROX and its metabolites, including arsenate (As[V]), arsenite (As[III]), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA). Animal manure is commonly land applied with phosphorous fertilizers in China. A pot experiment was conducted to investigate the phytoavailability of ROX, As(V), As(III), MMA, and DMA in water spinach (Ipomoea aquatica), with the soil amended with 0, 0.25, 0.50, 1.0, and 2.0 g PO(4)/kg, respectively, plus 2% (w/w manure/soil) chicken manure (CM) bearing ROX and its metabolites. The results indicate that this species of water spinach cannot accumulate ROX and MMA at detectable levels, but As(V), As(III), and DMA were present in all plant samples. Increased phosphorous decreased the shoot As(V) and As(III) in water spinach but did not affect the root As(V). The shoot DMA and root As(III) and DMA were decreased/increased and then increased/decreased by elevated phosphorous. The total phosphorous content (P) in plant tissue did not correlate with the total As or the three As species in tissues. Arsenate, As(III), and DMA were more easily accumulated in the roots, and phosphate considerably inhibited their upward transport. Dimethylarsinic acid had higher transport efficiency than As(V) and As(III), but As(III) was dominant in tissues. Conclusively, phosphate had multiple effects on the accumulation and transport of ROX metabolites, which depended on their levels. However, proper utilization of phosphate fertilizer can decrease the accumulation of ROX metabolites in water spinach when treated with CM containing ROX and its metabolites.
Assuntos
Ração Animal , Antibacterianos/metabolismo , Fertilizantes , Contaminação de Alimentos , Ipomoea , Fosfatos/metabolismo , Roxarsona/metabolismo , Animais , Arsênio/análise , Transporte Biológico , Galinhas , Humanos , Ipomoea/metabolismo , Fósforo/análiseRESUMO
The environmental and human health risk posed by veterinary antibiotics is of global concern. Antibiotic uptake by herbal plants has been studied, but little is known about perennial woody fruit crops. Litchi (Litchi chinensis Sonn.), a longevial fruit tree, is routinely fertilized with animal manure and, therefore, may be at risk of antibiotic uptake into its fruits. This study investigated the degradation of chlortetracycline and doxycycline present in manure used to amend orchard soil, and their subsequent assimilation by litchi plant, as affected by manure application rate. The results show that half-lives of chlortetracycline and doxycycline in soil were decreased by increased manure rate, with an average of 27 and 59 days, respectively. Chlortetracycline was readily transported to litchi shoots and increased with the growth of litchi plants. Doxycycline predominantly remained in the roots, and underwent growth dilution in the plants. The two tetracyclines could not be detected in fruits from litchi trees when applied with manures, at various rates, over 2 years. For litchi, chlortetracycline may pose human health risk through manure application, but doxycycline is unlikely to do so. Long-term field experiments are required to monitor antibiotic accumulation in fruits of perennial fruit trees fertilized with animal manure.
Assuntos
Antibacterianos/metabolismo , Clortetraciclina/metabolismo , Doxiciclina/metabolismo , Litchi/metabolismo , Poluentes do Solo/metabolismo , Animais , Antibacterianos/farmacocinética , Biodegradação Ambiental , China , Clortetraciclina/farmacocinética , Doxiciclina/farmacocinética , Frutas/química , Litchi/efeitos dos fármacos , Esterco , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Solo/química , Poluentes do Solo/farmacocinética , Distribuição Tecidual , ÁrvoresRESUMO
OBJECTIVES: Clematichinenoside AR (AR) is a saponin extracted for traditional Chinese medicine with the effects of improving the expression of tight junction (TJ) proteins and mediating anti-inflammatory activities. However, its effect on Crohn's disease (CD) is still unknown. We aimed to investigate the impact of AR on CD-like colitis and determine the mechanism underlying its effects. METHODS: Interleukin-10 gene knockout (Il-10-/-) mice (male, fifteen weeks old) with spontaneous colitis were allocated to the positive control and AR-treated (32â¯mg/kg AR administered every other day by gavage for 4 weeks) groups. Wild-type (WT) mice (male, fifteen weeks old) composed the negative control group. The effects of AR on intestinal barrier function and structure and T cell responses as well as the potential mechanisms underlying these effects were investigated. RESULTS: AR treatment significantly improved spontaneous colitis in Il-10-/- mice as demonstrated by reductions in the inflammatory score, disease activity index (DAI) and levels of inflammatory factors. The effects of AR on colitis in Il-10-/- mice were related to protecting intestinal barrier function and maintaining immune system homeostasis (regulatory T cell (Treg)/T helper 17 (Th17) cell balance). The anticolitis effect of AR may partly act by downregulating PI3K/Akt signaling. CONCLUSIONS: AR may have therapeutic potential for treating CD in humans.
Assuntos
Colite/tratamento farmacológico , Colite/genética , Interleucina-10/genética , Intestinos/patologia , Saponinas/uso terapêutico , Triterpenos/uso terapêutico , Animais , Translocação Bacteriana/efeitos dos fármacos , Colite/patologia , Citocinas/metabolismo , Intestinos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Linfócitos T/efeitos dos fármacos , Linfócitos T/imunologia , Linfócitos T Auxiliares-Indutores/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacosRESUMO
Objective To evaluate the therapeutic effect and possible mechanism of IL-12 monoclonal antibody (IL-12 mAb) on IL-10 knockout(IL-10-/-) mice and its possible mechanism. Methods Sixteen male IL-10-/- mice of 15 weeks old were randomly divided into control group and IL-12 mAb treatment group. The IL-12 mAb treatment group were given intraperitoneal injection of IL-12 mAb (25 mg/kg, once per week), and the control group was given intraperitoneal injection of 0.2 mL of normal saline. After 4 weeks of intervention, the inflammatory bowel disease activity index (DAI) and HE staining were used to evaluate the intestinal inflammation symptoms and histological changes. The intestinal mucosal permeability test was used to evaluate the intestinal mucosal barrier function of the two groups. The expression of claudin-1 in intestinal mucosa was detected by Western blot analysis. The Th1/Th2 cell balance of intestinal mucosa was evaluated by flow cytometry. The ELISA was used to evaluate IL-13 and tumor necrosis factor alpha(TNF-α) of intestinal mucosal of the two groups. The expression of phosphorylated signal transducer and activator of transcription (p-STAT6) in intestinal mucosa was detected by Western blot nanlysis. Results Three and 4 weeks after IL-12 mAb treatment, the DAI and intestinal inflammation scores of IL-12 mAb treatment group were significantly lower than the control group. At the same time, the intestinal mucosal permeability of IL-12 mAb treatment group was significantly lower than that of the control group, and the expression of claudin-1 in intestinal mucosa was significantly higher than that of the control group. At the same time, IL-12 mAb treatment inhibited the proportion of Th1 cells in the intestinal mucosa and up-regulated the proportion of Th2 cells. In the signal pathway analysis, IL-12 mAb treatment increased the levels of p-STAT6 and IL-13 in the intestinal mucosa and inhibited the level of TNF-α. Conclusion IL-12 mAb effectively alleviates intestinal inflammation in the Crohn's disease animal model and protect the intestinal mucosal barrier, which may be through inhibition of Th1 cell immune response in the intestinal mucosa and up-regulation of STAT6 signaling.
Assuntos
Mucosa Intestinal , Animais , Imunidade nas Mucosas , Inflamação , Interleucina-10 , Interleucina-12 , Masculino , Camundongos , Transdução de Sinais , Fator de Necrose Tumoral alfaRESUMO
Objective To evaluate the therapeutic effect and possible mechanism of PPARγ agonist rosiglitazone on 2, 4, 6-trinitrobenzenesulfonic acid (TNBS)-induced colitis in mice. Methods Twenty male BALB/c mice were selected to establish TNBS-induced colitis model and were randomly divided into rosiglitazone treated group and model group with 10 rats in each group. Rosiglitazone group was treated with rosiglitazone(0.2 mL, [20 mg/(kg.d)])and model group with normal saline(0.2 mL/d). After 6 weeks of administration, the mice were sacrificed. Inflammatory bowel disease disease activity index (DAI) and HE staining combined with Spencer colitis histological score were used to evaluate the degree of intestinal inflammation and histological changes in the two groups. ELISA was used to detect the levels of interleukin-1ß (IL-1ß), tumor necrosis factor alpha(TNF-α) and IL-10 in the intestinal mucosa, the levels of IL-6 and monocyte chemoattractant protein 1 (MCP-1) in the mesenteric adipose tissues. The mean diameter of adipocytes in the mesenteric adipose tissues was calculated under light microscope after HE staining.The number of F4/80+ macrophages and the expressions of peripherin, adiponectin and leptin in mesenteric adipose tissues were detected by immunohistochemical staining. The phosphorylation of NF-κBp65, IKK, IκB proteins in the mesenteric adipose tissues was detected by Western blot analysis. Results The DAI score of rosiglitazone group was significantly lower than that of model group at 5 and 6 weeks after rosiglitazone treatment. At the same time, the levels of IL-1ß and TNF-α in the intestinal mucosa of the treated group were significantly lower than those in the model group, while the IL-10 levels were significantly higher in the treated group than in the model group. Compared with the model group, the mesenteric adipocyte diameter and the perilipin level of adipocyte maturation markers in rosiglitazone treated mice were significantly higher than those in model group. Meanwhile, the number of infiltration of macrophages in mesenteric adipose tissues of mice treated with rosiglitazone and the levels of inflammatory mediators IL-6 and MCP-1 were significantly lower than that of the model group. Rosiglitazone significantly promoted the expression of adiponectin and inhibited the expression of leptin in mesenteric adipocytes. The phosphorylation of NF-κBp65, IKK and IκB proteins in mesenteric adipose tissues of rosiglitazone treated mice was significantly lower than those of model group. Conclusion Rosiglitazone significantly inhibites intestinal inflammation in TNBS-induced colitis in mice, which may be related to the inhibition of NF-κBp65 pathway in mesenteric adipose tissues.
Assuntos
Colite , Tecido Adiposo , Animais , Citocinas , Inflamação , Masculino , Camundongos , Camundongos Endogâmicos BALB C , NF-kappa B , Ratos , Rosiglitazona , Ácido TrinitrobenzenossulfônicoRESUMO
Roxarsone (ROX), a widely used feed organoarsenic additive, occurs as itself and its metabolites in animal manure that is commonly land used as fertilizer. Soil property impacts arsenic (As) speciation and bioavailability. Fourteen soils across China were used to conduct culture experiments to investigate As uptake by garland chrysanthemum (ChrysanthemumL coronarium), with the soils fertilized with chicken manure bearing ROX and its metabolites. The results show As(III) was the sole As form in garland chrysanthemum shoots, and As(III) and As(V) occurred in roots. Only inorganic As was detected in all soils when the plants were harvested. Stepwise regression analysis shows soil-exchangeable Ca predominated shoot As(III) concentration (shoot As(III) = 1.60030 soil Ca, R 2 = 0.8832***). Therefore, ROX is transferred into the human food chain finally as inorganic As in plants. Application of animal manure bearing ROX and its metabolites is not recommended in Ca-rich soils to avoid excess inorganic As dietary exposure.
Assuntos
Arsênio/farmacocinética , Cálcio , Chrysanthemum , Poluentes do Solo/farmacocinética , Solo/química , Animais , Galinhas , China , Fertilizantes , Esterco , RoxarsonaRESUMO
Roxarsone (ROX), a widely used feed additive, occurs as itself and its metabolites in animal manure. Rice is prone to accumulate As than other staple food. Four diets with 0, 40, 80 and 120mgROXkg(-1) were fed in chickens, and four chicken manures (CMs) were collected to fertilize rice plants in a soil culture experiment. Linear regression analysis shows that the slopes of As species including 4-hydroxy-phenylarsonic acid, As(V), As(III), monomethylarsonic acid (MMA) and dimethylarsinic acid (DMA) in CM versus dietary ROX were 0.033, 0.314, 0.033, 0.054 and 0.138, respectively. Both As(III) and DMA were determined in all rice grains, and As(III), As(V), MMA and DMA in rice hull, but detectable As forms in rice straws and soils increased with increasing ROX dose. Grain As(III) was unrelated to ROX dose but exceeded the Chinese rice As limit (0.15mgAs(III)kg(-1)). Dietary ROX enhanced straw As(III) mostly, with the slope of 0.020, followed by hull DMA (0.006) and grain DMA (0.002). The slopes of soil As(V) and As(III) were 0.003 and 0.001. This is the first report illustrating the quantitative delivery of ROX via food chain, which helps to evaluate health and environmental risks caused by ROX use in animal production.
Assuntos
Antibacterianos/metabolismo , Suplementos Nutricionais/análise , Microbiologia de Alimentos , Oryza/química , Roxarsona/metabolismo , Poluentes do Solo/análise , Animais , Galinhas , Dieta/veterinária , Relação Dose-Resposta a Droga , Esterco/análiseRESUMO
Roxarsone is an organoarsenic feed additive which can be finally degraded to other higher toxic metabolites after excreted by animal. In this work, the uptake of As species by vegetables treated with chicken manure bearing roxarsone and its metabolites was investigated. It was showed that more than 96% of roxarsone added in chicken feed was degraded and converted to arsenite, monomethylarsonic acid, dimethylarsinic acid, arsenate, 4-hydroxyphenylarsonic acid and other unknown As species. Arsenite and arsenate could be found in roots of vegetables but only arsenite transported up to shoots. Chicken manure bearing roxarsone and its metabolites increased 33-175% of arsenite and 28% â¼ seven times of arsenate in vegetable roots, 68-175% of arsenite in edible vegetable shoots. Arsenite, the most toxic As form, was the major extractable As species in vegetables accounted for 79-98%. The results reflected that toxic element As could be absorbed by vegetables via the way: roxarsone in feed â animal â animal manure â soil â crop and the uptake of As species would be enhanced by using chicken manure bearing roxarsone and its metabolites as organic fertilizer.
Assuntos
Arsênio/metabolismo , Galinhas/metabolismo , Esterco/análise , Roxarsona/metabolismo , Roxarsona/farmacologia , Verduras/efeitos dos fármacos , Verduras/metabolismo , Ração Animal/análise , Animais , Arsênio/análise , Transporte Biológico/efeitos dos fármacos , Biomassa , Poluentes Ambientais/análise , Poluentes Ambientais/metabolismo , Fertilizantes , Cadeia Alimentar , Solo/químicaRESUMO
Organoarsenics are widely used as excellent feed additives in animal production in the world. Roxarsone (ROX) and arsanilic acid (ASA) are two organoarsenics permitted to be used in China. We collected 146 animal feed samples to investigate the appearance of ROX, ASA, and potential metabolites, including 3-amino-4-hydroxyphenylarsonic acid (3-A-HPA), 4-hydroxyphenylarsonic acid (4-HPA), As(V), As(III), monomethylarsonic acid (MMA), and dimethylarsinic acid (DMA) in feeds. The stability of ROX in both ROX additives and animal feeds was also examined. The results show that 25.4% of the 146 animal feeds contained organoarsenics, with average contents of ROX and ASA as 7.0 and 21.2 mg of As/kg, respectively. Unexpectedly, As(III) and MMA frequently occurred as As impurities in feeds bearing organoarsenics, with higher contents than organoarsenics in some samples. 3-A-HPA, 4-HPA, and DMA were not detected in all samples. ROX and As impurities in both ROX additives and feeds stayed unchanged in the shelf life. It suggests that As impurities in animal feeds bearing organoarsenics should generate from the use of organoarsenics containing As impurities. This constitutes the first report of As impurities in organoarsenics.
Assuntos
Ração Animal/análise , Ácido Arsanílico/química , Arsenicais/análise , Aditivos Alimentares/química , Contaminação de Alimentos , Roxarsona/química , Animais , Antibacterianos/química , Galinhas , China , Coccidiostáticos/química , Estabilidade de Medicamentos , Sus scrofaRESUMO
Roxarsone (ROX), a widely used feed organoarsenic additive, is excreted as itself and its metabolites in animal manure. Animal manure is commonly applied with N fertilizer to meet the N demand of crop. We investigated the accumulation of As species in garland chrysanthemum plants fertilized with chicken manure (CM) bearing ROX and its metabolites, combined with different inorganic N sources (NH4(+), NO3(-) and urea), respectively. The change of pH, N forms and As species in soils was examined as well. The results show that As(V), As(III) and dimethylarsinic acid (DMA) were detectable in soils, and conversions between As species were affected by three inorganic N sources, irrespective of N form and soil pH. As(III) was the sole As species in garland chrysanthemum shoots, and As(III) and As(V) could be detected in roots. Urea, superior to NH4(+), significantly enhanced the uptake of As species in plants by promoting plant growth, while NO3(-) slightly reduced the As accumulation due to decreased biomass. As(III) was the dominant As compound (86.9-89.7%) in plants. Therefore, inorganic N fertilizers may inadvertently increase the risk of As contamination in plant from ROX via the way ROXâchickenâCMâsoilâcrop.
Assuntos
Arsênio/metabolismo , Chrysanthemum/efeitos dos fármacos , Esterco , Roxarsona/administração & dosagem , Poluentes do Solo/metabolismo , Animais , Arsênio/análise , Arsênio/química , Galinhas , Chrysanthemum/crescimento & desenvolvimento , Chrysanthemum/metabolismo , Fertilizantes , Concentração de Íons de Hidrogênio , Nitrogênio/administração & dosagem , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Poluentes do Solo/análise , Poluentes do Solo/químicaRESUMO
Seventy chicken and seventy-six pig feeds were collected from the feed stores in Guangdong province, and the species and concentrations of As, Cu and Zn were determined. We also examined the stability of roxarsone (ROX), one of the most widely used organoarsenical additives, either in the additive or in the feed at room temperature. The results showed that, averagely, the chicken and pig feeds contained 3.6 and 6.5 mg.kg-1 (As), 18.2 and 119.4 mg.kg-1 (Cu),and 124.6 and 486.2 mg.kg-1 (Zn), respectively. The excessive dosages of As, Cu and As in animal feeds will lead to higher residue of As, Cu and Zn in animal manures. Based on the national limit criteria for feed or feed additive, it was supposed that organoarsenicals had been used, only few feed samples exceeded the As limit, however, the excessive Cu and Zn in pig feeds were much more common. Organoarsenicals were found in 25.4% of the total feed samples, and As(Ill) and As(V) were the two most commonly detected As impurities in feeds bearing organoarsenicals. The mean detectable ROX and arsenilic acid were 7.0 and 21.2 mg.kg-1, respectively. Organoarsenicals were detectable in 24. 3% of the chicken feed samples and 26. 3% of the pig feed samples. Moreover, ROX was commonly used in chicken feeds, while p-ASA in pig feeds. ROX and the inorganic As impurities, either in the commercial additive or in the feed, remained stable for at least 30 days at room temperature, indicating the higher As impurities in feeds probably originated from the As impurities in organoarsenical additives. This is a new As exposure pathway for the producer and user of organoarsenicals and feeds amending organoarsenicals.
Assuntos
Ração Animal/análise , Arsênio/análise , Cobre/análise , Zinco/análise , Animais , Galinhas , China , Roxarsona/análise , SuínosRESUMO
Litchi is a famous tropical and subtropical fruit originated in South China. Guangdong is one of the most important litchi production areas in China. Two hundred and eight soil samples were collected in litchi orchards after harvesting the fruit, in which nine often-used pesticides including metalaxyl, mancozeb, carbendazim, deltamethrin, cypermethrin, cyhalothrin, dipterex, dimethoate and dichlorvos were detected. The results showed that the detectable rates of various pesticides were ranked cypermethrin (59.1%) > carbendazim (51.0%) > mancozeb (11.1%) > metalaxyl (6.7%) > cyhalothrin (3.4%). Dimethoate and dichlorvos were detectable in few soil samples, and deltamethrin and dipterex were undetectable in all samples. The percentages of soil samples where different pesticides could be detected in one sample followed the order: one pesticide detectable (40.4%) > two pesticides simultaneously detectable (31.3%) > pesticide undetectable (18.8%) > three pesticides simultaneously detectable (8.2%) > four pesticides simultaneously detectable (1.4%). The concentrations of mancozeb in detectable samples averaged 39.05 microg x kg(-1), and that of cypermethrin was 7.83 microg x kg(-1). The mean concentrations of the other five pesticides ranged from 0.19 microg x kg(-1) to 1.65 microg x kg(-1). Totally, the pesticide residue status in litchi orchards in Guangdong was venial.
Assuntos
Monitoramento Ambiental , Litchi/crescimento & desenvolvimento , Resíduos de Praguicidas/análise , Poluentes do Solo/análise , ChinaRESUMO
Organoarsenicals are widely used as growth promoters in animal feed, resulting in unabsorbed arsenic (As) left in animal manures. A pot experiment was conducted to investigate the growth and As uptake of amaranth (Amaranthus tricolor Linn, a crop with an axial root system) and water spinach (Ipomoea aquatica Forsk, a crop with a fibrous root system) grown in a paddy soil (PS) and a lateritic red soil (LRS) amended with 2% and 4% (w/w) As-bearing chicken manure and pig manure, respectively. Soils without any fertilizers were the controls. The biomass, As contents and total As uptake of the shoots, As transfer factors (TFs) from roots to shoots and the root/shoot (R/S) ratios of water spinach were significantly higher than those of amaranth (p<0.0015). The biomass, total As uptake and R/S ratios showed significant difference for soil types (p<0.0031). Manure amendments increased the biomass of both vegetables, reduced the As contents in amaranth but increased those in water spinach. The As contents were negatively correlated with the biomass in amaranth, but positive correlation was observed for water spinach. The total As uptake by amaranth was decreased in PS and insignificantly affected in LRS by manure application, but that by water spinach was significantly increased in both soils. We suggest that the higher As uptake by water spinach might be related to its root structure and R/S ratio. Heavy application of As-bearing animal manures should be avoided in water spinach.