RESUMO
Accidental or intentional releases of toxic gases or vapors are the most common occurrence in hazardous material (HAZMAT) incidents that result in human injuries. The most serious hazard from exposure to gases or vapors is via the respiratory system. Dermal uptake, as a secondary route, is still a concern, most acutely for the unprotected public. There is a limited evidence base describing skin absorption of toxic gases and vapors in HAZMAT exposure scenarios, which are relatively brief compared with traditional test periods for skin absorption studies. We describe research designed to provide experimental data to support decision-making by first responders regarding skin decontamination in HAZMAT-focused exposure scenarios involving toxic gases. We present findings for three common fumigants, methyl bromide, sulfuryl fluoride, and chloropicrin assessed using an Organization for Economic Co-operation and Development in vitro toxicology protocol utilizing human skin and gas/vapor exposures. Results indicate that for atmospheric concentrations that would be lethal via inhalation (LCLo), intact skin provides an excellent barrier to exposures up to 30 min, with little influence of common clothing fabric and high temperature and humidity conditions. The findings may challenge the current HAZMAT dogma requiring mass personal decontamination by strip and shower for short-term exposures to sulfuryl fluoride and chloropicrin gas/vapor.
Assuntos
Substâncias Perigosas/toxicidade , Hidrocarbonetos Bromados/toxicidade , Hidrocarbonetos Clorados/toxicidade , Praguicidas/toxicidade , Absorção Cutânea , Ácidos Sulfínicos/toxicidade , Células Cultivadas , Gases/toxicidade , Humanos , Dose Letal Mediana , Pele/citologia , Pele/efeitos dos fármacosRESUMO
Anti-leishmanial activity of allicin (=diallyl thiosulphinate) has been tested in vitro against promastigotes and intracellular amastigotes of Leishmania donovani and Leishmania infantum. Macrophage infections have been carried out in vitro in the murine cell line J774 and ex vivo with peritoneal macrophages from BALB/c mice with a modified method to isolate metacyclic promastigotes. The compound has shown a significant in vitro effect on the multiplication of promastigotes of L. donovani and L. infantum in a time- and dose-dependent manner. It has been shown for the first time the inhibition of multiplication of intracellular amastigotes of Leishmania by allicin. Inhibitory concentrations of the compound were in the micromolar range (10-30 µM) for both Leishmania species. Antileishmanial effect of allicin apparently was not related to products of degradation of the molecule as assessed by mass spectrometry analysis. Inhibitory activity of allicin against promastigotes and intracellular amastigotes increased when the compound was added to the cultures every 24 h. Two administrations of 5 µM allicin inhibited by ca. 50% the proliferation of Leishmania amastigotes. Low toxicity for mammalian cells of this compound suggests the interest of exploring the value of allicin in combined therapy against leishmanial infections.
Assuntos
Anti-Infecciosos/farmacologia , Leishmania donovani/efeitos dos fármacos , Leishmania infantum/efeitos dos fármacos , Macrófagos Peritoneais/parasitologia , Ácidos Sulfínicos/farmacologia , Animais , Anti-Infecciosos/metabolismo , Anti-Infecciosos/toxicidade , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Dissulfetos , Cães , Relação Dose-Resposta a Droga , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Temperatura Alta , Concentração Inibidora 50 , Leishmania donovani/crescimento & desenvolvimento , Leishmania donovani/ultraestrutura , Leishmania infantum/crescimento & desenvolvimento , Leishmania infantum/ultraestrutura , Leishmaniose Visceral/tratamento farmacológico , Leishmaniose Visceral/parasitologia , Macrófagos Peritoneais/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Eletrônica de Transmissão , Ácidos Sulfínicos/metabolismo , Ácidos Sulfínicos/toxicidade , Fatores de TempoRESUMO
OBJECTIVES: The aim of this work was to study the effect of the physically adsorbed Poloxamer 188 coating polymer on the cytotoxic activity of allicin-loaded gelatin nanoparticles. METHODS: The double desolvation method was utilised to prepare the nanoparticles which were characterised for particle size (PS), polydispersity index (PDI) and zeta potential and visualised using transmission electron microscopy. The coating density of the used polymer was determined using 1H-nuclear magnetic resonance (1H-NMR); 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay was used to evaluate the cytotoxicity on HepG-2 cell lines. KEY FINDINGS: The particles were spherical possessing a PS of 714 ± 25.21 nm and a PDI of 0.663 ± 0.143. These results together with the 1H-NMR results analysis confirmed the efficient coating of Poloxamer 188. The coating of particles rendered them more cytotoxic, scoring an IC50 of 6.736 µm (2-folds lower than the uncoated counter parts and 4-folds lesser than the allicin solution), and apt for cancer-targeting. Moreover, the prepared nanoparticles were stable to gamma-sterilisation and to a storage of 12 months. CONCLUSIONS: Augmented cytotoxicity on HepG-2 cell lines was obtained using the physical adsorption of an abundant and relatively cheap material, Poloxamer 188, on allicin-loaded gelatin nanoparticles.
Assuntos
Dissulfetos/toxicidade , Portadores de Fármacos/química , Sistemas de Liberação de Medicamentos/métodos , Nanopartículas/química , Poloxâmero/química , Ácidos Sulfínicos/toxicidade , Adsorção , Animais , Linhagem Celular Tumoral , Sobrevivência Celular , Gelatina/química , Células Hep G2 , Humanos , Concentração Inibidora 50 , Colagenase Microbiana , Tamanho da Partícula , SuínosRESUMO
Sulfuryl fluoride (SO(2)F(2)) is used primarily as a fumigant in replacement of methyl bromide, but it has the potential to contribute significantly to the global warming. This article introduces SO(2)F(2) in the physicochemical properties, the current uses in agriculture and industry, the toxicological data, and the environmental implications on the basis of its environmental properties. The health hazards of SO(2)F(2) and its probable decomposition products were also evaluated based on their occupational exposure limits and possible exposure sources. The resident and occupational exposure assessment was further discussed to understand seriousness of risk caused by SO(2)F(2) and its decomposition products.
Assuntos
Poluentes Atmosféricos/toxicidade , Exposição Ambiental/efeitos adversos , Fumigação , Substâncias Perigosas/toxicidade , Hidrocarbonetos Bromados/toxicidade , Ácidos Sulfínicos/toxicidade , Poluentes Atmosféricos/química , Animais , Fenômenos Químicos , Exposição Ambiental/análise , Recuperação e Remediação Ambiental , Fumigação/métodos , Aquecimento Global , Humanos , Hidrocarbonetos Bromados/química , Medição de Risco , Ácidos Sulfínicos/química , Testes de ToxicidadeRESUMO
To understand the response mechanisms of fungus cells upon exposure to the natural fungicide allicin, we performed commercial oligonucleotide microarrays to determine the overall transcriptional response of allicin-treated Saccharomyces cerevisiae strain L1190. Compared with the transcriptional profiles of untreated cultures, 147 genes were significantly upregulated, and 145 genes were significantly downregulated in the allicin-treated cells. We interpreted the microarray data with the hierarchical clustering tool, T-profiler. Major transcriptional responses were induced by allicin and included the following: first, Rpn4p-mediated responses involved in proteasome gene expression; second, the Rsc1p-mediated response involved in iron ion transporter activity; third, the Gcn4p-mediated response, also known as general amino acid control; finally, the Yap1p-, Msn2/4p-, Crz1p-, and Cin5p-mediated multiple stress response. Interestingly, allicin treatment, similar to mycotoxin patulin and artificial fungicide thiuram treatment, was found to induce genes involved in sulfur amino acid metabolism and the defense system for oxidative stress, especially DNA repair, which suggests a potential mutagenicity for allicin. Quantitative real-time reverse transcription-polymerase chain reaction was performed for selected genes to verify the microarray results. To our knowledge, this is the first report of the global transcriptional profiling of allicin-treated S. cerevisiae by microarray.
Assuntos
Antifúngicos/toxicidade , Perfilação da Expressão Gênica , Saccharomyces cerevisiae/efeitos dos fármacos , Saccharomyces cerevisiae/genética , Ácidos Sulfínicos/toxicidade , Dissulfetos , Análise de Sequência com Séries de Oligonucleotídeos , RNA Fúngico/biossíntese , RNA Fúngico/genética , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Reação em Cadeia da Polimerase Via Transcriptase ReversaRESUMO
PURPOSE: We examined genotoxicity, co-genotoxicity and induced genomic instability (IGI) in primary astrocytes exposed to radiofrequency (RF) radiation. MATERIALS AND METHODS: Rat primary astrocytes were exposed to 872 MHz GSM-modulated or continuous wave (CW) RF radiation at specific absorption rates of 0.6 or 6.0 W/kg for 24 h. Menadione (MQ) and methyl methanesulfonate (MMS; only in genotoxicity experiments) were used as co-exposures. Alkaline Comet assay and flow cytometric micronucleus scoring were used to detect genetic damage. RESULTS: No IGI was observed from RF radiation alone or combined treatment with MQ. RF radiation alone was not genotoxic. RF radiation combined with chemical exposure showed some statistically significant differences: increased DNA damage at 6.0 W/kg but decreased DNA damage at 0.6 W/kg in cells exposed to GSM-modulated RF radiation and MQ, and increased micronucleus frequency in cells exposed to CW RF radiation at 0.6 W/kg and MMS. CONCLUSIONS: Exposure to GSM modulated RF radiation at levels up to 6.0 W/kg did not induce or enhance genomic instability in rat primary astrocytes. Lack of genotoxicity from RF radiation alone was convincingly shown in multiple experiments. Co-genotoxicity of RF radiation and genotoxic chemicals was not consistently supported by the results.
Assuntos
Astrócitos/efeitos dos fármacos , Astrócitos/efeitos da radiação , Instabilidade Genômica/efeitos dos fármacos , Instabilidade Genômica/efeitos da radiação , Testes de Mutagenicidade , Ondas de Rádio/efeitos adversos , Ácidos Sulfínicos/toxicidade , Vitamina K 3/toxicidade , Animais , Dano ao DNA , RatosRESUMO
BACKGROUND: Susceptibility to phosphine (PH3 ) and sulfuryl fluoride (SF) and cross-resistance to SF were evaluated in two life stages (eggs and adults) of key grain insect pests, Rhyzopertha dominca (F.), Sitophilus oryzae (L.), Cryptolestes ferrugineus (Stephens), and Tribolium castaneum (Herbst). This study was performed with an aim to integrate SF into phosphine resistance management programmes in Australia. RESULTS: Characterisation of susceptibility and resistance to phosphine in eggs and adults showed that C. ferrugineus was the most tolerant as well as resistant species. Mortality responses of eggs and adults to SF at 25 °C revealed T. castaneum to be the most tolerant species followed by S. oryzae, C. ferrugineus and R. dominica. A high dose range of SF, 50.8-62.2 mg L-1 over 48 h, representing c (concentration) × t (time) products of 2438-2985 gh m-3 , was required for complete control of eggs of T. castaneum, whereas eggs of the least tolerant R. dominca required only 630 gh m-3 for 48 h (13.13 mg L-1 ). Mortality response of eggs and adults of phosphine-resistant strains to SF in all four species confirmed the lack of cross-resistance to SF. CONCLUSION: Our research concludes that phosphine resistance does not confer cross-resistance to SF in grain insect pests irrespective of the variation in levels of tolerance to SF itself or resistance to phosphine in their egg and adult stages. While our study confirms that SF has potential as a 'phosphine resistance breaker', the observed higher tolerance in eggs stresses the importance of developing SF fumigation protocols with longer exposure periods. © 2016 Society of Chemical Industry.
Assuntos
Besouros/efeitos dos fármacos , Resistência a Inseticidas , Fosfinas/toxicidade , Ácidos Sulfínicos/toxicidade , Animais , Austrália , Fumigação , Controle de Insetos/métodos , Inseticidas , ÓvuloRESUMO
Garlic (Allium sativum) and onion (Allium cepa) are being used in the food industry as flavoring but also for their antimicrobial activities. These activities are mainly derived from the organosulfur compounds (OSCs). Propyl propane thiosulfinate (PTS) is an OSC with potential use in the active packaging, but its safety should be guaranteed before being commercialized. The aim of this work was to investigate for the first time the cytotoxicity of PTS as well as its in vitro mutagenic/genotoxic potential using the following battery of genotoxicity tests:(1)the bacterial reverse-mutation assay in S. typhimurium (Ames test, OECD 471, 1997); (2) the micronucleus test (MN, OECD 487, 2016); (3) the mouse lymphoma thymidine-kinase assay (MLA, OECD 476, 2015), and (4) the comet assay (standard and modified with restriction enzymes). The results revealed that PTS was not mutagenic neither in the Ames test nor in MLA. However, genotoxic effects were recorded in the MN test on mammalian cells (L5178YTk+/-cells) after PTS exposure at the highest concentration tested (17.25 µM) without S9, and also its metabolites (+S9, from 20 µM). Moreover, in the comet assay, PTS induced DNA breaks damage in Caco-2 cells at the highest concentration tested (280 µM) but it did not induce oxidative DNA damage.
Assuntos
Sobrevivência Celular/efeitos dos fármacos , Dano ao DNA/efeitos dos fármacos , Alho/química , Linfoma/patologia , Extratos Vegetais/toxicidade , Salmonella typhimurium/efeitos dos fármacos , Ácidos Sulfínicos/toxicidade , Animais , Células CACO-2 , Ensaio Cometa , Humanos , Linfoma/tratamento farmacológico , Camundongos , Testes para Micronúcleos , Mutação/genética , Timidina Quinase/genética , Timidina Quinase/metabolismoRESUMO
Components of Allium species have antimicrobial and antioxidant properties. A commercial Allium sp. extract (Proallium AP(®)), of which the main constituent is propyl thiosulphinate oxide (PTSO), is being used in the development of active food packaging. In previous in vitro genotoxicity studies, PTSO, in the presence of metabolic activation, increased the appearance of micronuclei (MN). We assessed the genotoxicity PTSO in rats following oral administration (doses: 5.5, 17.4, and 55mg/kg). The comet assay in liver and stomach (OECD 489) and the MN assay in bone marrow (OECD 474) were carried out. After necropsy, histopathological examinations of the liver and the stomach were performed. The results revealed no in vivo genotoxicity and the histopathological analysis showed only slight modifications, such as increased glycogen storage in the liver and a degenerative process in stomach, with vacuolization of cell membranes, only at the highest dose. Therefore, the present work confirms that this compound is not genotoxic and could be considered as a natural alternative to synthetic preservatives used in the food packaging industry.
Assuntos
Allium/química , Ensaio Cometa/métodos , Testes para Micronúcleos/métodos , Ácidos Sulfínicos/toxicidade , Animais , Feminino , Embalagem de Alimentos , Cromatografia Gasosa-Espectrometria de Massas , Mucosa Gástrica/efeitos dos fármacos , Mucosa Gástrica/metabolismo , Mucosa Gástrica/ultraestrutura , Hepatócitos/efeitos dos fármacos , Hepatócitos/metabolismo , Hepatócitos/ultraestrutura , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Masculino , Microscopia Eletrônica de Transmissão , Testes de Mutagenicidade , Ratos Wistar , Estômago/efeitos dos fármacos , Estômago/patologia , Ácidos Sulfínicos/sangue , Ácidos Sulfínicos/metabolismoRESUMO
Some plant extracts have been proposed as potential alternative to the use of synthetic preservatives in the food industry. Among those, extracts from Allium species exhibit interesting antimicrobial and antioxidant properties for the food packaging industry. The present work aims to assess the usefulness and potential safety of the major organosulfur compound present in a commercial Allium sp. extract (PROALLIUM AP®), namely propyl thiosulfinate oxide (PTSO). For this purpose, its antimicrobial activity was studied in a wide range of microorganisms. Moreover, cytotoxicity and ultrastructural cellular damages caused by PTSO were studied in two human cell lines, Caco-2 and HepG2, being the colonic cells more sensitive to this compound. Finally, the protective role of PTSO against an induced oxidative situation was evaluated in the human intestinal Caco-2 cells. The results revealed damage at high concentration, although no significant adverse effects were recorded for the concentration to be used in food packaging. Moreover, the in vivo study also revealed the potential safety use at the established concentrations. In addition, the antimicrobial properties and the antioxidant role of PTSO were confirmed. Therefore, this compound could be considered as a good natural alternative to synthetic preservatives used in the food packaging industry.
Assuntos
Allium/química , Embalagem de Alimentos , Ácidos Sulfínicos/farmacologia , Ácidos Sulfínicos/toxicidade , Animais , Anti-Infecciosos/farmacologia , Antioxidantes/farmacologia , Células CACO-2/efeitos dos fármacos , Feminino , Humanos , Testes de Sensibilidade Microbiana , Microscopia Eletrônica , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Ratos , Testes de Toxicidade AgudaRESUMO
Essential oils from onion (Allium cepa L.), garlic (Allium sativum L.), and their main components, such as propyl thiosulfinate oxide (PTSO) are being intended for active packaging with the purpose of maintaining and extending food product quality and shelf life. The present work aims to assess for the first time the potential mutagenicity/genotoxicity of PTSO (0-50 µM) using the following battery of genotoxicity tests: (1) the bacterial reverse-mutation assay in Salmonella typhimurium (Ames test, OECD 471); (2) the micronucleus test (OECD 487) (MN) and (3) the mouse lymphoma thymidine-kinase assay (OECD 476) (MLA) on L5178YTk(+/-), cells; and (4) the comet assay (with and without Endo III and FPG enzymes) on Caco-2 cells. The results revealed that PTSO was not mutagenic in the Ames test, however it was mutagenic in the MLA assay after 24 h of treatment (2.5-20 µM). The parent compound did not induce MN on mammalian cells; however, its metabolites (in the presence S9) produced positive results (from 15 µM). Data from the comet assay indicated that PTSO did not induce DNA breaks or oxidative DNA damage. Further in vivo genotoxicity tests are needed to confirm its safety before it is used as active additive in food packaging.
Assuntos
Allium/química , Extratos Vegetais/farmacologia , Ácidos Sulfínicos/toxicidade , Animais , Células CACO-2 , Linhagem Celular , Ensaio Cometa , Embalagem de Alimentos , Humanos , Camundongos , Testes para Micronúcleos , Mutação , Extratos Vegetais/química , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Ácidos Sulfínicos/químicaRESUMO
The trisulfide disulfinate [Na32S(CH2)4S]2S (2) is an antiradiation drug which is atypical in having no nitrogen function. At low dose levels of 37.5 and 18.5 mg/kg intraperitoneally (ip), 2 protected respectively about 82 and 35% of lethally irradiated mice. By the oral route (po), 150 mg/kg of 2 protected about 73%, and 75 mg/kg protected about 20%. The LD50 either ip or po exceeded 900 mg/kg. Although a 2,3-diacetoxy analog 3 was inactive, cyclic disulfide and trisulfide sulfinate analogs showed promice. Among these, a sulfinate moiety is related to a di- or trisulfie moiety in the sense of 1,8 in a naphthyl system (4,5), 2,2' in a biphenyl system (6-9), and alpha,alpha' in an o-xylyl system (10,11). The 1,8-naphthyl disulfide sulfinate 4 was not tested biologically because a marked neighboring group effect of -SO2Na on -SS- caused rapid cyclization to the parent disulfide dioxide 14; the corresponding trisulfide 5 was more stable but only slightly protective. Other analogs lacking the coplanarity of 4 also were more stable. The biphenyl compounds 6 and 7 were quite active ip (e.g., 7 led to 90% survival at 4.6 mg/kg, with LD50 EQUALS 130 mg/kg, although protection with 6 and 7 at the doses given po was only fair). Dichloro counterparts 8 and 9 offered no advantages over 6 and 7. The xylylene compounds 10 and 11 were roughly comparable to each other by ip and op routes (e.g., given ip, 10 led to 93-100% survival at 75 mg/kg, with LD50 GREATER THAN 950 mg/kg; given po, 10 gave 100% survival at 60 mg/kg, with LD50 GREATER THAN 900 mg/kg). Compounds 7 and 11 join 2 as promising antiradiation drugs that lack the usual nitrogen function. The fact that sulfinate salts show activity, both ip and po, suggests that the -SO2Na moiety deserves more attention in medicinal chemistry. Hydration of sulfinate salts often made analytical characterization difficult. Confirmatory evidence for typical structures is given.
Assuntos
Dissulfetos/síntese química , Protetores contra Radiação/síntese química , Sulfetos/síntese química , Ácidos Sulfínicos/síntese química , Administração Oral , Animais , Radioisótopos de Césio , Dissulfetos/farmacologia , Dissulfetos/toxicidade , Feminino , Raios gama , Injeções Intraperitoneais , Dose Letal Mediana , Camundongos , Camundongos Endogâmicos , Efeitos da Radiação , Protetores contra Radiação/toxicidade , Sulfetos/farmacologia , Sulfetos/toxicidade , Ácidos Sulfínicos/farmacologia , Ácidos Sulfínicos/toxicidadeRESUMO
Various reducing agents have been evaluated for their potential usefulness in the preparation of 99mTc labeled radiopharmaceuticals for use in nuclear medicine. Adequate labeling of various radiopharmaceuticals was accomplished using formamidine sulfinic acid. Nitrogen-purging of solutions is not required, which is an advantage for in-house preparation. Tagging requires heating, however, so heat-labile material cannot be used. Various compounds that could not be labeled when stannous chloride was used, could be tagged with 99mTc when formanidine sulfinic acid was used as the reducing agent.
Assuntos
Cloretos , Hidrazinas , Marcação por Isótopo/métodos , Organofosfonatos , Ácidos Sulfínicos , Tecnécio , Estanho , Amidinas/toxicidade , Animais , Cloretos/toxicidade , Difosfatos , Camundongos , Organofosfonatos/toxicidade , Oxirredução , Ácido Pentético , Coelhos , Cintilografia , Ácidos Sulfínicos/toxicidade , Estanho/toxicidadeRESUMO
The sulfur-containing compound ajoene (4,5,9-trithiadodeca-1,6,11-triene-9-oxide) which arises from alliin, a cysteine derivative stored in garlic bulbs, was produced synthetically by decomposition of allicin. Its cytotoxic effect was tested using human primary fibroblasts (FS4), a permanent, non-tumorgenic cell line derived from baby hamster kidney cells (BHK21) and a tumorgenic lymphoid cell line derived from a Burkitt lymphoma (BJA-B). The cytotoxic action was in the range 2-50 micrograms/ml depending on the cell density. ED50 values, estimated on the basis of fmol ajoene/cell, revealed slightly higher doses for the primary cell (FS4) than the permanent line (BHK), whereas the tumorgenic BJA-B cells were most sensitive.
Assuntos
Sobrevivência Celular/efeitos dos fármacos , Dissulfetos/toxicidade , Extratos Vegetais/toxicidade , Animais , Transporte Biológico , Linhagem Celular , Cricetinae , Dissulfetos/metabolismo , Relação Dose-Resposta a Droga , Alho , Humanos , Técnicas In Vitro , Extratos Vegetais/metabolismo , Plantas Medicinais , Ácidos Sulfínicos/toxicidade , SulfóxidosRESUMO
Garlic (Allium sativum L.) water- and ethanol-soluble extracts were prepared and purified by column chromatography. They were tested on garlic-sensitive patients and showed that the allergenic fraction was well located in a few column chromatography fractions. Guinea-pigs were sensitized with garlic water-soluble extracts and tested (open epicutaneous tests) with several fractions. The presence of diallyldisulfide was detected in the sensitizing chromatographic fractions. Guinea-pigs were successfully sensitized to this product and cross-reacted to garlic; animals sensitized to garlic extracts cross-reacted to diallyldisulfide. Both groups reacted to allicin, an oxidized derivative of diallyldisulfide present in garlic. Garlic-sensitive patients showed positive tests to diallyldisulfide, allylpropyldisulfide, allylmercaptan and allicin.
Assuntos
Alérgenos/análise , Compostos Alílicos , Dermatite de Contato/etiologia , Alho/toxicidade , Hipoglicemiantes/toxicidade , Extratos Vegetais/toxicidade , Plantas Medicinais , Animais , Dissulfetos/toxicidade , Alho/análise , Cobaias , Humanos , Testes do Emplastro , Extratos Vegetais/análise , Ácidos Sulfínicos/toxicidadeRESUMO
Inhalation exposure of male and female Fischer 344 rats to sulfuryl fluoride [Vikane (Dow Chemical Company) gas fumigant] at 300 ppm for 6 hr/day, 5 days week, for 13 weeks caused diminished weight gain, dental fluorosis, a slight decrease in grooming, decreased flicker fusion threshold, slowing of flash, auditory and somatosensory evoked potentials, mild nasal and pulmonary inflammation, mild kidney effects, and mild vacuolation in the brain. Auditory brainstem responses (ABRs) and brain histology were evaluated two months postexposure in 2 male and 2 female rats. Both the ABRs and brain histology were within normal limits at this time, indicating that these treatment effects were, to at least a great extent, reversible. Exposure to 100 ppm resulted in dental fluorosis and very minor slowing of some evoked responses; all other measures, including brain histology, were normal. No treatment effects were noted at 30 ppm.
Assuntos
Inseticidas/toxicidade , Sistema Nervoso/efeitos dos fármacos , Ácidos Sulfínicos/toxicidade , Potenciais de Ação/efeitos dos fármacos , Animais , Audiometria de Resposta Evocada , Peso Corporal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Eletroencefalografia , Feminino , Fusão Flicker/efeitos dos fármacos , Masculino , Ratos , Ratos Endogâmicos F344 , Fatores SexuaisRESUMO
BACKGROUND: Root-knot nematodes and soil-borne diseases constrain the rapid development of protected agriculture in China, especially while phasing out methyl bromide (MB). The fumigant sulfuryl fluoride (SF) is currently used as an alternative to MB for the disinfestation of buildings and post-harvest commodities. Our experiments aimed to evaluate a novel application of SF as a soil fumigant in greenhouses in China. RESULTS: Dose-response experiments indicated that SF has good efficacy on root-knot nematodes (Meloidogyne spp.) and moderate activity against Fusarium spp. and weeds (Digitaria sanguinalis (L.) Scop. and Abutilon theophrasti Medicus). The field trials indicates that SF has good efficacy, between 80 and 94%, on Meloidogyne spp., and Fusarium spp. at the rates of 25-50 g m(-2) in tomato and cucumber in Beijing and Shandong Province. Marketable yield and plant vigour was not significantly different in SF and MB treatments. SF has lower emissions than MB during the fumigation operation. It is simple to apply, can be used at low temperature, and has a short plant-back time. SF was found to be an economically feasible alternative to MB for nematode control in China. CONCLUSION: SF can be used as a soil fumigant to control root-knot nematodes and to reduce the levels of key soil pathogens.
Assuntos
Fumigação/métodos , Praguicidas/toxicidade , Solo , Ácidos Sulfínicos/toxicidade , Animais , Bioensaio , China , Relação Dose-Resposta a Droga , Estudos de Viabilidade , Fumigação/economia , Fusarium/efeitos dos fármacos , Gases/química , Gases/toxicidade , Nematoides/efeitos dos fármacos , Praguicidas/química , Phytophthora/efeitos dos fármacos , Ácidos Sulfínicos/química , Controle de Plantas DaninhasRESUMO
Pneumolysin (PLY) is a key virulence factor contributes to the pathogenesis of Streptococcus pneumoniae. In this study we investigated the effect of allicin and aqueous garlic extracts on hemolytic activity of PLY both in prelysed and intact cells. Additionally the antimicrobial activity of allicin was tested against the bacteria. All tested materials potently inhibited the PLY hemolytic activity. Allicin neutralizes PLY in a concentration- and time-dependent manner. Twenty five minute incubation of PLY (2 HU/mL) with 0.61 µM/mL concentration of allicin, totally inhibited hemolytic activity of PLY (IC50 = 0.28 µM/mL). The inhibitory activity of old extract of garlic was similar to pure allicin (IC50 = 50.46 µL/mL; 0.31 µM/mL; P < 0.05). In contrast fresh extract of garlic inhibits the PLY hemolytic activity at lower concentrations (IC50 = 13.96 µL/mL; 0.08 µM/mL allicin). Exposure of intact cells to allicin (1.8 µM) completely inhibited hemolytic activity of PLY inside bacterial cells. The inhibitory effect of the allicin was restored by addition of reducing agent DTT at 5 mM, proposing that allicin likely inhibits the PLY by binding to cysteinyl residue in the binding site. The MIC value of allicin was determined to be 512 µg/mL (3.15 µM/mL). These results indicate that PLY is a novel target for allicin and may provide a new line of investigation on pneumococcal diseases in the future.
Assuntos
Anti-Infecciosos/toxicidade , Alho/química , Estreptolisinas/antagonistas & inibidores , Ácidos Sulfínicos/toxicidade , Proteínas de Bactérias/antagonistas & inibidores , Proteínas de Bactérias/metabolismo , Dissulfetos , Ditiotreitol/farmacologia , Antagonismo de Drogas , Eritrócitos/química , Eritrócitos/efeitos dos fármacos , Hemoglobinas/análise , Hemólise/efeitos dos fármacos , Humanos , Testes de Sensibilidade Microbiana , Oxirredução , Streptococcus pneumoniae/efeitos dos fármacos , Estreptolisinas/metabolismoAssuntos
Protetores contra Radiação/síntese química , Sulfetos/síntese química , Ácidos Sulfínicos/síntese química , Acetamidas/síntese química , Acetamidas/farmacologia , Acetamidas/toxicidade , Animais , Butanos , Cromatografia em Camada Fina , Isótopos do Cobalto , Dissulfetos/síntese química , Dissulfetos/farmacologia , Dissulfetos/toxicidade , Raios Infravermelhos , Dose Letal Mediana , Espectroscopia de Ressonância Magnética , Camundongos , Protetores contra Radiação/farmacologia , Protetores contra Radiação/toxicidade , Análise Espectral , Relação Estrutura-Atividade , Ácidos Sulfínicos/farmacologia , Ácidos Sulfínicos/toxicidadeRESUMO
Allicin was effective in decreasing the lethal concentration of Cu (2+) against various fungal strains including a plant pathogen, Fusarium oxysporum, so that the minimum fungicidal concentration (MFC) of the ion for the fungus could be reduced to 2 % of that detected without allicin. In Saccharomyces cerevisiae, Cu (2+) was not apparently taken up by cells when added alone at a non-lethal concentration, whereas the ion was efficiently incorporated into cells in the presence of allicin, as in the case of cells treated with the ion at a lethal concentration. Although allicin likely increased cellular permeability to Cu (2+) due to its promotive effect on plasma membrane phospholipid peroxidation, these cell-surface events did not result in endogenous reactive oxygen species (ROS) production, a typical toxic effect of the ion. Cu (2+) was detected in the cytoplasmic fraction of cells that had been treated with the ion at a lethal concentration, whereas the ion was entrapped in the plasma membrane fraction upon their treatment with the ion at a low concentration in combination with allicin. Cu (2+) could be solubilized from the plasma membrane fraction by a procedure for the extraction of hydrophobic proteins rather than the extraction of phospholipids, suggesting its complexation with a plasma membrane protein as a result of allicin treatment. Such a subcellular localization of Cu (2+) resulted in the selective leakage of intracellular K (+), but not in the disruptive damage on the plasma membrane, and was considered to underlie the synergistic fungicidal activity of Cu (2+) and allicin.