maneb and tetrachloroisophthalonitrile

Mancozeb (MZ), chlorothalonil (CT), and thiophanate methyl (TM) are pesticides commonly used in agriculture due to their efficacy, low acute toxicity to mammals, and short environmental persistence. Although the toxic effects of these pesticides have been previously reported, studies regarding their influence on the immune system are limited. As such, this study focused on the immunomodulatory effect of MZ, CT, and TM pesticides on macrophage cells. RAW 264.7 cells were exposed to a range of concentrations (0.1-100 μg/mL) of these pesticides. CT exposure promoted an increase in reactive oxygen species (ROS) and nitric oxide (NO) levels. The MTT and ds-DNA assay results demonstrated that MZ, CT, and TM exposure induced macrophage proliferation. Moreover, MZ, CT, and TM promoted cell cycle arrest at S phase, strongly suggesting macrophage proliferation. The levels of pro-inflammatory cytokines (IL-1β, IL-6, TNF-α, and IFN-γ) and caspases (caspase 1, 3, and 8) in macrophages exposed to MZ, CT, and TM pesticides increased, whereas the anti-inflammatory cytokine levels decreased. These results suggest that MZ, CT, and TM exert an immunomodulatory effect on the immune system, inducing macrophage activation and enhancing the inflammatory response.

Topics: Animals; Cytokines; Immunomodulation; Interleukin-1beta; Macrophages; Maneb; Nitric Oxide; Nitriles; Pesticides; Reactive Oxygen Species; Thiophanate; Toxicity Tests; Tumor Necrosis Factor-alpha; Zineb

This study determined the function of thioredoxin and glutaredoxin systems in the phytopathogenic fungus

Topics: Alternaria; Antifungal Agents; Biphenyl Compounds; Citrus; Drug Resistance, Fungal; Gene Deletion; Gene Expression Regulation, Fungal; Glutaredoxins; Glutathione Reductase; Hydrogen Peroxide; Maneb; NADPH Oxidases; Niacinamide; Nitriles; Oxidative Stress; Peroxiredoxins; Plant Leaves; Reactive Oxygen Species; Sulfhydryl Compounds; Thioredoxin-Disulfide Reductase; Thioredoxins; Zineb

Arbuscular mycorrhizal fungi (AMF) are mutualistic symbionts considered a key group in soil systems involved in the provision of several ecosystem services. Recently they have been listed by EFSA as organisms to be included in the test battery for the risk assessment of plant protection product (PPPs). This study aimed to contribute to improve the ISO Protocol (ISO 10832: 2009) by assessing the feasibility of using other AMF species under different test conditions. Overall, results showed that AMF species Gigaspora albida and Rhizophagus clarus (selected out of five AMF species) are suitable to be used in spore germination tests using the ISO protocol (14 days incubation with sand or artificial soil as substrate) to test PPPs. However, several modifications to the protocol were made in order to accommodate the use of the tested isolates, namely the incubation temperature (28 °C instead of 24 °C) and the change of reference substance (boric acid instead of cadmium nitrate). The need for these changes, plus the results obtained with the three fungicides tested (chlorothalonil, mancozeb and metalaxyl-M) and comparisons made with literature on the relevance of the origin of AMF isolates in dictating the adequate test conditions, emphasize the importance of adjusting test conditions (AMF species/isolates and test temperature) when assessing effects for prospective risk assessment targeting different climatic zones. So, further studies should be conducted with different AMF species and isolates from different climatic regions, in order to better define which species/isolate and test conditions should be used to assess effects of a particular PPP targeting a given climatic zone.

Topics: Alanine; Fungicides, Industrial; Glomeromycota; Maneb; Mycorrhizae; Nitriles; Risk Assessment; Soil; Soil Microbiology; Temperature; Time Factors; Toxicity Tests; Zineb

The aim of this study is to investigate the effects of the pesticides/polycyclic aromatic hydrocarbon mixture on aryl hydrocarbon receptor (AhR), p53 and ubiquitin mRNA level in haemocytes of Mya arenaria exposed to a mixture of chlorothalonil, mancozeb and benzo[a]pyrene (BaP) for 48 and 72 h. AhR, p53 and ubiquitin gene expression levels were quantified using quantitative Real-time PCR. For robust and accurate quantification of transcripts, suitable housekeeping genes were selected from four sets of ribosomal and elongation factors transcripts previously sequenced from Mya arenaria using geNorm open source software. Quantitative Real-time PCR data exhibited a significantly high expression of AhR after 72 h of exposure (P ≤ 0.05). p53 gene expression seems to be up-regulated by the mixture after 48 h, however not significantly; but the level of p53 mRNA is down-regulated by the xenobiotics between 48 and 72 h after exposure. This study postulates that AhR mRNA levels could be used as an indicator of the exposure of clams' haemocytes to a mixture of xenobiotics such as chlorothalonil, mancozeb and BaP. However, further studies have to be pursued in order to unravel the molecular mechanisms involved in the p53 signaling pathway.

Topics: Animals; Benzo(a)pyrene; Biomarkers; Gene Expression Regulation; Genes, p53; Hemocytes; Maneb; Mya; Nitriles; Pesticides; Real-Time Polymerase Chain Reaction; Receptors, Aryl Hydrocarbon; Ubiquitin; Water Pollutants, Chemical; Xenobiotics; Zineb

The aetiology of haemic neoplasia (HN) is unknown, so far but many causative factors are suggested such as viral, pollution and genetics. The aim of this study was to determine if, under chronic exposure, two major pesticides (chlorothalonil and mancozeb) which are used in potato production could induce HN in soft-shell clams (Mya arenaria). Short-term experiments with acute exposure were also performed. Clams were collected from an epizootic site (North River, PEI) and from a site free of the disease (Magdalen Islands, Quebec). The tetraploid level of haemocytes was assessed by flow cytometry for each clam to determine the HN status. The bioaccumulation of pesticides in tissues was quantified by gas chromatography/mass spectrometry (GC/MS) for chlorothalonil while mancozeb and manganese were quantified by inductively coupled plasma-mass spectrometer (ICP/MS). Long term exposure to fungicide Bravo 500((R)) did not induce high tetraploid levels on negative calm from North River and the analysis of the digestive gland and the mantle did not reveal any detectable level of chlorothalonil. In the Manzate 200 DF((R)), some clams revealed high level of tetraploid cells but no difference were observed between the treatments and the control. The analysis of the digestive gland and the mantle for manganese did not highlight any significant difference in tissue concentration (p=0.05). For the acute exposure, chlorothalonil analysis showed that the active ingredient is distributed between four chlorinated compounds: 99.5% for chlorothalonil isomers, 0.4% for pentachlorothalonil and 0.1% for trichlorothalonil isomers. For a 72 h experiment, the accumulation was within 4h; the higher tissue concentration of chlorothalonil was 59.2 microg g(-1) in the mantle after 48 h, following by a decrease to an undetectable level at the end. For the manganese, the accumulation was detected after 4h; the higher tissue concentration was 48.8 microg g(-1) in the mantle after 24h and, over the following 48 h, the accumulation decreased until the end of the trial. Based on the data, the accumulation of these fungicides seems to be transitory. Chlorothalonil and mancozeb are both oxidative-stress promoters and could have induced cell dysfunction while in the tissue. Study on the effect of these fungicides on the p53 protein system is an example of strategy that would provide information on cellular events promoting neoplasia.

Topics: Animals; Environmental Exposure; Fungicides, Industrial; Hemocytes; Maneb; Mya; Nitriles; Water Pollutants, Chemical; Zineb

Isolates of Cladobotryum dendroides from Serbian mushroom farms and Agaricus bisporus F56 were tested for sensitivity to selected fungicides in vitro. Chlorothalonil was the most toxic fungicide to C. dendroides isolates (EC(50) values were below 1.68 mg L(-1)). Trifloxystrobin and kresoxim-methyl were not effective in growth inhibition of C. dendroides isolates (EC(50) values exceeded 300 mg L(-1)). Metalaxyl-M+mancozeb was the most toxic fungicide to strain F56 of A. bisporus, and iprodione the least toxic. The fungicide selectivity indexes for both C. dendroides and A. bisporus indicated that iprodione, chlorothalonil, captan and metalaxyl-M+mancozeb had satisfactory selective fungitoxicity. Iprodione had the best selectivity to both the pathogen and the host, although inferior than prochloraz manganese and carbendazim, fungicides officially recommended for mushroom cultivation in European Union (EU) countries.

Topics: Acetates; Agaricus; Alanine; Aminoimidazole Carboxamide; Captan; Fungicides, Industrial; Hydantoins; Hypocreales; Imines; Lethal Dose 50; Maneb; Methacrylates; Nitriles; Phenylacetates; Serbia; Strobilurins; Zineb

Correlations between the chemical structures of agricultural fungicides and mRNA expression levels following exposure of Saccharomyces cerevisiae to toxic doses of thiuram, zineb, maneb, TPN, and PCP were examined. Structurally, thiuram, zineb, and maneb are dithiocarbamate fungicides, whereas TPN and PCP are not. To characterize chemical toxicity, genes expression was classified according to the functional groups used by the MIPS database. However, no correlations between the classification scheme and chemical structures were found. Hierarchical clustering of gene expression profiles was performed to characterize the effects of the five chemicals. According to this analysis the similarity of gene expression profiles depended on the similarity of chemical structures. These results suggest that DNA microarray technology has potential for predicting the major chemicals which will cause environmental toxicity and will provide information on new biomonitoring methods.

Topics: Environmental Pollutants; Fungicides, Industrial; Gene Expression Profiling; Genome, Fungal; Maneb; Nitriles; Oligonucleotide Array Sequence Analysis; Pentachlorophenol; RNA, Messenger; Saccharomyces cerevisiae; Structure-Activity Relationship; Thiram; Zineb

A new bioassay has been developed combining the simplicity of direct bioautography with the improved chromatographic resolution of 2D-TLC. Mixtures of structurally diverse antifungal agents were tested to establish the validity and utility of this method in the discovery of new natural products with activity against agriculturally important fungal pathogens.

Topics: Acrylates; Aniline Compounds; Antifungal Agents; Ascomycota; Benzimidazoles; Biological Assay; Captan; Carbamates; Chromatography, Thin Layer; Colletotrichum; Dimethyldithiocarbamate; Fungicides, Industrial; Guanidines; Maneb; Methacrylates; Nitriles; Nitrobenzenes; Oxazoles; Piperazines; Plant Diseases; Plants; Pyrimidines; Strobilurins; Thiabendazole; Thiophanate; Triazoles

In the present study we describe the effect of 4 fungicides on the induction of point mutations in strains biA1 methG1 (induction of methionine suppressors) and 118 (induction of arginine resistance) of Aspergillus nidulans. Captan, which was used as a known mutagen, Daconil 2787 and Dithane M-45 were effective in inducing these mutations, whereas the fungicide Cercobin caused no significant increase in the induction frequency of the point mutations selected. Actually, a decrease in the frequency of methionine suppressors was observed in relation to those occurring spontaneously. However, this effect could not be considered antimutagenic because the revertants were more sensitive to the fungicide than the biA1 methG1 strain. Although the induction of methionine suppressors was more convenient because it permits the visualization of several morphological types, the 118 strain system also proved to be effective in detecting point-mutation induction.

Topics: Antifungal Agents; Arginine; Aspergillus nidulans; Captan; Drug Resistance, Microbial; Maneb; Methionine; Mutagenicity Tests; Nitriles; Thiophanate; Zineb