Comparative effects of Mancozeb and Disulfiram-induced striated muscle myopathies in Long-Evans rats

The NLRP3 Inflammasome as a Pathogenic Player Showing Therapeutic Potential in Rheumatoid Arthritis and Its Comorbidities: A Narrative Review

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by chronic synovitis and the progressive destruction of cartilage and bone. RA is commonly accompanied by extra-articular comorbidities. The pathogenesis of RA and its comorbidities is complex and not completely elucidated. The assembly of the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activates caspase-1, which induces the maturation of interleukin (IL)-1β and IL-18 and leads to the cleavage of gasdermin D with promoting pyroptosis. Accumulative evidence indicates the pathogenic role of NLRP3 inflammasome signaling in RA and its comorbidities, including atherosclerotic cardiovascular disease, osteoporosis, and interstitial lung diseases. Although the available therapeutic agents are effective for RA treatment, their high cost and increased infection rate are causes for concern. Recent evidence revealed the components of the NLRP3 inflammasome as potential therapeutic targets in RA and its comorbidities. In this review, we searched the MEDLINE database using the PubMed interface and reviewed English-language literature on the NLRP3 inflammasome in RA and its comorbidities from 2000 to 2023. The current evidence reveals that the NLRP3 inflammasome contributes to the pathogenesis of RA and its comorbidities. Consequently, the components of the NLRP3 inflammasome signaling pathway represent promising therapeutic targets, and ongoing research might lead to the development of new, effective treatments for RA and its comorbidities.

Disulfiram: Mechanisms, Applications, and Challenges

Background: Since disulfiram’s discovery in the 1940s and its FDA approval for alcohol use disorder, other indications have been investigated. This review describes potential clinical applications, associated risks, and challenges. Methods: For this narrative review, a PubMed search was conducted for articles addressing in vivo studies of disulfiram with an emphasis on drug repurposing for the treatment of human diseases. The key search terms were “disulfiram” and “Antabuse”. Animal studies and in vitro studies highlighting important mechanisms and safety issues were also included. Results: In total, 196 sources addressing our research focus spanning 1948–2022 were selected for inclusion. In addition to alcohol use disorder, emerging data support a potential role for disulfiram in the treatment of other addictions (e.g., cocaine), infections (e.g., bacteria such as Staphylococcus aureus and Borrelia burgdorferi, viruses, parasites), inflammatory conditions, neurological diseases, and cancers. The side effects range from minor to life-threatening, with lower doses conveying less risk. Caution in human use is needed due to the considerable inter-subject variability in disulfiram pharmacokinetics. Conclusions: While disulfiram has promise as a “repurposed” agent in human disease, its risk profile is of concern. Animal studies and well-controlled clinical trials are needed to assess its safety and efficacy for non-alcohol-related indications.

Determination of histopathological effects and myoglobin, periostin gene-protein expression levels in Danio rerio muscle tissue after acaricide yoksorrun-5EC (hexythiazox) application

Although pesticides are essential agrochemicals to annihilate harmful organisms in agriculture, their uncontrolled use has become an important threat to environmental health. Exposure to pesticides can affect many biological systems including immune system, endocrine system, and nervous system. However, the potential side effects of pesticides to skeletal muscle system remain unclear. Present study has focused on the evaluation of this issue by using an acaricide, yoksorrun-5EC (hexythiazox), in an aquatic model organism, Danio rerio. The histological analyses revealed that increased concentrations of the acaricide cause degradation of skeletal muscle along with increased necrosis and atrophy in myocytes, intercellular edema, and increased infiltrations between perimysium sheaths of muscle fibers. The effects of acaricide on myoglobin and periostin, which are associated with oxygen transport and muscle regeneration, respectively, were investigated at the gene and protein levels. RT-PCR results suggested that high concentration yoksorrun-5EC (hexythiazox) can induce myoglobin and periostin genes. Similar results were also obtained in the protein levels of these genes by western blotting analysis. These results suggested that yoksorrun-5EC (hexythiazox)-dependent disruption of skeletal muscle architecture is closely associated with the expression levels of myoglobin and periostin genes in Danio rerio model.

Transcriptomics and metabolomics revealed the molecular mechanism of the toxic effect of mancozeb on liver of mice

Mancozeb (MCZ), a broad-spectrum fungicide, has been widely used in crops (tomatoes and potatoes) in the past few decades, resulting in its bioaccumulation in the food web. However, the mechanism of MCZ on liver injury has not been reported yet. This study combined transcriptomics and metabolomics to explore the potential mechanism of MCZ on liver injury. MCZ group was given 100 mg/kg MCZ every day, and the C group was given 0.2 mL of deionized water every day. One hundred mg/kg MCZ led to unclear hepatocyte structure and hemorrhagic inflammatory cell infiltration. Transcriptomics and metabolomics analyses showed that the MCZ group resulted in 326 differentially expressed genes (DEGs) and 179 differential metabolites. Joint analysis showed that DEGs and differential metabolites were mainly enriched in the adenosine monophosphate (AMP)-activated protein kinase (AMPK) signaling pathway. We found that MCZ could increase the content of reactive oxygen species (ROS) and reduce the activities of superoxide dismutase (SOD) and catalase (CAT). The contents of DNA methyltransferases (DNMT1, DNMT3A, and DNMT3B) in the liver decreased significantly, and the state of DNA methylation was significantly higher than the control (C) group (p < 0.05). Our results suggest that AMPK and mitogen‑activated protein kinase (MAPK) signaling pathways play an important role in MCZ-induced liver injury and are the key mechanisms for understanding the hepatotoxicity of MCZ.

The ethylene bisdithiocarbamate fungicides mancozeb and nabam alter essential metal levels in liver and kidney and glutathione enzyme activity in liver of Sprague-Dawley rats

Mancozeb is a fungicide of the ethylene bisdithiocarbamate (EBDC) class complexed to the metals manganese and zinc. Nabam is the sodium salt of the EBDC backbone. The purpose of this study was to determine if these EBDC compounds alter essential metal homeostasis and glutathione status in Sprague-Dawley rats. Our findings indicate EBDCs caused accumulation of copper in kidneys, but not liver. EBDC compounds also increased glutathione reductase activity in liver, but not kidneys, whereas only mancozeb increased glutathione peroxidase activity in the liver. Mancozeb and nabam increased total glutathione in liver, but only mancozeb increased total glutathione in the kidney. Neither mancozeb nor nabam altered glutathione ratio in either liver or kidney compared to control. Our data suggest that the EBDC backbone of mancozeb, and not the zinc or manganese moieties, is responsible for changes in glutathione status and alteration of essential metal homeostasis in rat liver and kidney.

Cardiac developmental toxicity and transcriptome analyses of zebrafish (Danio rerio) embryos exposed to Mancozeb

Mancozeb (MZ), an antibacterial pesticide, has been linked to reproductive toxicity, neurotoxicity, and endocrine disruption. However, whether MZ has cardiactoxicity is unclear. In this study, the cardiotoxic effects of exposure to environment-related MZ concentrations ranging from 1.88 μM to 7.52 μM were evaluated at the larval stage of zebrafish. Transcriptome sequencing predicted the mechanism of MZ-induced cardiac developmental toxicity in zebrafish by enrichment analysis of Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO). Consistent with morphological changes, the osm, pfkfb3, foxh1, stc1, and nrarpb genes may effect normal development of zebrafish heart by activating NOTCH signaling pathways, resulting in pericardial edema, myocardial fibrosis, and congestion in the heart area. Moreover, differential gene expression analysis indicated that cyp-related genes (cyp1c2 and cyp3c3) were significantly upregulated after MZ treatment, which may be related to apoptosis of myocardial cells. These results were verified by real-time quantitative RT-qPCR and acridine orange staining. Our findings suggest that MZ-mediated cardiotoxic development of zebrafish larvae may be related to the activation of Notch and apoptosis-related signaling pathways.