Honeybees are exposed to a wide range of pesticides for long periods via contaminated water, pollen and nectar. Some of those pesticides might constitute health hazards in a time- and dose-dependent manner. Time-dependent toxicity profiles for many applied pesticides are lacking, despite the fact that such profiles are crucial for toxicological evaluations. Therefore, we sought to determine the time-dependent toxicities of pesticides/pesticide metabolites frequently found in Israeli beehives, namely, amitraz metabolites, N'-(2,4-dimethylphenyl)-N-methylformamidine (DMPF) and N-(2,4-dimethylphenyl)-formamide (DMF), coumaphos, imidacloprid, thiacloprid, acetamiprid and dimethoate (toxic reference). By applying accepted methodological approaches such as the modified Haber's rule (product of concentration and exposure duration leads to a constant effect) and comparisons between cumulative doses at different time points, we determined the time-dependent toxicities of these pesticides. We also studied the mixture toxicities of frequently occurring pesticide combinations and estimated their potential contributions to the overall toxicities of neonicotinoids. Thiacloprid was the only pesticide that complied with Haber's rule. DMPF, dimethoate and imidacloprid exhibited time-diminished -toxicities. In contrast, DMF and acetamiprid exhibited time-reinforced toxicities. Neither the binary mixtures nor the tertiary mixtures of DMF, DMPF and coumaphos at 10 times their environmentally relevant concentrations potentiated the neonicotinoids' toxicities. DMPF and imidacloprid were found to present the greatest hazard to honeybees, based on their 50% lethal cumulative dose and 50% lethal time. Amitraz's instability, its low detection frequency and high toxicity profile of its metabolite, DMPF, lead us to the conclusion that DMPF constitutes the actual toxic entity responsible for amitraz's toxic effect.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.chemosphere.2020.128974 | DOI Listing |
Chem Biol Interact
January 2025
Institute of Vascular Biology and Thrombosis Research, Center for Physiology and Pharmacology, Medical University of Vienna, Schwarzspanierstrasse 17, 1090 Vienna, Austria. Electronic address:
A series of eight gold(I) N-heterocyclic carbene (NHC) complexes [Au(IMes)(HLn)] based on 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes) and 7-azaindole derivatives (HLn), where n = 1-8 for HL1 = 5-flouro-7-azaindole, HL2 = 5-bromo-7-azaindole, HL3 = 3-chloro-7-azaindole, HL4 = 3-iodo-7-azaindole, HL5 = 5-bromo-3-chloro-7-azaindole, HL6 = 5-bromo-3-iodo-7-azaindole, HL7 = 4-chloro-2-methyl-7-azaindole and HL8 = 7-azaindole, was prepared, characterised and studied for their in vitro anti-cancer and anti-inflammatory effects. The complexes showed significant cytotoxicity on human ovarian cancer cell lines (A2780, IC ≈ 8-19 μM and A2780R, IC ≈ 8-19 μM) and lowered toxicity in normal HaCat and MRC-5 cells. Cellular effects of the selected complexes 1 and 7 were evaluated in A2780 cells using flow cytometry.
View Article and Find Full Text PDFMicrosc Res Tech
January 2025
Molecular Biology and Genetics Department, Faculty of Engineering and Natural Sciences, Uşak University, Uşak, Turkey.
Sulfoxaflor (SFX) is an insecticide that is commonly used for the control of sap-feeding insects. Since SFX is extensively applied globally, it has been implicated in the substantial induction of environmental toxicity. Therefore, in this study, Allium cepa roots have been employed to elucidate the potential cytogenotoxic effects of SFX in non-target cells by examination of mitotic index (MI), chromosomal aberrations (CAs), and DNA damage.
View Article and Find Full Text PDFExp Cell Res
January 2025
Cardiovascular Center, College of Medicine, University of Cincinnati, Ohio-45267, United States of America; School of Chemical and Biotechnology, SASTRA Deemed University, Tirumalaisamudram, Thanjavur-613401, Tamil Nadu, India. Electronic address:
Multiple forms of cell death contribute significantly to cardiovascular pathologies, negatively impacting cardiac remodeling and leading to heart failure. While myocardial cell death has been associated with PM induced cardiotoxicity, the temporal dynamics of various cell death forms, such as apoptosis, ferroptosis, necroptosis, and pyroptosis, in relation to inflammatory processes, remain underexplored. This study examines the time-dependent onset and progression of these cell death pathways in the myocardium and their correlation with inflammation in a Wistar rat model.
View Article and Find Full Text PDFCancer Treat Res Commun
January 2025
Department of Pharmaceutical Sciences and Experimental Therapeutics, College of Pharmacy, University of Iowa, Iowa City, IA 52242, USA; Holden Comprehensive Cancer Center, University of Iowa, Iowa City, IA 52242, USA. Electronic address:
Clear cell renal cell carcinoma (ccRCC) poses a significant global health challenge as its incidence continues to rise, resulting in a substantial annual mortality rate. Major clinical challenges to current ccRCC treatments include high drug-resistance rates as well as dose-limiting adverse events; underlining the need to identify additional 'druggable' targets. TGF-β1, VEGF, and PD-L1 are potential therapeutic targets in ccRCC.
View Article and Find Full Text PDFBioorg Chem
January 2025
Chemistry Department, Faculty of Science, Ain Shams University, Abbasia, 11566 Cairo, Egypt.
The escalating prevalence of antibiotic-resistant bacteria has led to a serious global public health problem; therefore, there is an urgent need for the development of structurally innovative antibacterial agents. In our study, different series of tetra-substituted thiophene derivatives were designed and synthesized by multi-component reactions (MCRs) in moderate to excellent yields. Some of the designed final compounds were synthesized by both microwave assisted method and traditional synthesis.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!