Short-term exposure of Balb/c mice to buprofezin insecticide induces biochemical, enzymatic, histopathologic and genotoxic damage in liver and kidney tissues

Ecotoxicity of commonly used oilfield-based emulsifiers on Guinean Tilapia (Tilapia guineensis) using histopathology and behavioral alterations as protocol

This study examined the histological aberrations in the gill and liver tissues and behavioural changes of Tilapia guineensis fingerlings exposed to lethal concentrations of used Oilfield-based emulsifiers for 96 h. Various concentrations of the surfactants were tested, ranging from 0.0 to 15.0 ml/L. The behaviour of the fish was observed throughout the experiment, and the results showed that increasing concentrations of the surfactants led to progressively abnormal behaviour, including hyperventilation and altered opercular beat frequency. These behavioural changes indicated respiratory distress and neurotoxic effects. Histological analysis revealed structural aberrations in the gill and liver tissues, with higher concentrations causing more severe damage, such as lesions, necrosis, inflammation, and cellular degeneration. This implies that surfactants released even at low concentrations are capable of inducing changes in the tissues of aquatic organisms. These findings highlight the toxic effects of the surfactants on fish health and provide biomarkers of toxicity. Future research should focus on understanding the specific mechanisms and long-term consequences of surfactant toxicity on fish genetic composition, populations, and ecosystems to implement effective conservation measures.

Mitochondria-Mediated Apoptosis and Autophagy Participate in Buprofezin-Induced Toxic Effects in Non-Target A549 Cells

Buprofezin (BUP) is an insecticide used for control of sucking pests. Its widespread use has raised concerns about possible adverse effects on the environment, and especially human health. The mechanism of toxicity of BUP, with respect to human health, is still unclear. Consequently, human A549 cells were employed to clarify the cytotoxicity and toxic mechanism of BUP at the molecular and cellular levels. The outcomes revealed BUP latent toxicity to A549 in a time- and dose-related way. Moreover, BUP induced mitochondrial dysfunction associated with mitochondrial membrane potential collapse, mitochondrial calcium overload, and ROS aggregation, ultimately resulting in the apoptosis and autophagy of A549 cells. Symbolic apoptotic and autophagic modifications were detected, including leakage of cyt-c, elevation of Bax/Bcl-2, activation of cas-9/-3, constitution of autophagic vacuoles, promotion of Beclin-1, conversion of LC3-II, and reduction of p62. Additionally, in total, 1216 differentially expressed genes (DEGs) were defined after BUP treatment. Several apoptosis- and autophagy-related genes, such as BCL2, ATG5, and ATG16, down- or upregulated at the RNA transcription level, and functional DEGs enrichment analysis showed their involvement in the metabolism of xenobiotics by cytochrome P450, mTOR signalling pathway, and AMPK signalling pathway. Results confirmed that BUP could induce cytotoxicity associated with mitochondria-mediated programmed cell death in A549 cells.

Interaction of the insecticide bioallethrin with human hemoglobin: biophysical, in silico and enzymatic studies

Bioallethrin is an insecticide that is widely used in households resulting in human exposure. Bioallethrin is cytotoxic to human erythrocytes. Here we have studied the interaction of bioallethrin with human hemoglobin (Hb) using in silico and biophysical approaches. Incubation of Hb (5 μM) with bioallethrin (1-50 µM) led to increase in absorbance at 280 nm while the Soret band at 406 nm was slightly reduced. The intrinsic fluorescence of Hb was enhanced with the appearance of a new peak around 305 nm. Synchronous fluorescence showed that the binding of bioallethrin to Hb mainly affects the tyrosine microenvironment. The structural changes in Hb were confirmed with a significant shift in CD spectra and about 25% loss of α-helix. Molecular docking and visualisation through Discovery studio confirmed the formation of Hb-bioallethrin complex with a binding energy of -7.3 kcal/mol. Molecular simulation showed the stability and energy dynamics of the binding reaction between bioallethrin and Hb. The structural changes induced by bioallethrin led to inhibition of the esterase activity of Hb. In conclusion, this study shows that bioallethrin forms a stable complex with human Hb which may lead to loss of Hb function in the body.Communicated by Ramaswamy H. Sarma.

Investigating binding of insecticide buprofezin to DNA by experimental and metadynamics simulation studies

Buprofezin (BUP) is an insecticide which belongs to the thiadiazine structural family and known to damage DNA in mice. Though its toxic effect on human is not known clearly, understanding the mechanism of interaction of BUP with DNA can prove useful when required. Multi-spectroscopic experiments such as UV-Vis, fluorescence, circular dichroism (CD) and ¹H NMR coupled with viscosity measurements, urea effect and voltametric studies were performed to ascertain the mode of binding of BUP with calf thymus DNA (CT-DNA). Analysis of UV-Vis and fluorescence spectra indicated the formation of a complex between BUP and CT-DNA. Other experiments such as competitive binding assays with ethidium bromide (EB) and Hoechst 33258, viscosity measurements, effect of urea, CD, voltammetric studies and ¹H NMR spectral analysis suggested that BUP intercalates into the base pairs of CT-DNA. All these results revealed that the binding mode of BUP with CT-DNA should be intercalation and the binding constant is in the order of 10⁴ M^-1. The ΔH^o < 0 and ΔS^o < 0 suggested that H-bonding or van der Waals force was the main binding force between BUP and CT-DNA. The proposed mode of binding of BUP with CT-DNA has been visualized using in silico molecular docking and metadynamics simulation studies, which showed that the phenyl ring of BUP binds to CT-DNA via π-π stacking interaction in addition to H-bond formation.Communicated by Ramaswamy H. Sarma.

Multiresidues of environmental contaminants in bats from Turkey

Bat populations have been steadily declining, most likely because of anthropogenic factors. Identification and classification of these risks have crucial importance in ensuring the survival of this species. Bats often coexist with humans in urban, industrial, and agricultural areas and are potentially exposed to a range of environmental pollutants. Two bat species widely distributed in Turkey were selected, and the residues of pesticides and organic contaminants in their carcasses were analyzed using: gas chromatography-mass spectrometry, gas chromatography-tandem mass spectrometry, and liquid chromatography-tandem mass spectrometry. Species and sex specific differences were evaluated along with their potential to be used as bioindicators. During the rigor mortis period, 23 adult Pipistrellus pipistrellus (11 female and 12 male) and 19 adult Myotis myotis (9 female and 10 male) were collected and 322 contaminants (pesticides and organic contaminants) were analyzed in whole carcasses of bats by using a validated method. Multiple pesticides and organic contaminants were detected in all collected 42 bats. The most frequent contamination was detected as 4,4-DDE, followed by ethoprophos, quinalphos, methidation, paraoxon-methyl, phosalone and tetramethrin. The least common compounds were as follows: 2,4-DDD, endrin, HCH-alpha, fenamiphos sulfoxide, parathion ethyl, bitertanol, oxycarboxin, procymidone, fluazifop-butyl, trifluralin, bifenazate, DMF, fenpyroximate, PBDE-47, benzo(a)anthracene, benzo(b)fluoranthene, and benzo(g,h,i) perylene; of these only one was found in each bat. In terms of frequency and concentration, there was no significant difference between species and sex. An average of 26.1 pollutants was found in each bat. Thus, it was concluded that bats can be used as potential bioindicators in determining environmental pollution.

TUNEL Assay: A Powerful Tool for Kidney Injury Evaluation

Terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) assay is a long-established assay used to detect cell death-associated DNA fragmentation (3'-OH DNA termini) by endonucleases. Because these enzymes are particularly active in the kidney, TUNEL is widely used to identify and quantify DNA fragmentation and cell death in cultured kidney cells and animal and human kidneys resulting from toxic or hypoxic injury. The early characterization of TUNEL as an apoptotic assay has led to numerous misinterpretations of the mechanisms of kidney cell injury. Nevertheless, TUNEL is becoming increasingly popular for kidney injury assessment because it can be used universally in cultured and tissue cells and for all mechanisms of cell death. Furthermore, it is sensitive, accurate, quantitative, easily linked to particular cells or tissue compartments, and can be combined with immunohistochemistry to allow reliable identification of cell types or likely mechanisms of cell death. Traditionally, TUNEL analysis has been limited to the presence or absence of a TUNEL signal. However, additional information on the mechanism of cell death can be obtained from the analysis of TUNEL patterns.