Autophagy response in the liver of pigeon exposed to avermectin

Proteomic analysis in the brain and liver of sea bream (Sparus aurata) exposed to the antibiotics ciprofloxacin, sulfadiazine, and trimethoprim

Antibiotics, frequently detected in aquatic ecosystems, can negatively impact the health of resident organisms. Although the study on the possible effects of antibiotics on these organisms has been increasing, there is still little information available on the molecular effects on exposed non-target organisms. In our study we used a label free proteomic approach and sea bream, Sparus aurata, to evaluate the effects of exposure to environmentally relevant concentrations of the antibiotic compounds ciprofloxacin (CIP), sulfadiazine (SULF) and trimethoprim (TRIM) produced at the protein level. Individuals of sea bream were exposed to single compounds at 5.2 ± 2.1 μg L-1 of CIP, 3.8 ± 2.7 μg L-1 of SULF and 25.7 ± 10.8 μg L-1 of TRIM for 21 days. After exposure, the number of differentially expressed proteins in the liver was 39, 73 and 4 for CIP, SULF and TRIM respectively. In the brain, there was no alteration of proteins after CIP and TRIM treatment, while 9 proteins were impacted after SULF treatment. The differentially expressed proteins were involved in cellular biological, metabolic, developmental, growth and biological regulatory processes. Overall, our study evidences the vulnerability of Sparus aurata, after exposure to environmentally relevant concentrations of the major antibiotics CIP, SULF and TRIM and that their chronic exposure could lead to a stress situation, altering the proteomic profile of key organs such as brain and liver.

Evaluation of genotoxic effect via expression of DNA damage responsive gene induced by ivermectin on MDBK cell line

Ivermectin (IVM) is an anti-parasitic drug which is used for treating parasitic infestations. It has been used in humans for treating intestinal strongyloidiasis and onchocerciasis however, currently researchers are investigating its potential for treating coronavirus SARS-CoV-2. Due to its broad-spectrum activities, IVM is being used excessively in animals which has generated an interest for researchers to investigate its toxic effects. Cytotoxic and genotoxic effects have been reported in animals due to excessive usage of IVM. Therefore, this study aims to evaluate the cytotoxic and genotoxic effects of IVM on the Madin-Darby-Bovine-Kidney (MDBK) cell line by examining the expression of a DNA damage-responsive gene (OGG1). Cytotoxicity of IVM was tested using an assay (MTT 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide), whereas the genotoxicity was evaluated using comet assay along with micronucleus assay. Moreover, the gene expression of DNA damage response gene (OGG1) was measured by qRT-PCR, after extraction of RNA from the MDBK cell line using the TRIzol method and its conversion to cDNA by reverse-transcriptase PCR. During the experiment, cell viability percentage was measured at different doses of IVM i.e., 25%, 50%, 75%, along with LC50/2, LC50 and LC50*2. It was observed that the gene expression of OGG1 increased as the concentration of IVM increased. It was concluded that IVM has both cytotoxic and genotoxic effects on the MDBK cell line. Furthermore, it is recommended that studies related to the toxic effects of IVM at molecular level and on other model organisms should be conducted to combat its hazardous effects.

Hepatotoxicity of the Pesticide Avermectin Exposure to Freshwater-Farmed Carp: Evidence from In Vivo and In Vitro Research

Avermectin (AVM) is presently one of the most extensively employed insecticides across the globe. A number of toxicity research studies of AVM have been carried out in freshwater-farmed carp; however, there are currently no toxicity studies on the liver. This investigation aims to replicate an acute liver injury model induced by AVM in carp, subsequently analyzing the adverse effects imposed on the nontarget species while delving into potential mechanisms underlying its toxicity. In this study, we found that AVM-exposed carp liver tissue showed cellular hydration degeneration and necrosis and reduced the viability of hepatocyte L8824. Second, AVM induced oxidative stress in carp, and AVM stimulation led to reactive oxygen species (ROS) accumulation and Ca2+ overload in hepatocyte L8824, suggesting that AVM exposure induces mitochondrial dysfunction in hepatocytes. AVM induced inflammation in carp liver tissue by inducing mitochondrial kinetic disruption, which triggered hepatic tissue injury. AVM induced autophagy and apoptosis in carp liver tissue and ROS mediated AVM-induced autophagy and apoptosis. The formation of autophagy attenuated the AVM-induced liver injury. In conclusion, the present study elucidated the hepatotoxicity and potential mechanisms of freshwater aquaculture carp exposed to the pesticide AVM, emphasized the importance of monitoring pesticide AVM contamination in freshwater aquaculture aquatic environments, and provided theoretical references for the targeted prevention of AVM-induced toxicity in carp.

Carvacrol Reduces Mercuric Chloride-Induced Testicular Toxicity by Regulating Oxidative Stress, Inflammation, Apoptosis, Autophagy, and Histopathological Changes

Mercuric chloride (HgCl2) is a heavy metal that is toxic to the human body. Carvacrol (CAR) is a flavonoid found naturally in plants and has many biological and pharmacological activities including anti-inflammatory, antioxidant, and anticancer activities. This study aimed to investigate the efficacy of CAR in HgCl2-induced testicular tissue damage. HgCl2 was administered intraperitoneally at a dose of 1.23 mg/kg body weight alone or in combination with orally administered CAR (25 mg/kg and 50 mg/kg body weight) for 7 days. Biochemical and histological methods were used to investigate oxidative stress, inflammation, apoptosis, and autophagy pathways in testicular tissue. CAR treatment increased HgCl2-induced decreased antioxidant enzyme (SOD, CAT, and GPx) activities and GSH levels. In addition, CAR reduced MDA levels, a marker of lipid peroxidation. CAR decreased the levels of inflammatory mediators NF-κB, TNF-α, IL-1β, COX-2, iNOS, MAPK14, MAPK15, and JNK. The increases in apoptotic Bax and Caspase-3 with HgCl2 exposure decreased with CAR, while the decreased antiapoptotic Bcl-2 level increased. CAR reduced HgCl2-induced autophagy damage by increasing Beclin-1, LC3A, and LC3B levels. Overall, the data from this study suggested that testicular tissue damage associated with HgCl2 toxicity can be mitigated by CAR administration.

Mitigation of avermectin exposure-induced brain tissue damage in carp by quercetin

Avermectin is widely used as an important insecticide in agricultural production, but it also shows strong toxicity to non-target organisms. Quercetin is a natural flavonoid that is widely used due to its good anti-inflammatory and antioxidant effects. We believe that quercetin may have a potential therapeutic effect on avermectin poisoning. This experiment was proposed to observe the effect of quercetin on the toxic response to avermectin by observing the toxic response caused by avermectin in the brain of carp. In this project, 60 carp were studied as control group (Control), quercetin administration group (QUE), avermectin exposure group (AVM) and quercetin treatment avermectin exposure group (QUE + AVM) with different interventions to study the effect of quercetin on avermectin. The carp brain tissues were stained and simultaneously analyzed for blood-brain barrier (BBB), oxidative stress indicators, inflammatory factors, and apoptosis using qPCR technique. The results of the study indicate that avermectin exhibits a neurotoxic mechanism of action in fish by decreasing the transcript levels of tight junction protein-related genes, which in turn leads to the rupture of the BBB in the carp brain tissue. Avermectin induced apoptosis in carp brain tissue by increasing oxidative stress response and promoting inflammatory cell infiltration. Quercetin could reduce the accumulation of reactive oxygen species (ROS) in the brain tissue of carp caused by avermectin exposure toxicity, maintain redox homeostasis, reduce inflammatory response, and protect brain tissue cells from apoptosis. The present study confirmed the therapeutic and protective effects of quercetin on neurotoxicity in carp caused by avermectin exposure.

Avermectin reduces bone mineralization via the TGF-β signaling pathway in zebrafish

Avermectin, a widely used insecticide, is primarily effective against animal parasites and insects. Given its extensive application in agriculture, a large amount of avermectin accumulates in natural water bodies. Studies have shown that avermectin has significant toxic effects on various organisms and on the nervous system, spine, and several other organs in humans. However, the effects of avermectin on bone development have not been reported yet. In this study, zebrafish embryos were treated with different concentrations of avermectin to explore the effects of avermectin on early bone development. The results showed that avermectin disturbed early bone development in zebrafish, caused abnormal craniofacial chondrogenesis, and reduced bone mineralization. Avermectin treatment significantly reduced mineralization in zebrafish scales and increased osteoclast activity. Real-time quantitative PCR results showed that avermectin decreased the expression of genes related to osteogenesis and transforming growth factor-β (TGF-β) and bone morphogenetic protein (BMP) signaling pathways. The TGF-β inhibitor SB431542 rescued avermectin-induced bone mineralization and osteogenesis related gene expression in zebrafish during early development. Thus, this study provides insight into the mechanism of damage caused by avermectin on bone development, thus helping demonstrate its toxicity.

Cytotoxicity and Autophagy Induced by Ivermectin via AMPK/mTOR Signaling Pathway in RAW264.7 Cells

The widespread and excessive use of ivermectin (IVM) will not only cause serious environmental pollution, but will also affect metabolism of humans and other mammals that are exposed. IVM has the characteristics of being widely distributed and slowly metabolized, which will cause potential toxicity to the body. We focused on the metabolic pathway and mechanism of toxicity of IVM on RAW264.7 cells. Colony formation and LDH detection assay showed that IVM significantly inhibited the proliferation of and induced cytotoxicity in RAW264.7 cells. Intracellular biochemical analysis using Western blotting assay showed that LC3-B and Beclin-1 were upregulated and p62 was down-regulated. The combination of confocal fluorescence, calcein-AM/CoCl₂, and fluorescence probe results showed that IVM could induce the opening of the mitochondrial membrane permeability transition pore, reduce mitochondrial content, and increase lysosome content. In addition, we focused on induction of IVM in the autophagy signal pathway. The Western blotting results showed that IVM increased expression of p-AMPK and decreased p-mTOR and p-S6K expression in protein levels, indicating that IVM activated the AMPK/mTOR signaling pathway. Therefore, IVM may inhibit cell proliferation by inducing cell cycle arrest and autophagy.

Biomarkers of oxidative stress, metabolic processes, and lysosomal activity in the muscle tissue of the great tit (Parus major) living in sodium industry and agricultural areas in Inowrocław region (central part of northern Poland)

An region of ecological hazard (EHR) is an area where, as a result of intensive human economic activity, degradation of components of the natural environment has taken place, leading to the deterioration of the ecological balance. EHR management is a globalised ever-increasing challenge. To eliminate the hazardous effect of these pollutants, research has been accelerated worldwide. The current study analyzed the specific biomarkers of the lipid and protein oxidation, total antioxidative status, activities of antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and peroxidase), lysosomal enzymes (alanyl aminopeptidase, leucyl aminopeptidase, acid phosphatase), and biomarkers of aerobic and anaerobic metabolic pathways (activities of alanine and aspartate aminotransferases, succinate dehydrogenase, lactate dehydrogenase, lactate and pyruvate levels) in skeletal muscle tissue of wild great tit nestlings in environments with different levels of anthropogenic pressure such as sodium industry and agriculture in the central part of northern Poland (Inowrocław EHR). Control samples were collected from Tuchola Forest and Borkowo village, where no direct sources of contamination were found. The relevance of the study was to assess the changes in lysosomal functioning caused by pollution-induced oxidative stress that may indicate multidirectional adaptative mechanisms of metabolic processes occurring in the wild birds to compensate for the negative effects of contamination. It was shown that the initiation of oxidative stress caused by anthropogenic pollution shifted the balance of the normal functioning of lysosomal enzymes towards their increased activity. A general tendency towards an increase in the intensity of lipid peroxidation processes with an increasing level of oxidatively modified proteins (aldehydic and ketonic derivatives) and a simultaneous reduction in the TAS was observed in the muscle tissue of great tits living in the anthropogenically modified areas. The intensity of lipid peroxidation and protein damage caused changes and reorganization of the energy-related metabolic pathways in the muscle tissue of wild great tits living in the sodium industry and agricultural areas of the EHR.

Assessment of Avermectins-Induced Toxicity in Animals

Macrocyclic lactones, particularly the avermectins, have completely revolutionized the approaches aimed at control of parasites. These avermectins are the most widely used anti-parasitic drugs in veterinary field with sales exceeding one billion US dollars annually. However, before clinical usage, their safety evaluation in the animals is a major critical factor that must be considered. Many studies have reported the negative effects of avermectins like ivermectin, abamectin, doramectin, and eprinomectin on the host animals. These harmful effects arise from avermectins targeting GABA and glutamate-gated chloride channels present both in the parasites and the host animals. In this review, various modes of avermectins action along with the negative effects on the host like nephrotoxicity, hepatotoxicity, neurotoxicity, reproductive toxicity, and endocrine disruption were discussed in detail. Furthermore, other important issues like ecotoxicity, drug resistance, and drug residues in milk associated with avermectins usage were also discussed, which need special attention.

Investigation of the effects of hesperidin administration on abamectin-induced testicular toxicity in rats through oxidative stress, endoplasmic reticulum stress, inflammation, apoptosis, autophagy, and JAK2/STAT3 pathways

In this study, the potential effects of hesperidin (HES) on chronic toxicity caused by abamectin (ABM) in the testicular tissue were investigated through oxidative stress, inflammation, endoplasmic reticulum stress (ERS), apoptosis, and autophagy pathways. Male Sprague Dawley rats were used in the study. Animals in the ABM group were orally administered 1 mg/kg ABM every other day for 28 days, while HES used against ABM was given at 100 or 200 mg/kg 30 min after ABM administration for 28 days. Markers of oxidative stress, inflammation, ERS, apoptosis, and autophagy in the testicular tissues removed after the animals are sacrificed were analyzed using biochemical, real-time polymerase chain reaction (RT-PCR), or western blot techniques. The results obtained showed that ABM caused oxidative stress, and triggered ERS, inflammation, apoptosis, and autophagy. On the other hand, HES showed antioxidant effect by increasing superoxide dismutase, catalase, glutathione peroxidase enzyme activities, and glutathione levels in testis tissue and attenuated lipid peroxidation. Accordingly, MAPK14 reduced the NF-κB, IL-1β, TNF-α, and IL-6 expression levels, presenting an anti-inflammatory effect. In addition, Bax protected against apoptosis and autophagy by reducing the caspase-3, beclin-1, LC3A, and LC3B expressions, and increasing Bcl-2 expression. It was observed that HES also interrupted the JAK2/STAT3 signaling pathway by suppressing IL-6 expression. Taken into consideration together, HES provided significant protection against the destruction caused by ABM in testicular tissue with antioxidant, anti-inflammatory, antiapoptotic, and anti-autophagic effects. Thus, it was revealed that HES has the potential to serve as an alternative treatment option in ABM toxicity.

Avermectin inhibits neutrophil extracellular traps release by activating PTEN demethylation to negatively regulate the PI3K-ERK pathway and reducing respiratory burst in carp

Excessive residual avermectin (AVM) in the environment can have toxic effects on non-target organisms. AVM can exert immunotoxicity by inducing genomic demethylation, but its effect on neutrophil extracellular traps (NETs) release in carp is unclear. In this study, carp neutrophils were pretreated with 5 μg/L AVM or 4 μM DNA demethylation inhibitor (aurintricarboxylic acid, ATA), alone or in combination, and then treated with 4 μM phorbol 12-myristate 13-acetate (PMA) to stimulate NETs release. The results showed that exposure of carp neutrophils to AVM significantly suppressed NETs release and MPO expression, increased ROS production, and dramatically reduced PMA-induced cellular respiratory burst. In addition, AVM could bind to the MBD2 molecule, markedly upregulate MBD2 expression to cause demethylation, and clearly activate PTEN expression, thereby inhibiting the expression of PI3K, AKT, Raf, MEK, and ERK. However, these effects were alleviated by ATA. In conclusion, our study showed that AVM could inhibit NETs release in carp by inducing demethylation of PTEN to negatively regulate NETs synthesis pathways and reducing respiratory burst level. Our findings clarify the mechanism of AVM immunotoxicity to fish and are of great significance for efforts to protect the ecological environment and human health.

The regulation of autophagy in the pesticide-induced toxicity: Angel or demon?

Pesticides have become an essential tool for pest kill, weed control and microbiome inhibition for both agricultural and domestic use. However, with the massive use, pesticides can exist in soil, air and water, and sometimes even accumulate in the human or other mammals through food chains. Lots of researches have proven that pesticides possess toxicity to mammals on endocrine, neural and immune systems. Autophagy, as a conservative intracellular process, which is activated by stress-related signals, plays a pivotal role, either "angle" or "demon", in regulation of cell fate and function. Recent evidences in researches elucidated a strong link between the autophagy and the toxicity of pesticides. In this review, we summarized the previous researches which focus on the autophagy regulation in the pesticides-induced toxicity, and hope that this work can help us to discover a potential strategy for the treatment of the disease caused by pesticides.

Characterization of in vivo autophagy during avian spermatogenesis1

Spermatogenesis is a complex cellular process that includes many subcellular events that are essential for the production of healthy spermatozoa. Autophagy is a physiological process that plays a significant role in the process of spermatogenesis; however, autophagy during avian spermatogenesis has not yet been reported. In the current study, we characterized in vivo autophagy throughout the process of domestic fowl spermatogenesis. Autophagy-specific markers, including microtubule-associated protein light chain 3 (LC3), sequestosome 1 (p62), and autophagy-related 7 (Atg7), were used to confirm the occurrence of autophagy in testicular germ cells. The protein expression of Atg7, LC3, and p62 in domestic fowl testes was confirmed by Western blotting. The immunohistochemical staining indicated a strong localization of LC3 and Atg7 within spermiogenic cells (intermediate and late spermatids) and primary spermatocytes. However, poorly expressed in cells (spermatogonia) that were located near the basement membrane. The immunofluorescence staining results showed the opposite tendency for LC3 and p62. LC3 was more strongly localized within the elongated spermatids, while p62 was strongly localized within the early spermatids. Moreover, the ultrastructural components of autophagy were revealed by transmission electron microscopy. Well-developed autophagosomes and multivesicular bodies were found to be prominent in primary spermatocytes (zygotene and pachytene) and spermiogenic cells. Furthermore, other vesicular structures, such as early endosomes and amphisomes, were also observed during spermatogenesis. The above findings collectively suggest that autophagy is active during spermatogenesis and that the level of autophagy increases from the basal to the luminal regions of the seminiferous tubules of domestic fowl testes. We propose that autophagic pathways may be involved in multiple functions to sustain spermatogenesis.

Abamectin induces apoptosis and autophagy by inhibiting reactive oxygen species-mediated PI3K/AKT signaling in MGC803 cells

Abamectin (ABA) is one of the most widely used compounds in agriculture and veterinary medicine. However, the cytotoxicity of ABA in human gastric cells is utterly unknown. In this study, ABA suppressed the proliferation of MGC803 cells by arresting the cell cycle at the G0/G1-phase. Moreover, ABA induced mitochondrial-mediated apoptosis by inducing the loss of mitochondrial membrane potential, upregulation of Bax/Bcl-2, and activation of caspase-3. ABA significantly improved the LC3-II/LC3-I ratio and reduced P62 protein expression in a dose-dependent manner. Through detection of the reactive oxygen species (ROS) levels, we found ABA induced the accumulation of intracellular ROS and then reduced PI3K/AKT signaling activation related to MGC803 cell apoptosis and autophagy. Our results indicate that ABA exerts cytotoxic effects on human MGC803 cells through apoptosis and autophagy by inhibiting ROS-mediated PI3K/AKT signaling. Furthermore, ABA may be a potential risk to human gastric health.