Diazinon toxicity in hepatic and spleen mononuclear cells is associated to early induction of oxidative stress

Assessment of the Cytotoxicity Mechanism of Diazinon on HFFF2 Cells: A Bioinformatic and Experimental Study

Pesticide exposure can cause many skin diseases such as hypopigmentation and contact dermatitis, but the underlying mechanisms remain unclear. Furthermore, Organophosphate pesticides (OPs) including Diazinon (DZN) can affect cellular pathways like ATPase, leading to mitochondrial energy deficit and even apoptosis in the cell's functions. Following cell exposure to the OP pesticide DZN through treatment, we evaluated alteration in gene expression and DNA damage. Bioinformatic analysis was performed based on the AutoDock, Protein Data Bank, STRING, Way2Drug, and Comparative Toxicogenomics databases and tools. The MTT assay, wound healing, DAPI staining, flow cytometry, and real-time PCR were applied in the current study. The results showed that the viability and migration capacity of HFFF2 cells decreased, and the apoptosis rate increased in the DZN-treated group. These findings revealed that DZN regulated the expression of the apoptotic genes in DZN cells.

Effects of diazinon on the ovarian tissue of rats: a histochemical and ultrastructural study

Despite the negative environmental and biologic effects, organophosphates have currently been widely used. We aimed to examine the possible negative effects of diazinon, a type of organophosphate, on rat ovarian tissue. Wistar Albino rats were divided into four groups. No treatment was given to control, olive oil was applied to sham group. Experimental groups were injected intraperitoneally with 30 and 60 mg/kg/day diazinon, respectively. 24 h later, ovarian tissues were extracted, preparated, examined via light and electron microscope. In the experimental groups granulosa and corpus luteum showed degenerative changes. Dilatation of endoplasmic reticulum cisterns and morphological alterations of mitochondria in granulosa cells were detected utrastructurally. Also, accumulation of lipid droplets and autophagic vacuoles was observed in cells of corpus luteum. A statistically significant dose-dependent decrease in superoxide dismutase and catalase reactivity and a statistically significant increase in caspase-3 expression in cells of atretic follicles and corpus luteum were observed. Results show that exposure to a single dose of diazinon may disrupt antioxidant system, trigger atresia in follicles and negatively effect corpus luteum functions. It was concluded that studies applying possible antioxidant treatments should be carried out to reduce and prevent the negative effects of diazinon on the reproductive system.

Mechanisms of Neurotoxicity of Organophosphate Pesticides and Their Relation to Neurological Disorders

Organophosphates (OPs) refers to a diverse group of phosphorus-containing organic compounds; they are widely used all over the world and have had an important beneficial impact on industrial and agricultural production and control of vector transmission. Exposure to OPs of different toxicities (high, moderate, slight, and low toxicity) can all have negative consequences on the nervous system, such as nausea, vomiting, muscle tremors, and convulsions. In severe cases, it can lead to respiratory failure or even death. Notably, OPs induce neuropathy in the nervous system through specific interactions with nicotinic or muscarinic receptors, phosphorylating acetylcholinesterase, or neuropathic target esterases. This review summarizes the possible toxicological mechanisms and their interplay underlying OP pesticide poisoning, including cholinesterase inhibition and non-cholinesterase mechanisms. It outlines the possible links between OP pesticide poisoning and neurological disorders, such as dementia, neurodevelopmental diseases, and Parkinson's disease. Additionally, it explores OP interactions' potential therapeutic implications that may help mitigate the deleterious impact of OPs on the nervous system.

A photoelectrochemical aptasensor based on W6+-doped carbon nitride with carbon-rich structure for sensitive detection of diazinon

A photoelectrochemical (PEC) aptasensor us reported based on W6+-doped carbon nitride with carbon-rich structure (WCCN). WCCN exhibited excellent photoelectric conversion performance owing to the carbon-rich structure and W6+ doping. C atoms can replace the center N/edge N atoms to form a carbon-rich structure, improving the insufficient light absorption of CN in the visible region. Also, W6+ doping forms a directional electron transfer channel, achieving the efficient separation and transport of carriers. W6+ doping and carbon-rich structure can promote the generation, transfer, and separation of photogenerated carriers, further enhancing PEC performance. The fabricated PEC aptasensor based on WCCN demonstrated a wide detection range (3.92 ~ 588 pg L-1), a low detection limit (1.31 pg L-1, S/N = 3), good reproducibility, selectivity, stability, and practical application in actual water samples. This work explores the modification strategy of element doping for carbon nitride with high photoelectric property and offers a cost-effective and simplified method for the detection of pesticide residues.

Comprehensive investigation of the mutagenic potential of six pesticides classified by IARC as probably carcinogenic to humans

Pesticides are significant environmental pollutants, and many of them possess mutagenic potential, which is closely linked to carcinogenesis. Here we tested the mutagenicity of all six pesticides classified probably carcinogenic (Group 2A) by the International Agency of Research on Cancer: 4,4'-DDT, captafol, dieldrin, diazinon, glyphosate and malathion. Whole genome sequencing of TK6 human lymphoblastoid cell clones following 30-day exposure at subtoxic concentrations revealed a clear mutagenic effect of treatment with captafol or malathion when added at 200 nM or 100 μM initial concentrations, respectively. Each pesticide induced a specific base substitution mutational signature: captafol increased C to A mutations primarily, while malathion induced mostly C to T mutations. 4,4'-DDT, dieldrin, diazinon and glyphosate were not mutagenic. Whereas captafol induced chromosomal instability, H2A.X phosphorylation and cell cycle arrest in G2/M phase, all indicating DNA damage, malathion did not induce DNA damage markers or cell cycle alterations despite its mutagenic effect. Hypersensitivity of REV1 and XPA mutant DT40 chicken cell lines suggests that captafol induces DNA adducts that are bypassed by translesion DNA synthesis and are targets for nucleotide excision repair. The experimentally identified mutational signatures of captafol and malathion could shed light on the mechanism of action of these compounds. The signatures are potentially suitable for detecting past exposure in tumour samples, but the reanalysis of large cancer genome databases did not reveal any evidence of captafol or malathion exposure.

Resveratrol as modulator of PSA-NCAM expression in the hippocampus of diazinon-injured rat fetuses

Polysialylated neural cell adhesion molecule (PSA-NCAM) is expressed in the developing central nervous system (CNS) and plays an important role in neurogenesis. Organophosphorus (OP) toxins, including diazinon (DZN), cause oxidative stress (OS) and damage the CNS. Resveratrol (RV), with its antioxidant effect, leads to the reduction of OS. Therefore, this research was conducted with the aim of the effect of RVon the expression of PSA-NCAM in the hippocampus (HPC) of rat fetuses treated with DZN. In this study, 24 female Wistar rats were divided into 4 groups (n = 6): Control, DZN (40 mg/kg), RV(10 mg/kg), and DZN + RV(40 mg/kg + 10 mg/kg) after confirming they were pregnant. On the 21st day of pregnancy, the mother mice were anesthetized with ketamine and xylazine, and the fetuses were removed; after anesthesia, their brains were removed for immunohistochemistry and western blot (WB) technique. The results of the study showed that in the group receiving DZN, the level of PSA-NCAM protein expression decreased significantly compared to the control group, and the group receiving RV with its antioxidant property increased the expression of PSA-NCAM protein compared to the DZN group. All in all, the exposure of pregnant mice to DZN causes disorders in the CNS, especially the level of PSA-NCAM protein expression in the HPC of fetuses, and the use of RV as an antioxidant by pregnant mothers neutralizes the effects of DZN in the HPC of their fetuses.

Gut microbial metalloproteins and its role in xenobiotics degradation and ROS scavenging

The gut microbial metalloenzymes play an important role in maintaining the balance between gut microbial ecosystem, human physiologically processes and immune system. The metals coordinated into active site contribute in various detoxification and defense strategies to avoid unfavourable environment and ensure bacterial survival in human gut. Metallo-β-lactamase is a potent degrader of antibiotics present in periplasmic space of both commensals and pathogenic bacteria. The resistance to anti-microbial agents developed in this enzyme is one of the global threats for human health. The organophosphorus eliminator, organophosphorus hydrolases have evolved over a course of time to hydrolyze toxic organophosphorus compounds and decrease its effect on human health. Further, the redox stress responders namely superoxide dismutase and catalase are key metalloenzymes in reducing both endogenous and exogenous oxidative stress. They hold a great importance for pathogens as they contribute in pathogenesis in human gut along with reduction of oxidative stress. The in-silico study on these enzymes reveals the importance of point mutation for the evolution of these enzymes in order to enhance their enzyme activity and stability. Various mutation studies were conducted to investigate the catalytic activity of these enzymes. By using the "directed evolution" method, the enzymes involved in detoxification and defense system can be engineered to produce new variants with enhance catalytic features, which may be used to predict the severity due to multi-drug resistance and degradation pattern of organophosphorus compounds in human gut.

The protective effect of methanolic extract of Verbascum cheiranthifolium and Biebersteinia multifida DC on hippocampus damage induced by diazinon in male Wistar rats: An experimental study

Diazinon (DZN) an organophosphate (OP), with the most important mechanism of action of DZN being induction of oxidative stress (OS) and inhibition of the enzyme acetylcholinesterase (AChE). Verbascum cheiranthifolium (VER) and Biebersteinia multifida (BM) belong to the Scrophulariaceae and Biebersteiniaceae family respectively. These plants are widely used in Iranian traditional medicine due to their beneficial effects. Thus, this research aimed to appraise the protective effects of the methanolic extract of the VER and BM on changes in the level of expression of α7 and α4 subunits of nicotinic acetylcholine receptors (nAChRs) in hippocampus (HPC) of DZN-treated rats. In this research, 36 male Wistar rats were used and randomly divided into six groups: Control, DZN (40 mg/kg), VER (1 g/kg), DZN+VER (40 mg/kg+1 g/kg), BM (150 mg/kg), and DZN+BM (40 mg/kg+150 mg/kg). At the end of treatment periods, the animals of all groups underwent the Morris water maze (MWM) test. The rats were anesthetized, and blood sampling was performed. Eventually, the brain was removed for histological study and evaluation of OS parameters. The results indicated that DZN increased the extent of expression of nAChRs in the HPC and significantly inhibited cholinesterase (ChEs) activity plus OS parameters. Also, in MWM, the time to find the platform was significantly longer in the DZN group, while the time and the distance in the probe test were lower than in the control groups. VER and BM extract in the treatment groups simultaneously improved the extent of expression of nAChRs, ChEs activity, as well as the parameters of OS and spatial memory significantly. In conclusion, our results support the neuroprotective properties of VER and BM extract versus DZN in rats. Accordingly, the extracts of VER and BM may be useful as an approach for the treatment of learning disorders and memory enhancement.

Ameliorative Effect of Thymoquinone and Thymoquinone Nanoparticles against Diazinon-Induced Hepatic Injury in Rats: A Possible Protection Mechanism

The health benefits of thymoquinone (TQ) have been a significant focus of numerous studies. However, more research is needed to ascertain whether its nano-form can effectively treat or prevent chronic diseases. In this study, we investigated how thymoquinone and its nanoparticles can mitigate liver damage induced by diazinon in male Wistar rats and explored the intracellular mechanisms involved. Forty-two Wistar male rats (n = 42) were randomly allotted into seven groups. Group 1 served as the control. Group 2 (vehicle) consisted of rats that received corn oil via a gastric tube daily. In Group 3 (TQ), rats were given a daily oral administration of TQ (40 mg/kg bw). Group 4 (thymoquinone nanoparticles, NTQ) included rats that received NTQ (0.5 mg/kg bw) orally for 21 days. Group 5 (DZN) involved rats that were administered diazinon (DZN, 15 mg/kg bw) orally. In Group 6 (TQ + DZN), rats first received TQ orally, followed by DZN. Group 7 (NTQ + DZN) consisted of rats receiving NTQ orally, then DZN. After 21 days of treatment, the rats were euthanized. After oral administration of DZN, liver enzymes were significantly elevated (p < 0.05). Additionally, there were noticeable increases in oxidative injury markers, such as nitric oxide, malondialdehyde, redox oxygen radicals, and overall increases in hydrogen peroxide and liver protein carbonyl concentrations. This was accompanied by the upregulation of apoptotic markers (Bax, caspase9, caspase 3, bax/Bcl2 ratio), inflammatory cytokines (TNF-α, IL-6), and DNA damage. There was also a noteworthy decrease (p < 0.05) in the activities of antioxidant enzymes and anti-apoptotic markers. However, the oral administration of thymoquinone or its nanoparticle form mitigated these diazinon complications; our histopathological findings corroborated our biochemical and molecular observations. In conclusion, the significant antioxidant properties of thymoquinone, or its nanoparticle form, in tandem with the downregulation of apoptotic markers and inflammatory cytokines, provided a protective effect against hepatic dysfunction caused by diazinon.

Electrochemical and Optical Sensors for the Detection of Chemical Carcinogens Causing Leukemia

The incidence and mortality due to neoplastic diseases have shown an increasing tendency over the years. Based on GLOBOCAN 2020 published by the International Agency for Research on Cancer (IARC), leukemias are the thirteenth most commonly diagnosed cancer in the world, with 78.6% of leukemia cases diagnosed in countries with a very high or high Human Development Index (HDI). Carcinogenesis is a complex process initiated by a mutation in DNA that may be caused by chemical carcinogens present in polluted environments and human diet. The IARC has identified 122 human carcinogens, e.g., benzene, formaldehyde, pentachlorophenol, and 93 probable human carcinogens, e.g., styrene, diazinone. The aim of the following review is to present the chemical carcinogens involved or likely to be involved in the pathogenesis of leukemia and to summarize the latest reports on the possibility of detecting these compounds in the environment or food with the use of electrochemical sensors.

Malignant growth of arsenic-transformed cells depends on activated Akt induced by reactive oxygen species

Arsenic is an identified carcinogen for humans.In this study, chronic exposure of human hepatocyte L-02 to low-doses of inorganic arsenic caused cell malignant proliferation. Meanwhile, compared with normal L-02 cells, arsenic-transformed malignant cells, L-02-As displayed more ROS and significantly higher Cyclin D1 expression as well as aerobic glycolysis. Moreover, Akt activation is followed by the upregulation of Cyclin D1 and HK2 expression in L-02-As cells, since inhibition of Akt activity by Ly294002 attenuated the colony formation in soft agar and decreased the levels of Cyclin D1 and HK2. In addition, scavenging of ROS by NAC resulted in a decreased expression of phospho-Akt, HK2 and Cyclin D1, and attenuates the ability of anchorage-independent growth ofL-02-As cells, suggested that ROS mediated the Akt activation in L-02-As cells. In summary, our results demonstrated that ROS contributes to the malignant phenotype of arsenic-transformed human hepatocyte L-02-As via the activation of Akt pathway.

Role of biotransformation in the diazinon-induced toxicity in HepG2 cells and antioxidant protection by tetrahydrocurcumin

Diazinon (DZN) is an insecticide extensively used to control pests in crops and animals. However, its indicriminated use may lead to liver damage in animals and humans. This study aimed to evaluate the toxicity of DZN (25-150 µM) on human hepatoblastoma (HepG2) cells after 24 and 48 h of exposure and the role of its biotransformation on the toxicological potential. We also tested the protective effect of tetrahydrocurcumin (THC), an antioxidant agent, in the DZN-induced citotoxicity. DZN caused cytotoxicity in the HepG2 cells, inhibiting cell proliferation and reducing cell viability in a dose- and time-dependent manner. The pre-incubation of HepG2 cells with chemical inducers of cytochrome P450 monooxygenase 3-methylcholanthrene and phenobarbital resulted in a further decrease of cell viability associated with DZN exposure. In addition, the metabolite diazoxon was more toxic than DZN. Our results also revealed that THC alleviated DZN-induced cytotoxicity and reactive oxygen and nitrogen species (RONS) generation in HepG2 cells. In conclusion, our data provide novel insights into the involvement of biotransformation in the mechanisms of DZN-induced cytotoxicity and suggest that amelioration of RONS accumulation might be involved in the protective effect of THC on DZN-induced liver injury.