Assessment of genotoxic potential of the insecticide Dichlorvos using cytogenetic assay

Cellular metabolism and health impacts of dichlorvos: Occurrence, detection, prevention, and remedial strategies-A review

Dichlorvos (2,2-Dichlorovinyl dimethyl phosphate, [DDVP]) belongs to the class of organophosphates and is widely used as an insecticide in agriculture farming and post-harvest storage units. Extensive research has been conducted to assess the factors responsible for the presence of DDVP in terrestrial and aquatic ecosystems, as well as the entire food chain. Numerous studies have demonstrated the presence of DDVP metabolites in the food chain and their toxicity to mammals. These studies emphasize that both immediate and chronic exposure to DDVP can disrupt the host's homeostasis, leading to multi-organ damage. Furthermore, as a potent carcinogen, DDVP can harm aquatic systems. Therefore, understanding the contamination of DDVP and its toxicological effects on both plants and mammals is vital for minimizing potential risks and enhancing safety in the future. This review aimed to comprehensively consolidate information about the distribution, ecological effects, and health impacts of DDVP, as well as its metabolism, detection, prevention, and remediation strategies. In summary, this study observes the distribution of DDVP contaminations in vegetables and fruits, resulting in significant toxicity to humans. Although several detection and bioremediation strategies are emerging, the improper application of DDVP and the alarming level of DDVP contamination in foods lead to human toxicity that requires attention.

Synergistic/antagonistic toxicity characterization and source-apportionment of heavy metals and organophosphorus pesticides by the biospectroscopy-bioreporter-coupling approach

Many anthropogenic chemicals are manufactured and eventually enter the surrounding environment, threatening food security and human health. Considering the additive or synergistic effects of pollutant mixtures, there is an expanding need for rapid, cost-effective and field-portable screening methods in environmental monitoring. This study used a recently developed biospectroscopy-bioreporter-coupling (BBC) approach to investigate the binary toxicity of Ag(I), Cr(VI) and four organophosphorus pesticides (dichlorvos, parathion, omethoate and monocrotophos). Ag(I) and Cr(VI) altered the toxicity mechanisms of pesticides, explained by the synergistic or antagonistic effect of Ag/Cr-induced cytotoxicity and pesticide-induced genotoxicity. The discriminating Raman spectral peaks associated with organophosphorus pesticides were 1585 and 1682 cm-1, but 750, 1004, 1306 and 1131 cm-1 were found in heavy metal and pesticide mixtures. More spectral alterations were related to pesticides rather than Ag(I) or Cr(VI), hinting at the dominant toxicity mechanisms of pesticides in mixtures. Ag(I) supplement significantly increased the levels of reactive oxygen species induced by organophosphorus pesticides, attributing to the increased permeability of cell membrane and entrance of toxic substances into the cells by the oligodynamic actions. This study lends deeper insights into the interactions between microbes and pollutant mixtures, offering clues to assess the cocktail effects of multiple pollutants comprehensively.

Assessment of genotoxic potential of the treated hospital wastewater using cytogenetic assays

The cytogenetic study using hospital effluent was carried out engaging three cytogenetic end points—chromosomal aberration (CA) assay, mitotic indices (MIs), and micronucleus (MN) Analysis. These bioassays were performed in hematopoietic bone marrow cells of Mus musculus. The experiment commenced with the collection of hospital effluent from the final outlet when wastewater gets collected after undergoing treatment by a multistep process. The pure treated sample water was collected at different times between March 2019 to January 2020 and was given ad libitum to mice at its low (90% dilution) and high (pure form), i.e. 100% concentration for 3 different durations i.e. 7, 15, and 30 days, respectively. The results indicated a significant (P < 0.01) decrease in the MI in all the groups but was more pronounced in the group which was given 100% concentrated sample water collected in the month of March 2019. Besides this, the major finding was presence of CAs like breaks, fragments, rings, and pulverization in bone marrow cells in different groups; however, the frequency of these aberrations varied from group to group. A significant (P < 0.01) increase in MN Induction and decreased ratio (P < 0.01) of polychromatic to normonochromatic erythrocytes were observed in samples collected in month of March both at 10% and 100% concentrations. However, decrease in the ratio was observed in the samples of September and January at low-concentration sample water. The results thus indicated that there was some lacuna in the treatment process earlier in the month of March, which was rectified to some extent in the subsequent months. Hence, the treated wastewater collected in the month of January next year was more suitable for its use than other samples. Summary: These findings thus draw attention toward ensuring efficiency of the treatment plant and quality of water by the hospital management before it being disposed off into the municipal supply; a step that can help society to live a healthy life. With these findings, it is conveyed that all the hospitals, diagnostic labs, and other health care establishments must pay utmost attention at liquid waste disposal mechanism to make environment pollution-free.

Effect of N-acetylcysteine on attenuation of chlropyrifos and its methyl analogue toxicity in male rats

The attenuating effect of 150 mg/kg of N-acetylcysteine (NAC) against the oral administration of 7.88 and 202.07 mg/kg/day for 14 days of either chlropyrifos-ethyl (CPE-E) or chlropyrifos-methyl (CPF-M), respectively, in male rat was investigated using biochemical and genetic markers. Biomarkers such as acetylcholinesterase (AChE), butyrylcholinesterase (BuChE), paraoxonase (PON), adenosine 5'-triphosphatase (ATP-ase), glutathione-S-transferase (GST), catalase (CAT), glutathione reduced (GSH) in serum showed a significant decline in their levels, while calcium (Ca⁺²), cytochrome C reduction (CYC-R), lipid peroxidation (LPO), nitric oxide (NO) levels showed a significant increase in serum of treated rats. Regarding the genotoxic parameters, when rats are treated either with CPE-E or CPF-M, liver DNA, chromosomal aberration (CA), and micronucleated polychromatic erythrocytes (MnPCE) significantly increased, while the mitotic index (MI) and polychromatic erythrocytes (PCE)/ normochromatic erythrocytes (NCE) ratio were significantly decreased. However, the administration of NAC following the intoxication of CPF-E or CPF-M attenuated the tested biochemical and genotoxic markers. It can be concluded that NAC can be used to ameliorate the toxicity of certain organophosphorus compounds such as CPF-E and CPF-M.

Dimethoate Induces DNA Damage and Mitochondrial Dysfunction Triggering Apoptosis in Rat Bone-Marrow and Peripheral Blood Cells

Dimethoate (DM) is an organophosphorus (OP) pesticide with wide use in the pest control. Its persistence in crops and soils could possibly cause adverse health consequences in humans as well as other non-target species. Since molecular studies confirming potential genotoxicity of DM have not been previously reported, the acute in vivo toxicological impact was evaluated in Wistar rats. Significant micronuclei induction and metaphase chromosome abnormalities in bone marrow cells exposed to three different DM doses (20, 40 and 60 mg/kg-bw) at multiple treatment durations (24, 48 and 72 h) indicated positive dose response relationship, confirming its genotoxic and cytotoxic potential. Significant mitotic index decrease was seen in dosed animals compared to vehicle control. The study used peripheral blood comet assay, indicating DM-mediated damage to DNA at all exposure levels in a time responsive manner. These assays were found to be an effective, precise, and fast technique with applied value in biomonitoring studies. Cell cycle and apoptosis along with mitochondrial membrane potential (MMP) in flow cytometric analyses confirmed DM exposure decreased MMP, affected the cell cycle, and inflicted DNA damage, which led to cellular apoptosis of leukocytes culminating into immunotoxic effects. The in silico experiments consequently augmented that DM showed acceptable binding energy value for Cyclin A2, suggesting that it could inhibit the cell cycle progression by inhibiting cyclin A2.

Atrazine or bisphenol A mediated negative modulation of mismatch repair gene, mlh1 leads to defective oogenesis and reduced female fertility in Drosophila melanogaster

The study reports the effects of an herbicide (atrazine) and a plasticizer (Bisphenol A, BPA) on the transcriptional modulation of a mismatch repair gene (mlh1) and its adverse consequences on female fertility using Drosophila as a model. Through a chemical screen, we show that exposure to atrazine or BPA significantly downregulates mlh1 and the exposed flies had reduced fertility with smaller ovaries having reduced number of mature oocytes and abnormal distribution of ovarian follicles with increased apoptosis in them. These females had increased double-strand breaks as well as reduced synaptonemal complex formation in their ovaries suggesting altered meiotic crossing over. The eggs of these females were defective in their maternal transcripts as well as proteins and consequently, after fertilization, these eggs exhibited abnormal embryonic development. Interestingly, these phenotypes parallel that of mlh1 mutants. Further, exposure of females having reduced Mlh1 levels (mlh1^e00130/CyO) to atrazine or BPA caused severe defective phenotypes at a higher proportion than normal flies. Our findings reveal the critical role of mlh1 in atrazine and BPA mediated female reproductive toxicity, and opens up a possibility of toxicants affecting female fertility by modulating the MMR genes.

Dichlorvos toxicity: A public health perspective

Pesticides are used in agriculture and in domestic pest control. Dichlorvos, an organophosphate, is a predominant pesticide used in domestic insect control in developing countries. Acute and prolonged exposure may lead to death, genotoxic, neurological, reproductive, carcinogenic, immunological, hepatic, renal, respiratory, metabolic, dermal and other systemic effects. Its toxicity is due to the ability of the compound to inhibit acetyl cholinesterase at cholinergic junction of the nervous system. This study is a review of the toxicological effects of dichlorvos in a public health perspective.

Occupational and life-style factors-acquired mutagenicity in agric-workers of northeastern Brazil

Pesticides are a complex mixture of chemicals used to protect crops from a number of pests and diseases. They have been considered as potential mutagenic agents. This study aims at evaluation of the mutagenic effect of pesticide exposure to agricultural workers through chromosomal aberrations (CA) and micronucleus (MN) assay in peripheral blood lymphocytes and oral mucosal cells, respectively. The exposed group was consisted with 97 farmers, while the control (un-exposed) group consisted of 55. The results showed a significant (p < 0.05) increase in frequency of CA and MN in the exposed group. Both CA and MN profiles were linked to a significant (p < 0.05) co-relation with the confounding factors such as smoking habits, alcohol, vegetables, tea/coffee, vitamins, and sweetener consumptions. More cytogenetic events were denoted in smoking and alcohol consumption as well as non-personal protective equipment (non-PPE) and low/no vegetables user farmers. In conclusion, a deficiency of dietary and medicaments-derived antioxidants, while consumption of alcohol and tobacco, as well as effects of radiation, heavy metal poisoning (especially from sweeteners), and non-PPE using habits, may contribute cytogenetic damage to the workers.

Toxicogenetic evaluation of dichlorophene in peripheral blood and in the cells of the immune system using molecular and flow cytometric approaches

Dichlorophene; a halogenated phenolic compound with wide applications as a fungicide, bactericide and antiprotozoan. Dichlorophene spray also has therapeutic use in the disease digital dermatitis. In guinea pigs, a few studies obtained mixed results in dicholorophene sensitization tests. In consideration of the fact, that the mechanism of its genotoxicity has not been adequately elucidated lead to present study assessing the acute in vivo toxicological impact in Rattus norvegicus. A systematic research has been made encompassing the use of molecular and flow cytometric approaches. The study was designed on blood cells for comet assay which revealed dichlorophene induced DNA damage in all exposures understandable in time dependent manner. The feasibility of this assay was also established as an effective, fast and accurate method with a great potential in biomonitoring. Contemporary molecular techniques were further engaged using leukocytes for the cell apoptosis/cycle and mitochondrial membrane potential employing propidium iodide staining and rhodamine 123 respectively. The effect on cell cycle phases and mitochondrial membrane permeability was analyzed through flow cytometry. These indicators exposed that dichlorophene decreased the mitochondrial membrane potential, altered the cell cycle and confirmed the DNA damage leading to apoptosis of the cells of the immune system accountable for immunotoxic effects of dichlorophene on rat leukocytes.