Mancozeb fungicide-induced genotoxic effects, metabolic alterations, and histological changes in the colon and liver of Sprague Dawley rats

Lipid peroxidation and changes in major antioxidant markers in copper quinolate fungicide-exposed rats

The present study investigated the toxic effects of sub-chronic exposure to copper quinolate (CuQ) fungicide on liver and kidney function. Twenty-four adult male Wistar rats were equally divided into a control group, and three treated groups received, respectively, by oral gavage, three increasing doses of CuQ: 47; 67.1; and 94 mg/kg b.w corresponding, respectively, LD50/100, LD50/70, and LD50/50 daily for 8 weeks. CuQ resulted in a significant increase in the serum enzymatic activity of aspartate aminotransferase (AST), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), and the serum levels of urea, creatinine, uric acid, and malondialdehyde, along with a marked decrease in alanine aminotransferase (ALT) activity, and the contents of total protein and albumin compared to those of the control group. Furthermore, glutathione content and the enzymatic activity of superoxide dismutase (SOD), catalase (CAT), glutathione S-transferase (GST), and glutathione peroxidase (GPx) decreased significantly in a dose-dependent manner with respect to CuQ. The adverse effects of CuO were supported by the histopathological evaluations of liver and kidney tissues. Conclusively, sub-chronic CuQ exposure was shown to induce kidney and liver oxidative damage and dysfunction.

Therapeutic effects of avocado (Persea americana Mill.) seed powder against reproductive toxicity induced by Mancozeb (herbicide) in female rabbits

Pesticides like Mancozeb are being increasingly indispensable in the control of crop pests. Unfortunately, they have been implicated in genotoxicity due to their ubiquity, toxicological properties, persistence and presence in the food chain. This study sought to evaluate the efficacy of powdered avocado seed on reproductive parameters in the management of oxidative stress in female rabbits caused by the herbicide Mancozeb. Twenty-eight female rabbits aged 7-8 months and weighing between 2780.4 g and 3143.7 g were randomly divided into four groups of seven rabbits each. Each group received for 90 consecutive days distilled water or Mancozeb associated or not with avocado seed powder orally as follows: T1: 10 ml distilled water; T2, T3 and T4: 100 mg/kg bw Mancozeb. This was followed by oral administration of 250, 500, and 0 mg/kg of avocado seed powder for T2, T3, and T4, respectively. Water and feed were distributed ad libitum. Collected data concerned growth, carcass and reproductive performances, hematological and biochemistry characteristics. Results demonstrated that pregnant and lactating female rabbits administered Mancozeb exhibited a significant decrease (P < 0.05) in food intake, body weight, and body weight gain. Female rabbits exposed to Mancozeb had a decrease in litter size and weight from birth to weaning, as well as in weaning body weight and weight increase, fertility and prolificacy rate, milk yield, and daily milk efficiency. However, administration of avocado seed powder reversed (P < 0.05) the trends in these parameters in a dose-dependent manner. The increase in relative weight of the kidney and liver, concentrations of urea, creatinine, alanine and aspartate aminotransferases, mean cell volume, white blood cells, and lymphocytes were all associated with increased Mancozeb rates (P < 0.05). On the contrary, administration of the Mancozeb caused decrease in hemoglobin (Hb), Red blood Cell (RBC) and protein content. Administration of avocado seed powder significantly (P < 0.05) ameliorated the Mancozeb effects on these parameters. Applying 500 mg/kg b.w Avocado seed powder may be suggested as an alternative therapy for reproductive defects induced by Mancozeb in female rabbits.

Effects of Nelumbonucifera Gaertn. Petal Tea Extract on Hepatotoxicity and Oxidative Stress Induced by Mancozeb in Rat Model

Mancozeb (Mz) is one of the most widely used pesticides that has been reported to cause adverse human health risks. White Nelumbo nucifera (N. nucifera) petals have therapeutic properties to prevent toxicity. Hence, this study attempted to determine the effects of N. nucifera extract on hepatotoxicity and oxidative stress in mancozeb-treated rats. Seventy-two male rats were divided into nine groups and designed with a control; N. nucifera extract was administered at the doses of 0.55, 1.1, and 2.2 mg/kg bw/day, Mz was administered at 500 mg/kg bw/day, and the co-treatment groups (N. nucifera and Mz) were administered 0.55, 1.1, and 2.2 mg/kg bw/day of N. nucifera followed by administering Mz 500 mg/kg bw/day daily for 30 days. The results showed that all doses of N. nucifera extract did not induce hepatic toxicity and could suppress the toxicity of mancozeb by increasing body weight gain and decreasing relative liver weight, lobular inflammation, and total injury score. The combination treatment also decreased the molecular markers of oxidative stress (2-hydroxybutyric acid, 4-hydroxynonenal, l-tyrosine, pentosidine, and N6-carboxymethyllysine). Furthermore, the reduced glutathione and oxidized glutathione contents were adjusted close to the normal level. Therefore, N. nucifera extract is a natural antioxidant supplement that could decrease the toxicity of mancozeb and can be safely consumed.

Changes in the gut microbiota of rats after exposure to the fungicide Mancozeb

Mancozeb is a fungicide commonly used in pest control programs, especially to protect vineyards. Its toxicity has already been evidenced in several studies. However, its influence on the composition and diversity of the gut microbiota remains unknown. In this work, the adverse impact of Mancozeb on the intestinal microbiota was investigated using a rodent model. Adult male Sprague Dawley rats were randomized into three groups: Control (standard diet), MZ1 (Mancozeb dose: 250 mg/kg bw/day), and MZ2 (Mancozeb dose: 500 mg/kg bw/day). After 12 weeks of experiment, animals were euthanized, and feces present in the intestine were collected. After fecal DNA extraction, the V4 region of the 16S rRNA gene was amplified followed by sequencing in an Ion S5™ System. Alpha and beta diversity analysis showed significant differences between Control and Mancozeb groups (MZ1 e MZ2), but no difference between MZ1 and MZ2 was observed. Seven genera significantly increased in abundance following Mancozeb exposure, while five genera decreased. Co-occurrence analyses revealed that the topological properties of the microbial networks, which can be used to infer co-occurrence interaction patterns among microorganisms, were significantly lower in both groups exposed to Mancozeb when compared to Control. In addition, 23 differentially abundant microbial metabolic pathways were identified in Mancozeb-treated groups mainly related to a change in energy metabolism, LPS biosynthesis, and nucleotide biosynthesis. In conclusion, the exposure to Mancozeb presented side effects by changing the composition of the microbiota in rats, increasing bacterial diversity regardless of the dose used, reducing the interaction patterns of the microbial communities, and changing microbial metabolic pathways.

Mancozeb-induced hepatotoxicity: protective role of curcumin in rat animal model

Background

Mancozeb-a widely used fungicide in the agricultural sector-is believed to cause toxicity by increasing oxidative stress. This work investigated the efficacy of curcumin in protecting mancozeb-induced hepatotoxicity.

Materials and Methods

Mature Wistar rats were assigned into 4 equal groups: control, mancozeb (30 mg/kg/day, ip), curcumin (100 mg/kg/day, po), and mancozeb+curcumin. The experiment lasted for 10 days.

Results

Our results reported that mancozeb elevated aspartate transaminase, alanine transaminase, alkaline phosphatase, lactate dehydrogenase, gamma glutamyltranspeptidase enzyme activities, and total bilirubin level in plasma; and decreased total protein and albumin levels, compared with the control group (P < 0.05-0.001). Hepatic tissue levels of malondialdehyde, and advanced oxidation protein products were significantly increased; whereas activities of superoxide dismutase, catalase, glutathione peroxidase, as well as levels of reduced glutathione, vitamin C, and total protein were reduced (P < 0.05-0.001). Histopathological examination showed marked histological changes. Co-treatment with curcumin improved the antioxidant activity; reversed oxidative stress and biochemical changes; and restored most of the liver histo-morphological alterations; thus, attenuating the hepatic toxicities induced by mancozeb.

Conclusion

These results indicated that curcumin could protect against detrimental hepatic effects induced by mancozeb.

Hepatotoxicity of Short Term Exposure to Mancozeb Fungicide in Male Wistar Rats

Mancozeb is a dithiocarbamate fungicide used effectively to protect plant products against fungi. The hepatic effects of short term exposure to mancozeb in adult male Wistar rats were investigated in the present study. Twenty-four animals were divided into four equal groups. Two groups were administered mancozeb (60 mg/kg body weight as single dose or 30 mg/kg body weight daily for 10 days, intraperitoneally), and the others, which served as control groups, received normal saline. Liver biochemical parameters in plasma were measured using standard methods. Liver homogenates were analysed for oxidative stress biomarkers and liver histopathology was studied. Single dose and 10 days exposures of mancozeb caused elevation in the activities of Alanine Transaminase (ALT), Aspartate Transaminase (AST), Alkaline Phosphatase (ALP), Lactate Dehydrogenase (LDH), and Gamma Glutamyl Transpeptidase (GGT) in plasma (p<0.05-0.001) compared with control. Mancozeb also caused elevation in the plasma level of total bilirubin, and reductions in albumin, total protein, and conjugated bilirubin. In addition, Malondialdehyde (MDA) and Advanced Oxidation Protein Product (AOPP) levels were increased in hepatic tissues (p<0.001) of all mancozeb exposed rats. Furthermore, hepatic levels of protein, reduced Glutathione (GSH) and vitamin C were decreased (p<0.01), together with the activities of Superoxide Dismutase (SOD), catalase, and Glutathione Peroxidase (GPx) enzymes (p<0.01-0.001). Histological analysis showed severe histopathological changes in mancozeb exposed rats. The results demonstrated that single dose intraperitoneal exposure of mancozeb (60 mg/kg body weight) or short term (10 days) daily exposure at 30 mg/kg body weight is capable of causing hepatotoxic effects in rats.

How advanced are we on the consequences of oral exposure to food contaminants on the occurrence of chronic non communicable diseases?

The development of an individual during fetal life and childhood is characterized by rapid growth as well as gradual maturation of organs and systems. Beyond the nutritional intake in essential nutrients, food contaminants can permanently influence the way organs mature and function. These processes are called "programming" and play an essential role in the occurrence of non-communicable chronic diseases throughout the lifespan. Populations as pregnant women, fetuses and young children are vulnerable and particularly sensitive to food contaminants which can induce epigenetic modifications transmissible to future generations. Among these contaminants, pesticides are found in most food matrices exposing humans to cocktails of molecules through variable concentrations and duration of exposure. The Maillard reaction products (MRPs) represent other food contaminants resulting from heat treatment of food. Modern diet, rich in fats and sugars, is also rich in neoformed pathogenic compounds, Advanced Glycation End products (AGEs), the levels of which depend on the heat treatment of foods and eating habits and whose effects on health are controversial. In this review, we have chosen to present the current knowledge on the impacts of selected pesticides and MRPs, on the risk of developing during life non-communicable chronic diseases such as IBD, metabolic disorders or allergies. A large review of literature was performed via Pubmed, and the most appropriate studies were summarised.

Histopathological, immunohistochemical and biochemical alterations in liver tissue after fungicide-mancozeb exposures in Wistar albino rats

PURPOSE

To evaluate the histopathological, immunohistochemical, and biochemical effects of liver changes after mancozeb administration.

METHODS

Rats were divided into groups-the control group (n=7) and the mancozeb group (n=7)-, given 500 mg/kg mancozeb dissolved in corn oil daily for four weeks by an orogastric tube. Caspase-3 and tumor necrosis factor-alpha (TNF-α) primary antibodies were used for immunohistochemical analysis.

RESULTS

Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) values of the mancozeb group increased significantly than ones of the control group. Venous dilatation, inflammation, hepatocyte degeneration, TNF-α, and caspase-3 expression scores increased significantly in the mancozeb group. In the mancozeb group, intensive caspase-3 expression was observed in hepatocyte cells around the central vein in the center of the liver lobule, and there was an increase in TNF-α expression in the inflammatory cells around the enlarged central vein and Kupffer cells and apoptotic hepatocyte cells.

CONCLUSIONS

Subacute mancozeb exposure in rats leads to elevated toxicity with impaired liver function, increased inflammation in tissue and increased apoptosis due to cellular damage in the liver, and decreased liver regeneration ability due to congestion and degeneration of blood vessels.

Thiram exposure in environment: A critical review on cytotoxicity

Thiram is used in large quantities in agriculture and may contaminate the environment by improper handling or storage in chemical plants and warehouses. A review of the literature has shown that thiram can affect different organs in animals and its toxic mechanisms can be elucidated in more detail at molecular level. We have summarized several impacts of thiram on animals: the effects of the perspectives of oxidative stress, mitochondrial damage, autophagy, apoptosis, and the IHH/PTHrP pathway on regulating abnormal skeletal development in particular tibial dyschondroplasia and kyphosis; angiogenesis inhibition was investigated from the perspective of angiogenesis factor inhibition, PI3K/AKT signaling pathway and CD147; the inhibition effect of thiram on fibroblasts and erythrocytes via the perspective of oxidative stress, mitochondrial damage and inhibition of growth factors in animal skin fibroblasts and erythrocytes; studied fertilized egg size, reduced fertility, neurodegeneration, and immune damage from the perspectives of CYP51 inhibition and dopamine-b-hydroxylase inhibition in the reproductive system, vitamin D deficiency in the nervous system, and inflammatory damage in the immune system; embryonic dysplasia in terms of thyroid hormone repression in animal embryonic development and repression of the SOX9a transcription factor. The elucidation of the mechanisms of toxicity of thiram on various organs of animals at molecular level will enable a more detailed understanding of the mechanisms of toxicity of thiram in animals and will facilitate the exploration of the treatment of thiram poisoning at molecular level.

Cytotoxicity of mancozeb on Sertoli-germ cell co-culture system: Role of MAPK signaling pathway

Mancozeb (MZB) is a worldwide fungicide for the management of fungal diseases in agriculture and industrial contexts. Human exposure occurs by consuming contaminated plants, drinking water, and occupational exposure. There are reports on MZB's reprotoxicity such as testicular structure damage, sperm abnormalities, and decrease in sperm parameters (number, viability, and motility), but its molecular mechanism on apoptosis in testis remains limited. To investigate the molecular mechanisms involved in male reprotoxicity induced by MZB, we used primary cultures of mouse Sertoli-germ cells. Cells were exposed to MZB (1.5, 2.5, and 3.5 μM) for 3 h to evaluate viability by 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay, reactive oxygen species (ROS) generation, and oxidative stress parameters (lipid peroxidation). Cell death and mitogen-activated protein kinase (MAPK) signaling were measured in these cells using flow cytometry and western blotting. In addition, some groups were exposed to N-acetylcysteine (NAC, 5 mM) in the form of co-treatment with MZB. Mancozeb reduced viability and increased the level of intracellular ROS, p38 and c-Jun N-terminal kinases (JNK) MAPK proteins phosphorylation, and apoptotic cell death, which could be blocked by NAC as an inhibitor of oxidative stress. The present study indicated for the first time the toxic manifestations of MZB on the Sertoli-germ cell co-culture. Redox imbalance and p38 and JNK signaling pathway activation might play critical roles in MZB-induced apoptosis in the male reproductive system.

Oral administration of thiram inhibits brush border membrane enzymes, oxidizes proteins and thiols, impairs redox system and causes histological changes in rat intestine: A dose dependent study

Pesticides are extensively employed worldwide, especially in agriculture to control weeds, insect infestation and diseases. Besides their targets, pesticides can also affect the health of non-target organisms, including humans The present study was conducted to study the effect of oral exposure of thiram, a dithiocarbamate fungicide, on the intestine of rats. Male rats were administered thiram at doses of 100, 250, 500 and 750 mg/kg body weight for 4 days. This treatment reduced cellular glutathione, total sulfhydryl groups but enhanced protein carbonyl content and hydrogen peroxide levels. In addition, the activities of all major antioxidant enzymes (catalase, thioredoxin reductase, glutathione peroxidase and glutathione-S-transferase) except superoxide dismutase were decreased. The antioxidant power of the intestine was impaired lowering the metal-reducing and free radical quenching ability. Administration of thiram also led to inhibition of intestinal brush border membrane enzymes, alkaline phosphatase, γ-glutamyl transferase, leucine aminopeptidase and sucrase. Activities of enzymes of pentose phosphate pathway, citric acid cycle, glycolysis and gluconeogenesis were also inhibited. Histopathology showed extensive damage in the intestine of thiram-treated rats at higher doses. All the observed effects were in a thiram dose-dependent manner. The results of this study show that thiram causes significant oxidative damage in the rat intestine which is associated with the marked impairment in the antioxidant defense system.

Mancozeb impairs mitochondrial and bioenergetic activity in Drosophila melanogaster

Mancozeb (MZ) is a broad-spectrum fungicide used worldwide in several crops. Neurological disorders in humans and animals have been associated with exposure to this compound by mechanisms still not fully understood. Drosophila melanogaster represents a reliable model in toxicological studies, presenting genetic and biochemical similarities with mammals. In this study, D. melanogaster flies were exposed for 15 days to MZ through the food (5 and 10 mg/mL). After that period, the efficiency of mitochondrial respiration complexes and metabolic markers were analyzed and evaluated. Flies presented weight loss, lower glucose, trehalose, and glycogen levels, and augmented levels of triglycerides concerning control (non-treated group). Acetyl-CoA Synthetase (ACeCS-1) and Acyl-Coenzyme Synthetase (ACSL1) contents were unchanged by MZ treatment. Mitochondrial respiration of flies was targeted by MZ treatment, evidenced by a decrease in oxygen consumption and bioenergetics rate and inhibition in mitochondrial complexes I/II. These results suppose that an impairment in mitochondrial respiration jointly with reduced levels of energetic substrates might be a mechanism involved in MZ deleterious effects, possibly by the limitation of ATP's availability, necessary for essential cellular processes.

Endocrine-disrupting activity of mancozeb

The objective of the present study was to review the existing data on the mechanisms involved in the endocrine disrupting activity of mancozeb (MCZ) in its main targets, including thyroid and gonads, as well as other endocrine tissues that may be potentially affected by MCZ. MCZ exposure was shown to interfere with thyroid functioning through impairment of thyroid hormone synthesis due to inhibition of sodium-iodine symporter (NIS) and thyroid peroxidase (TPO) activity, as well as thyroglobulin expression. Direct thyrotoxic effect may also contribute to thyroid pathology upon MCZ exposure. Gonadal effects of MCZ involve inhibition of sex steroid synthesis due to inhibition of P450scc (CYP11A1), as well as 3β-HSD and 17β-HSD. In parallel with altered hormone synthesis, MCZ was shown to down-regulate androgen and estrogen receptor signaling. Taken together, these gonad-specific effects result in development of both male and female reproductive dysfunction. In parallel with clearly estimated targets for MCZ endocrine disturbing activity, namely thyroid and gonads, other endocrine tissues may be also involved. Specifically, the fungicide was shown to affect cortisol synthesis that may be mediated by modulation of CYP11B1 activity. Moreover, MCZ exposure was shown to interfere with PPARγ signaling, being a key regulator of adipogenesis. The existing data also propose that endocrine-disrupting effects of MCZ exposure may be mediated by modulation of hypothalamus-pituitary-target axis. It is proposed that MCZ neurotoxicity may at least partially affect central mechanisms of endocrine system functioning. However, further studies are required to unravel the mechanisms of MCZ endocrine disrupting activity and overall toxicity.

Biochemical and histopathological responses in peripubertal male rats exposed to agrochemicals isolated or in combination: A multivariate data analysis study

The widespread use of agrochemicals results in the exposure of the general human population, including children, to several of these chemicals simultaneously. In the present preclinical study, it was investigated the hepatic damages caused by exposure to acephate, carbendazim and mancozeb when administered alone or in different combinations (binary and ternary). Juvenile male Wistar rats were exposed to agrochemicals from post-natal day 53, by gavage. The doses of agrochemicals applied here were determined from previous studies whose results showed no signs of systemic toxicity. All exposures provoked a significant increase in DNA damage (except for acephate alone) and activation of the xenobiotic biotransformation system (except for the ternary mixture). Interestingly, the ternary mixture did not exhibit an exacerbation in adverse effects caused by agrochemicals isolated or in binary combination, even though they are sharing genotoxicity damage induction as a common toxicity pathway. Conversely, some effects observed for isolated or binary combinations of agrochemicals were not observed for ternary combination, suggesting a chemical interaction that could imply antagonism character. Using a multivariate data analysis approach, exposure to isolated agrochemicals were related to a group of adverse effects characterized by hepatic lesion and the attempt of the tissue to mobilize defense cells and increase mitotic rates to minimize damages. Binary mixtures also share similarities in relation to the effects they exhibited, mainly a moderate to high increase in the GST activity and in histopathological alterations suggesting that binary combinations trigger an increased response of the mechanism of xenobiotics biotransformation. Together, obtained results bring important insights regarding adverse effects and possible interaction of the three agrochemicals whose residues are commonly detected in agro-food products.

Increased levels of genotoxic damage in a Bolivian agricultural population exposed to mixtures of pesticides

During the past decades, farmers in low to middle-income countries have increased their use of pesticides, and thereby the risk of being exposed to potentially genotoxic chemicals that can cause adverse health effects. Here, the aim was to investigate the correlation between exposure to pesticides and genotoxic damage in a Bolivian agricultural population. Genotoxic effects were assessed in peripheral blood samples by comet and micronucleus (MN) assays, and exposure levels by measurements of 10 urinary pesticide metabolites. Genetic susceptibility was assessed by determination of null frequency of GSTM1 and GSTT1 genotypes. The results showed higher MN frequency in women and farmers active ≥8 years compared to their counterpart (P < 0.05). In addition, age, GST genotype, alcohol consumption, and type of water source influenced levels of genotoxic damage. Individuals with high exposure to tebuconazole, 2,4-D, or cyfluthrin displayed increased levels of genotoxic damage (P < 0.05-0.001). Logistic regression was conducted to evaluate associations between pesticide exposure and risk of genotoxic damage. After adjustment for confounders, a significant increased risk of DNA strand breaks was found for high exposure to 2,4-D, odds ratio (OR) = 1.99 (P < 0.05). In contrast, high exposure to pyrethroids was associated with a reduced risk of DNA strand breaks, OR = 0.49 (P < 0.05). It was also found that high exposure to certain mixtures of pesticides (containing mainly 2,4-D or cyfluthrin) was significantly associated with increased level and risk of genotoxic damage (P < 0.05). In conclusion, our data show that high exposure levels to some pesticides is associated with an increased risk of genotoxic damage among Bolivian farmers, suggesting that their use should be better controlled or limited.