Protective effect of selenium and vitamin C on the fertility of male rats given penconazole

OBJECTIVE

Penconazole is used in agriculture and human and veterinary medicine applications. It has been included in the acute toxicity hazard category by the WHO. This study examines the protective effect of selenium and vitamin C on the fertility of male rats given penconazole.

METHODS

Nine groups of rats were given penconazole at concentrations of 50 and 75 mg/ml and selenium and vitamin C at concentrations of 0.5 and 100 mg/ml, respectively. Serum levels of LH and FSH were measured with ELISA kits; β-actin, GPX4, AQP7, PRM2, and BAX gene expression was evaluated with real-time PCR performed on the left testis of each rat.

RESULTS

LH, FSH, and testosterone levels were lower in the groups given penconazole (50 and 75 mg/kg). Histopathology showed that the groups given penconazole had the lowest number of spermatogonia and primary spermatocytes; these numbers were greater in the groups receiving penconazole together with selenium or vitamin C; and the highest counts were observed in separate groups given Se and vitamin C. GPX4, AQP7, PRM2 and BAX gene expression in the groups receiving penconazole was different from controls and was modulated by treatment with selenium or vitamin C.

CONCLUSIONS

This study showed that antioxidant compounds have a strengthening effect on the reproductive system and can mitigate the destructive effects of chemical fungicides.

Protective effects of N-acetyl-l-cysteine against penconazole-triggered hepatorenal toxicity in adult rats

Introduction

Penconazole (PEN) is a widely applied triazole fungicide. This study sought to define the efficacy of N-acetyl-l-cysteine (NAC) in mitigating PEN-triggered hepatorenal toxicity in rats.

Material and Methods

Twenty-eight adult male albino Wistar rats were assigned to four groups: a normal control (NC), a PEN group, a NAC group and a PEN+NAC group. Administration of PEN (50 mg/kg body weight (b.w.) every 2 days) and NAC (150 mg/kg b.w., daily) took place via oral gavage for 10 days.

Results

Effective amelioration by NAC of PEN-induced liver and kidney dysfunction was indicated by a significant reduction in the circulating liver and kidney markers (aspartate aminotransferase, alanine aminotransferase, urea and creatinine). Attenuation of PEN-induced oxidative stress and lipid peroxidation in liver and kidney tissues was evident in a significant reduction in malondialdehyde and enhanced total antioxidant capacity. Moreover, NAC significantly reduced the histopathological alterations and the expression of tumour necrosis factor α in liver and kidney tissue. Furthermore, NAC maintained the messenger RNA levels of nuclear factor erythroid 2-related factor 2 (Nrf2), haem oxygenase 1, and Kelch-like erythroid cell-derived protein 1 and prevented nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) protein upregulation caused by PEN.

Conclusion

N-acetyl-1-cysteine protected against PEN-induced hepatorenal oxidative damage and inflammatory response via activation of Nrf2 and inhibition of NF-κB pathways.

Triazoles as a Potential Threat to the Nutritional Quality of Tomato Fruits

Triazole fungicides can threaten plants as abiotic stressors but can also positively affect plant defense by inducing priming. Thus, plant yield is also both protected and endangered by triazoles that may influence several metabolic pathways during maturation processes, such as the biosynthesis of saccharides or secondary metabolites. Here, Solanum lycopersicum L. plants were exposed to foliar and soil applications of penconazole, tebuconazole, or their combination, and their resulting effect on tomato fruits was followed. The exposure to the equimolar mixture of both triazoles influenced the representation of free proteinogenic amino acids, especially Gln, Glu, Gly, Ile, Lys, Ser and Pro, saccharide content, and led to a significant increase in the contents of total phenolics and flavonoids as well as positive stimulation of the non-enzymatic antioxidant system. Among the identified secondary metabolites, the most abundant was naringenin, followed by chlorogenic acid in tomato peel. In turn, all triazole-treated groups showed a significantly lower content of rosmarinic acid in comparison with the control. Foliar application of penconazole affected the fruit more than other single triazole applications, showing a significant decrease in antioxidant capacity, the total content of secondary metabolites, and the activities of total membrane-bound peroxidases and ascorbate peroxidase.

Induced Expression of CYP51a and HK1 Genes Associated with Penconazole and Fludioxonil Resistance in the Potato Pathogen Fusarium oxysporum

Preventing antifungal resistance development and identifying pathogens with high, medium, and low risk of resistance development to a particular fungicide or fungicide class is crucial in the fight against phytopathogens. We characterized the sensitivity of potato wilt-associated Fusarium oxysporum isolates to fludioxonil and penconazole and assessed the effect of these fungicides on the expression of fungal sterol-14-α-demethylase (CYP51a) and histidine kinase (HK1) genes. Penconazole stunted the growth of F. oxysporum strains at all concentrations used. While all isolates were susceptible to this fungicide, concentrations of up to 1.0 μg/mL were insufficient to cause a 50% inhibition. At low concentrations (0.63 and 1.25 μg/mL), fludioxonil stimulated growth in F. oxysporum. With an increase in the concentration of fludioxonil, only one strain (F. oxysporum S95) exhibited moderate sensitivity to the fungicide. Interaction of F. oxysporum with penconazole and fludioxonil leads to respective elevated expressions of the CYP51a and HK1 genes, which upsurge with increasing concentration of the fungicides. The data obtained indicate that fludioxonil may no longer be suitable for potato protection and its continuous use could only lead to an increased resistance with time.

Evaluation of confirmatory data following the Article 12 MRL review and modification of the existing maximum residue levels for penconazole in various crops

The applicant Syngenta Crop Protection AG submitted a request to the competent national authority in Germany to evaluate the confirmatory data that were identified for penconazole in the framework of the maximum residue level (MRL) review under Article 12 of Regulation (EC) No 396/2005 as not available. Moreover, in the application submitted to Germany, the applicant also included a request to raise the existing MRLs in pome fruits, raspberries and blackberries. To address the data gaps, detailed results on the metabolism substudy in tomato, a new storage stability on metabolites CGA127841, CGA132465 and CGA190503 and new residue trials were submitted. The data gap on metabolism was considered satisfactorily addressed. The data gap on complete sets of residue trials analysing simultaneously for monitoring and risk assessment residue definitions was considered addressed for raspberries, blackberries, pumpkins and watermelons; not addressed for pome fruits, stone fruits, grapes, gooseberries, tomatoes and aubergines. The new information provided justified an increase of the existing MRLs for pome fruits, plums, blackberries and raspberries and a revision of the risk assessment performed for penconazole. Adequate analytical methods for enforcement are available to control the residues of penconazole on the commodities under consideration at the validated limit of quantification (LOQ) of 0.01 mg/kg. Based on the risk assessment results, EFSA concluded that the short-term and long-term intake of residues resulting from the use of penconazole according to the reported agricultural practices is unlikely to present a risk to consumer health.

The ameliorative effect of N-acetylcysteine against penconazole induced neurodegenerative and neuroinflammatory disorders in rats

Penconazole (PEN) is a widely used systemic fungicide to treat various fungal diseases in plants but it leaves residues in crops and food products causing serious environmental and health problems. N-acetylcysteine (NAC) is a precursor of the antioxidant glutathione in the body and exerts prominent antioxidant and anti-inflammatory effects. The present study aimed to explore the mechanistic way of NAC to ameliorate the PEN neurotoxicity in male rats. Twenty-eight male rats were randomly divided into four groups (n = 7) and given the treated material via oral gavage for 10 days as the following: Group I (distilled water), Group II (50 mg/kg body weight [bwt] PEN), Group III (200 mg/kg bwt NAC), and Group IV (NAC + PEN). After 10 days all rats were subjected to behavioral assessment and then euthanized to collect brain tissues to perform oxidative stress, molecular studies, and pathological examination. Our results revealed that PEN exhibits neurobehavioral toxicity manifested by alteration in the forced swim test, elevated plus maze test, and Y-maze test. There were marked elevations in malondialdehyde levels with reduction in total antioxidant capacity levels, upregulation of messenger RNA levels of bax, caspase 3, and caspase 9 genes with downregulation of bcl2 genes. In addition, brain sections showed marked histopathological alteration in the cerebrum and cerebellum with strong bax and inducible nitric oxide synthetase protein expression. On the contrary, cotreatment of rats with NAC had the ability to improve all the abovementioned neurotoxic parameters. The present study can conclude that NAC has a neuroprotective effect against PEN-induced neurotoxicity via its antioxidant, anti-inflammatory, and antiapoptotic effect. We recommend using NAC as a preventive and therapeutic agent for a wide variety of neurodegenerative and neuroinflammatory disorders.

Impacts of Penconazole and Its Enantiomers Exposure on Gut Microbiota and Metabolic Profiles in Mice

Exposure to chiral pesticides poses many potential health risks. In this study, we examined the impacts of exposure to penconazole and its enantiomers on gut microbiota and metabolic profiles in mice. The relative abundance of microbiota in cecal content significantly changed following exposure to penconazole and its enantiomers. At the genus level, the relative abundances of seven gut microflora were altered following exposure to (-)-penconazole. Both (±)-penconazole and (+)-penconazole caused significant changes in the relative abundances of five gut microflora. In addition, targeted serum metabolomics analysis showed disturbed metabolic profiles following exposure. Respectively, (±)-penconazole, (+)-penconazole, and (-)-penconazole exposure significantly altered the relative levels of 29, 23, and 36 metabolites. In general, exposure to penconazole and its enantiomers caused disorders in gut microbiota and metabolic profiles of mice. The potential health risks of penconazole and its enantiomers now require further evaluation.

Quantifying pesticide deposits and spray patterns at micro-scales on apple (Malus domesticus) leaves with a view to arthropod exposure

BACKGROUND

Pesticides used in commercial crop systems can adversely affect non-target arthropod populations. The spatial distribution of pesticide residues is rarely studied at scales relevant to these populations. Here, we combine two methods for assessing pesticide spray deposits at spatial scales relevant to non-target arthropods found in apple orchards. Pesticide residues were determined on individual apple leaves through conventional residue analysis; water-sensitive paper was used to investigate spatial distributions in deposits at the micro-scale. We also evaluated how accurately a digital image analysis program estimated pesticide residues.

RESULTS

We found that mean pesticide spray coverage on water-sensitive paper varied by up to 6.1% (95% CI 9.4%, 2.7%) within an apple orchard, and leaf residues varied by up to 0.95 (95% CI 0.54, 1.36) mg kg^-1 within a tree. Leaf residues based on analytical chemistry were six times lower than pesticide deposition estimated through image analysis of water-sensitive paper, although these correlated strongly. This correlation allowed estimation of actual residues by application of a correction factor.

CONCLUSION

Our method demonstrates accurate estimation of pesticide deposits at the individual leaf scale through digital analysis of water-sensitive paper and is a low-cost, rapid alternative to conventional residue analysis techniques. © 2018 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Development of a Biomarker for Penconazole: A Human Oral Dosing Study and a Survey of UK Residents' Exposure

Penconazole is a widely used fungicide in the UK; however, to date, there have been no peer-reviewed publications reporting human metabolism, excretion or biological monitoring data. The objectives of this study were to i) develop a robust analytical method, ii) determine biomarker levels in volunteers exposed to penconazole, and, finally, to iii) measure the metabolites in samples collected as part of a large investigation of rural residents' exposure. An LC-MS/MS method was developed for penconazole and two oxidative metabolites. Three volunteers received a single oral dose of 0.03 mg/kg body weight and timed urine samples were collected and analysed. The volunteer study demonstrated that both penconazole-OH and penconazole-COOH are excreted in humans following an oral dose and are viable biomarkers. Excretion is rapid with a half-life of less than four hours. Mean recovery of the administered dose was 47% (range 33%-54%) in urine treated with glucuronidase to hydrolyse any conjugates. The results from the residents' study showed that levels of penconazole-COOH in this population were low with >80% below the limit of detection. Future sampling strategies that include both end of exposure and next day urine samples, as well as contextual data about the route and time of exposure, are recommended.

Enantioselective analysis and dissipation of triazole fungicide penconazole in vegetables by liquid chromatography-tandem mass spectrometry

Penconazole is a typical triazole fungicide, which is commonly used to control powdery mildew in vineyard and vegetable field. In this study, the enantioselective dissipation of penconazole in cucumber, tomato, head cabbage, and pakchoi was investigated by field experiments. A sensitive method for enantiomeric analysis of penconazole was established on the basis of the buffered QuEChERS sample preparation technique followed by reverse-liquid chromatography equipped with a TSQ Discovery triple quadrupole mass spectrometer and a Lux Cellulose-2 chiral column. Methanol and 2 mM ammonium acetate buffer solution containing 0.1% formic acid (70:30, v/v) were used as mobile phase at a 0.2 mL L(-1) flow rate isocratic elution. The linearity, recovery, and precision of this method were also evaluated. Finally, the results of this study demonstrated that enantioselective dissipation occurred in head cabbage and pakchoi, with the preferential degradation of (-)-penconazole, and resulting in an enrichment of the (+)-penconazole residue in the two vegetables. However, the enantioselective behavior was not observed in cucumber and tomato. More importantly, this is the first report of enantioselective behavior of penconazole, and the result may provide useful information for the risk evaluation of penconazole in food and environmental safety.

Effect of Wine-Making Practices on the Concentrations of Fenarimol and Penconazole in Rosé Wines

The changes in and influence of the anti-powdery-mildew fungicides fenarimol and penconazole were studied in the production and quality of rosé wines made with Monastrell grapes grown in the Jumilla wine-producing region in SE Spain. Fungicide concentrations were estimated by gas-liquid chromatography with electron-capture detection. Fermentation was retarded more by penconazole than by fenarimol; in both cases, the slowdown was directly proportional to fungicide concentration. However, the mature wine contained normal concentrations of residual sugars; other enological parameters (pH, volatile acidity, intensity of color and hue) were not significantly affected. Thirty-four days after the start of the experiment, 67% of fenarimol and 52% of penconazole, with respect to the smaller amount initially added (1 mg/liter), were found in the finished wine. The calculated half-life times were 45 and 59 days for penconazole and fenarimol respectively. Different wine-making techniques (racking, clarification, and filtration) had no decisive influence on the removal of fungicide residues from the must, although they eliminated slightly more penconazole than fenarimol.