Assessment of Mancozeb Exposure, Absorbed Dose, and Oxidative Damage in Greenhouse Farmers.

Mancozeb (MNZ) is a fungicide commonly employed in many countries worldwide. This study assesses MNZ absorption dynamics in 19 greenhouse farmers, specifically following dermal exposure, aiming to verify the efficacy of both preventive actions and protective equipment. For data collection, a multi-assessment approach was used, which included a survey to record study population features. MNZ exposure was assessed through the indirect measurement of ethylene thiourea (ETU), widely employed as an MNZ biomarker. The ETU concentration was measured with the patch method, detecting environmental ETU trapped in filter paper pads, applied both on skin and working clothes, during the 8 h work shift. Urine and serum end-of-shift samples were also collected to measure ETU concentrations and well-known oxidative stress biomarkers, respectively, namely reactive oxygen metabolites (ROMs), advanced oxidation protein products (AOPPs), and biological antioxidant potential (BAP). It was observed that levels of ETU absorbed and ETU excreted were positively correlated. Additionally, working clothes effectively protected workers from MNZ exposure. Moreover, following stratification of the samples based on the specific working duty (i.e., preparation and spreading of MNZ and manipulation of MNZ-treated seedlings), it was found that the spreading group had higher ETU-related risk, despite lower chronic exposure levels. AOPP and ROM serum levels were higher in MNZ-exposed subjects compared with non-exposed controls, whereas BAP levels were significantly lower. Such results support an increase in the oxidative stress upon 8 h MNZ exposure at work. In particular, AOPP levels demonstrated a potential predictive role, as suggested by the contingency analysis results. Overall, this study, although conducted in a small group, confirms that ETU detection in pads, as well as in urine, might enable assessment of the risk associated with MNZ exposure in greenhouse workers. Additionally, the measurement of circulating oxidative stress biomarkers might help to stratify exposed workers based on their sensitivity to MNZ. Pivotally, the combination of both ETU measurement and biological monitoring might represent a novel valuable combined approach for risk assessment in farmhouse workers exposed to pesticides. In the future, these observations will help to implement effective preventive strategies in the workplace for workers at higher risk, including greenhouse farmers who are exposed to pesticides daily, as well as to clarify the occupational exposure levels to ETU.

Contribution of the Glucosinolate Fraction to the Overall Antioxidant Potential, Cytoprotection against Oxidative Insult and Antimicrobial Activity of Eruca sativa Mill. Leaves Extract.

BACKGROUND: Eruca sativa Mill. (Brassicaceae) is commonly utilized as an ingredient in salads and also as a folk remedy to treat various diseases. OBJECTIVE: The objective of this study was to establish the contribution of the glucosinolate (GLS) fraction to the overall antioxidant, cytoprotection against oxidative insult and antimicrobial properties of the hydro-alcoholic extract of E. sativa leaves from Sicily (Italy), characterized phytochemically. MATERIALS AND METHODS: The antioxidant activity was evaluated by different in vitro systems. The cytoprotective effect against hydrogen peroxide (H2O2)-induced oxidative stress was tested in human peripheral blood mononuclear cells (PBMCs). The antimicrobial potential against bacteria and fungi was assayed by standard methods. RESULTS: E. sativa extract exhibited both radical scavenging (50% inhibitory concentration [IC50] 1.04 ± 0.04 mg/mL) and ferrous ions-chelating activity (IC50 0.327 ± 0.0032 mg/mL) and mild reducing power; the GLS fraction showed chelating ability only (IC50 0.225 ± 0.009 mg/mL). In the experimental model of H2O2-induced oxidative stress in human PBMCs, a significant cytoprotective effect and a suppression of reactive oxygen species production by both extract and GLS fraction were observed (P < 0.001). E. sativa extract displayed moderate antimicrobial activity against Gram-positive bacteria, and Staphylococcus aureus was the most sensitive strain (minimum inhibitory concentration 0.125 mg/mL), whereas the GLS fraction was not active. CONCLUSION: GLSs are not involved in the primary antioxidant activity of E. sativa leaf extract but they are, almost in part, responsible for its ferrous ion-chelating properties. Iron-chelating compounds in E. sativa extract may protect cells under conditions of oxidative stress, and GLSs might play a chief role in this effect. SUMMARY: Eruca sativa Mill. leaf extract exhibited antioxidant activity in different in vitro systems, whereas the glucosinolate (GLS) fraction showed Fe2+-chelating ability onlyA significant cytoprotective effect and a suppression of intracellular reactive oxygen species production by both extract and GLS fraction were observed in human peripheral blood mononuclear cellsE. sativa extract displayed moderate antimicrobial activity against Gram-positive bacteria, whereas the GLS fraction was not active. Abbreviations used: GLS: Glucosinolate; H2O2: Hydrogen peroxide; PBMCs: Peripheral blood mononuclear cells; IC50: 50% inhibitory concentration; MIC: Minimum inhibitory concentration.

Release of nickel and chromium in common foods during cooking in 18/10 (grade 316) stainless steel pots.

BACKGROUND: Literature data on the release of nickel and chromium from stainless steel cookware during food preparation are contrasting, have often been obtained with uncommon foods and/or procedures, and are thus not widely applicable. OBJECTIVES: To assess the release of nickel and chromium from 18/10 (grade 316) stainless steel pots in cooking conditions that are common in an urban lifestyle. METHODS: Tomato sauce and lemon marmalade were cooked for 1 h, alone or with added EDTA, in used or unused stainless steel pots from different manufacturers. Additionally, aqueous solutions at pH 2.3, 7.7 and 9 were boiled for 1 h in the same pots. Metal release was assessed with inductively coupled plasma mass spectrometry. RESULTS: The release of nickel and chromium increased with cooking/boiling time, was higher with unused pots, at low pH or with EDTA, and was sometimes remarkably different between manufacturers. In all experiments, the amounts released were below known allergy-triggering thresholds. CONCLUSIONS: Under common conditions, the use of 18/10 stainless steel pots is considered to be safe for the majority of nickel-allergic and/or chromium-allergic subjects. However, the total amount of nickel contained in foods and released from pots may exceed the individual threshold for triggering allergy, potentially causing problems for highly sensitive patients, or, conversely, contribute to induction of immunotolerance by oral low-dose exposure.

IL-17 and IL-22 serum levels in greenhouse workers exposed to pesticides.

INTRODUCTION: Altered immune function may be an indicator of increased potential for the development of immunologically based diseases such as cancer, hypersensitivity and autoimmunity. MATERIALS AND METHODS: To investigate whether Th17 and Th22 cells are targeted by pesticide exposure, we analyzed IL-17 and IL-22 serum levels in a population of 64 greenhouse workers. RESULTS AND CONCLUSION: A significant increase in IL-22 concentration was observed in serum of the exposed subjects compared to controls. These findings support the hypothesis that exposure to pesticides may reduce host defenses against infections and cancer.

Cytokine patterns in greenhouse workers occupationally exposed to α-cypermethrin: an observational study.

The immunotoxicity of the synthetic pyrethroid α-cypermethrin (αCYP) was assessed in 30 occupationally exposed greenhouse workers and 30 non-exposed controls by comparing plasma levels of IL-1ß, IL-2, IL-4, IL-5, IL-6, IL-8, IL-10, IL-12p70, TNF-α, TNF-ß and INF-γ. Urinary 3-phenoxybenzoic acid was used as an exposure biomarker. Exposed workers showed neither clinical signs of immunosuppression nor alterations in total leukocytes or leukocyte subpopulations, whereas significant differences (p<0.05) were found for IL-12p70 and highly significant differences (p<0.001) for INF-γ, IL-2 and IL-8, which are involved in antitumor immunity and response to infection. Proinflammatory cytokines IL-2, IL-8, IL-12p70 and IFN-γ play a significant role against infection and cancer. We report the first data on the ability of αCYP to reduce proinflammatory cytokine levels in an exposed healthy human population. Findings support the hypothesis that pyrethroid exposure may reduce host defenses against infection and cancer, particularly in subjects with impaired immune capacity.

Antiproliferative activity of the dietary isothiocyanate erucin, a bioactive compound from cruciferous vegetables, on human prostate cancer cells.

It is becoming increasingly clear that many dietary agents, such as isothiocyanates (ITCs) from cruciferous vegetables, can retard or prevent the process of prostate carcinogenesis. Erucin (ER) is a dietary ITC, which has been recently considered a promising cancer chemopreventive phytochemical. The potential protective activity of ER against prostate cancer was investigated using prostate adenocarcinoma cells (PC3), to analyze its effects on pathways involved in cell growth regulation, such as the cyclin-dependent kinase (CDKs) inhibitor p21(WAF1/CIP1) (p21), phosphatidylinositol-3 kinase/AKT, and extracellular signal-regulated kinases (ERK)1/2 signaling pathways. We have shown for the first time that ER increases significantly p21 protein expression and ERK1/2 phosphorylation in a dose-dependent manner to inhibit PC3 cell proliferation (P ≤ 0.01). Compared to the structurally related sulforaphane, a well-studied broccoli-derived ITC, ER showed lower potency in inhibiting proliferation of PC3 cells, as well as in modulating p21 and pERK1/2 protein levels. Neither of the naturally occurring ITCs was able to affect significantly pAKT protein levels in prostate cells at all concentrations tested (0-25 µM). It is clearly important for the translation of laboratory findings to clinical approaches to investigate in animal and cell studies the molecular mechanisms by which ITCs may exert health promoting effects.

Antimicrobial activity and phenolic content of natural site and micropropagated Limonium avei (De Not.) Brullo & Erben plant extracts.

This study reported the antimicrobial activity and phenolic content of natural site and micropropagated Limonium avei (De Not.) Brullo & Erben inflorescences. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of ethanolic extracts were determined according to the Clinical Laboratory Standards Institute guidelines. Individual phenolic acids and flavonoids were detected by a high performance liquid chromatography (HPLC-DAD) method. The samples showed a comparable antimicrobial activity, although the natural site extract possessed the lower MIC values. The best activity was detected against Gram-positive bacteria, such as Staphylococcus aureus including methicillin resistant strains (MIC and MBC values ranging from 7.81 to 62.50 µg mL(-1) and from 500 to 2000 µg mL(-1) respectively). In contrast, a low activity was found on Gram-negative bacteria and Candida albicans. The HPLC-DAD analysis revealed ten phenolic acids and four flavonoids with a major amount of m-coumaric acid, naringin and quercetin in the natural site extract.

Interaction of a functionalized complex of the flavonoid hesperetin with the AhR pathway and CYP1A1 expression: involvement in its protective effects against benzo[a]pyrene-induced oxidative stress in human skin.

Skin cancer pathogenesis is partially associated to the oxidative stress conditions induced by environmentally carcinogens such as benzo[a]pyrene (BaP). The protective effects against BaP-induced oxidative stress of the flavonoid hesperetin as a complex with the 2-hydroxypropyl-ß-cyclodextrin (HE/HP-ß-CyD) have been evaluated using an ex vivo human skin model. Human healthy skin has been pre-treated with the functionalized complex HE/HP-ß-CyD (0.5-50 µM) before BaP (5 µM) application simulating occupational and environmental exposure. Oxidative stress was evaluated in terms of 3-(4, 5-dimethylthiazol-2-yl)-2, 5-dipheyltetrazolium bromide reduction, protein peroxidation and reactive oxygen species (ROS) formation. Additionally, it has been investigated whether the potential protective effects of HE/HP-ß-CyD may be correlated to the interaction with aryl hydrocarbon receptor (AhR) pathway. A significant protection by HE/HP-ß-CyD against the BaP-induced increase in ROS and carbonyl compound production, as well as reduction in tissue viability, has been observed (p<0.001). Results obtained showed that HE/HP-ß-CyD was also able to reduce BaP-induced AhR and CYP1A1 protein expression (p<0.001). Experimental evidences provided from this study suggest significant preventive properties of HE/HP-ß-CyD in the toxicity caused by environmental carcinogens such as PAHs.

Changes induced by exposure of the human lung to glass fiber-reinforced plastic.

The inhalation of glass dusts mixed in resin, generally known as glass fiber-reinforced plastic (GRP), represents a little-studied occupational hazard. The few studies performed have highlighted nonspecific lung disorders in animals and in humans. In the present study we evaluated the alteration of the respiratory system and the pathogenic mechanisms causing the changes in a group of working men employed in different GRP processing operations and exposed to production dusts. The study was conducted on a sample of 29 male subjects whose mean age was 37 years and mean length of service 11 years. All of the subjects were submitted to a clinical check-up, basic tests, and bronchoalveolar lavage (BAL); microscopic studies and biochemical analysis were performed on the BAL fluid. Tests of respiratory function showed a large number of obstructive syndromes; scanning electron microscopy highlighted qualitative and quantitative alterations of the alveolar macrophages; and transmission electron microscopy revealed the presence of electron-dense cytoplasmatic inclusions indicating intense and active phlogosis (external inflammation). Biochemical analyses highlighted an increase in protein content associated with alterations of the lung oxidant/antioxidant homeostasis. Inhalation of GRP, independent of environmental concentration, causes alterations of the cellular and humoral components of pulmonary interstitium; these alterations are identified microscopically as acute alveolitis.

In vitro evaluation of oxidative damage from organic solvent vapours on human skin.

Aim of this study is to focus on the cutaneous effects of occupational exposure to the vapours of common organic solvents. Higher incidence of cancer is suspected in subjects exposed to organic solvents characterized by reactive metabolic intermediates, which are assumed to induce oxidative damage on liver, kidney and haematopoietic system. To our knowledge there are no relevant data about the oxidative effect of the organic solvents on skin after exposure to their vapours. An in vitro model was optimized to evaluate the viability and integrity of the barrier function of human skin following occupational exposure to solvent vapours. To evaluate the role of oxidative stress, the antioxidant status of skin and some biomarkers of oxidative damage as lipid and protein peroxidation products and DNA fragmentation were also studied. It was investigated if decreasing concentrations of styrene, toluene, acetone, xylene and perchloroethylene vapours, up to be comparable to the TLV-TWA, were able to damage skin integrity. Solvent vapours reduced tissue viability and impaired skin barrier function, as indicated by the increase of transepidermal water loss. Reduced glutathione depletion, decreased activity of antioxidant enzymes and oxidative damage of biological macromolecules were also observed. The overall trend of these results indicates that the tested compounds damage human skin even at concentrations comparable to their TLV, and that oxidative stress is involved in these effects.

Evaluation of extracts and isolated fraction from Capparis spinosa L. buds as an antioxidant source.

The antioxidant activity of extracts from Capparis spinosa L. buds was evaluated using different in vitro tests: ascorbate/Fe(2+)-mediated lipid peroxidation of microsomes from rat liver; bleaching of 1,1-diphenyl-2-picryl-hydrazyl radical; and autoxidation of Fe(2+) ion in the presence of bathophenanthroline disulfonate. The methanolic extract showed strong activities in all of these in vitro tests. The amount of total phenols was determined in the methanolic extract. In addition, the level of rutin was calculated as 0.39% (w/w) by HPLC analysis. Our findings indicate the following: (a) the antioxidant efficiency of the methanolic extract may be attributed to its phenolic content; and (b) the antioxidant activity of the methanolic extract was maintained after removal of glucosinolates, confirming that these compounds do not interfere with the antioxidant properties of the extract. The results obtained from this study exalt the nutritional value of the flowering buds (capers) which are widely used as a source of flavor.