Mancozeb impairs mitochondrial and bioenergetic activity in Drosophila melanogaster

Investigation on the mancozeb toxicity in adult zebrafish (Danio rerio)

Agriculture has gained increasing importance in response to the continuous growth of the world population and constant need for food. To avoid production losses, farmers commonly use pesticides. Mancozeb is a fungicide used in agriculture as this compound is effective in combating fungi that harm crops. However, this fungicide may also produce damage to non-target organisms present in soil and water. Therefore, this study aimed to investigate the influence of exposure to mancozeb on survival rate, locomotor activity, behavior, and oxidative status utilizing adult zebrafish (Danio rerio) as a model following exposure to environmentally relevant concentrations of this pesticide. The experimental groups were negative control, positive control, and mancozeb (0.3; 1.02; 3.47; 11.8 or 40 μg/L). Zebrafish were exposed to the respective treatments for 96 hr. Exposure to mancozeb did not markedly alter survival rate and oxidative status of Danio rerio. At a concentration of 11.8 μg/L, the fungicide initiated changes in locomotor pattern of the animals. The results obtained suggest that the presence of mancozeb in the environment might produce locomotor alterations in adult zebrafish, which subsequently disrupt the animals' innate defense mechanisms. In nature, this effect attributed to mancozeb on non-target organisms might result in adverse population impacts and ecological imbalance.

Pre-imaginal exposure to mancozeb induces morphological and behavioral deficits and oxidative damage in Drosophila melanogaster

Mancozeb (MZ), a manganese/zinc containing ethylene-bis-dithiocarbamate, is a broad-spectrum fungicide. Chronic exposure to MZ has been related to several organisms' neurological, hormonal, and developmental disorders. However, little is known about the post-natal effects of developmental exposure to MZ. In this study, Drosophila melanogaster was subjected to a pre-imaginal (eggs-larvae-pupae stage) model of exposure to MZ at 0.1 and 0.5 mg/mL. The emergence rate, body size, locomotor performance, sleep patterns, and molecular and biochemical parameters were evaluated in post-emerged flies. Results demonstrate that pre-imaginal exposure to MZ significantly impacted early emerged flies. Additionally, reduced progeny viability, smaller body size and delaying in emergence period, locomotor impairment, and prolonged sleep time were observed. Content of glucose, proteins, and triglycerides were altered, and the bioenergetics efficiency and oxidative phosphorylation at complex I were inhibited. mRNA stade state levels of genes responsive to stress, metabolism, and regulation of circadian cycle (Nrf2, p38, Hsp83, Akt1, GPDH, tor, per, tim, dILP2, and dILP6) were augmented, pointing out to stimulation of antioxidant defenses, insulin-dependent signaling pathway activation, and disruption of sleep regulation. These data were followed by increased lipid peroxidation and lower glutathione levels. In addition, the activity of catalase and glutathione-S-transferase were induced, whereas superoxide dismutase was inhibited. Together, these results demonstrate that developmental exposure to MZ formulation led to phenotype and behavioral alterations in young flies, possibly related to disruption of energetic metabolism, oxidative stress, and deregulation of genes implied in growth, sleep, and metabolism.

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.