Acute exposure to a commercial formulation of Azoxystrobin alters antioxidant enzymes and elicit damage in the aquatic macrophyte Myriophyllum quitense

Abstract

Azoxystrobin is a strobilurin of growing concern in aquatic environments because it is the most sold fungicide worldwide, however, the information available about its effect on aquatic non-target organisms is scarce. The objective of the present study was to evaluate potential physiological, biochemical, and genetic effects at environmentally relevant (1-10 lg/L) and elevated (100-500 lg/L) concentrations in the aquatic macrophyte Myriophyllum quitense exposed to the commercial formulation AMISTAR Ò . Following an acute 24-h exposure, there were no effects of AMISTAR Ò on photosynthetic pigments at any of the concentrations evaluated. Glutathione-S-transferase activity was significantly elevated at 1 and 10 lg/L AZX. Significant decrease of catalase and guaiacol peroxidase activities in plants exposed to 500 lg/ L, and to 100 and 500 lg/L, respectively, and an increase in glycolate oxidase activity at 500 lg/L was observed. DNA damage at 100 and 500 lg/L was observed. These data indicate that although environmentally relevant levels of AMISTAR Ò did not result cytotoxic, this fungicide was genotoxic, affecting the physiological process of photorespiration and caused oxidative damage at high concentrations. In this sense, it is necessary to explore sublethal responses in non-target organisms because some effects could promote further potential long-term biological consequences in a context of repeated pulses of exposure.

Azoxystrobin Impairs Neuronal Migration and Induces ROS Dependent Apoptosis in Cortical Neurons

“…Mounting evidence suggests that activated mTORC1 and its downstream S6K enhance axon formation and elongation [13]. Here, we investigated whether the reduction of neurite formation on primary cortical neurons by AZOX treatment was related to the mTORC1-S6 axis.…”

“…We observed markers Tuj1 and pS6 were significantly reduced in AZOX treatment, implying a reduction in neurite length and S6 activity (Figure 5C-F). Mounting evidence suggests that activated mTORC1 and its downstream S6K enhance axon formation and elongation [13]. Here, we investigated whether the reduction of neurite formation on primary cortical neurons by AZOX treatment was related to the mTORC1-S6 axis.…”

“…Moreover, it induces mitochondria-mediated apoptosis in KYSE-150esophageal squamous carcinoma cells [2]. In another instance, this fungicide was defined as a genotoxic element that alters the physiological process by oxidative damage at high concentrations, which can promote possible long-term biological consequences [13]. In lower organisms, AZOX compromises with superoxide dismutase (SOD), peroxidase (POD), glutathione S transferase (GST), glutathione peroxidase (GPx) activities, and glutathione (GSH) content, and induces reactive oxygen species (ROS) overproduction [14], demonstrated to cause acute mortality to tadpoles [15].…”

The impact of pesticides on non-target organisms

“…Fungicide exposure can lead to rapid depletion of animal intracellular glutathione and decreased cellular respiration, altering healthy physiological functioning, which may explain these responses 26 transpiration. The decreased growth and reproduction of plants may be linked to reductions in photosynthesis through known modes of action of herbicides 28 , as well as by off-target effects for selected insecticides 29 and fungicides 30 . These include impacts on the cell cycle (e.g.…”

Cytological Effects of Herbicidal and Fungicidal Pesticides on Root Apex Meristem Cells of Triticum Aestivum

“…Pesticides have selective and targeted activity against mycopathogens and crop weeds. However, the selectivity of pesticide activity is not absolute: the evolutionary conservatism of many molecular-cellular events determines the activity of pesticides with respect to non-target organisms [16,17,18,19,20,21,22]. In this regard, cytogenetic studies of pesticides with respect to cereal crops, which are the main source in the nutritional structure of the world's population, are very important.…”