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Abstract

The aim of the present study was to ascertain whether the metallothioneins (MTs) of freshwater mussels can serve as a biomarker of environmental quality in the spontaneously polluted area. Anodonta anatina mussels from an agricultural site (A), the cooling pond of a nuclear power plant (N) and a forestry as a reference site (F) in Western Ukraine were studied during spring, summer and autumn. Concentrations of copper (Cu), zinc (Zn) and cadmium (Cd) in MTs and in the tissue, MTs protein (MT-SH) level, oxidative stress indices and apoptotic activities were determined in the digestive gland. The three sites were clear distinguished by biomarkers. In the A-group, the specimens, despite higher concentrations of Cu and Zn in the tissue, had low level of MT-SH level (in two seasons) making the metal-keeping function of MTs invalid. MTs-bound metals dropped to about 2.3% of Cu, 0.4% of Zn and 9.1% of Cd in the tissue in autumn in this polluted area. Lower level of glutathione redox-index reflected the oxidative stress in this group. The N-group displayed high levels of MT-bound Cu (corresponding to up to 57.7% of the total tissue metal) and caspase-3 activity (up to 7 times higher than in the reference Fgroup), indicating specific for cooling pond pollution by Cu and thermal effects. In group F, the set of markers showed the characteristic of the reference site. An extremely low redox-index of glutathione (RI GSH: 0.45) was observed in the A-group in spring, and high levels of protein carbonyls and TBA-reactive substances in autumn in group N.Hence, multi-marker approach needed to provetoxicityassesments in mussel sexposed byspontaneous and mixed pollution.

Zebrafish as a suitable model for studying the mode of action and harmfulness of organophosphate pesticides

“…Thus, it is highly likely that roundup and chlorpyrifos would have caused alterations in DNA integrity of Danio rerio. Our data corroborate with previously reported pesticide-mediated DNA damage in different fish species [2,8]. However, when fish were exposed by mix of organophosphate pesticides unexpected DNA strand break level in line with control was disclosed.…”

“…For the characteristics of apoptosis, activities of both cytosolic and lysosomal proteases were detected. The activity of an apoptosis executor caspase-3 was assayed at 405 nm (ε mM = 10.5 mM −1 ⋅cm −1 ) [8,16]. Acetylcholinesterase (AChE) activity was spectrophotometrically determined in the supernatant of brain tissue homogenate (1:10 w:v) as an increase in optical density of the sample measured at 412 nm [17] with acetylthiocholine applied as a substrate.…”

“…A lot of pollutants provoke oxidative stress in animals, including cyprinid fish, which is considered to be one of the main mechanisms of non-specific effects of pollutants [2,8,33]. It has been shown that organophosphate pesticides stimulate the generation of ROS and cause lipid peroxidation and/or protein carbonylation.…”

“…Zebrafish demonstrate universal to vertebrates' responses to stress and toxicants, which make these organisms important in extrapolating the results for assessment of the biosafety of human environment. The state of the body was assessed by the indicators of stress and toxicity validated in our previous studies [7][8][9]. In particular, the oxidative stress block included catalase activity, total antioxidant capacity, lipid and protein peroxidation.…”