In vitro genotoxicity assays for environmental monitoring at the upper Paraná River waters (Misiones, Argentina)

CAFFETTI JD; MANTOVANI MS; BALMACEDA R; PASTORI MC; FENOCCHIO AS

Natal, Río Grande do Norte

Congreso; 9th Congress of Toxicology in Developing Countries and XIX Congresso Brasileiro de Toxicologia; 2015

International Union of Toxicology and Sociedade Brasileira de Toxicologia

The Paraná River is the second most important drainage basin in South America and concentrates some of the major urban and industrial areas from Brazil and Argentina through its course. This freshwater system has received special attention due to the intensive anthropic modifications suffered. In vitro assays based on mammalian cell lines are commonly used in genotoxicity test and can offer an interesting alternative in ecotoxicology studies. The present work proposes to evaluate the genotoxic and cytotoxic potential of water from four different sites along the Upper stretch of Parana River (Misiones Province, Argentina) during the period 2009-2011. For this purpose, were applied the in vitro micronucleus (MN), nuclear alterations (NA) and comet (CA) assays by exposing CHO cells during 2 hours (CA) and 15 hours (MN and NA). The mitotic index (MI) was calculated to assess the cytotoxicity. Positive and negative controls were performed employing 0.4 mM of Methilmetanesulphonate and PBS solutions respectively. Simultaneously, a Water Quality Index (WQI) was established for each sample site and the results obtained for all treatments were compared using ANOVA and Kruskal-Wallis test. Genotoxic effects were detected in all cases, both the MN/NA and CA assays showed the higher DNA damage over the last two years (2010 and 2011). Statistical differences (p< 0.05) from the negative control were observed in almost all sampling sites and these data correlate with lower values of WQI and MI. Water samples from the two sites that receive effluents from paper mill industries promoted the higher DNA damage level detected with both techniques. Only the site that receives wastes without any treatment system showed statistical differences in relation to the control in all studied years. The other two sample sites, northern and southern, induced lower damage level. Complex mixtures of paper mill industries and urban wastes in Upper Paraná River waters could induce direct damage potentially repairable as detected by comet assay, as well as other DNA damage evidenced by the presence of MN, nuclear buds and nucleoplasmic bridges associated to the presence of substances that induce aneugenic and clastogenic effects. The in vitro assay using CHO cells showed high sensitivity to DNA damage after exposure to the different water samples with both genotoxicity tests and can represent a suitable alternative for environmental monitoring of freshwater bodies. Genetic biomarkers like MN, NA and CA represent sensitivity early-warning signals in response to pollution and constitute a good complementary tool with physicochemical analysis for an integral evaluation of aquatic environments.