Combined cytotoxicity and genotoxicity of a marine toxin and seafood contaminant metal ions (chromium and cadmium)

Abstract

Algal bloom with consequent production of marine toxins contaminating bivalves is increasing in costal regions worldwide because of sea water quality worsening. Contamination of seafood by diarrheic shellfish poisoning toxins (DSP) together with metals is frequently reported, a phenomenon not fully explained yet. In this context, metal ions were assayed in clams collected from the banned area of Boughrara, Tunisia, contaminated by Gymnodinium and other algae such as Dinophysis sp, accumulated by these bivalves. The presence of toxic metals ions such as Chromium (Cr) and Cadmium (Cd) in meat, shells, and water released by the clams prompted us to experiment in Caco-2 intestinal cell line toxic effects of these heavy metals ions in combination with okadaic acid, one DSP present in clams to assess the potential global toxicity. Cr and Cd produce additive effects in (i) reactive oxygen species production, (ii) cytotoxicity as assessed by the mitochondrial activity testing method (MTT test), and (iii) DNA lesions evaluated by agarose gel electrophoresis and acridine orange staining. Exaggerated DNA fragmentation is observed, suggesting an overloading of repair capacity of Caco-2 cells. The apoptosis suggested by a DNA fragment sizing (180-200 bp) in agarose gel and mechanisms underlying these additive effects in Caco-2 cells still need to be more comprehensively explained.

Effect of okadaic acid on cultured clam heart cells: involvement of MAPkinase pathways

“…The cytotoxic effect of OA has been assessed in a wide variety of cell lines (HepG-2, Glioma cells and Caco-2) after treatment with OA 50 nM during 12 h (Souid-Mensi et al, 2008) and in primary neonatal rat cardiac myocytes after exposure during 18 h to OA 100 nM (Singh et al, 2000). The IC 50 was observed with low nanomolar range of OA: 40 nM in primary cortical cultures (Yi et al, 2005), 27 nM inV79 cells (Rodrigues et al, 2010) and 100 nM in Hela cells (Jayaraj et al, 2009) and U-937 (Ravindran et al, 2011) after 24 h treatment.…”

Effects of microcystins-containing cyanobacteria from a temperate ecosystem on human lymphocytes culture and their potential for adverse human health effects

“…Cyanobacteria are effective biological metal sorbents, representing an important sink for metals in aquatic environment (Cavet et al, 2003;Baptista and Vasconcelos, 2006). Therefore, the studied crude cyanobacterial extracts could contain trace metals, which evoke a variety of acute and chronic toxicity effects including apoptotic changes (Baptista and Vasconcelos, 2006;Palus et al, 2007;Souid-Mensi et al, 2008).…”

Assessment of Cr(VI)-Induced Cytotoxicity and Genotoxicity Using High Content Analysis

“…Although Caco-2 cells originate from the colon, when grown to post-confluency (∼21 days) they spontaneously differentiate and develop morphological characteristics of the small intestine including polarity, intercellular junctions, microvilli, and express markers for mature enterocytes such as brush border hydrolases; as such, Caco-2 are a well-accepted model for studying intestinal absorption, metabolism and cytotoxicity [30], [31], [32], [33], [34], [35]. A previous study reported that chromium (unspecified valence) increased lipid peroxidation in Caco-2 cells [36]. However, to our knowledge, the current study is the first to explore the genotoxicity of Cr(VI) in undifferentiated and differentiated Caco-2, a cell line highly relevant to the intestinal carcinogenicity of ingested Cr(VI).…”