Cytotoxic effects induced by hexachlorobenzene in Squilla mantis (L.) (Crustacea, Stomatopoda)

Abstract

Contamination of marine environments by hexachlorobenzene (HCB) represents a serious concern for potential consequences on ecosystem and human health. Despite this, information on cytotoxic effects on marine organisms is still largely lacking. In this study, we investigated cytotoxic effects induced by HCB on gonads and muscular tissue of Squilla mantis by analysing Na 1 /K 1 -ATPase activity and plasma membrane fluidity. This crustacean species was selected as a model for its habitat, trophic level, feeding behavior, and commercial exploitation for human consumption. Time course experiments revealed that low concentrations of HCB (i.e. 50 nM) determine an exponentially decrease of Na 1 /K 1 -ATPase activity and a significant modification of cellular membrane fluidity. Significant negative relationships between Na 1 /K 1 -ATPase activity and membrane fluidity were observed, suggesting that changes in the structure and packing of cellular membranes induced by HCB may be the primary factor affecting the activity of essential bilayer-associated enzymes. Overall these findings suggest that even small concentrations of HCB may determine important changes on cell metabolism with potential cascade effects on recruitment of this commercial species.

Hexachlorobenzene exerts genotoxic effects in a humpback whale cell line under stable exposure conditions

“… 29 Conversely, a study conducted with the crustacean Squilla mantis found that HCB caused an increase in rigidity of plasma membranes of muscular and gonadic primary cells at a concentration of 14 μg L −1 . 53 An increase in rigidity – which leads to a decrease in permeability – may also be the cause for the transient increase in CFDA-AM fluorescence we observed. A potential explanation is described in a study conducted with the prokaryote Pseudomonas putida , where a cis – trans -isomerisation of membrane lipids was found to be the cause of an increase in rigidity following exposure to a concentration range of 0.01 to 1 μg L −1 HCB.…”