An evaluation of the toxicity and bioaccumulation of cisplatin in the marine environment using the macroalga, Ulva lactuca

The cytotoxic drug, cisplatin (cis-PtCl2(NH3)2), has been added to cultures of the marine macroalga, Ulva lactuca, under various experimental conditions. Both accumulation and internalisation over a 48 h period was greater when cisplatin was added to coastal sea water (salinity = 33) from a distilled water solution than when added to either sea water or estuarine water (salinity = 16.5) from a saline solution. This effect is attributed to the greater abundance of the more reactive monoaqua complex (cis-PtCl(OH2)(NH3)2+) in the distilled water solution and kinetic constraints on its conversion back to cis-PtCl2(NH3)2 in sea water. Despite its mode of action at the cellular level, cisplatin added up to concentrations of 150 nM did not incur a measurable reduction in the efficiency of photochemical energy conversion under any of experimental conditions tested.

► This study is the first to examine the biogeochemistry and toxicity of a cytotoxic drug in the marine environment. ► Cisplatin is accumulated and internalised by the marine macroalga, Ulva lactuca. ► Accumulation is greater when the drug is administered from a distilled water solution than from a saline solution. ► Results are consistent with the greater abundance of the more reactive aquated complexes in pure water. ► Cisplatin is not phytotoxic to the alga over the concentration range (<150 nM) studied.