Preliminary data suggest that venlafaxine environmental concentrations could be toxic to plants.

Venlafaxine hydrochloride is a structurally novel antidepressant. Its occurrence in surface waters and drinking water has only been reported in recent works. The aim of this work is to assess the acute and chronic sublethal toxicity of venlafaxine in relevant taxa of riparian ecosystems. We used the fern Polystichum setiferum during the critical life stage of development. Reliable biomarkers of cell viability (mitochondrial activity), plant physiology (chlorophyll), and growth (DNA content) were assessed as sensitive endpoints of toxicity. About DNA quantification, our results show that venlafaxine induces acute lethal phytotoxicity at 24 and 48 h (LOECs 1 µg L(-1) and 0.1 µg L(-1), respectively). At 24 h, hormetic effects in spores of P. setiferum mitochondrial activity mask lethality and adverse effects are observed (LOEC 1 µg L(-1)). At 48 h a reduction in the mitochondrial activity happens (LOEC 10 µg L(-1)). In chronic exposure of 1 week, LOEC for DNA is 0.1 µg L(-1). Mitochondrial activity showed a strong hormetic stimulation of a surviving spore population (LOEC 10 µg L(-1)). Changes were not observed in chlorophyll autofluorescence. Environmental concentrations of venlafaxine can be deleterious for the development of significant populations of sensitive individuals in riparian ecosystems.

Biomarker assessment of toxicity with miniaturised bioassays: diclofenac as a case study.

The development of suitable biomarker-based microbioassays with model species with ecological relevance would help increase the cost-efficiency of routine environmental monitoring and chemical toxicity testing. The anti-inflammatory drug diclofenac has been widely reported in the environment but ecotoxicological data are scarce. The aim of this work is to assess the acute and chronic sublethal toxicity of diclofenac in relevant taxa of aquatic and riparian ecosystems (the fish Danio rerio and the fern Polystichum setiferum). Reliable biomarkers of cell viability (mitochondrial activity), plant physiology (chlorophyll), growth (DNA content) or oxidative damage (lipid peroxidation) were assessed as sensitive endpoints of toxicity. DNA quantification shows that diclofenac induces acute lethal phytotoxicity at 24 and 48 h (LOECs 30 and 0.3 µg l(-1), respectively). Hormetic effects in mitochondrial activity in spores of Polystichum setiferum mask lethality, and adverse effects are only observed at 48 h (LOEC 0.3 µg l(-1)). In chronic exposure (1 week) LOEC for DNA is 0.03 µg l(-1). Mitochondrial activity shows a strong hormetic stimulation of the surviving spore population (LOEC 0.3 µg l(-1)). Little changes are observed in chlorophyll autofluorescence (LOEC 0.3 µg l(-1)). A very short exposure (90 min) of zebrafish embryos induces a reduction of lipid peroxidation at 0.03 µg l(-1). Environmental concentrations of diclofenac can be deleterious for the development of significant populations of sensitive individuals in aquatic and riparian ecosystems.