Interaction of pharmaceutical metabolites with blood proteins and membrane lipids in the view of bioconcentration: A preliminary study based on in vitro assessment

Accumulation and metabolization of the antidepressant venlafaxine and its main metabolite o-desmethylvenlafaxine in non-target marine organisms Holothuria tubulosa, Anemonia sulcata and Actinia equina

The assessment of exposure to the antidepressant venlafaxine and its major metabolite o-desmethylvenlafaxine in Holothuria tubulosa, Anemonia sulcata and Actinia equina is proposed. A 28-day exposure experiment (10 μg/L day) followed by a 52-day depuration period was conducted. The accumulation shows a first-order kinetic process reaching an average concentration of 49,125/54342 ng/g dw in H. tubulosa and 64,810/93007 ng/g dw in A. sulcata. Venlafaxine is considered cumulative (BCF > 2000 L/kg dw) in H. tubulosa, A. sulcata and A. equina respectively; and o-desmethylvenlafaxine in A. sulcata. Organism-specific BCF generally followed the order A. sulcata > A. equina > H. tubulosa. The study revealed differences between tissues in metabolizing abilities in H. tubulosa this effect increases significantly with time in the digestive tract while it was negligible in the body wall. The results provide a description of venlafaxine and o-desmethylvenlafaxine accumulation in common and non-target organisms in the marine environment.

Uptake and depuration of three common antibiotics in benthic organisms: Sea cucumber (Holothuria tubulosa), snakelocks anemone (Anemonia sulcata) and beadlet anemone (Actinia equina)

Antibiotics are widely used drugs in human and veterinary medicine, which has attracted great attention in relation to the development of bacterial resistance, currently a problem of great concern for governments and states, as it is related to the resurgence of infectious diseases already eradicated. Understanding the bioaccumulation of antibiotics in aquatic organisms is an important key to understanding their risk assessment. The present study was designed to study the bioaccumulation of target antibiotics in relevant organisms inhabiting benthic marine environments. The uptake and elimination of ciprofloxacin (CIP), sulfamethoxazole (SMX) and trimethoprim (TMP) were investigated in sea cucumbers (Holothuria tubulosa), snakelock anemone (Anemonia sulcata) and beadlet anemone (Actinia equina) under controlled laboratory conditions. The results show that antibiotics have a particular trend over time during all periods of absorption and depuration. The tissue distribution of antibiotics in sea cucumber is strongly influenced by the structure of the compounds, while CIP is concentrated in the body wall; TMP is concentrated in the digestive tract. Two different approaches were used to estimate bioconcentration factors (BCFs) in different animal models, based on toxicokinetic data and measured steady-state concentrations. The BCF ranges were 456-2731 L/kg, 6-511 L/kg and 9-100 L/kg for TMP, CIP and SMX, respectively. The estimated BCF values obtained classify TMP as cumulative in A. equina and H. tubulosa, underlining the potential bioconcentration in these marine organisms. A correlation was observed between the BCFs of the target antibiotics and the octanol-water distribution coefficient (D_ow) (r² > 0.7). The animal-specific BCF followed the order of beadlet anemone > sea cucumber > snakelock anemone.

Bioaccumulation/bioconcentration of pharmaceutical active compounds in aquatic organisms: Assessment and factors database

There is increasing evidence that the presence of certain pharmaceuticals in the environment leads to biota exposure and constitute a potential risk for ecosystems. Bioaccumulation is an essential focus of risk assessment to evaluate at what degree emerging contaminants are a hazard both to the environment and the individuals that inhabit it. The main goals of the present review are 1) to summarize and describe the research and factors that should be taken into account in the evaluation of bioaccumulation of pharmaceuticals in aquatic organisms; and 2) to provide a database and a critical review of the bioaccumulation/bioconcentration factors (BAF or BCF) of these compounds in organisms of different trophic levels. Most studies fall into one of two categories: laboratory-scale absorption and purification tests or field studies and, to a lesser extent, large-scale, semi-natural system tests. Although in the last 5 years there has been considerable progress in this field, especially in species of fish and molluscs, research is still limited on other aquatic species like crustaceans or algae. This revision includes >230 bioconcentration factors (BCF) and >530 bioaccumulation factors (BAF), determined for 113 pharmaceuticals. The most commonly studied is the antidepressant group, followed by diclofenac and carbamazepine. There is currently no reported accumulation data on certain compounds, such as anti-cancer drugs. BCFs are highly influenced by experimental factors (notably the exposure level, time or temperature). Field BAFs are superior to laboratory BCFs, highlighting the importance of field studies for reliable assessments and in true environmental conditions. BAF data appears to be organ, species and compound-specific. The potential impact on food web transfer is also considered. Among different aquatic species, lower trophic levels and benthic organisms exhibit relatively higher uptake of these compounds.

Transformation products of pharmaceuticals in the environment: Their fate, (eco)toxicity and bioaccumulation potential

Nowadays, a huge scientific attention is being paid to the chemicals of emerging concern, which may pose a significant risk to the human and whole ecosystems. Among them, residues of pharmaceuticals are a widely investigated group of chemicals. In recent years it has been repeatedly demonstrated that pharmaceuticals are present in the environment and that some of them can be toxic to organisms as well as accumulate in their tissues. However, even though the knowledge of the presence, fate and possible threats posed by the parent forms of pharmaceuticals is quite extensive, their transformation products (TPs) have been disregarded for long time. Since last few years, this aspect has gained more scientific attention and recently published papers proved their common presence in the environment. Also the interest in terms of their toxicity, bioconcentration and stability in the environment has increased. Therefore, the aim of our paper was to revise and assess the current state of knowledge on the fate and effects resulting from the presence of the pharmaceuticals' transformation drugs in the environment. This review discusses the metabolites of compounds belonging to six major pharmaceutical groups: SSRIs, anticancer drugs, antibiotics, antihistamines, NSAIDs and opioids, additionally discussing other individual compounds for which literature data exist. The data presented in this paper prove that some TPs may be as harmful as their native forms, however for many groups of drugs this data is still insufficient to assess the risk posed by their presence in the environment.