Abstract
Pharmaceuticals are currently frequently monitored environmental contaminants. In the European Union over 3000 pharmacologically active substances are used in human and veterinary medicine, such as analgesics, antibiotics, antidiabetics, contraceptives, antidepressants, lipid regulators, beta blockers, etc.
Drugs and their metabolites are preferably excreted from patients via urine and contaminate municipal wastewaters. Wastewater treatment plants are only able to remove this pollution to a limited extent and residues of drugs contaminate surface waters.
The water ecosystem is primarily influenced, but the subsequent penetration of contaminants into the terrestrial ecosystem can affect all living organisms. The concentrations of drugs in environment are much lower than therapeutic and acute toxicity data are not relevant to the evaluation of effects.
Unfortunately, the chronic toxicity potential subtle effects are only marginally known. The uptake of drugs and their metabolites by plants can cause food chain contamination.
It has been demonstrated that plants can extract drug contaminants from water and soil. It can be used for phytoremediation technology, as an attractive method for environment cleaning.
At the same time, however, it means that plants can be contaminated by drug residues. Therefore, it is important to study the interactions of plants with drugs to assess possible risks of food chain contamination to prevent potential health effects.
The model experiments of plant drug uptake were performed using in vitro cultivated whole plants. The cultivation medium was supplemented with defined amount of tested drugs from different pharmacological groups (e.g. ibuprofen, diclofenac, bromazepam, fluoxetine, carbamazepine, trazodone).
The uptake ability, translocation, and extractable residues were evaluated using HPLC/UV analyses. It was found that all tested plants (Zea mays, Helianthus annuus, Pisum sativum, Hordeum vulgare) can extract drugs from the liquid medium and at least partially translocate them into aboveground parts.
The extraction efficiency depends on the chemical structure of the drug and is usually between 30-90%. The amount of extractable residues reaches concentrations µg/g of plant fresh weight.