Biotransformation of Non-steroidal Anti-inflammatory Drugs Induces Ultrastructural Modifications in Green Leafy Vegetables

More than we would like to admit, pharmaceutical products represent a high risk for the environment since, in the past decades, their concentration in natural, drinking, and irrigation waters reached concerning concentrations. The threat also resides in the fact that they tend to accumulate in edible plants and crops, and in the end, they could affect other organisms in the food chain, including humans. The aim of the work was to address some of these probable threats of pharmaceutical drugs. Therefore, the effects of three essential non-steroidal anti-inflammatory drugs (NSAIDs) on the ultrastructural aspects, uptake capacity, and biotransformation were investigated in green leafy vegetables. Thus, diclofenac (DCF), ibuprofen (IBU), and naproxen (NAP) were selected to assess the impact on three of the most consumed leafy vegetables: Atriplex patula L., Spinacia oleracea L., and Lactuca sativa L. The abiotic stress consisted of watering the vegetables once every 2 days, with different concentrations of the chosen NSAIDs (from 0.1 to 1 mg L−1). The uptake in leaves and soil was determined by high-performance liquid chromatography, after solid-phase extraction successfully optimized herein. The morphological and anatomical changes were monitored through scanning and transmission electron microscopy analyses. The concentration of the NSAIDs determined in the leaf samples increased in a dose-dependent manner and the analyzed soil samples had NSAIDs concentrations ranging from 0.38 μg g−1 soil to 9.00 μg g−1 soil. The morphological aspect of the green leafy vegetables was not affected compared to untreated controls, while several ultrastructural changes were observed, where oily accumulations were detected in the cell walls and vacuoles and damaged mitochondria with ruptured membranes were frequent. The obtained results demonstrated that under the current experimental abiotic stress conditions, edible plants can uptake high amounts of NSAIDs, depending on the concentration used. As a future perspective, this could also have adverse effects on the consumers through bioaccumulation or other metabolic processes.