Increasing amounts of pharmaceutical waste in the environment has disrupted the balance of ecosystems, and may have subsequent effects on human health. Although, a handful of previous studies have shown impacts of pharmaceutically active compounds on the environment, the toxicological effects of their degradation products remains largely unknown. In the current study, photo-degradation products of environmental ibuprofen were assessed for both ecotoxicological and human health effects. Here the identified degradation products are synthesized with high purity (&gt; 98%), and characterized with 1HNMR, 13CNMR, FT-IR, and HRMS. To evaluate human health effects, three gut microbiota species; Lactobacillus acidophilus, Enterococcus faecalis, and Escherichia coli, and two human cell lines; HEK293K and HepG2, are exposed to various concentrations of ibuprofen and its degradation products. On L. acidophilus, the degradation product, (2R,3R)-2-(4-isobutylphenyl)-5-methylhexan-3-ol, shows a greater toxic effect while ibuprofen enhances its growth, at lower concentrations. At higher concentrations, ibuprofen shows at least 2-fold higher toxicity compared to that of its degradation products. However, E. faecalis shows little or no effect upon expose to these compounds. An induction of the SOS response in E. coli is observed but limited to only ibuprofen and 4-acetylbenzoic acid. In human cell line studies, survival of both HEK293T and HepG2 cell lines are profoundly impaired by photo-degradation products of (2R,3R)-2-(4-isobutylphenyl)-5-methylhexan-3-ol, (2R,3S)-2-(4-isobutylphenyl)-5-methylhexan-3-ol, and 1-(4-(1-hydroxy-2methylpropyl)phenyl)ethan-1-one. In this work, environmental impact is assessed using a bioluminescence bacteria, Vibrio fischeri. Both ibuprofen and degradation products inhibit the growth of this gram-negative bacteria while the primary compound ibuprofen shows the greatest impact. Overall, our results highlighted that some of the degradation products of ibuprofen can be more than or at least as toxic as the parent compound to humans as well as environmental species.

Toxicological study on photo-degradation products of environmental ibuprofen: Ecological and human health implications

2019 Fall National Meeting

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