In silico evaluation of interactions between antibiotics in aquaculture and nuclear hormone receptors

Antibiotics have been commonly used as antimicrobial agents in the process of aquaculture worldwide. However, very few studies are available on the endocrine disruption-related health risks brought about by antibiotic residues from human consumption of aquatic products. Nuclear hormone receptors (NHRs) could mediate many endocrine-disrupting activities. Therefore, in the present study, a reverse docking method was used to predict the direct binding interactions between 16 NHR conformations and 15 common antibiotics in aquaculture, thereby determining their potential endocrine-disrupting risks. To reach a compromise between the extremely scarce experimental data and an urgent need for distinguishing antibiotics of high concern with potential food-borne endocrine-disrupting risks in aquaculture, a risk-ranking system was then developed based on a comprehensive risk score for each category of antibiotics, which was the sum of the products of endocrine-disrupting potential coefficients and annual usages of antibiotics in aquaculture. The results indicated that 15% of 224 docking simulations showed a relatively high probability of binding. Sulfonamides seemed to possess the greatest endocrine-disrupting potential. The antagonistic conformation of the androgen receptor was the most susceptible NHR conformation. The rank orders of the endocrine-disrupting risk of different categories of antibiotics varied greatly from country to country, which were significantly affected by the annual usage. These findings pose questions regarding public health and safety associated with human consumption of antibiotic-containing aquatic products. In addition, we provide an approach to rank antibiotics for a specific country or region, with respect to their potential endocrine-disrupting activity, that can be used to inform regulation and prioritize experimental verification.