Oliana Carnevali

This review presents several alternatives to replace antibiotic therapy and make the European aquaculture industry more friendly and environmentally sustainable. The first part of this review highlights the growing importance of the aquaculture industry worldwide for its ability to supply low-cost proteins and lipids. The second part discusses different strategies for these replacements, from recombinant vaccines to diets with low environmental impact and rich in bioactive molecules that can benefit other species. Specifically, the beneficial effects of bioactive compounds present within insect meals are discussed. In addition, particular focus is placed on the importance of adopting sustainable protocols for fish farming, including supplements such as probiotics, prebiotics, and synbiotics capable of modulating the gut microbiota as the second brain. Those feed additives can stimulate European farmed species’ immunological systems, growth, and welfare.

The demand for organic UV filters as active components in sunscreen products has rapidly risen over the last century, as people have gradually realized the hazards of overexposure to UV radiation. Their extensive usage has resulted in their ubiquitous presence in different aquatic matrices, representing a potential threat to living organisms. In this context, the need to replace classic UV filters such as octyl methoxycinnamate (OMC), one of the most popular UV filters reported to be a potential pollutant of aquatic ecosystems, with more environmentally friendly ones has emerged. In this study, using zebrafish, the first in vivo results regarding the effect of exposure to tempol-methoxycinnamate (TMC), a derivative of OMC, are reported. A comparative study between TMC and OMC was performed, analyzing embryos exposed to similar TMC and OMC concentrations, focusing on morphological and molecular changes. While both compounds seemed not to affect hatching and embryogenesis, OMC exposure caused an increase in endoplasmic reticulum (ER) stress response genes, according to increased eif2ak3, ddit3, nrf2, and nkap mRNA levels and in oxidative stress genes, as observed from modulation of the sod1, sod2, gpr, and trx mRNA levels. On the contrary, exposure to TMC led to reduced toxicity, probably due to the presence of the nitroxide group in the compound’s molecular structure responsible for antioxidant activity. In addition, both UV filters were docked with estrogen and androgen receptors where they acted differently, in agreement with the molecular analysis that showed a hormone-like activity for OMC but not for TMC. Overall, the results indicate the suitability of TMC as an alternative, environmentally safer UV filter.