Malignant canine mammary tumors represent 50% of all neoplasms in female dogs. Matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) are thought to be involved in tumor progression, and they are also associated with the reactive stroma, which provides structural and vascular support for tumor growth.
The occurrence of antibiotic residues in the environment is of concern not only because of their contribution to the spread of bacterial resistance, but also due to their possible toxicity to non-target organisms. In this study, the aquatic environmental toxicity of ciprofloxacin (CIP) and sulfamethoxazole (SMX) was assessed in the following model organisms: Daphnia magna and Artemia salina (embryonic and immobilisation test with a 10-d follow-up), Phaeodactylum tricornutum (algal growth inhibition test), and Spirodela polyrhiza (duckweed growth inhibition test). Results showed that among the two saltwater organisms, A. salina was insensitive to both antibiotics, whilst P. tricornutum responded only to SMX with an EC50 of 2.7 mg L−1. In freshwater species, D. magna embryos were more sensitive than juveniles to SMX (EC50 53.8 and 439.2 mg L−1, respectively), whereas the opposite trend was observed for CIP (EC50 95.9 and 15 mg L−1, respectively). S. polyrhiza confirmed the remarkable sensitivity of aquatic plants to fluoroquinolones, with EC50 values between 0.28 and 0.34 mg L−1 depending on the endpoint considered. Notably, this species was also more sensitive to SMX than expected, with EC50 values between 1.5 and 2.5 mg L−1, which are an order of magnitude lower than those typically obtained with Lemna spp. exposed to sulphonamides. Considering the high environmental input of these antibiotics from both human and veterinary treatments, adverse effects on aquatic plants cannot be excluded, potentially leading to ecosystem-level consequences.
Among veterinary antibiotics, flumequine (FLU) is still widely used in aquaculture due to its efficacy and cost-effectiveness. Although it was synthesized more than 50 years ago, a complete toxicological framework of possible side effects on non-target species is still far from being achieved. The aim of this research was to investigate the FLU molecular mechanisms in Daphnia magna, a planktonic crustacean recognized as a model species for ecotoxicological studies. Two different FLU concentrations (2.0 mg L−1 and 0.2 mg L−1) were assayed in general accordance with OECD Guideline 211, with some proper adaptations. Exposure to FLU (2.0 mg L−1) caused alteration of phenotypic traits, with a significant reduction in survival rate, body growth, and reproduction. The lower concentration (0.2 mg L−1) did not affect phenotypic traits but modulated gene expression, an effect which was even more evident under the higher exposure level. Indeed, in daphnids exposed to 2.0 mg L−1 FLU, several genes related with growth, development, structural components, and antioxidant response were significantly modulated. To the best of our knowledge, this is the first work showing the impact of FLU on the transcriptome of D. magna.
1 August 2004 in Veterinary Research Communications
Aflatoxin B1 (AFB1) is a major food safety concern, threatening the health of humans and animals. Bentonite (BEN) is an aluminosilicate clay used as a feed additive to reduce AFB1 presence in contaminated feedstuff. So far, few studies have characterized BEN toxicity and efficacy in vitro. In this study, cytotoxicity (WST-1 test), the effects on cell permeability (trans-epithelial electrical resistance and lucifer yellow dye incorporation), and transcriptional changes (RNA-seq) caused by BEN, AFB1 and their combination (AFB1 + BEN) were investigated in Caco-2 cells. Up to 0.1 mg/mL, BEN did not affect cell viability and permeability, but it reduced AFB1 cytotoxicity; however, at higher concentrations, BEN was cytotoxic. As to RNA-seq, 0.1 mg/mL BEN did not show effects on cell transcriptome, confirming that the interaction between BEN and AFB1 occurs in the medium. Data from AFB1 and AFB1 + BEN suggested AFB1 provoked most of the transcriptional changes, whereas BEN was preventive. The most interesting AFB1-targeted pathways for which BEN was effective were cell integrity, xenobiotic metabolism and transporters, basal metabolism, inflammation and immune response, p53 biological network, apoptosis and carcinogenesis. To our knowledge, this is the first study assessing the in vitro toxicity and whole-transcriptomic effects of BEN, alone or in the presence of AFB1.