Sessions

Chronic enteropathy (CIE) in dogs is a disease associated with vomiting and diarrhea, in which several factors play a role, including environmental antigens, abnormal immune responses, and genetic predispositions. Bacteria, such as certain strains of Salmonella and E. coli, may also contribute to the development of CIE. Conservative therapy for CIE is based on dietary management, as well as the use of antibiotics and immunosuppressive drugs. However, long-term use of the latter carries several risks, which is why increasing attention is being directed towards studies investigating the effects of plant-derived dietary supplements. Such natural compounds include flavonoids, whose beneficial effects have already been confirmed by numerous studies. The aim of our study was to demonstrate the safety and the anti-inflammatory and antioxidant effects of the flavonoid quercetin, luteolin, and grape seed-derived proanthocyanidin on canine intestinal cell cultures.

In our experiment, we first prepared intestinal biopsies from the duodenum of a dog with a healthy digestive system. The tissue samples were placed in a 96-well culture plate and treated with LPS derived from E. coli and Salmonella to model inflammation and oxidative stress. The explant cultures were also treated with quercetin, luteolin, and proanthocyanidin at concentrations of 25 and 50 μg/ml. The metabolic activity of the cells was assessed using the CCK-8 assay, while cell viability was evaluated by measuring LDH activity. The levels of intracellular reactive oxygen species were measured with the DCFH-DA assay, and extracellular hydrogen peroxide levels were determined using the Amplex Red assay. The concentration of the inflammatory cytokine TNF-α in the cell supernatant was quantified by ELISA.

In our experiments, we found that all three tested flavonoids significantly reduced the elevated levels of intracellular reactive oxygen species induced by E. coli- and Salmonella-derived LPS at both applied concentrations (25 and 50 μg/ml). Only luteolin was able to decrease the amount of extracellular H2O2. The concentration of TNF-α was significantly increased by E. coli-derived LPS compared to the control, and this increase was reduced by all flavonoids, except luteolin at 25 μg/ml.

Based on our results, flavonoids may represent promising adjuncts in the treatment of chronic enteropathy in dogs, although further in vivo studies are necessary to better understand the effects of these compounds in vivo.