Feed-drug interaction of orally applied butyrate and phenobarbital on hepatic cytochrome P450 activity in chickens

Regulatory B cells in autoimmune diseases: Insights and therapeutic potential

Autoimmune diseases are characterized by the body's immune system attacking its own cells, such as systemic lupus erythematosus (SLE), rheumatoid arthritis (RA), and multiple sclerosis (MS). In recent studies, regulatory B cells (Bregs), which play a vital role in maintaining peripheral tolerance and controlling persistent autoimmune diseases (ADs), have shown great potential in treating ADs. This review synthesizes the latest advancements in targeted therapies for ADs, with a particular emphasis on the subgroups, phenotypic markers, and signal pathways associated with Bregs. Following an examination of these elements, the discussion pivots to innovative Breg-based therapeutic approaches for the management of ADs.

Induction by Phenobarbital of Phase I and II Xenobiotic-Metabolizing Enzymes in Bovine Liver: An Overall Catalytic and Immunochemical Characterization

In cattle, phenobarbital (PB) upregulates target drug-metabolizing enzyme (DME) mRNA levels. However, few data about PB's post-transcriptional effects are actually available. This work provides the first, and an almost complete, characterization of PB-dependent changes in DME catalytic activities in bovine liver using common probe substrates and confirmatory immunoblotting investigations. As expected, PB increased the total cytochrome P450 (CYP) content and the extent of metyrapone binding; moreover, an augmentation of protein amounts and related enzyme activities was observed for known PB targets such as CYP2B, 2C, and 3A, but also CYP2E1. However, contradictory results were obtained for CYP1A, while a decreased catalytic activity was observed for flavin-containing monooxygenases 1 and 3. The barbiturate had no effect on the chosen hydrolytic and conjugative DMEs. For the first time, we also measured the 26S proteasome activity, and the increase observed in PB-treated cattle would suggest this post-translational event might contribute to cattle DME regulation. Overall, this study increased the knowledge of cattle hepatic drug metabolism, and further confirmed the presence of species differences in DME expression and activity between cattle, humans, and rodents. This reinforced the need for an extensive characterization and understanding of comparative molecular mechanisms involved in expression, regulation, and function of DMEs.

Comparative study on the modulation of incretin and insulin homeostasis by butyrate in chicken and rabbit

The pancreatic secretion of insulin, a key endocrine regulator of metabolism and growth, can be greatly influenced by the gut-derived incretin hormones, namely by GIP (Glucose-dependent Insulinotropic Peptide) and GLP-1 (Glucagon-like Peptide 1). As insulin is a major stimulator of growth, affecting its producion may be of special importance in food-producing livestock. The aim of the present study was to investigate novel ways of modulating incretin and insulin homeostasis in chickens and rabbits by nutrition, e.g. by oral butyrate application, also studying the mechanisms of incretin action in both species as a comparative approach. Acute oral butyrate challenge significantly decreased plasma GIP levels by approx. 40% in both species: significant interactions of butyrate exposure and incubation time were found in both chickens (P = 0.038 and P = 0.034 at 30 and 60 min following butyrate ingestion [1.25 g/kg BW], respectively) and rabbits (P = 0.036 and P = 0.039 at 30 and 60 min after butyrate ingestion [0.25 g/kg BW], respectively), while plasma GLP-1, insulin and glucose concentrations remained unaffected by butyrate in both species over time. These results are in contrast to butyrate’s stimulating effect on both incretin and insulin secretion in mice, indicating specific, species-dependent differences even among mammalian species. Further, based on the analyzed correlations between the measured endocrine parameters (regardless of the butyrate exposure), it can be assumed that incretins may regulate pancreatic insulin release in rabbits on a partly different way compared to mice, humans and chickens.