Immunological effects of ractopamine in rabbits receiving the viral inactivated rabbit hemorrhagic disease vaccine.

Background: There is an obvious lack of information about the effects of ractopamine, a ß-adrenergic agonist, on the growth performance and immune responses of rabbits, particularly in those receiving the viral rabbit hemorrhagic disease (RHD) vaccine. Aim: The current study was undertaken to study the effects of ractopamine on growth performances and immunological parameters in rabbits inoculated with the viral RHD vaccine. Methods: Experimental rabbits were grouped into four groups, the first acted as a control and received distilled water, the second received ractopamine, the third received inactivated RHD vaccine, and the fourth received both ractopamine, and inactivated RHD vaccine. Then, blood analysis, histopathological, histomorphometric, and immunohistochemistry (IHC) examinations were followed. Results: The obtained results demonstrated that ractopamine induced significant increases in body weight gain, neutrophils, monocytes, nitric oxide, lysosome, and improved feed conversion rate. A significant decrease in lymphocytes with insignificant decreases in eosinophils, phagocytic % and index, serum total protein, α, ß, and γ globulin were observed. Vaccinated rabbits only showed a marked rise in WBCs, neutrophils, monocytes, eosinophils, basophils, phagocytic index and activity, nitric oxide, lysosome activity, total protein, albumin, γ globulin, and a decrease in lymphocytes. Rabbits that received ractopamine and then vaccinated had insignificant increases in body weight, weight gain, WBCs, neutrophils, monocyte, eosinophils, basophils, phagocytic activity, and index, globulins besides a significant decrease in lymphocytes. Pathologically, rabbits that received ractopamine alone, with a vaccine or vaccinated only showed an increase in villus length, villus width, and absorption surface area. IHC of rabbits' liver and kidneys of the control and vaccinated group showed negative expression for caspase-3, but rabbits received ractopamine only or rabbits vaccinated and received ractopamine showed diffuse positive moderate expression for caspase-3. Conclusion: Ractopamine induced several adverse effects on the immune responses of the rabbits inoculated with the viral HRD vaccine.

Baicalein prevents capecitabine-induced heart damage in female Wistar rats and enhances its anticancer potential in MCF-7 breast cancer cells.

AIM: We investigated the ability of baicalein (BAI) to enhance the anticancer potential of capecitabine (CAP) in the MCF-7 cell line and its protective effect on CAP-induced cardiotoxicity in female Wistar rats. METHODS AND KEY FINDINGS: In vitro study involved evaluating the effect of BAI and/or CAP on cell viability, cell cycle progression, and BAX and Bcl2 gene expression in MCF-7 cells. Co-treatment of BAI with CAP significantly reduced the viability of MCF-7 cells, improved their cytotoxic effect, markedly elevated the percentage of the sub-G1 population, drastically reduced the G2/M population, and significantly altered the mRNA expression of BAX and Bcl2 genes compared with each treatment alone. In vivo study revealed that the oral administration of CAP (140 mg/kg BW) to adult female rats significantly elevated the levels of serum creatine kinase-myocardial band (CK-MB), lactate dehydrogenase (LDH), tumor necrosis factor (TNF)-α, and interleukin (IL)-1ß and cardiac TNF-α, IL-1ß malondialdehyde (MDA) concentration, whereas it reduced the serum and cardiac total antioxidant capacity (TAC), level of cardiac glutathione (GSH) and activity of glutathione peroxidase (GPx) with a vast array of circulatory, inflammatory, degenerative, and necrotic alterations in the cardiac tissue. Furthermore, CAP administration significantly upregulated the mRNA expression of NF-κB, TLR4, MyD88, ATF6, CHOP, and JNK genes. Concurrent administration of BAI (200 mg/kg BW) and CAP significantly improved the biochemical alterations and cardiac oxidant/antioxidant status and architecture. In addition, it modulated the TLR4/MyD88/NF-κB pathway and endoplasmic reticulum stress. SIGNIFICANCE: Altogether, BAI can augment the anticancer potential of CAP and alleviate its cardiotoxic effects during cancer treatment.

Chitosan propolis nanocomposite alone or in combination with apramycin: an alternative therapy for multidrug-resistant Salmonella Typhimurium in rabbits: in vitro and in vivo study.

Introduction. The emergence of multidrug-resistant Salmonella Typhimurium strains has increased the need for safe, alternative therapies from natural sources with antibacterial properties.Hypothesis/Gap Statement. There are no published data regarding the use of chitosan propolis nanocomposite (CPNP) either alone or in combination with antibiotics as antimicrobials against S. Typhimurium, especially in Egypt.Aim. This study evaluated the antibacterial activities of five antimicrobials [apramycin, propolis, chitosan nanoparticles (CNPs), chitosan propolis nanocomposite (CPNP) and CPNP +apramycin] against ten virulent and multidrug-resistant (MDR) S. Typhimurium field strains recovered from diarrheic rabbits through in vitro and in vivo study.Methodology. The expression levels of three virulence genes of S. Typhimurium strains were determined by quantitative reverse-transcription PCR (RT-qPCR) after exposure to sub-inhibitory concentrations of apramycin, propolis, CNPs, CPNP alone, and CPNP +apramycin. Additionally, 90 New Zealand rabbits were divided into control and experimentally S. Typhimurium-infected groups. The infected rabbits were orally administered saline solution (infected-untreated); 10 mg apramycin/kg (infected-apramycin-treated); 50 mg propolis/kg (infected-propolis-treated); 15 mg CPNP/kg (infected-CPNP-treated) and 15 mg CPNP +10 mg apramycin/kg (infected-CPNP +apramycin-treated) for 5 days.Results. The RT-qPCR analysis revealed different degrees of downregulation of all screened genes. Furthermore, the treatment of infected rabbits with CPNP or CPNP +apramycin significantly improved performance parameters, and total bacterial and Salmonella species counts, while also modulating both oxidative stress and altered liver and kidney parameters.Conclusion. This work demonstrates the use of CPNP alone or in combination with apramycin in the treatment of S. Typhimurium in rabbits.