Introduction: The effects of Jin-Ying-Tang (JYT) on Toll-like Receptor 4 (TLR4) signalling transduction of lipopolysaccharide (LPS)-stimulated mouse mammary epithelial cells (MECs) in vitro were examined. Material and Methods: The cytotoxicity of JYT (0.06-62.50 mg/mL) on mouse MECs was determined by MTT assay. The MECs were co-cultured with LPS in the presence or absence of JYT (39.10 μg/mL, 391 μg/mL, 3910 μg/mL). The concentrations of interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) in the culture supernatants were detected by ELISA. The mRNA expression of TLR4 and downstream TLR4 signalling molecules such as myeloid differentiation factor 88 (MyD88), tumour necrosis factor receptor associated factor 6 (TRAF-6), inhibitor κB (IκB), and nuclear factor κB inducing kinase (NIK) were determined by quantitative real-time polymerase chain reaction (qRT-PCR). Results: The results showed that the IC₅₀ of JYT on MECs was 12.25 mg/mL and JYT could significantly decrease the concentrations of IL-6 and TNF-α in LPS-stimulated MECs (P < 0.05). The mRNA expression of TLR4, MyD88, TRAF-6, IκB, and NIK was also significantly decreased when the LPS-stimulated MECs were cocultured at appropriate concentrations of JYT (P < 0.05, P < 0.01). Conclusion: These observations indicate a potential mechanism through which JYT attenuates the systemic inflammatory response to LPS-stimulated mouse mammary epithelial cells by inhibiting the activation of TLR4/MyD88/ TRAF-6/NIK pathway at the mRNA level.

Introduction: The aim of the study was to explore the effect of enrofloxacin on production of selected cytokines by porcine peripheral blood mononuclear cells (PBMCs).Material and Methods: Twenty pigs (10 control and 10 experimental) were used in this research. Pigs from experimental group received enrofloxacin at therapeutic doses. Blood samples were collected before, during, and after treatment with enrofloxacin. PBMCs were incubated with or without lipopolysaccharide (LPS). Production of IL-6, IL-10, INF-γ, and TNF-α were determined by ELISA.Results: Administration of enrofloxacin to healthy pigs for 5 d induced a transient reduction of the PBMCs response to LPS in terms of IL-6 and TNF-α secretion. The concentration of IL-6 returned to the day 0 level shortly after treatment, while TNF-α production remained reduced for 10 d after the treatment. The production of IL-10 was not affected by enrofloxacin. The level of IFN-γ was below the detection limit of the tests.Conclusion: The results indicate that enrofloxacin administered in vivo in therapeutic doses has an immunomodulatory effect through its capacity to inhibit secretion of IL-6 and TNF-α by porcine PBMC stimulated by LPS.