Immunohaematological status and mRNA expression of the genes encoding interleukin-6, nuclear-factor kappa B, and tumor-necrosis factor-α in the spleen of broilers supplemented with dietary rutin

Abstract

Rutin, also known as vitamin P or rutoside, has been explored for many pharmacological activities. Apples, tea leaves, and many other plants contain rutin as one of the active constituents. Haematological, immunological indices and the expression of inflammatory cytokine genes in spleen tissue were assessed to investigate the influence of different levels of dietary rutin supplement (0.25, 0.5, or 1 g/kg diet) on the immune response of broilers. After 6 weeks, rutin-fed chickens showed an increase in the haematological indices, including the number of blood lymphocytes. Similarly, serum total protein and globulin were also elevated. By contrast, serum cholesterol, triglycerides and liver enzymes were lower in the experimental birds than in the control birds. Moreover, compared with the control birds, there was no significant change in the bilirubin concentration, either total or direct, and kidney-function indices in response to rutin supplementation in the experimental birds. Among the immune parameters examined, lysozyme activity, nitric oxide concentrations, and immunologlobulin M (IgM) production were significantly higher in rutin-fed birds than in the control birds; however, there was no significant effect of rutin at any concentration on the IgG and IgA concentrations and lymphoid organ weight. Of the cytokine-encoding genes studied, the genes encoding interleukin-6, nuclear-factor kappa B, and tumour-necrosis factor-α were upregulated in the spleen of the experimental birds, while the expression of interferon gamma-encoding gene was unaffected in the experimental birds. Here, rutin promoted the immune strength in birds mainly at 1 g/kg diet, suggesting that rutin is a promising feed additive for broilers.