Investigation of the immune effects of Scutellaria baicalensis on blood leukocytes and selected organs of the chicken's lymphatic system.

BACKGROUND: The health of chickens and the welfare of poultry industry are central to the efforts of addressing global food security. Therefore, it is essential to study chicken immunology to maintain and improve its health and to find novel and sustainable solutions. This paper presents a study on investigation of the effect of Scutellaria baicalensis root (SBR) on the immune response of broiler chicken, especially on lymphocytes and heterophils reactivity, regarding their contribution to the development of immunity of the chickens.

METHODS: The 121-day-old Hubbard Hi-Y male broiler hybrids were randomly assigned to four treatment groups, three SBR supplemented groups (0.5, 1.0, and 1.5% of SBR) and one control group. Each treatment was replicated five times with six birds per replicate pen in a battery brooder. Blood was collected after 3(rd) and 6(th) wk of the experiment, and hemoglobin and hematocrit values were determined, as well as total leukocyte count and differential count were performed. Nitroblue tetrazolium test and phagocytosis assay as nonspecific immune parameters and humoral immune responses to the antigenic challenge by sheep red blood cells were performed. Moreover, the ability of peripheral blood lymphocytes to form radial segmentation (RS) of their nuclei was analyzed. Body weight and relative weight of spleen, liver, and bursa of Fabricius were recorded.

RESULTS: Results showed that mean heterophile/lymphocyte ratio increased in the SBR groups compared to the control group and the blood of the chickens showed lymphocytic depletion. The results also demonstrated that the relative weight of bursa of Fabricius and spleen in groups fed with SBR significantly decreased compared to the control group. This study also showed that the addition of SBR significantly inhibited the formation of RS of nuclei compared to some cytotoxic substances.

CONCLUSION: We found that SBR supplementation should be carefully evaluated when given to poultry. The excess intake of SBR supplementation may cause immunologic inhibition and may negatively affect the development of immune organs. SBR has inhibited the formation of radial segmentation nuclei showing antimetastatic properties and also the phagocytosis of chicken heterophils.