Adjuvant effects of Sijunzi decoction in chickens orally vaccinated with attenuated Newcastle-disease vaccine.

Many Chinese Herbal medicines (CHMs) and their components have been reported to enhance immunity. In this study, the capacity for the Chinese herbal medicine, oral administration Sijunzi Decoction (SJZD) in stimulating Newcastle disease virus(NDV) immunity in chickens was examined. Serum was sampled on days 20, 30, 40, 50 and 60 and tissues were collected on days 20, 40 and 60, respectively. The immune responses were determined by means of hemagglutination inhibition test, immunohistochemistry examination and semi-quantitative RT-PCR. The results showed that SJZD could increase the antibody titers and the area coefficient of IgA secreting cells, promote the expression of IL-2 mRNA in the whole immune period and IFN-γ mRNA was increased in the initial stage. The SJZD used was safe with no adverse effects on chicken weight or survival, providing evidence for the use of SJZD as an oral adjuvant.