AUTHOR=Zhou Hui , Dai Chen , Cui Xuejie , Zhang Tao , Che Yanyun , Duan Kun , Yi Lei , Nguyen Audrey D. , Li Nannan , De Souza Cristabelle , Wan Xin , Wu Yu , Li Kun , Liu Yuhong , Wu Yi TITLE=Immunomodulatory and antioxidant effects of Glycyrrhiza uralensis polysaccharide in Lohmann Brown chickens JOURNAL=Frontiers in Veterinary Science VOLUME=Volume 9 - 2022 YEAR=2022 URL=https://www.frontiersin.org/journals/veterinary-science/articles/10.3389/fvets.2022.959449 DOI=10.3389/fvets.2022.959449 ISSN=2297-1769 ABSTRACT=Glycyrrhiza glycyrrhiza polysaccharide (GPS-1) is one of the main bioactive components of glycyrrhiza uralensis. It has the characteristics of antibacterial, antiviral, anti-tumor, liver protection and immune regulation, which has a low cost and easy to obtain, so it has a high application value. To study the effects of glycyrrhiza glycyrrhiza polysaccharide on antioxidant and immune function of Roman chickens, we studied the effects of different concentrations of GPS-1 on immune cell proliferation, supernatant cytokines, serum antibody titer, morphological changes of immune organs and antioxidant activity in vitro. The results of in vitro experiments showed that GPS-1 significantly promoted the proliferation of immune cells, the secretion of IL-12, IFN-γ and TNF-α by ymphocytes, and the secretion of IL-1β, IL-12, IL-12p70, IFN-γ, TNF-α and NO by dendritic cells. In vivo experiment results showed that GPSM-1 medium-dose group (9.766 μg/mL) and GPSH-1 high-dose group (19.53 μg/mL) combined with Newcastle disease vaccine had the best efficacy.  Both doses of GPS-1 significantly increased the body weight and serum antibody titer, enhanced the secretion of IL-2 and IFN- γ in serum, and promoted the development of immune organs. In addition, GPS-1 also has significant scavenging ability on DPPH, hydrogen peroxide, ABTS, superoxide anion radical and other free radicals. The results of this study indicate that GPS-1 can enhance immune regulation and antioxidant activity in vitro.