A polysaccharide found in Paulownia fortunei flowers can enhance cellular and humoral immunity in chickens

A water-soluble polysaccharide known as Paulownia fortunei flower polysaccharide (PFFPS) was isolated from the flowers of Paulownia fortunei. Gel permeation chromatography (GPC) analysis showed that approximately 92.5% of PFFPS fractions had molecular weights under 500 kDa. High performance liquid chromatograph (HPLC) analysis revealed that PFFPS was composed of 10 monosaccharides, including galactose (28.61%), rhamnose (18.09%), glucose (15.21%), and arabinose (15.91%). Fourier transform infrared (FT-IR) spectra revealed the specific absorption peaks of the polysaccharide. Using in vivo tests in chickens, we found that even very low doses of PFFPS could significantly promote the development of the immune organs, increase the quantity of leukocytes and the ratio of lymphocytes, and improve antibody titers against Newcastle disease virus (NDV). In addition, PFFPS also increased the concentrations of IL-2 and IFN-γ, as well as the content of SIgA in the duodenum. Furthermore, PFFPS was found to be able to relieve immunosuppression caused by cyclophosphamide (CTX). This study therefore suggests that PFFPS may be a valuable component of new immunopotentiator and/or adjuvant for the livestock and poultry industries. •PFFPS was first extracted from Paulownia fortunei flowers.•PFFPS was found to significantly enhance cellular and humoral immune function.•Galactose, rhamnose, glucose and arabinose were the major monosaccharide components of PFFPS.