A Water-Soluble Polysaccharide from the Fibrous Root of Bge. and Its Immune Enhancement Effect in Vivo and in Vitro.

BACKGROUND

The fibrous roots of Bge. (FRAAB) are byproducts of the rhizome of . Some studies have revealed secondary metabolic small molecules in FRAAB, but there are few reports on the polysaccharides of FRAAB (PFRAAB). The present study aimed to investigate the preliminary characterization and underlying mechanism of immune stimulation of PFRAAB.

MATERIALS AND METHODS

The crude polysaccharide of FRAAB was obtained by hot water extraction and alcohol precipitation, and PFRAAB was purified by a diethylaminoethyl-52 (DEAE-52) cellulose chromatographic column and graphene dialysis membrane. The preliminary characterization of PFRAAB was studied by ultraviolet (UV) scanning and Fourier Transform Infrared Reflection (FTIR). The molecular weight and composition of PFRAAB were analysed by high-performance gel permeation chromatography (HPGPC) and high-performance liquid chromatography (HPLC), respectively. The immune stimulation of PFRAAB was investigated by using cyclophosphamide- (CCP-) treated mice and RAW264.7 cells.

RESULTS

A water-soluble PFRAAB was obtained with a molecular weight of 115 kDa and was mainly composed of arabinose (ara), galactose (gal), glucose (glc), and mannose (man). Compared with CCP-induced mice, PFRAAB significantly ( < 0.05 or < 0.01) increased the spleen and thymus index, ameliorated injury to the spleen and thymus, and evaluated immunoglobulin levels. In addition, PFRAAB also increased the secretion of nitric oxide (NO), interleukin-1 (IL-1), tumour necrosis factor- (TNF-), and IL-6 in RAW264.7 cells and upregulated the expression of toll-like receptor 4 (TLR4), Myd88, nuclear factor kappa-B (NF-B) P65, p-NF-B P65, IKB-, and p-IKB-.

CONCLUSION

PFRAAB possesses immune stimulation activity and can be used as a potential resource for immune-enhancing drugs. Our present study provides a scientific basis for the comprehensive development of medicinal plant resources.