Structural characterization of a pectic polysaccharide from Codonopsis pilosula and its immunomodulatory activities in vivo and in vitro

A pectic polysaccharide (named as CPP1c) extracted from Codonopsis pilosula was evaluated for its structural features and potential of immune-modulating activities in an aging mouse model of senescence accelerated mouse prone 8 (SAMP8) in vitro and in vivo. The relative molecular weight and the absolute molecular weight of CPPlc were 1.26 x 10(5) Da and 1.49 x 10(5) Da, respectively. Investigation of structural features by a combination of chemical and instrumental analysis showed CPPIc was composed of -> 1)-alpha-L-Rhap-(2,4 ->,-> 1)-alpha-L-Araf-(5 ->,-> 1)-alpha-D-Galp-(6 -> and -> 1)-alpha-D-GalpA-(4 -> in a molar ratio of 3:1:2:33. CPP1 c could promote lymphocyte proliferation, modulate the percentage of CD4(+), CDS8(+), CD28(+) and CD152(+) T cells and enhance the production of IL-2, TNF-alpha and IFN-gamma. Moreover, PCR assay revealed CPPlc augmented the expressions of CD28, PI3 K and p38MAPK mRNA, and the increase of protein expressions of the same genes was also confirmed by western blot analyses. In addition, CPPlc had the potential of promoting the homing of lymphocytes. Taking all factors into consideration, we deduced CPPl c might exert its immunostimulating potency via promoting T cell activation by TCR/CD28 signaling pathways. (C) 2017 Published by Elsevier B.V.