Structure characterization and in vitro immunomodulatory activities of carboxymethyl pachymaran

Carboxymethyl pachymaran (CMP) was prepared from Poria cocos polysaccharide by carboxymethylation. Two types of CMP(CMP-1 and CMP-2) were further purified byDEAE-52 anion-exchange chromatography. The structure characteristics and immunomodulatory activities of CMP-1 and CMP-2were investigated. CMP-1was determined as beta-(1 -> 3)-D-glucan. A beta-(1 -> 3)-D-glucan backbone structure was also found in CMP-2, which was mainly consistent of mannose and glucose, with the mole ratio of 0.03:1. The molecular weight of CMP-1 was 126.1 kDa with a 30.4 nm irregular sphere in distilled water. However, the molecular weight of CMP-2 was 172.6 kDa in a 19.9 nm spherical structure in water solution. Both CMP-1 and CMP-2 had triple helical structure, which can promote the proliferation and the phagocytosis of macrophages. Moreover, CMP-1 and CMP-2 both could improve the secretions of NO, TNF-alpha and IL-6 by increasing the expression of iNOS, TNF-alpha and IL-6 mRNA, but CMP-1 exhibited a stronger immunomodulatory ability than that of CMP-2. Our results indicated that CMP-1 and CMP-2 can act as potential immunomodulatory agents. (C) 2021 Elsevier B.V. All rights reserved.

Automated summary

Carboxymethyl pachymaran (CMP) was prepared from Poria cocos polysaccharide by carboxymethylation, resulting in two types of CMP (CMP-1 and CMP-2) with immunomodulatory activities. Both CMP-1 and CMP-2 contain a beta-(1 -> 3)-D-glucan structure that can promote macrophage activity, with CMP-1 exhibiting stronger immunomodulatory ability.