Structural characteristics and in vitro and in vivo immunoregulatory properties of a gluco-arabinan from Angelica dahurica.

A water-soluble polysaccharide identified here as ADP80-2 was acquired from Angelica dahurica. ADP80-2 was a gluco-arabinan composed of arabinose and a trace of glucose with a molecular weight of 9950 g/mol. The backbone of ADP80-2 comprised →5)- α -L-Ara f -(1→, →3, 5)- α -L-Ara f -(1→, →6)- α -D-Glc p -(1→, with a terminal branch α -L-Ara f -(1 → residue. In terms of immunoregulatory activity, ADP80-2 can significantly promote the phagocytosis, the production of nitric oxide (NO), and the secretion of cytokines (IL-6, IL-1 β , and TNF- α) of macrophage. In addition to the cellular immunomodulatory activities, the chemokines related to immunoregulation were significantly increased in the zebrafish model after treated with ADP80-2. These biological results indicated that ADP80-2 with immunomodulatory effects was expected to be useful for the development of new immunomodulatory agents. Simultaneously, the discovery of ADP80-2 further revealed the chemical composition of A. dahurica used as a traditional Chinese medicine and spice. [Display omitted] • An active polysaccharide ADP80-2 was isolated from Angelica dahurica. • ADP80-2 was a gluco-arabinan without triple helix conformation in solution. • ADP80-2 showed prominent immunomodulatory activity both in vivo (zebrafish embryo) and in vitro (RAW264.7). [ABSTRACT FROM AUTHOR]