The invention discloses
rhodobryum roseum
polysaccharide as well as a preparation method and application thereof. The
molar content of glucose in
monosaccharide composition of the
rhodobryum roseum
polysaccharide is not lower than 97%, and the
rhodobryum roseum
polysaccharide contains terminal and 1-6, 1-4, 1-4, 6, 1-3 and 6 connected glucose residues. The preparation method comprises the following steps:
degreasing a
rhodobryum roseum medicinal material with
acetone, adding hot water, carrying out
ethanol gradient
precipitation, Sevag-method deproteinization and
dialysis impurity removal on an extracting solution, and purifying through a DEAE-52
cellulose column and a
Sephadex G-75 gel column in sequence to obtain the
rhodobryum roseum extract. Experiments prove that the polysaccharide can remarkably improve
spleen and thymus indexes and serum IgA, IgG and IgM levels of immunosuppressed mice and shows excellent humoral immune enhancement activity, and the action mechanism of the polysaccharide is related to regulation and control of
signal channels such as PI3K / Akt. The invention also provides application of the polysaccharide in preparation of an immunomodulator and a pharmaceutical composition.