Immunomodulatory effect of polysaccharides isolated from Thunb. in cyclophosphamide-treated BALB/c mice.

() is utilized as foods and healthy drink around the world. Until now, the immunomodulatory activity of polysaccharides from (LJP) is little studied. In our previous work, LJP was fractionated to a neutral component (LJP-N) and an acidic component (LJP-A) by a DEAE-Cellulose column, and LJP-N was a starch-like polysaccharide and LJP-A was a pectic polysaccharide. In this study, LJP-N and LJP-A were investigated for their immunomodulatory effect, and the protective effect of these two polysaccharide fractions against immune injury by cyclophosphamide (CTX) in BALB/c mice was evaluated. Results showed that when compared with CTX group, LJP fractions, especially for LJP-A (200 mg kg) can enhance the immune function, improve atrophy of the lymphoid organs thymus and spleen (the increased approximately 1.8- and 1.6-fold), increase the phagocytic function of macrophages (increased approximately 1.7-fold), increase the secretion of cytokines (the levels of IL-6, IL-2, and TNF-α increased approximately 2.5-, 2.0-, and 1.4-fold) and immunoglobulins levels (the levels of IgM and IgG increased approximately 1.2- and 1.7-fold) in serum, and enhance the cytotoxic activity of NK cells (increased approximately 3.5-fold). Taken together, the present results suggest that LJP-A, rich in uronic acid, with a molecular weight of 400 kDa, may be a potential candidate as the functional foods.