ABSTRACT
Objective:To investigate the effect of wild Cistanche deserticola crude polysaccharides (WCDCP) on the immune response of ovalbumin (OVA).Methods:42 ICR mice were randomly divided into the 9 g/L NaCl group (blank sample), WCDCP group (400 μg WCDCP), OVA group (10 μg OVA), low-dose WCDCP/OVA group (100 μg WCDCP+10 μg OVA), medium-dose WCDCP/OVA group (400 μg WCDCP+10 μg OVA), high-dose WCDCP/OVA group (800 μg WCDCP+10 μg OVA), and aluminum adjuvant/OVA group (positive concentration, 200 μg aluminum adjuvant+10 μg OVA). Each group included 6 mice. The mice were immunized by using two-point injection into the muscles of the hind legs of the mice. A total of 2 immunizations, and the immunization was boosted once every 2 weeks after the initial immunization. The body weight of the mice was weighed 7, 14, 21, and 28 days after the initial immunization of the mice, and the changes in body weight and growth status of the mice were observed. The IgG antibodies and antibody fractions were detected by indirect enzyme-linked immunosorbent assay. Twenty-one days after the initial immunization, the spleen lymphocyte proliferation level was detected by the thiazole blue method. Flow cytometry was used to detect the proportion of T cell subsets in the spleen and lymph nodes.Results:At 7 days after the initial immunization, the serum IgG antibody level (0.597 6±0.110 7) in the high-dose WCDCP/OVA group was significantly higher than (0.254 4±0.074 8) of the OVA group ( P<0.05). At 28 days after the initial immunization, the serum IgG, IgG1 and IgG2a antibody levels in the high-dose WCDCP/OVA group were higher than those in the OVA group, the comparison respectively were 0.972 3±0.243 8 vs. 0.389 2±0.077 4 ( P<0.05), 1.156 0±0.088 4 vs. 0.612 6±0.059 7 ( P<0.001), 1.648 0±0.103 9 vs. 0.557 2±0.181 5 ( P<0.001), and the differences were statistically significant. High-dose WCDCP can significantly promote the proliferation of spleen cells induced by concanavalin A ( P<0.001) and lipopolysaccharide ( P<0.05). High-dose WCDCP/OVA group can significantly stimulate the activation ratio of T cell subsets in the spleen. The proportion of CD3 +CD8 + T cells in the high-dose WCDCP/OVA group [(10.83±0.44)%] was significantly higher than that in the OVA group[(6.76±0.58)%] ( P<0.01), and the proportion of CD3 +CD4 + T cells [(28.17±1.67)%] was also significantly higher than that in the OVA group [(19.17±2.73)%] ( P<0.05). WCDCP had no effect on body weight (all P>0.05) and growth of mice. Conclusions:WCDCP can enhance humoral immune response and cellular immune response, and has no side effect on the growth of mice, suggesting that WCDCP can be used as a potential adjuvant for OVA.