Effects of polysaccharide-containing aqueous extracts of Cistanche deserticola Y. C. Ma on T lymphocyte subsets and duration of antibody response

Abstract

Objective To study the effects of aqueous extracts of cultivated Cistanche deserticola Y. C. Ma (AECCD) on T cell responses and the duration of antibody response and to investigate its immunoenhancing activities in mice. Methods Two batches of female ICR mice were used in this study with 30 from each batch. Each batch of mice was randomly divided into six groups (n=5). Low, medium and high doses of AECCD in combination with ovalbumin (OVA) were used to set up three experimental groups, while 0.9% NaCl, OVA alone and aluminium adjuvant were respectively used as blank, negative and positive controls. All mice were intramuscularly injected twice at an interval of two weeks. Flow cytometry was used to detect the expression of T lymphocyte subsets, cytokines and surface molecules of dendritic cells (DC). Indirect ELISA was used to detect IgG antibody levels. Results AECCD could significantly increase the percentage of CD4+ and CD8+ T lymphocytes in spleen (P<0.05), up-regulate the expression of CD4+ CD44+ and CD8+ CD44+ effector T lymphocytes (P<0.05), promote the secretion of IFN-γ in T lymphocytes and enhance the expression of CD40 and CD80 on the surface of DC (P<0.05). ELISA results showed that high-dose AECCD could significantly prolong the duration of IgG antibody response induced by OVA (P<0.05). Conclusion AECCD could enhance the T lymphocyte immune response induced by OVA and keep it maintained at a high level, which might help to improve the body′s immune response. Key words: Cultivated Cistanche deserticola Y. C. Ma; T cell response; Immune enhancement