Abstract: OBJECTIVE: To investigate whether Hydrolyzed Seawater Pearl tablet(HSPT) could modulate the Th1/Th2 imbalance in an immunosuppressed mouse model with Th1 to Th2 shift induced by Cyclosporine A(Cs A) which can be used in the clinical treatment of Th2 to Th1 shift diseases, and explore the possible mechanism for the adjuvant therapeutic efficacy of HSPT on recurrent respiratory infections(RRI) and acquired immune deficiency syndrome(AIDS).METHODS: The mice were randomly divided into six groups of five animals each, namely normal group, model group, lentinan polysaccharide tablet(LPT) group and three HPST treated groups. HPST treated groups were administered with HPST(0.51,1.02, 2.04 g/kg) via intragastric gavage(i.g) for 30 consecutive days. LPT used as reference drug for positive control, LPT group was administered with LPT(8.2 mg/kg) for 30 consecutive days. Normal group and model group were received distilled water. The animals in model group, LPT group and HPST treated groups were injected intraperitoneally with Cs A(50 mg/kg) to establish the immunosuppressed mice model with Th1 to Th2 shift on the20 th, 22 nd and 24 th day, one hour after the administration of the respective treatment. Animals were sacrificed one hour after the last administration to collect blood and splenic tissue. The proportion of T cells including CD8+ and CD4+ T cells, Th1 and Th2 in peripheral blood of experimental mice were measured by flow cytometric. The protein level in serum and m RNA level in splenic tissue of experimental mice for interleukin(IL)-2, IL-12, interferon-γ(IFN-γ), IL-4, IL-6, IL-10 and IL-13 were measured by enzyme linked immunosorbent assay and fluorescence quantitative polymerase chain reaction respectively.RESULTS: HSPT elevated the proportion of T cells including both CD8+ and CD4+ T cells, in which the proportion of Th1 and Th2 cells increased, while the ratio of Th1/Th2 cells decreased in peripheral blood of the immunosuppressed mouse model with Th1 to Th2 shift induced by Cs A. Furthermore,HSPT elevated both protein and m RNA level of Th1-type cytokines IL-2 and IFN-γ, while had no significant effect on protein and m RNA level of Th1-type cytokine IL-12 and Th2-type cytokines IL-4, IL-6, IL-10, IL-13 in mouse model.CONCLUSION: Our findings suggest that HSPT can increase proportion of T cells including both CD8+and CD4+T cells and induce Th2 to Th1 shift in both cells and cytokines, which probably was the mechanism to account for the adjuvant therapeutic efficacy of HSPT on RRI and AIDS.

Key words: respiratory tract infections, acquired immunodeficiency syndrome, Th1-Th2 balance, interleukins, interferon-gamma, Hydrolyzed Seawater Pearl tablet