Abstract: The study aimed to determine immune enhancement activities of ethanolic extract from wild C. deserticola with dual Th₁ and Th₂ responses by promoting DCs maturation in mice. OVA was used as antigen, three different doses of EEWCD (low, medium, high) were combined with OVA in 0.9% NaCl. ICR mice were randomly separated into seven groups, 0.9% NaCl group, EEWCD group, OVA group, OVA-EEWCD-L group, OVA-EEWCD-M group, OVA-EEWCD-H group, and OVA-Alum group. ICR mice were subcutaneously injected twice with a 2-week interval. After vaccination, IgG titers, IgG subclasses were detected by ELISA, splenocyte proliferation was performed with MTT method, cytokine, DCs surface markers and Treg frequency were tested by FACS. The data showed that EEWCD significantly enhanced the serum IgG titers and IgG subclasses (P<0.05). Meanwhile, EEWCD significantly promoted OVA-specific splenocyte proliferation and T/B-proliferation (P<0.05). EEWCD also could significantly promote the level of CD4⁺IL-4,CD4⁺IFN-γ and CD8⁺IFN-γ (P<0.05). Furthermore, the expression levels of CD40, CD80, CD86 and MHC-Ⅱ in DCs were significantly improved (P<0.05), whereas the frequency of Treg was significantly decreased (P<0.05). EEWCD-M showed remarkable immunomodulatory activity. No abnormal behavior and significant difference in mice body weight were observed (P>0.05). The data showed that subcutaneous administration of EEWCD significantly enhanced Th₁/Th₂ immune responses by promoting DCs maturation and reducing the frequency of Treg.

Key words: ethanol extracts, wild Cistanche deserticola in Xinjiang, Th₁/Th₂ response, immune enhancement, dendritic cells