Immunomodulatory effects and mechanisms of Tiepishihu Xiyangshen granules on cyclophosphamide induced immuno-suppression via TLR4/MAPKs and PI3K/AKT/FOXO3a signal pathways

Ethnopharmacological relevance: Tiepishihu Xiyangshen granules (TXG) is a traditional Chinese medicine formula composed of Panax quinquefolius L, Dendrobium officinale Kimura & Migo and Ganoderma lucidum (Curtis) P. Karst. It has long been used as a nutritional supplement and an immune enhancer in China. However, the immunomodulatory effects and the underlying mechanisms of TXG have not been clarified.

Aim of the study: This study aims to investigate the immunomodulatory effects of TXG and clarify the underlying mechanism.

Materials and method: TXG was administered by gavage for 18 days. From the 15th day, the immunosuppression model was induced by intraperitoneally injecting 80 mg/kg CTX for 3 days. The immune regulatory effects of TXG on immune organs were verified by calculating the organ index and observing the spleen tissue structure through HE staining. The effects of TXG on immune cells were examined by recording the PBWC, the proliferation rate of lymphocyte and the T lymphocyte phenotype. The effects of TXG on immune molecules were measured by detecting serum hemolysin and the content of cytokines. In parallel, kit was utilized to detect its antioxidant capacity. RNA seq and Western blot were used to analyze the possible immune regulation mechanism of TXG. HPLC and UPLC-Q-TOF-MS were used to identify the chemical components in TXG.

Results: At the level of immune organs, TXG effectively reduced the adverse reaction to the body and the substantial damage to the spleen after chemotherapy by improving the spleen damage. At the level of immune molecules, TXG upregulated the expression of cytokines and antibodies. At the level of immune cells, TXG antagonized bone marrow suppression by increasing the PBWC of immunosuppressed mice. Meanwhile, TXG upregulated the ratio of CD4⁺/CD8⁺ lymphocytes and ameliorated the proliferation of T and B lymphocytes. And the mechanism of TXG to improve immunity might be through TLR4/MAPKs and PI3K/AKT/FOXO3a signaling pathways.

Conclusion: The results of this study confirmed that TXG has prominent immunomodulatory activities, and the immunity regulations of TXG may be achieved by regulating TLR4/MAPKs and PI3K/AKT/FOXO3a signal pathways.