| Objective: This study aimed to evaluate the inhibitory effects of Astragalus granules in combination with a PD-1 inhibitor on gastric cancer xenografts and to elucidate the underlying immunological mechanisms.
Methods: Human gastric cancer MKN-45 cells were subcutaneously inoculated into BALB/c nude mice, which were randomly divided into four groups (n = 6 per group): the model group, PD-1 inhibitor group, Astragalus granules group, and combination group. Astragalus granules were administered daily via oral gavage, while the PD-1 inhibitor (Tislelizumab) was delivered intraperitoneally according to treatment cycles. The combination group received both treatments concurrently. After nine weeks, general conditions, tumor weight and volume, serum cytokine concentrations, and immune cell proportions in tumor tissues were evaluated.
Results: Compared with the model group, all treatment groups showed significantly higher activity scores and reduced tumor weight and volume (P < 0.05). The combination group exhibited the greatest tumor inhibition rate (71.49%), with tumor weight and volume significantly lower than those in either monotherapy group (P < 0.05). Immunological analyses indicated that the combination group had markedly increased proportions of CD8? T cells and NK cells in tumor tissues, accompanied by significantly reduced serum IL-6 and TGF-β1 levels (P < 0.05). Furthermore, Astragalus granules helped maintain stable serum IL-2 levels, in contrast to the decrease observed in the PD-1 inhibitor group.
Conclusion: The combination of Astragalus granules with a PD-1 inhibitor produced superior anti-tumor effects compared with monotherapy in gastric cancer xenografts. The enhanced efficacy may result from the activation of CD8? T-cell and NK-cell responses, improvement of the inflammatory tumor microenvironment, and preservation of key immune signaling pathways. These findings provide experimental evidence supporting Astragalus granules as a promising adjuvant in gastric cancer immunotherapy. |