Tehran University of Medical Sciences Iranian Journal of Allergy, Asthma and Immunology 1735-1502 22 2 2023 04 30 172 182 EN Elham Shokati Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran Morteza Motallebnezhad Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran Elaheh Safari Department of Immunology, School of Medicine, Iran University of Medical Sciences, Tehran, Iran AND Immunology Research Center, Iran University of Medical Sciences, Tehran, Iran 2022 08 22 2023 01 09 Astragalus polysaccharide (APS) is a functional component of Astragalus membranaceus with antitumor and immunomodulatory properties. This study evaluated the effect of APS on the peripheral blood mononuclear cell (PBMC) proliferation, cytokine secretion, and regulatory T cell (Treg) induction in an in vitro coculture model of human PBMCs and A2780 human ovarian cancer cells. PBMC proliferation and Treg frequency were measured by flow cytometry. Cytokine levels were assessed by enzyme-linked immunosorbent assay. APS significantly enhanced the PBMC proliferation, reduced Treg frequency, decreased anti-inflammatory cytokines including interleukin [IL]-10, transforming growth factor beta (TGF-β), and vascular endothelial growth factor-A (VEGF-A), and increased the pro-inflammatory cytokine IL-6. These findings suggest that APS may be an effective immunomodulatory supplement for cancer therapy, particularly for ovarian cancer by enhancing antitumor immune responses. https://ijaai.tums.ac.ir/index.php/ijaai/article/view/3638 https://ijaai.tums.ac.ir/index.php/ijaai/article/download/3638/1943