Page 210 - 2025中醫藥與天然藥物聯合學術研討會-中醫藥與天然藥物的挑戰Ｘ機遇與未來大會手冊

PP-28

Bioactive component of Astragalus membranaceus attenuates inflammation

by inhibiting IL-6/IL-6R interaction and antigen-presenting cell activation

#,1
Y a -Ti Chan, Hung-Rong Yen, 1,2,3 Ying-Chyi Song* ,3,4

1 School of Chinese Medicine, College of Chinese Medicine, China Medical University,
Taichung, Taiwan
2 Integration of Chinese and Western Medicine, China Medical University Hospital, Taichung,
Taiwan
3 Chinese Medicine Research Center, China Medical University, Taichung, Taiwan
4 Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical
University, Taichung, Taiwan
* Email: songyingchyi@gmail.com

Abstract
Interleukin-6 (IL-6) is an essential pro-inflammatory cytokine predominantly produced by
antigen-presenting cells (APCs) in response to tissue injury or infection. While IL-6 supports
host immune defence, persistent or excessive expression drives chronic inflammation and
autoimmune pathologies, such as multiple sclerosis. Accordingly, targeting the IL-6 signaling
pathway has emerged as a therapeutic approach for chronic inflammatory disease. Calycosin
(CA), an isoflavone derived from Astragalus membranaceus, is known for its anti-inflammatory
properties, but its specific effects on the IL-6 pathway remain unclear. This study investigated
the anti-inflammatory mechanisms of CA, focusing on IL-6 and its receptor (IL-6R).
Experiments involved treating LPS-induced mouse bone marrow-derived dendritic cells
(BMDCs) and macrophages (Raw264.7) with CA. Production of pro-inflammatory cytokines,
including IL-6, IL-12, and TNF-α, was quantified by ELISA, and the expression of
costimulatory molecules (CD40 and CD80) was analysed by flow cytometry. CA treatment
markedly suppressed the secretion of IL-6, IL-12, and TNF-α in both BMDCs and Raw264.7
cells. Moreover, CA significantly downregulated the surface expression of CD40 and CD80 on
BMDCs. Competitive ELISA revealed that CA inhibited the binding of mouse IL-6 and IL-6R.
Drug affinity responsive target stability (DARTS) assays further showed that CA conferred
dose-dependent protease protection to both mouse and human recombinant IL-6 and IL-6R,
suggesting direct interaction. Collectively, these findings suggest that CA exerts anti-
inflammatory effects by inhibiting APC activation, suppressing pro-inflammatory cytokine
secretion, and directly interfering with IL-6/IL-6R interaction. These findings provide
mechanistic insights into the potential of CA as a therapeutic agent for IL-6–mediated
inflammatory diseases.

Keywords: Astragalus membranaceus; calycosin; antigen-presenting cells; IL-6; IL-6 receptor