Therapeutic Effects of Low-Intensity Pulsed Ultrasound and Astragalus Extract on Collagen-Induced Rheumatoid Arthritis in a Mouse Model

Background/Aims: The objective of this experiment was to determine the therapeutic effects of low-intensity pulsed ultrasound (LIPUS) and Astragalus extract on rheumatoid arthritis (RA) in collagen-induced arthritis mice in terms of reducing inflammation, increasing pain thresholds, and tissue repair.

Materials and Methods: Thirty-five male Institute of Cancer Research (ICR) (CD-1) mice were randomly allocated into 5 groups: healthy control, arthritis control, LIPUS-treated, Astragalus-treated, and combined LIPUS + Astragalus-treated arthritis groups. Collagen-induced arthritis was induced using bovine type 2 collagen emulsified in complete Freund’s adjuvant. Serum anti-type 2 collagen (anti-CII) antibodies were measured 1 week after the booster injection (fifth week, day 36), and delayed-type hypersensitivity (DTH) responses were assessed on day 40. On day 41 (sixth week), the animals were euthanized for evaluation of CII-induced lymphocyte proliferation and histopathological analysis. Furthermore, the severity of RA, nociceptive thresholds (paw pressure and Von Frey tests), cytokine profiles, and oxidative stress markers (malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GPx)) were assessed among the groups.

Results: Arthritic mice showed significantly increased anti-CII antibodies, DTH response, RA severity scores, lymphocyte proliferation, pro-inflammatory cytokines (interleukin (IL)-1β, tumor necrosis factor-α), and MDA levels, together with significantly decreased nociceptive thresholds, antioxidant enzymes (SOD, GPx), and anti-inflammatory cytokines (IL-10, transforming growth factor-beta (TGF-β1)) compared with healthy controls (P < .001). Both LIPUS and Astragalus extract significantly improved these parameters vs. RA control group (P < .05-.01). The combination therapy produced the greatest reduction in anti-CII levels, inflammatory cytokines, oxidative stress markers, arthritis severity, and lymphocyte proliferation (P < .01), along with the highest increase in pain thresholds, IL-10, TGF-β1, SOD, and GPx activities (P < .05).

Conclusion: Low-intensity pulsed ultrasound and Astragalus extract effectively reduced inflammation and oxidative stress and promoted tissue repair, with combination therapy demonstrating superior efficacy. These findings highlight the potential of LIPUS and Astragalus extract as promising, non-invasive, natural therapeutic strategies for managing RA.

Cite this article as: Chen C, Firouzjah RA, Luo Y. Therapeutic effects of low-intensity pulsed ultrasound and Astragalus extract on collageninduced rheumatoid arthritis in a mouse model. ArchRheumatol. 2026;41(4):286-297.