Editor’s Note: This column by the Society for Acupuncture Research (www.acupunctureresearch.org) offers research insights relevant to acupuncture practitioners. Visit the SAR online columnist page for access to previous articles.
Knee osteoarthritis (OA) is a leading cause of pain and disability, often managed with pharmacological and surgical interventions. However, acupuncture has long been used as a non-invasive treatment for knee pain, and recent research provides new insights into its underlying mechanisms.
A recently published study reveals how acupuncture alleviates knee OA symptoms by modulating the melatonin (MLT) / cyclic adenosine monophosphate (cAMP) / protein kinase A (PKA) / cAMP response element-binding protein (CREB) signaling pathway – a key regulator of pain and inflammation.
Study Overview
Researchers induced knee OA in rabbits using the Hulth method, which involves surgical ligament and meniscal damage. The rabbits were divided into three groups: control (no OA induction), OA group (OA model with no acupuncture treatment), or OA + acupuncture group (OA model with daily acupuncture treatment).
Acupuncture was performed at Neixiyan (EX-LE 4), Dubi (ST 35), Xuehai (SP 10), Zusanli (ST 36), Hegu (LI 4), and Yanglingquan (GB 34) for 20 minutes daily over 28 days. Researchers assessed pain tolerance, joint swelling, cartilage integrity, and inflammatory markers using histological scoring, immunohistochemistry, real-time polymerase chain reaction, and Western blotting.
Key Findings
Acupuncture significantly improved pain scores, joint swelling, and gait mobility in the OA+A group compared to the untreated OA group. Histopathology results showed that acupuncture reduced cartilage damage and subchondral bone exposure, indicating protective effects on joint structures.
On a molecular level, acupuncture upregulated melatonin-related proteins and receptors (MT1, MT2, AANAT mRNA) while also increasing expression of cAMP, PKA, and CREB, which are key molecules in pain regulation. Furthermore, acupuncture downregulated the inflammatory marker MMP-3, which is commonly elevated in OA, suggesting a strong anti-inflammatory effect.
Together, these findings indicate that acupuncture modulates pain and inflammation by stimulating sympathetic nerve activity and enhancing the MLT/cAMP/PKA/CREB signaling pathway, contributing to improved pain relief and joint protection.
Clinical Relevance for Acupuncture Practitioners
This study reinforces traditional East Asian medicine theory that acupuncture can modulate pain and inflammation. It also provides further verification of the local and distal acupoints frequently used to treat knee OA, supporting their role in managing pain, restricted mobility, and joint degeneration.
Moreover, the study highlights the importance of consistent and frequent acupuncture treatments in the early phase of care, with ongoing maintenance to sustain benefits, which aligns with acupuncture clinical practice.
Conclusion
Acupuncture continues to emerge as a valuable adjunctive therapy for knee OA, offering pain relief, inflammation reduction, and potential joint-protective effects. This study enhances our understanding of the mechanisms behind acupuncture’s efficacy, further validating its role in knee OA management.
Reference
- Zhang C, Yu M, Zhang L, et al. Exploring the analgesic effect of acupuncture on knee osteoarthritis based on MLT/cAMP/PKA/CREB signaling pathway. J Inflamm Res, 2025;18:237-249.
Dr. Simone Ormsby has an Honours Degree in Molecular Biology/Genetics; a Bachelor of Health Science in Chinese Medicine (acupuncture); and a Higher Degree by Research PhD. She is a postdoctoral researcher in the School of Nursing and Midwifery, and NICM Health Research Institute; an adjunct fellow at the NICM Health and Research Institute; and co-lead of the SARs Basic Science Special Interest Group, for which she writes newsletter snapshots of acupuncture mechanistic investigations.
Sandro Graca is a member of the SAR Board of Directors; a doctoral researcher at the Faculty of Education, Health and Wellbeing, University of Wolverhampton, University of Wolverhampton, U.K., focusing on research on polycystic ovary syndrome (PCOS) and women’s health; Social Media and Outreach Editor for the European Journal of Integrative Medicine; and lead author on the Cochrane Review Group on acupuncture for assisted reproductive technology.
