The Anti-Inflammatory Actions and Mechanisms of Acupuncture from Acupoint to Target Organs via Neuro-Immune Regulation

Acupuncture is a longstanding medical practice that has demonstrated efficacy in the treatment of various inflammatory conditions. A comprehensive scientific review study, recently published in the Journal of Inflammation Research, investigated the mechanisms by which acupuncture exerts its powerful anti-inflammatory effects across multiple systems of the human body.

## Background and Importance of the Topic

Inflammation is a natural defense response of the body, essential for combating infections and repairing damaged tissues. However, when it becomes chronic or uncontrolled, it can lead to the development of various serious diseases, including rheumatoid arthritis, asthma, cardiovascular diseases, and neurological disorders. Conventional anti-inflammatory medications, although effective, frequently cause significant side effects such as hypertension, diabetes, gastrointestinal problems, and immunosuppression, making patients more vulnerable to infections.

The World Health Organization recognizes acupuncture as an effective treatment for 16 types of inflammatory diseases, and various clinical studies have demonstrated its ability to reduce excessive inflammatory responses without the adverse effects of traditional medications. This makes understanding its mechanisms of action fundamental for expanding its therapeutic use.

## Study Objective and Methodology

The main objective of this study was to clarify the common mechanisms by which acupuncture produces anti-inflammatory effects, from stimulation of acupuncture points to target organs, through neuro-immune regulation. The investigators conducted a systematic review of the scientific literature from the past five years, analyzing studies that investigated the anti-inflammatory effects of acupuncture in different organ systems.

The methodology involved searching scientific databases (PubMed and Embase) using specific terms related to acupuncture and inflammation. After a rigorous selection process, 363 basic-research studies meeting the established criteria were included. The data were organized according to the organ systems affected and the biological mechanisms involved.

## Main Results and Findings

Results revealed that acupuncture exerts consistent anti-inflammatory effects across multiple systems: immune, digestive, respiratory, nervous, locomotor, circulatory, endocrine, and genitourinary. The central mechanism involves regulation of immune system cells, particularly macrophages and lymphocytes.

The research demonstrated that acupuncture promotes the transformation of type M1 macrophages (pro-inflammatory) into type M2 macrophages (anti-inflammatory). This process occurs through activation of PPARγ, a negative regulator of the TLR4 receptor, which in turn inhibits intracellular signaling pathways such as TLR/MyD88 and NOD. As a consequence, the NF-κB and P38 MAPK pathways are suppressed, reducing the production of pro-inflammatory substances such as TNF-α, IL-1β, IL-6, and IL-18, while increasing the production of anti-inflammatory mediators such as IL-10.

In addition, acupuncture modulates the balance of T helper (Th) cells, promoting a more anti-inflammatory profile depending on the condition treated. In autoimmune diseases, it favors Th2 and Treg cells; in allergic conditions, it promotes Th1 cells. The study also revealed that acupuncture combats oxidative stress through the Nrf2/HO-1 pathway, increasing superoxide dismutase (SOD) activity and eliminating harmful free radicals.

## Clinical Implications for Patients and Clinicians

These findings have important implications for clinical practice. For patients, the study offers a solid scientific basis for the use of acupuncture as an alternative or complement to conventional anti-inflammatory treatments. Acupuncture has been shown to be particularly effective in conditions such as rheumatoid arthritis, asthma, inflammatory bowel disease, stroke, neurodegenerative diseases, and sepsis.

For clinicians, the results provide important guidance on acupuncture point selection. The study identified that points such as Zusanli (ST-36), Hegu (LI-4), and Baihui (GV-20) are frequently the most effective for different inflammatory conditions. Combining multiple points generally produces better results than using isolated points.

The identified neuro-immune mechanism explains how stimulation of specific points on the skin can produce systemic effects. Acupuncture activates neural pathways that transmit signals to the brain, which responds by activating systems such as the cholinergic anti-inflammatory pathway, the hypothalamic-pituitary-adrenal axis, and the sympathetic nervous system, releasing neurotransmitters and hormones that modulate the immune response throughout the body.

## Limitations and Final Considerations

Although the results are promising, there are some important limitations to consider. Most included studies were conducted in animal models, primarily rats, which may limit direct applicability to humans. There is a need for more controlled clinical studies to fully validate these mechanisms in patients.

Another limitation is the variability in acupuncture parameters used across studies, including electrical stimulation frequency, treatment duration, and point combinations. This makes it difficult to establish standardized protocols for specific conditions. Future studies should focus on optimizing these parameters to maximize therapeutic benefits.

The study also highlights the need for more research on the interaction between acupuncture and conventional medications, since some work has suggested interesting synergistic effects that could benefit patients. Finally, there is a need for more in-depth investigation of the exact mechanisms by which different acupuncture points exert specific effects on different organs and systems.

In conclusion, this comprehensive review provides robust scientific evidence that acupuncture has well-defined and clinically relevant anti-inflammatory mechanisms. These findings offer a solid basis for the integration of acupuncture into conventional healthcare, especially for patients with chronic inflammatory conditions who seek alternatives to traditional medications or who want a safer and more effective complementary approach.