Electroacupuncture Attenuates Inflammation in a Rat Model

Acupuncture has been used for thousands of years in traditional Chinese medicine to treat a wide variety of conditions, including inflammatory diseases. In the West, its use has been growing especially because many patients face significant side effects with conventional medications such as nonsteroidal anti-inflammatory drugs, opioids, and COX-2 inhibitors. Although up to 42% of patients seek complementary therapies such as acupuncture, clinical results regarding its anti-inflammatory effects have been inconsistent. Some studies show benefits for rheumatoid arthritis, while others find no positive effects.

In addition, the mechanisms by which acupuncture may reduce inflammation remained poorly understood, making more in-depth research necessary to clarify how and when this technique may be effective.

This study aimed primarily to evaluate the efficacy of electroacupuncture in the treatment of inflammation and to investigate the biological mechanisms involved. The researchers used a well-established model of inflammation in rats, inducing paw swelling by injecting a substance called complete Freund's adjuvant. Four complementary experiments were performed using male rats divided into groups of 8 to 9 animals each. In the first experiment, they tested different electroacupuncture frequencies (10 Hz and 100 Hz) compared with sham treatment.

In the second, they investigated the role of the adrenal glands by surgically removing them in some animals. The third measured the levels of corticosterone, a natural anti-inflammatory hormone, in blood plasma. The last experiment verified whether the observed effects resulted from nonspecific stress, measuring indicators such as heart rate and blood pressure. Electroacupuncture was applied at specific points equivalent to the Huantiao point of Chinese medicine, located in the lateral thigh region.

The results demonstrated that electroacupuncture at 10 Hz was significantly effective in reducing inflammation, but only in mild to moderate cases. Interestingly, the 100 Hz frequency showed no anti-inflammatory effect, suggesting that the specific frequency of stimulation is crucial for therapeutic success. Efficacy depended on the intensity of the initial inflammation: smaller and moderate doses of the inflammatory agent responded well to treatment, whereas severe inflammation showed no improvement. The study revealed that the mechanism of action involves activation of the hypothalamic-pituitary-adrenal axis, an important hormonal system in the body's natural response to inflammation.

When the adrenal glands were removed from the animals, the anti-inflammatory effect of acupuncture was partially blocked, confirming their importance. Additionally, electroacupuncture significantly increased corticosterone levels in the blood, a natural hormone with anti-inflammatory properties similar to the synthetic corticosteroids used in medicine.

Clinically, these findings suggest that electroacupuncture may be a valuable therapeutic option for patients with mild to moderate inflammatory conditions, offering an alternative or complement to conventional medications. The discovery that the treatment works through activation of the body's own natural mechanisms to combat inflammation is particularly encouraging. This means patients can obtain relief without the side effects associated with traditional anti-inflammatory medications, such as gastrointestinal or cardiovascular problems. For healthcare professionals, the study provides solid scientific evidence on how and when to use electroacupuncture, especially the importance of the correct stimulation frequency.

The technique may be particularly useful as adjuvant therapy, allowing reduced medication doses in some patients or offering an option for those who do not tolerate conventional treatments well.

It is important to recognize the limitations of this research for an adequate interpretation of the results. The study was conducted only in animals, and although experimental models are valuable, the results need to be confirmed in clinical studies in humans before definitive conclusions can be drawn. Electroacupuncture proved ineffective against severe inflammation, suggesting that it may not be suitable for all types or stages of inflammatory diseases. In addition, the study focused only on short-term effects, not clarifying the long-term benefits or the durability of effects after treatment discontinuation.

The mechanisms identified, although important, may not represent the full complexity of the effects of acupuncture in the human body. Future research should include controlled clinical trials in patients with different inflammatory conditions, investigate optimized treatment protocols, and explore combinations with other therapies. This study represents a significant step in the scientific understanding of acupuncture, providing a solid basis for its rational use and demonstrating its potential as a legitimate therapeutic tool in the modern medical arsenal.