Electroacupuncture Attenuates Inflammation in a Rat Model

Abstract

Acupuncture has traditionally been used in China and is being increasingly applied in Western countries to treat a variety of conditions, including inflammatory disease. However, clinical trials investigating the effectiveness of the anti-inflammatory effects of acupuncture have yielded inconsistent results, and the underlying mechanisms of acupuncture-produced anti-inflammation are unclear. To evaluate the effectiveness of electroacupuncture (EA) on inflammation in a rat model. Four experiments were conducted on male Sprague-Dawley rats (n = 8-9 per group). Inflammation was induced by injecting complete Freund's adjuvant (CFA) subcutaneously into the plantar surface of one hind paw of the rat. Experiment 1: To determine the effect of EA (10 and 100 Hz) versus sham treatment on inflammation. Experiment 2: To investigate the involvement of the adrenal glands on the effect of EA treatment using adrenalectomized (ADX) rats. Experiment 3: To determine the effects of EA on plasma levels of corticosterone. Experiment 4: To determine the effects of EA treatment versus immobilization on such stress indicators as heart rate and blood pressure. At 10 Hz EA significantly reduced CFA-induced hind paw edema. The effect was partially blocked in the ADX rats. EA significantly increased plasma levels of corticosterone but produced no noticeable signs of stress. At 10 Hz but not 100 Hz, EA suppresses inflammation by activating the hypothalamus-pituitary-adrenal axis (HPA) and the nervous system.