Stimulation of the auricle of the human ear has been used as medical remedy since the ancient times, both in the East and in the West. In 1957, Nogier described a new therapy called “auriculotherapy”, which could treat several pathologies including the relief of pain. According to Nogier, the different areas of the body, as well as the viscera, are represented with a well-defined somatotopic organisation on the auricle, in a pattern that resembles an upside-down fetus. The points of auricular acupuncture are found in a region where points of low electrical impedance have been described. A double-blind study was conducted using Sprague-Dawley rats to study whether low frequency auricular electroacupuncture (EA) inhibits acute local inflammation in the carrageenan-induced paw edema and the mechanisms involved in the anti-inflammatory effect. Methyl atropine, a muscarinic receptor antagonist, and naloxone, an opioid antagonist, were investigated for the involvement of the parasympathetic and the opioid system on the effects of auricular EA. Rats were divided into 4 groups: a control group (CA), an acupuncture group (CA+EA), an acupuncture group pretreated with naloxone (CA+EA +NX) (5mg/kg i.p.) and an acupuncture group pretreated with methyl atropine (CA+EA +MA) (0.2 mg/ml i.p). Bilateral stimulation was applied at the 12 o'clock position of the “anterior conchae” of the rats at an intensity of 0.8 mA, which is within the range of clinical application of electroacupucture. Prior to the CA injection and at 1 hour intervals for 4 hours after the injection, paw volume was measured with the use of a plethysomometer (Ugo Basile, Comerior, Italy) to record the changes in paw edema. Results showed that the rats which received auricular acupuncture (CA+EA) showed significant reduction in inflammation over the control group (CA) as shown in the lower levels of edema observed in the CA+EA group. The CA+MA group showed increased edema over the CA group. Although no significance was seen between the CA+EA+MA group and CA+MA group, a trend was seen where the CA+EA+MA group showed a decrease in edema to the CA+MA group. Studies with naloxone were not conclusive in the involvement of the opioid system because the CA+NX group showed a decrease in edema in comparison to the CA group; it is unknown what anti-inflammatory effect naloxone itself has. The results showed that low frequency auricular acupuncture does inhibit acute local inflammation, but the mechanisms of the anti-inflammatory effect remains to be clarified.
Statistics from Altmetric.com
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.