Acupuncture at the "Huatuojiaji" point affects nerve root regional interleukin-1 level in a rat model of lumbar nerve root compression

Yaochi Wu; Junfeng Zhang; Chongmiao Wang; Yanyan Xie; Jinghui Zhou

摘要：BACKGROUND: It has been shown that interleukin-1 (IL-1) may cause inflammatory reactions, which stimulate the nerve root of patients with lumbar intervertebral disc protrusion and leads to pain. Whether the clinical curative effects of acupuncture in the treatment of lumbar and leg pain are linked to an inhibition of local IL-1 secretion is unknown.OBJECTIVE: To assess the influence of acupuncture on IL-1, this study was designed to verify the effects of acupuncture at the "Huatuojiaji (Extra)" point on the nerve root in a rat model of lumbar nerve root compression, compared with administration of meloxicam, a non-steroidal anti-inflammatory drug.DESIGN, TIME AND SETTING: Randomized, controlled, molecular biology experiment, performed at the Experimental Center, Sixth People's Hospital Affiliated to Shanghai Jiao Tong University between September 2005 and April 2006.MATERIALS: Forty healthy adult Sprague Dawley rats of either gender were included in this study. The rats were randomly and evenly divided into the following four groups: normal control, model, acupuncture,and meloxicam groups. Lumbar nerve root compression was induced in rats in the model, acupuncture,and meloxicam groups by inserting a specially made silicon rubber slice at the juncture of the L5 nerve root and the dural sac. The acupuncture needle (pattern number N3030, 30#, 1.5 inch) was purchased from Suzhou Medical Appliance Factory, China. IL-1 enzyme linked immunosorbent assay (ELISA) kit was purchased from Santa Cruz Biotechnology, Inc., USA.METHODS: The acupuncture group was acupunctured at the "Huatuojiaji" point, which is lateral to the compressed L5-6 nerve root, with an acupuncture depth of 0.5 cm. There were two treatment courses, each of involved seven 20-minute acupuncture sessions, one session a day. The meloxicam group was administered intragastrically 3.75 mg/kg meloxicam (5 mg meloxicam/10 mL physiological saline). Rats in the normal control group and model group received an intragastric administration of 10 mL/kg physiological saline. All administrations were performed once a day.MAIN OUTCOME MEASURES: At day 14 post-surgery, the IL-1 level in the compressed nerve root was determined by a streptavidin-peroxidase (S-P) immunohistochemical method, and IL-1β mRNA expression in the compressed nerve root was simultaneously detected by real-time reverse transcription-polymerase chain reaction.RESULTS: The expression levels of IL-1 and IL-1βmRNA in the L5 nerve root were significantly higher in the model group than in the control group (P < 0.01). However, the expression levels of IL-1 and IL-1β mRNA were significantly lower in the acupuncture and meloxicam groups than in the model group (P < 0.05-0.01). Expression levels of IL-1 and IL-1β mRNA were significantly higher in the acupuncture group than in the meloxicam group (P < 0.01).CONCLUSION: Acupuncture at the "Huatuojiaji" point decreases the IL-1 level by inhibiting IL-1βmRNA expression to a greater extent than meloxicam administration.