[Effect of electroacupuncture of auricular concha on inflammatory reaction in endotoxaemia rats]

To evaluate the effect of electroacupuncture (EA) of the auricular concha (EA-AC) on serum cytokines contents and pulmonary transcription factor nuclear factor-kappaB (NF-kappaB) expression in lipopolysaccharide (LPS) induced endotoxaemia rats so as to study its mechanism underlying cholinergic anti-inflammatory efficacy.

Male SD rats were randomized into normal control, model (LPS), simple EA-AC, EA-AC + LPS, vagal nerve stimulation (VNS) + LPS, and EA-Zusanli (ST 36) + LPS groups (n = 12/group). Endotoxaemia model was duplicated by intravenous (tail vein) injection of LPS (0.5 mL/kg). Two intradermal needles were inserted into the central sites of the cavity of concha and cymba of auricular concha respectively on each side and stimulated electrically by using an electrical stimulator (i.e, EA-AC). VNS was applied to the left cervical vagal nerve, and EA (1 mA, 10 Hz, pulse-width 1 ms) was also applied to bilateral "Zusanli" (ST 36). Serum cytokines (TNF-alpha IL-6) contents 2 h after modeling were determined by using enzyme linked immunosorbent assay (ELISA), and pulmonary NF-kappaB p 65 expression 2 h after modeling was detected by using western blotting.

Compared with the normal control group, serum TNF-alpha and IL-6 contents, and pulmonary NF-kappaB p65 expression level in the model group were increased significantly (P < 0.01). In comparison with the model group, serum TNF-alpha contents in the simple EA-AC, EA-AC + LPS, VNS+ LPS and ST 36 + LPS groups, and serum IL-6 contents and pulmonary NF-kappaB p 65 expression levels in the simple EA-AC, EA-AC + LPS and VNS + LPS groups were down-regulated considerably (P < 0.05, P < 0.01). Compared with the VNS + LPS group, serum TNF-alpha -28) and IL-6 contents, and pulmonary NF-kappaB p 65 expression level in the ST 36 + LPS group were increased significantly (P < 0.05, P < 0.01). In comparison with the EA-AC + LPS group, pulmonary NF-kappaB p 65 expression level in the ST 36 + creased remarkably (P < 0.05).

Both EA of auricular concha and vagus nerve stimulation can serum TNF-alpha and IL-6 contents, and down-regulate pulmonary NF-kappaB p 65 expression level in endotoxaemia similar cholinergic anti-inflammatory mechanism between them.