To observe the anti-inflammatory effects of electroacupuncture (EA) at "Quchi" (LI 11) and its influence on IL-1beta, TNF-alpha concentrations and mRNA expressions in carrageenan (CAR)-induced inflammation rats, so as to reveal partial mechanisms of EA in relieving acute inflammation.
Sixty male Wistar rats were divided into control, model, Indomethacin (IND, 7.5 mg/kg, oral perfusion), Rofecoxib (7.5 mg/kg, oral perfusion), EA-pre-treatment (EA was given once daily for 5 days before modeling), EA-post-treatment (EA was given once after modeling) groups, with 10 cases in each. EA (2 Hz, 5 mA and persistent waves) was applied to "Quchi" (LI 11) for 30 min each time. Arthritis model was established by subcutaneous injection of 1% CAR, 0.1 mL into the right hind paw. Paw edema degree of the affected hind paw was measured with a foot-volume surveyor. After processing samples of the affected paw toes (including smashing, centrifugalization, etc.), concentrations of prostaglandin (PG) E2, interleukin (IL)-1beta, tumor necrosis factor (TNF)-alpha were measured by enzyme linked immunosorbent assay (ELISA). Expressions of IL-1beta mRNA and TNF-alpha mRNA in the local inflammatory tissues were detected by reverse-transcription polymerase chain reaction (RT-PCR) assay.
Compared with model group, the affected hind-paw-volume decreased significantly from 2 h on in EA-post-treatment group and from 1 h on in IND group after injection of CAR. Compared with control group, PGE2, IL-1beta and TNF-alpha contents in the toe tissue of model group increased significantly; while in comparison with model group, PGE2 and IL-1beta levels in EA-post-treatment group, IL-1beta level in IND group decreased significantly (P < 0.05), and TNF-alpha level in IND group increased significantly. No significant differences were found between model group and Rofecoxib and EA-pre-treatment groups in most time-courses of the hind-paw-volume, between model and IND, Rofecoxib and EA-pre-treatment groups in PGE2, between model and EA-pre-treatment groups in IL-1beta, and between model and Rofecoxib, EA-pre-treatment and EA-post-treatment groups in TNF-alpha contents (P > 0.05). Compared with model group, IL-1beta mRNA expression of the local inflammatory tissues in IND and EA-post-treatment groups was down-regulated, and TNF-alpha mRNA expression in Rofecoxib and two EA groups down-regulated slightly.
EA possesses anti-inflammatory effect in acute arthritis rats, which is closely related to its effects in reducing the secretion of PGE2, IL-1beta and TNF-alpha and the expression of IL-1beta mRNA and TNF-alpha mRNA.