Comparative Study of Anti-Inflammatory Effects of Low-Intensity Extremely High-Frequency Electromagnetic Radiation and Diclofenac on Footpad Edema in Mice

Abstract

Anti-inflammatory effects of low-intensity extremely high-frequency electromagnetic radiation (EHF EMR) was compared to the action of sodium diclofenac on zymosan-induced footpad edema in NMRI mice. Diclofenac in doses of 2, 3, 5, 10, and 20 mg/kg was injected intraperitoneally (ip) 30 min after zymosan injection. The mice were whole-body exposed to EHF EMR (42.0 GHz, 0.1 mW/cm2) for 20 min at 1 h after zymosan injection. Inflammation was assessed over 3–8 h after initiation by measuring the footpad edema and hyperthermia of the inflamed paw. Diclofenac caused a dose-dependent anti-inflammatory effect. Doses of 5–20 mg/kg reduced the footpad edema on the average by 26% as compared to the control. Hyperthermia decreased with increasing in a dose of diclofenac, and at a dose of 20 mg/kg decreased by 60% compared to control. EHF EMR reduced both the footpad edema and hyperthermia by about 20% that was comparable with the effect of single therapeutic dose of diclofenac (3–5 mg/kg). Combined action of diclofenac and EHF EMR exposure caused a partial additive effect. The results obtained suggest that the adjunctive use of low-intensity EHF EMR with non-steroid anti-inflammatory drugs can provide more pronounced therapeutic effects.