Effects of Extremely Low Frequency Magnetic Field (ELF-MF) on Formalin Induced Chronic Pain in Mice

Background: Effects of Extremely Low Frequency Magnetic Field) ELF-MF (in the elevation of blood sugar, cholesterol, triglyceride and reduction of withdrawal syndrome of morphine have been reported so far. Since pain is one of the main concerns in medicine and usually analgesic drugs are not much beneficial or cause considerable side effects, the present project was carried out with the aim of evaluating the effects of (ELF-MF (in chronic pain using formalin test in mice. Materials & Methods: In this experimental study, thirty two adult male mice were used and divided into 4 groups (n = 8). Three groups of animals exposed daily for thirty minutes to 25, 50, 75 HZ (intense 250 μT) of electromagnet field for one week, respectively and one group considered as control with no exposure. At the end of a week, formalin test was performed. Responses to formalin were observed for sixty minutes. The results were compared between tests and control group. Findings: In acute phase of formalin test, ELF-MF reduced significantly the pain scores following formalin injection at all 3 frequencies, especially at 25 and 50 HZ (p < 0.001) rather 75 HZ (p < 0.05). In chronic phase of formalin test, ELF-MF reduced pain scores at 25 and 50 HZ (p < 0.05). However, the most effective responses were obtained at 50 HZ frequency. Conclusion: The findings show that ELF-MF is effective to reduce formalin induced chronic pain in mice at both acute and chronic phases.