Activation of Antioxidative Functions by Radon Inhalation Enhances the Mitigation Effects of Pregabalin on Chronic Constriction Injury‐Induced Neuropathic Pain in Mice

Abstract

Radon inhalation brings pain relief for chronic constriction injury- (CCI-) induced neuropathic pain in mice due to the activation of antioxidative functions, which is different from the mechanism of the pregabalin effect. In this study, we assessed whether a combination of radon inhalation and pregabalin administration is more effective against neuropathic pain than radon or pregabalin only. Mice were treated with inhaled radon at a concentration of 1,000 Bq/m3 for 24 hours and pregabalin administration after CCI surgery. In mice treated with pregabalin at a dose of 3 mg/kg weight, the 50% paw withdrawal threshold of mice treated with pregabalin or radon and pregabalin was significantly increased, suggesting pain relief. The therapeutic effects of radon inhalation or the combined effects of radon and pregabalin (3 mg/kg weight) were almost equivalent to treatment with pregabalin at a dose of 1.4 mg/kg weight or 4.1 mg/kg weight, respectively. Radon inhalation and the combination of radon and pregabalin increased antioxidant associated substances in the paw. The antioxidant substances increased much more in radon inhalation than in pregabalin administration. These findings suggested that the activation of antioxidative functions by radon inhalation enhances the pain relief of pregabalin and that this combined effect is probably an additive effect.

Antioxidants, Biochemical, and Hematological Parameters Change in Workers Occupationally Exposed to Radon Inhalation at Certain Construction Material Industries in Erbil, Iraq

“…Only females demonstrated a statistically significant association among age and enzyme activity in GPX (Saraymen et al, 2003). In animal models, equivalent findings were also made; Rats encountering radon at high levels show an increase in SOD activity in numerous organs (Ma et al, 1996, Kataoka et al, 2011, Kataoka et al, 2016, Kataoka et al, 2012, Mitsunobu et al, 2003, Yamaoka et al, 2004, Yamaoka et al, 2005. However, according to research by Eken et al, in Turkey, there are drastically higher levels of the SOD, GPX, and catalase compared to the control group (Eken et al, 2012).…”

Confirmation of efficacy, elucidation of mechanism, and new search for indications of radon therapy

“…Regarding the painsuppressing effect, radon inhalation corresponded to pregabalin administration of approximately 1.4 mg/kg body weight, and combination of radon inhalation and pregabalin administration (3 mg/kg body weight) corresponded to pregabalin administration of approximately 4.1 mg/kg body weight. (22) This suggested the occurrence of an additive effect.…”