Effect of Fe2O3 Nanoparticles on Anxiety Behavior and Nociception in Adult Male Rat

Background & Aims: Iron is an essential element for correct brain function. Iron deficiency changes some behaviors such as anxiety and nociception. Recently, nano-iron, Ferric or ferro oxide (nano-Fe2O3 or Fe3O4), are used in various applications in agriculture, industry and medicine, but their effects on the heath and behavior is not clear. In this study, the effects of Fe2O3 nanoparticles on animal models of anxiety and nociception were investigated. Methods: Adult male Wistar rats (mean weight: 200-250 g) were used in 12 groups: 3 control groups (receiving saline 0.9%) and 9 groups received nano-Fe2O3 in doses of 0.2, 1 and 5 mg/kg, intraperitoneally. Elevated plus maze apparatus and hot-plate and tail-flick tests were used to evaluate anxiety and nociception, respectively. Data were analyzed by one-way ANOVA and post hock least significant difference (LSD) and P < 0.05 used as significant level. Results: Fe2O3 nanoparticles with dose addition increased open arm time percent (OAT%) (P<0.05). Locomotor activity, just in dose of 5 mg/kg, increased pain delay time in both hot-plate (P<0.01) and tailflick (P<0.01) tests. Conclusion: Acute administration of Fe2O3 nanoparticle decreases anxiety behaviors in elevated plus maze and increases an acute pain threshold in both hot-plate and tail-flick tests in rats.