ABSTRACT
With appearance of nano particles as an important component in modern medicine, and considering to new properties of these components, study of their effects on human health is essential. Since zinc components influences mechanisms of nociception, the aim of this study was to evaluate the effect of nano zinc oxide as a new source of zinc and important components in pharmaceutical and hygienic cosmetic production on nociception in adult female rats. Female rats were divided into groups: control [receiving saline 0.9%] and receiving nano ZnO [0.5, 1, and 5 mg/kg]. Hot plate and tail flick tests as models of somatic acute pain were used for evaluation of the pain. The mean of latency time in paw licking and tail withdrawal respectively recorded as nociception indexes in each test for every animal. The animal numbers in each group was seven. In tail flick test, nano ZnO [0.5, 1 mg/kg] and in the hot plate test in dose of 0.5 mg/kg, induces significant analgesia [p<0.05] and with increasing of dose reduced its analgesic effect. It seems nano ZnO inhibit the nociception mechanisms and these analgesic properties are more efficient in the low doses. Probably by increasing dose of nano particles aggregation phenomenon prevent of anti-nociception effects of nano ZnO
ABSTRACT
In recent years, nanotechnology has produced new forms of materials that are more effective than their predecessors. Magnesium is an essential element in the human body and certain studies have proved that its deficiency can induce anxiety in animals. In this study, the effect of magnesium oxide nanoparticles [MgO NPs] on anxiety, related behaviors, and interaction between their effects and anxiolytic effect of the exercises were examined in comparison to the conventional MgO [cMgO]. Adult male Wistar rats weighing 190 +/- 20 gr were divided into control groups [receiving saline, without physical activity], and exercise groups [receiving cMgO and/or MgO NPs [1 mg/kg i.p.] daily for 6 weeks with or/and without exercise]. Exercise groups were performing their daily physical activity protocol 30 minutes after injection. At the end of period, an elevated plus maze apparatus was used to evaluate the anxiety [%pen arm time [%OAT] and%open arm entries [%OAE] and locomotor activity. Exercise significantly increased%OAT and%OAE [P<0.05]. MgO NPs caused an increase in%OAT, while cMgO did not have any effect on%OAT or%OAE. There was no notable difference among anxiety parameters in exercise groups with or without taking MgO NPs. It seems that the anxiolytic effect of exercise and MgO NPs has been mediated through common mechanisms that were a part of the anxiety process of the central nervous system