Evaluation of Nano-Silver on Anxiety-Related Behavior in Rats

Silver nanoparticles (Ag NPs) have been widely used as new potent antimicrobial agents in cosmetic and hygienic products. The silver induced a decrease in the total volume of hippocampal cells and high doses of silver caused cell death. On the other hand, the hippocampus may be an important brain site in the modulation of fear and anxiety. The purpose of this study was to investigate the possible protective role of Ag NPs on anxiety-like Behavior in rats.
Forty male Wistar rats (200-250 gr) were divided into five groups of eight rats in control group and treatment groups with different doses. Control group rats were injected saline and treatment groups were injected Ag NPs at doses of 50, 250, 500, and 1000 mg/kg/day intraperitoneal (IP). After two weeks of treatment, the anxiety-related behavior in the rats was examined by the plus maze test.
Our results showed that Ag NPs at dose of 1000 mg/kg/day after 14 days significantly decreased the percentage of open arm duration and the percentage of open arm entries but did not affect the locomotor activities.
These data suggest that IP application of Ag NPs causes an anxiogenic response.