Background: Nowadays, nanotechnology has become a key word of public interest, and is a part of their daily life. Considering the extensive applications of nanosilver in our country and lack of detailed documentation on the toxicity of these nanoparticles, the aim of this study was to evaluate the effect of nanosilver on the enzyme Alkalin phosphtase.

Methods and Materials: In this study, 40 adult male Wistar rats were injected by 50,100,200 and 400 ppm of nanosilver. Then blood samples were collected and tissue samples from the liver prepared and studied using silver staining. Data were analyzed using a two-way ANOVA.

Results : Results showed that different concentrations of silver nanoparticles hah no significant effect on the Alkalin phosphatase (P=0.705) . Moreover, the tissue changes were seen in 400 PPm concentration of silver nanoparticles compared to the control group .

Conclusion: According to the results of this study, the use of nanoparticle is safe for this enzyme in the above-mentioned condition. The histological changes were shown that nano silver in 400ppm concentration induced apoptosis in liver probability. Considering the physiological similarities between rats and humans , these results could be used in preventing the side effects of using appliances containing silver nanoparticles.