Evaluation of apoptotic effects of intraperitoneal administration of nano-silver on rat hippocampal cells

Silver nanoparticles have numerous applications in food technology and medical industry. These applications are mediated via their mitotic، oxidative and apoptotic effects. In this study، the apoptotic effects of short and long term administrations of nanosilver on rat hippocampus، which is involved in memory and learning، was investigated. 56 male Wistar rats were divided into two groups of short term and long term injections which were treated for 5 and 10 consecutive days، respectively. Each group was divided into four subgroups of control، 100، 200 and 400 ppm nanosilver administration. The control subgroup received saline and the treatment subgroups received intraperitoneal injections of silver nanoparticles at doses of 100، 200 and 400ppm. Ten days after the last injection، the hippocampal tissue sections were prepared and the extent of apoptosis was evaluated using TUNEL assay. In short term (5-day injection) group، the percentage of apoptotic cells between control and 100 (p<0. 01)، 200 and 400 ppm were significant (p<0. 001)، showing statistically significant difference between control and treatment subgroups. In long term (10-day injection) group، the percentage of apoptotic cells between control and 200 and 400 ppm subgroups were significant (p<0. 001)، respectively، again representing statistically significant difference between control and treatment subgroups. Silver nanoparticles induce apoptosis in rat hippocampal cells. For the administration regime considered in this study، this apoptotic effect increases at higher doses but is independent of the duration of exposure.