Silver Nanoparticles: Evaluation of In Vivo Toxicity in Rats

Nanomaterials have various applications in biomedical and pharmaceutical sciences. Silver nanoparticles (AgNPs) are well known for their antimicrobial properties. Hence, the present in vivo toxicity study was carried out in Sprague-Dawley rats to assess whether the green synthesized AgNPs create any toxicity in vivo animal model. Based on our previous report, the AgNPs were synthesized. The synthesized nanomaterials were characterized using UV-Vis spectroscopy and transmission electron microscopy (TEM). The surface plasmon resonance (SPR) peak of silver nanoparticles synthesized by a plant-based biogenic approach was observed at 414 nm. TEM image of nanoparticles showed monodispersed spherical shape with an average size of 18 nm. The oral toxicity study was carried out for synthesized AgNPs in rats for 28-day repeated dose as per Organization for Economic Cooperation and Development (OECD) test guidelines no. 407. AgNPs at the dosage of 0.85 mg in 5 mL, 1.25 mg in 7.5 mL, and 1.7 mg in 10 mL/kg body weight/day and control group (water) were administrated for acute and subacute toxicity study. Results indicated that AgNPs did not show any visible signs of histopathological changes in the kidney, liver, lung, heart, adrenal, spleen of Sprague-Dawley rats. No-observed adverse effect level (NOAEL) of AgNPs was found to be at a high dose of 1.7 mg in 10 mL/kg body weight/day in rats. Haematological parameters and biochemical assays indicated that there was no difference when compared with the AgNP-treated and control groups and these results indicating that AgNPs did not induce toxicity in Sprague-Dawley rats at the higher dose of 1.7 mg in 10 mL/kg body weight/day.