Modulation of liver and kidney toxicity by herb Withania somnifera for silver nanoparticles: a novel approach for harmonizing between safety and use of nanoparticles.

In the present study, toxicity of nanoparticles is evaluated for assessing their effect on liver and kidney. We have synthesized highly mono-disperse spherical and rod-shaped silver nanoparticles using reverse microemulsion and aqueous phase methods. These were characterized by UV-vis spectrophotometer, dynamic light scattering, and transmission electron microscope confirming the formation of different sizes of spherical-shaped and rod-shaped silver nanoparticles (Ag NPs). Acute toxicity of different shapes and sizes of Ag NPs and their modulations by using Withania somnifera were evaluated through biochemical and histopathological changes in liver and kidney tissues of Wistar rats. We also evaluated cytotoxicity in specific murin macrophages through confocal microscopy. Cytotoxicity analysis indicates that median lethal dose (LD50) for 20, 50, and 100-nm size spherical and 100-nm rod-shaped Ag NPs was 0.25, 0.35, 0.35, and 0.35 mg/ml, respectively. We also calculated clinically important protein concentration to illustrate the efficacy of Ag nanomaterials. These studies indicated that 20, 50, and 100-nm spherical Ag NPs (35 mg/kg, 23 days) increased the biochemically important enzymes and substrate levels glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), creatinine, and urea concentration in serum, showing liver and kidney tissue damage. After 23 days of treatment of Ag NPs (20, 50, and 100 nm spherical), along with W. somnifera, toxicity of Ag NPs significantly decreased and marginalized. However, no significant changes were observed for 100-nm rod-shaped Ag NPs on normal liver and kidney architecture. Given their low toxic effects and high uptake efficiency, these have a promising potential as to lower the toxicity of Ag NPs.