Accumulation of biosynthesized gold nanoparticles and its impact on various organs of Sprague Dawley rats: a...

Background: Many in vivo studies have revealed that the cytotoxic potential of gold nanoparticles results in controversial conclusions. The aim of this study is to establish a systematic method for determining the biological effects of gold nanoparticles in rats. Methods: In the present investigation AuNPs were prepared using Helianthus tuberosus extract as a reducing agent. The synthesized AuNPs were characterized using various techniques, such as Bio-TEM, SEM-EDS, X-ray diffraction and FT-IR. Cytotoxicity of the synthesized AuNPs was assessed using the rat as an animal model. Subchronic oral administration of AuNPs (5 and 10 mg kg^-1) and its effect on major organs (liver, kidney, lungs, and spleen) and its accumulation were analyzed using haematoxylin & eosin staining and ICP-MS respectively. The extent of apoptosis in the liver cells was determined using western blotting. Results: The results of the current study revealed that the synthesized AuNPs at a mild concentration of 5 mg kg^-1 have been found to cause a hypoglycemic state and an increase in the HDL cholesterol level in normal rats. Nevertheless, histopathological results revealed that AuNPs could cause inflammation in the lungs at increasing concentrations. Conclusion: The biologically synthesized AuNPs were evaluated in this study showed a hypoglycemic effect at a concentration of 5 mg kg^-1 AuNPs. A systemic study on the accumulation of AuNPs revealed that the lung is the major target organ and further suggests that enduring administration could lead to organ damage as majorly observed in lung tissue. This study highlights the necessity of complete in vivo toxicity analysis, prior to introducing nanoparticles in any application field. Further, this study warrants the application of the synthesized AuNPs in drug delivery related to lung disorders.