Biosynthesis of silver nanoparticles and the identification of possible reductants for the assessment of in vitro cytotoxic and in vivo antitumor effects

Abstract

Silver nanoparticles (AgNPs) are well-known for their applications at nano-scale and are potential anticancer agents. Biosynthesis of AgNPs has fashioned an immense realization among the researchers of the nano-community. The present study was therefore conducted to identify the phytoconstituents of Andrographis paniculata, fabricate AgNPs using its aqueous leaf extract and evaluate the cytotoxic effects in vitro against HeLa cells. Further, the antitumor effects were tested ex vivo and in vivo against Ehrlich's ascites carcinoma (EAC) cells in mice model. The leaf extract was prepared and the phytoconstituents were quantified. The phytoconstituents were further identified using GC-MS. After identification of the possible reductants and encapsulates, AgNPs were fabricated using the aqueous extract, characterized using standard techniques and published in our previous reports. Further, in this study, transmission (TEM) and scanning (SEM) electron microscopes, X-ray powder diffraction (XRD) and Dynamic Light Scattering (DLS) were used for characterization purposes. In vitro cytotoxicity of the AgNPs was tested against HeLa cell line. The cytotoxic effect was dose-dependent, and the half maximal inhibitory concentration value was 7.285 μg/ml. An ex vivo analysis was used to determine the dose for the treatment in vivo. After the dose was determined (40 μl), twenty-four male Swiss albino mice were divided into four groups of six animals each and injected intraperitoneally with AgNPs (≈350 μg/kg BW) and the plant extract (80 mg/kg BW) for a period of 10 days after tumor induction. The biochemical and hematological parameters analyzed were revived efficiently to near-normal in all treatment groups. Hence, the AgNPs derived using A. paniculata were effective against carcinoma cells in vitro, ex vivo and in vivo and therefore settles its candidature for future antitumor medications at preclinical and clinical levels.