Investigating In Vitro and In Vivo Anti-Tumor Activity of Curvularia-Based Platinum Nanoparticles

The use of platinum (Pt)-based anticancer drugs, although widespread in clinical practice, is severely limited due to toxic side-effects. One of the strategies for making Pt-based chemotherapy more effective is the synthesis and use of Pt nanoparticles (PtNPs). However, increasing evidence suggestD that nanoplatinum also pose potential risk to human health. This study examined the toxicity and anticancer activity of mycosynthesized PtNPs against sarcoma-180 (S-180) cells in vitro and in vivo. Curvularia affinis Boedijn, a phyto-pathogenic fungi isolated from rice, was used to synthesize PtNPs (named as CaPtNP). Well dispersed, mostly spherical CaPtNPs, with sizes ranging from 3-9 nm were characterized by Transmission electron microscopy (TEM), field emission scanning electron microscopy, X-ray diffraction, atomic force microscopy, and Fourier transform infrared spectrometry. Two concentrations of the CaPtNPs (2.31 and 4.63 ng/mL) were selected based on in vitro cytotoxicity assay on erythrocytes and peripheral blood mononuclear cells. The selected doses were found to induce significant in vitro and in vivo anti-proliferative and pro-apoptotic activity in S-180 cells. Elevated levels of pro-apoptotic markers (p53, Bax/Bcl2 ratio, Cyt c, caspase-3, cleaved PARP) and reduced BrdU incorporation validated the anticancer activity of CaPtNPs. The antitumor activity was further confirmed in S-180 transplanted tumor bearing mice. Moreover, examination of the impact of sub-chronic exposure (three months) of CaPtNPs on the ultra-structural features of renal and hepatic tissue by TEM revealed no significant toxicological manifestation in these organs. The CaPtNPs were also found to reduce oxidative stress and improve liver function in tumor bearing mice compared with untreated controls. Thus, this green CaPtNPs was well tolerated in mice and displayed significant antitumor property.