Evaluation of cytotoxic activity of platinum nanoparticles against normal and cancer cells and its anticancer potential through induction of apoptosis

Abstract

Background: Plant mediated green synthesis of nanoparticles is an eco-friendly and efficacious approach which finds immense application in the field of medicine. This study aimed to evaluate the cytotoxicity of platinum nanoparticles (ptNPs) synthesized through green technology against normal and different cancer cell lines.

Methods: Platinum nanoparticles were synthesized by green technology and characterized earlier. In this study we examined the cytotoxic effect of platinum nanoparticles (ptNPs) on human lung adenocarcinoma (A549), ovarian teratocarcinoma (PA-1), pancreatic cancer (Mia-Pa-Ca-2) cells and normal peripheral blood mononucleocyte (PBMC) cells and evaluate anticancer potential through induction of apoptosis on PA-1 cells if any. Cytotoxicity was evaluated using MTT assay, trypan blue dye exclusion assay and anticancer potential assessed through clonogenic assay, apoptosis assay, cell cycle analysis.

Results: We found that ptNPs exerted cytotoxic effect on cancer cell lines, whereas no cytotoxic effect was observed at highest dose on normal cells. The results showed that ptNPs had potent anticancer activities against PA-1 cell line via induction of apoptosis and cell cycle arrest.

Conclusion: Overall, these findings have proved that biosynthesized ptNPs could be potent anti-ovarian cancer drugs. Further studies are required to elucidate the molecular mechanism of ptNPs induced anti-tumor effect in vivo.

Keywords: Anti-cancer potential; Apoptosis; Cytotoxicity; In vitro; Platinum nanoparticles.

Fig 1

Effect of ptNPs on viability of lung adenocarcinoma (A549), ovarian teratocarcinoma (PA-1), pancreatic cancer (Mia-Pa-Ca-2) cells. A. Cells were treated with vehicle, different concentrations of ptNPs and positive control (10 μg/ml cisplatin) for 48 hours. Cell viability was analyzed using the MTT assay. Data represented as mean ± SE of three independent experiments made in three replicates. *P < 0.05, **P < 0.01, ***P < 0.001 versus vehicle control (VC) group.

Fig. 2

Cytotoxic effect of ptNPs (200 μg/ml) and cisplatin (10 μg/ml) on normal PBMC cells. Data represented as mean ± SE of three independent experiments. **P < 0.01 versus control group.

Fig. 3

Effect of platinum nanoparticles on colony forming capacity or clonogenic survival of exponentially growing PA-1 cells studied by a clonogenic assay. PA-1 cells were treated with ptNPs (50, 100, 200 μg/ml) and cisplatin (10 μg/ml), allowed to form colonies in fresh medium for 14 days. A = Control; B = ptNPs (50 μg/ml); C = ptNPs (100 μg/ml); D = ptNPs (200 μg/ml); E = Cisplatin (10 μg/ml). F: Representative histogram showing percentage of platting efficiency in PA-1 cells. Data are expressed as mean ± SE (n = 3). *P < 0.05, ***P < 0.001 versus control group.

Fig. 4

PA-1 cells were stained by AO/EB and observed under fluorescence microscope. PA-1 cells were treated with (A) vehicle control, (B) 100 μg/ml and (C) 200 μg/ml of ptNPs for 48 hours. L indicates live cells, EA indicates early apoptotic cells and LA indicates late apoptotic cells.

Fig. 5

Apoptosis induced by ptNPs in PA-1 cells. PA-1 cells were treated with (A) vehicle control and (B) 200 μg/ml of ptNPs for 48 hours. Then cells were stained with FITC-conjugated Annexin V and PI for flow cytometric analysis. The flow cytometry profile represents Annexin V-FITC staining in x axis and PI in y axis. (C) Results showing the percentage of early apoptotic cells, late apoptotic cells and necrotic cells. Data are expressed as Mean ± SE (n = 3). **P < 0.01 versus control group.

Fig. 6

Flow cytometry analysis of cell cycle phase distribution in PA-1 cells. Histogram representing propidium iodide staining of control (A) and ptNPs (100 and 200 μg/ml) (B-C) treated PA-1 cells for 48 hours. D: Bar diagram showing the cell distribution in the subG1, G0/G1, S and G2/M phases for PA-1 cells treated with vehicle control and ptNPs (100 and 200 μg/ml). Data are expressed as mean ±SE (n = 3). *P < 0.05 versus control group.