Anti-cancer effects of green synthesized gold nanoparticles using leaf extract of Annona muricata. L against squamous cell carcinoma cell line 15 through apoptotic pathway.

Background: Oral cancer remains one of the most dreadful diseases in developing nations. Currently, there has been a rise in the prevalence of tongue squamous cell carcinoma (SCC), with a poor prognosis. The use of standard treatment approaches against oral cancer patients brings about several side effects. In recent years, nanomedicine has provided a versatile platform for developing new targeted therapeutic modalities. However, safety remains a concern in the synthesis of nanoparticles (NPs). Therefore, the present study aims to synthesize safer phytoconstituent-mediated gold NPs (AuNPs) utilizing leaf extracts of Annona muricata, where the biochemical components of the plant leaf act as the reducing and capping agents in the synthesis of NPs, and to evaluate its anti-cancer activity against SCC.

Materials and methods: In this in vitro experimental study, AuNPs were synthesized through an effective, simple, and ecologically sound green synthesis method. After characterization of these synthesized AuNPs, in vitro assays such as 3-(4, 5-dimethylthiazole2-yl)-2, 5-biphenyl tetrazolium bromide, wound healing, and clonogenic assays were carried out to investigate the anti-cancer potential of green synthesized AuNPs in the human tongue SCC cell line (SCC-15), and the possible mechanism of action was evaluated through gene and protein expression analysis of Bax, Bcl-2, and p53 genes. The results were expressed as mean ± standard deviation using Statistical Package for Social Sciences (SPSS) 20.0 software and Student's t-test was performed for experimental data. P ≤0.05 were considered statistically significant.

Results: The in vitro assays demonstrated that the synthesized AuNPs are exhibiting anti-cancer activity by apoptosis of SCC-15 cells in a dose-dependent manner. Further, it also revealed a highly significant decrease in anti-apoptotic Bcl-2 gene expression, whereas pro-apoptotic genes p53 and Bax revealed a highly significant increase, which is statistically significant compared to the control (P < 0.05).

Conclusion: Our findings demonstrated that the AuNPs synthesized from A. muricata leaf extract could act as a novel anticancer agent, particularly against SCC, after further scrutiny.