Unveiling the anticancer effect of cytisine against oral cancer: Insights from bioinformatics and in-vitro approaches.

INTRODUCTION: Oral squamous cell carcinoma (OSCC), the most common malignancy, involves molecular alterations including p53 mutations, TGF-α, and EGFR overexpression. Targeting biomarkers is essential for effective therapy. Cytisine, a natural smoking-cessation alkaloid with diverse pharmacological activities, was evaluated using bioinformatics to identify potential anticancer targets and subsequently validated in vitro. MATERIALS AND METHODS: The in silico analysis included predictions of toxicity, drug-likeness, and potential targets for cytisine. OSCC-associated targets were retrieved from GeneCards and ACTREC databases. Cytoscape was used to construct cytisine-target pathways. Molecular docking and 100 ns molecular dynamics simulations were performed to evaluate cytisine binding affinity and structural stability to key targets. The in vitro validation was performed using the MTT assay and cell migration assay on an epithelial carcinoma cell model (KB-3-1 cell line). RESULTS: Cytisine was non-toxic and modulated 23 target proteins and 13 signalling pathways. Gene enrichment analysis revealed significant interactions with EGFR and TP53. Molecular docking and 100 ns molecular dynamics simulation showed strong intermolecular interactions and low binding energies with EGFR (-6.9 kcal/mol) and TP53 (-7.7 kcal/mol) compared with standard drugs. In vitro assays demonstrated significant cytotoxicity and inhibition of cell migration in epithelial carcinoma cell lines while maintaining the viability of L929 normal fibroblast cells. CONCLUSION: Cytisine exhibits strong interactions and lower binding energies with EGFR and TP53, and cytotoxic and anti-migratory effects against the epithelial carcinoma cell model. However, further validation using primary oral squamous carcinoma cell lines and in vivo studies is necessary to confirm its therapeutic relevance to epithelial carcinoma.