Cytotoxic effect of Pouteria torta leaf extracts on human oral and breast carcinomas cell lines

Aims: This study aimed at investigating the cytotoxic activity and the type of cell death induced by Pouteria torta (P. torta) leaf extracts on human oral squamous cell carcinoma and breast carcinoma cell lines. Material and Methods: The effects of P. torta leaf hexanic (PTH), ethanolic (PTE) and aqueous (PTA) extracts at the concentration of 500 mg/mL were evaluated on OSCC-3 and MCF-7 cell lines, using crystal violet staining after 24 and 48 h of treatment. To obtain the dose-response curve, cells were treated with decreasing concentrations of the extracts (1000, 750, 500, 250, 125 mg/mL) for 24 h. To investigate the mechanism of cell death (apoptosis vs. necrosis), DNA fragmentation assay was performed. Results: All extracts were cytotoxic to both OSCC-3 and MCF-7, albeit at differing levels. PTH and PTE were effective at the concentration of 500 mu g/mL, resulting in nearly 50% of cell death in both cancer cell lines. PTA was more effective at lower concentrations, with more significant cell death at 125 mu g/mL. Treatment with PTA and PTE caused apoptosis in MCF-7, whereas in OSCC-3 cells, the same effect could only be caused by PTH. On the other hand, PTA was able to induce necrosis in OSCC-3. Conclusions: These findings demonstrated that P. torta leaf extracts may contain useful compounds to combat oral and breast cancer, and this study highlights the potential biological relevance of the Brazilian Cerrado Biome in cancer therapy.