Methanolic extract of teucrium polium l. potentiates the cytotoxic and apoptotic
effects of anticancer drugs of vincristine, vinblastine and doxorubicin against a panel of
cancerous cell lines
S. Rajabalian*
Kerman University of Medical Sciences, Kerman Neuroscience Research Center, Kerman,
Iran
Abstract. A growing body of evidence indicates that specific phytochemicals can increase an
efficacy of cancer chemotherapy. Aim: To evaluate promoting effect of the methanolic
extract of Teucrium Polium (Me-TP) on cytotoxic and apoptotic activity of anticancer drugs
of vinblastine, vincristine and doxorubicin in vitro. Methods: Skmel-3, Saos-2, SW480,
MCF-7, KB, EJ and A431 cell lines were used. Cytotoxicity was determined by MTT assay and
colony formation assay. The nature of interactions was analyzed by combination index (CI)
method. Apoptotic cells were assessed by DAPI staining. Results: The vincristine/Me-TP,
vinblastine/Me-TP and doxorubicin/Me-TP combinations showed a strong synergistic effect in
the cell growth inhibition (0.13 < CI < 0.36). Similar results were observed by
colony formation assay. Furthermore, the combinations of vincristine/Me-TP and
vinblastine/Me-TP resulted in a massive apoptosis (> 80%) compared to effect of
individual drugs (0–3%). At the additional experiments, Me-TP reduced marginally to
significantly the cytotoxic effects of vincristine and vinblastine toward the human
fibroblasts (p < 0.05 to 0.001). Conclusions: The present study suggests that Me-TP has
the potential to be an effective and safe chemosensitizer agent for cancer therapy.
