In Vitro Evaluation of Apoptotic Induction of Hypericum triquetrifolium and Arum palaestinum Plant Extracts on Cancer Cell lines

Herbal medicines in treatment of cancer as complementary and alternative therapy are accepted increasingly with growing scientific evidences of biomedical research and clinical trials. Anticancer drugs discovered from herbal medicines have a long history and some of them have been used in clinical setting as the conventional anticancer drugs.Actually, herbal medicines are a source for anticancer drug discovery and drug development. The traditional Arab-Islamic herbal-based medicines might be promising candidates for new cancer therapeutics, especially natural herbal products with low toxicity and minimal side effects. This study aimed to investigate the anti-cancer effect of two medicinal plants extracts: Arum palaestinum (AP) and Hypericum triquetrifolium (HT). Two cancer cell lines: Colon and Lung (HCT-116, A549) and one normal (control) cell line (skeletal muscle, L6) were selected to test the efficacy of AP and HT different extracts in apoptosis induction. The cells were treated with an increasing concentration of(distilled water, 50%water-50% ethanol, and hexane) plant extracts (0, 8, 16, 32, 62, 125, 250, 500, 1000 and 2000µg/ml) for 24h. Then we used MTT assay to test cytotoxicity of the extracts, Annexin V-Cy3 to test apoptosis and ELISA kit specific for cytochrome c release. Results show that none of the three extraction methods of HT has a toxic effect on all treated cell lines at all concentrations tested. However, they had induced apoptosis in colon cancer cell line (HCT116), muscle cell line (L6), and lung cancer cell line (A549) at the concentration 500µg/ml through mitochondrial dependent pathway by releasing cytochrome c at the concentration 250µg/ml. Surprisingly, AP(distilled water and 50%water/50% ethanol) had no cytotoxic or apoptotic effect in all selected cell lines at non-toxic concentration up to 1000 µg/ml, whereas hexane extract had induced apoptosis at the concentration 500µg/ml through mitochondrial dependent pathway by releasing cytochrome c in the three cell line at non-toxic concentration 250µg/ml. Taken together, these results indicate that HT (but not AP) might be an effective herbal candidate in cancer chemotherapy.