Medicinal plants play a major role in primary health care in many developing countries; and their use had increased in recent years. More than 1200 species of plants are used as medicinal plants. Scientific evidence has been documented for some plants, however further research is needed to ascertain the efficacy and safety of many others. T. violacea is of the plants with biological activities that need to be scientifically investigated. Its activities have been postulated to be similar to those found in garlic, since both plants belong to the Alliacea family. This study investigated the anticancer and anticoagulant activities of T. violacea. A comparison between the anticoagulant/antithrombotic activities (using the thrombin-induced clotting time (TT) and the thrombin inhibition assays) of the bulb and leaf extracts of T. violacea and garlic. The IC200 were 0.4 and 0.3 mg/ml for the leaf and the bulb extract, respectively during the TT assay and the IC50 value was 1.725 mg/ml for the bulb extact of T. violacea and not obtained for the leaf extract. The IC200 and IC50 values were not obtained for the garlic extract. It is postulated that the inhibitory activity in T. violacea extracts was due to unstable compounds, possibly the sulphur compounds. T. violacea leaf and bulb extracts inhibited growth of MCF-7, WHCO3, HT29 and HeLa cancer cell lines. The HeLa and MCF-7 cells were significantly inhibited by the bulb extract and had IC50 values of 228 � 2.57 �g/ml, respectively. The growth inhibitory activity of T. violacea was due to the induction apoptosis in all four cell lines. This was shown by the staining of cells with Hoechst, indicating that the cells had fragmented nuclear material and condensed chromatin. As was expected, HeLa and MCF-7 cells treated with the bulb extract had higher apoptic indices than the other two cell lines (HeLa, 25.8 � 3.85%; MCF-7, 19.0 � 4.32%). Treated cells stained with Annexin V but not with propidium iodide (PI), indicating that the extract possibly induces apoptosis and not in the cells. Finally, it was shown that the extract possible induces apoptosis through a caspase dependent apoptic pathway since PARP, a protein usually cleaved by caspase 3, was cleaved in HeLa cells treated with bulb extract of T. violacea. These findings provide evidence for anticancer and anticoagulant/antithrombotic activities in T. violacea. The presence of both activities and induction of apoptosis by the extract is promising for anticancer therapy as it is desirable for anticancer agents to have mild anticoagulant properties and induce apoptosis. These results also indicate that T. violacea can be used as an alternative to garlic.
|Degree Type||Masters degree|