Leukemia Chemoprevention and Therapeutic Potentials: Selected Medicinal Plants with Anti-Leukemic Activities

Haematological malignancies account for more than one million cases of all cancers yearly worldwide. While survival has improved due to newer drugs used in their management, relapsed/refractory disease remains a challenge, and treatment modalities come with side effects and morbidities. The management of leukaemias with medicinal plants and their natural products remain a viable option. Numerous studies have shown the potentials and viability of medicinal plants and their natural products as good options against leukaemias. However many of these natural products face peculiar challenges such as low systemic bioavailability, hydrophobic nature and displayed toxicities when given at different pharmacologic doses, while the medicinal plants face the threat of extinction. The development of semi-synthetic analogues and better regulations have helped overcome some of these challenges. This review briefly analyzes four medicinal plants and their different natural products that are used traditionally in the management of cancers, and have been scientifically proven to have some form of activity against leukemia. These plants include Tanacetum parthenium, Garcinia hanburyi, Scutellaria baicalensis, and Combretum caffrum. This review discusses these medicinal plants and their natural products under the following headings: ethnobotany, phytochemistry, mechanism of action, antileukaemic activity and toxicity.