Nature promises new anticancer agents: Interplay with the apoptosis-related BCL2 gene family

Natural products display special attributes in the treatment and prevention of a variety of human disorders including cancer. Their therapeutic capacities along with the fact that nature comprises a priceless pool of new compounds have attracted the interest of researchers worldwide. A significant number of organic compounds from terrestrial and marine organisms exhibit anticancer properties as attested by both in vitro and in vivo studies. Emerging evidence supporting the antineoplastic activity of natural compounds has rendered them promising agents in the fight against cancer. As a result, numerous natural compounds or their derivatives have entered clinical practice and are currently in the forefront of chemotherapeutics, showing beneficial effects for cancer patients. Induction of apoptosis seems to be the major mechanism of action induced by these natural agents in the race against cancer. This is mainly achieved through modulations of the expression of B-cell CLL/lymphoma 2 (BCL2) family members. These molecules appear to be the pivotal players determining cellular fate. In the current review, we provide a comprehensive overview of the major alterations in the gene and/or protein levels of BCL2-family members evoked in cancer cells after treatment with a gamut of natural compounds. The data cited suggest the need for exploitation of newly discovered natural products that, along with the improvement of currently employed chemotherapeutics, will significantly enrich the anticancer armamentarium.