THE ANTIANGIOGENIC, ANTIOXIDANT AND PROAPOPTOTIC CHEMOPREVENTIVE PROPERTIES OF TANNINS FROM MEMECYLON MALABARICUM (Cl.)

Tannins, the non-nutritive substances from plant sources exhibit potent biological activities that lower the risk of chronic diseases without any side effects. Tannins are most abundant and multipotent molecules exhibiting antioxidant, proapoptotic and antiangiogenic activity and thus being effective in the treatment of degenerative diseases including initiation and progression of tumors.   The study aims to prove the chemopreventive properties of tannins that target several key events involved in the development of cancer. Partially purified tannins from the acetone extract of Memecylon malabaricum was subjected to shell less CAM assay and in vitro studies to note the antiangiogenic and antioxidant activities respectively, while the proapoptotic activity was noted by its effect on EAT cells. Inhibiting the proliferation of capillaries in shell less CAM assay proved their antiangiogenic property. 1, 1-diphenyl 2-picrylhydrazyl (DPPH) radical scavenging activity (EC₅₀ of 2.67 µg/ml), Hydroxyl radical scavenging activity (EC₅₀ of 7.73 µg/ml), Nitric oxide radical scavenging activity (EC₅₀ of 11.3 µg/ml) and superoxide anion radical scavenging activity (EC₅₀ of 19 µg/ml) established their antioxidant activity, while the proapoptotic activity of the compound on EAT cells showed characteristic nuclear condensation with cytoplasmic and nuclear blebbing. The induction of apoptosis is attributed to DNA fragmentation incited by tannins. The leaves of MM which are primarily rich in a wide group of natural multipotent molecules like tannins with manifold chemopreventive activities represent a promising class as anticancer drugs.