CLL cells express receptors for vascular endothelial growth factor (VEGF) and also secrete VEGF. The resulting constitutive phosphorylation of VEGF receptors was suppressed by the green tea polyphenol epigallocatecin-3-catechate (EGCG), which also induced apoptosis of CLL cells. One phase I trial of the green tea extract polyphenon E reported only one partial remission with low toxicity, although the maximum tolerated dose is unknown.
Curcumin induced apoptosis of CLL cells. The key target of curcumin is unknown, but it decreased expression of several anti-apoptotic proteins, including NF-κB, activated AKT, MCL-1 and XIAP, while increasing expression of pro-apoptotic BIM. Furthermore, sequential administration of EGCG followed by curcumin reversed the expected protective action of stromal cells.