Catalytic therapy of cancer with ascorbate and extracts of medicinal herbs.

Catalytic therapy (CT) is a cancer treatment modality based on the generation of reactive oxygen species (ROS) using a combination of substrate molecules and a catalyst. The most frequently used substrate/catalyst pair is ascorbate/Co phthalocyanine (PcCo). In the present work, herb extracts containing pigments have been studied as a catalyst in place of PcCo. Extracts from herbs are expected to have efficiency comparable with that of phthalocyanines but as natural products, to exhibit fewer side effects. The present studies demonstrate that a combined use of ascorbate and herbal extracts results in ROS production and a significant decrease in the number of cancer cells after a single in vitro treatment. Treatment with ascorbate in conjunction with extracts prepared from several medicinal herbs stimulated apoptosis and disrupted the cell cycle. The number of cells accumulating in the sub-G0/G1 stage of the cell cycle was increased 2- to 7-fold, and cells in G(2)/M increased 1.5- to 20-fold, indicating that the treatment protocol was highly effective in suppressing DNA synthesis and potentially reflecting DNA damage in the tumor cells. In addition, 20-40% of the cells underwent apoptosis within 24 h of completing treatment. Our results suggest that herbal extracts can function as CT catalysts in the treatment of cancer.