The role of traditional Chinese herbal medicines in cancer therapy--from TCM theory to mechanistic insights

Traditional Chinese medicine-based herbal medicines have gained increasing acceptance worldwide in recent years and are being pursued by pharmaceutical companies as rich resources for drug discovery. For many years, traditional Chinese medicines (TCM) have been applied for the treatment of cancers in China and beyond. Herbal medicines are generally low in cost, plentiful, and show very little toxicity or side effects in clinical practice. However, despite the vast interest and ever-increasing demand, the absence of strong evidence-based research and the lack of standardization of the herbal products are the main obstacles toward the globalization of TCM. In recent years, TCM research has greatly accelerated with the advancement of analytical technologies and methodologies. This review of TCM specifically used in the treatment of cancer is divided into two parts. Part one provides an overview of the philosophy, approaches and progress in TCM-based cancer therapy. Part two summarizes the current understanding of how TCM-derived compounds function as anticancer drugs.