ABSTRACT
Tumor has become one of the major diseases threatening human health at present. Conventional therapies for tumor have serious side effects and are prone to drug resistance， while new therapies are expensive and impose a heavy burden on patients. Chinese herbs effective in the treatment of tumor contain a variety of natural active ingredients， and many anti-tumor drugs used in clinical practice are derived from Chinese herbs. Polysaccharides， ubiquitous in Chinese herbs， are easy to extract and have antitumor， antiviral， and antioxidant activities. Studies have demonstrated that the polysaccharides from Chinese herbs have significant anti-tumor effect and are characterized by multi-target and multi-mechanism functioning， which can avoid the development of drug resistance， exhibiting a great research value and the potential to be developed into novel anti-tumor drugs. Their anti-tumor mechanisms mainly include the inhibition of tumor proliferation， promotion of apoptosis， induction of autophagy， influence on cell cycle， inhibition of tumor angiogenesis， modulation of epithelial-mesenchymal transition （EMT） and immunity， promotion of tumor oxidative stress， and regulation of phosphatidylinositol 3-kinase/ protein kinase B （PI3K/Akt）， Toll-like receptor 4 （TLR4）， mitogen-activated protein kinase/nuclear factor-kappa B （MAPK/NF-κB）， adenosine 5'-monophosphate （AMP）-activated protein kinase/mechanistic target of rapamycin （AMPK/mTOR）， epidermal growth factor receptor/extracellular signal-regulated kinase （EGFR/ERK）， p53， and Wnt/β-catenin signaling pathways.