A series of low molecular compounds from Chinese herbal medicines which have proved to be, in some cases, highly effective especially in tumor therapy, is listed here (part II will deal with high molecular compounds, to be published in the next issue). In contrast to synthetic agents used in cancer chemotherapy, these natural compounds have relatively low toxicities. Many of the clinical studies referred to in this paper have been carried out on Asians. Because genetic factors influence enzyme levels, sometimes leading to striking differences in metabolism and pharmacokinetics of drugs, results obtained in clinical studies carried out in China are not 100 % transferable to the European population. The mechanisms of action of these compounds are manifold, consisting of reactions with DNA bases, intercalation in DNA, inhibition of topoisomerases, inhibition of protein kinases, induction of apoptosis etc. Some of the compounds have interesting structural features, that may be used as lead structures for the development of further antitumor agents.
High molecular compounds from Chinese herbal medicines, including ribosome-inactivating proteins and polysaccharides from both fungi and high plants have been tested for the treatment of malignant diseases. Polysaccharides possessing immunostimulating activities can be used as adjuvants in tumor treatment. The fungi containing such polysaccharides are usually edible mushrooms or tonics in Traditional Chinese Medicine. Parts from high plants such as Radix Astragali and Fructus Lycii containing polysaccharides are mainly used as tonic in Traditional Chinese Medicine. Ribosome-inactivating proteins are a group of proteins exerting cytotoxic activities via inhibition of protein synthesis. Some of the ribosome-inactivating proteins have been used as the cytotox-ic part in conjugates with monoclonal antibodies as tumor-targeting drugs. The cytotoxic and antineoplastic mechanisms of the high molecular compounds are rather different from those of the low molecular compounds described in part I.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.