Over the centuries, Chinese herbal drugs have served as a major source of medicines for the prevention and treatment of diseases including diabetes mellitus (known as 'Xiao-ke'). It is estimated that more than 200 species of plants exhibit hypoglycaemic properties, including many common plants, such as pumpkin, wheat, celery, wax guard, lotus root and bitter melon. To date, hundreds of herbs and traditional Chinese medicine formulas have been reported to have been used for the treatment of diabetes mellitus. This paper provides a brief review of the antidiabetic drugs of plant origin that have been approved by the Chinese health regulatory agency for commercial use in China. It was believed, through pharmacological studies, that medicinal herbs were meticulously organized in these antidiabetic drug formulas such that polysaccharide containing herbs restore the functions of pancreatic tissues and cause an increase in insulin output by the functional beta cells, while other ingredients enhance the microcirculation, increase the availability of insulin and facilitate the metabolism in insulin-dependent processes. Pharmacological and clinical evaluations indicated that these drugs had a mild, but significant, blood glucose lowering effect and that the long-term use of these agents may be advantageous over chemical drugs in alleviating some of the chronic diseases and complications caused by diabetes. Additionally, the use of these natural agents in conjunction with conventional drug treatments, such as a chemical agent or insulin, permits the use of lower doses of the drug and/or decreased frequency of administration which decreases the side effects most commonly observed. Copyright (C) 2003 John Wiley Sons, Ltd.
