Assessment of anti-inflammatory effects of Japanese Kampo medicine versus functional foods

Background: Traditional Japanese drugs called Kampo medicine are widely used in Japan. Each Kampo medicine consists of several crude drugs, most of which are derived from medicinal plants. Clinical administration has empirically evaluated the effects of Kampo medicine In contrast, functional foods are prepared from foods and edible plants (e.g., herbs, vegetables, and fruits). Due to the relatively low content of a pharmacologically active constituents in functional foods, their effectiveness has not been well evaluated and thus should be better investigated. Kampo medicine and functional foods have beneficial effects for humans, and many of them exhibit anti-inflammatory effects. Here, we discuss the principles and methods to assess the anti-inflammatory effects of functional foods and Kampo medicine.To investigate pharmacological effects of functional foods and Kampo medicines, their constituents should be isolated to identify their chemical structures. Cell-based studies are commonly performed to evaluate anti-inflammatory effects of the constituents in Kampo medicine and functional foods. Primary cultured rat hepatocytes are used and produce pro-inflammatory mediators, including nitric oxide. When an extract from a Kampo medicine, functional food, or a respective constituent is added to the medium, pro-inflammatory mediator production decreases, and the anti-inflammatory activity is estimated. Animal experiments have been performed using disease models, such as the endotoxemia model for animals, to which bacterial endotoxin is administered. Administering an effective functional food or Kampo medicine improves the survival of the model animals. The action of the anti-inflammatory effects of functional foods and Kampo medicines can be investigated by the above-mentioned methods. The studies using cells and animals will provide a basis for the safe and effective use of functional foods and Kampo medicine in humans to treat diseases or improve health conditions.Keywords: herbal drug, Kampo medicine, nitric oxide, inflammation, hepatocytes.