Analysis of pharmacological effect and molecular mechanisms of a traditional herbal medicine by global gene expression analysis: an exploratory study

Although traditional herbal medicines have been used for more than 2000 years, there are few studies on their molecular mechanisms of action. We examined the pharmacological effect and mechanism of action of a traditional herbal medicine (Kososan) with global gene expression analysis using a DNA chip.

Fourteen healthy subjects were given the herbal medicine (Kososan) for 2 weeks and interviewed. Peripheral blood was collected before and after 2-week medication. Based on the outcomes of the interview, the subjects were divided into responders and non-responders. We analysed the blood samples from responder and non-responder groups, respectively, using a DNA chip.

In the Kososan responder group, 70 genes were over-expressed (2-fold or more), and their over-expression was normalized by Kososan (0.5-fold or less), whereas 24 genes were under-expressed (0.5-fold or less), and the under-expression was normalized by Kososan (2-fold or more).

This exploratory study suggests that gene expression profiling is a possible approach for studying the effects of complex herbal remedies. Some of the genes studied seem to have functions related to the pharmacological effects of Kososan, which have been known for a long time.