Thyroid hormone synthesis: a potential target of a Chinese herbal formula Haizao Yuhu Decoction acting on iodine-deficient goiter

Haizao Yuhu Decoction (HYD), a famous multi-component herbal formula, has been widely used to treat various thyroid-related diseases, including iodine-deficient goiter. Herb pair Thallus Sargassi Pallidi (HZ) and Radix Glycyrrhizae (GC), one of the so-called "eighteen antagonistic medicaments", contains in HYD. To explore pharmacological mechanisms of HYD acting on iodine-deficient goiter and to provide evidence for potential roles of herb pair HZ and GC in HYD, our genome-wide microarray detection and network analysis identified a list of goiter-related genes, mainly involved into the alterations in hypothalamus-pituitary-thyroid/gonad/growth axes. Then, the disease genes-drug genes interaction network illustrated the links between HYD regulating genes and goiter-related genes, and identified the candidate targets of HYD acting on goiter. Functionally, these candidate targets were closely correlated with thyroid hormone synthesis. Moreover, the potential regulating genes of herb pair HZ and GC were revealed to be crucial components in the pathway of thyroid hormone synthesis. The prediction results were all verified by following experiments based on goiter rats. Collectively, this integrative study combining microarray gene expression profiling, network analysis and experimental validations offers the convincing evidence that HYD may alleviate iodine-deficient goiter via regulating thyroid hormone synthesis, and explains the necessity of herb pair HZ and GC in HYD. Our work provides a novel and powerful means to clarify the mechanisms of action for multi-component drugs such as herbal formulae in a holistic way, which may improve drug development and applications.