Evidence-Based Study to Compare Daodi Traditional Chinese Medicinal Material and Non- Daodi Traditional Chinese Medicinal Material.

Background: Daodi medicinal material is widely used in Chinese herb medication. However, there is a lack of systematic methodology for identifying characteristics associated with good quality and reliable efficacy of Daodi med-material.

Purpose: The purpose of this study is to provide some evidence to further substantiate the use of Daodi medicinal materials.

Methods: Seven relevant databases were searched before July 2014. Two evaluators were responsible for screening and categorizing the results. The data was analyzed with Microsoft Excel 2007 and SPSS 21.0 statistical software.

Results: Overall, 107 articles were systematically analyzed. Of these studies, 55.1% (59/107) focused on the methodology to assess Daodi med-material, and 38.3% (41/107) were interested in med-material ingredients, soil physical and chemical properties, and the geological background system (GBS). Only 6.5% (7/107) of studies were mainly conducted as clinical trials and animal experiments.

Conclusion: Comparisons between Daodi and non- Daodi materials have been studied mainly in terms of the ingredients or composition of medical materials, soil physics and chemistry, and the GBS, and some identifying methodologies have been created to identify Daodi attributes. Until now, there is still no consensus of comparison criteria between Daodi and non- Daodi medicinal material. Only a few studies were conducted through animal experiments and clinical trials to determine Daodi superiority.