Principles and strategies in cold/hot property studies of traditional Chinese medicine: an evolution from traditional theory to modern elucidation

Property of traditional Chinese medicine (TCM) is the core of the basic theories of TCM. Especially, the cold and hot properties are considered as closely related to the clinical medication and have the guiding significance. Driven by the ongoing advances of modern analytical technology, studies on the ancient theory of TCM cold and hot properties are flourishing recently, however, the review focusing on the applied research methods is insufficient. This review, by the bibliometric analysis of 996 associated publications, discloses the methodological evolution in researching the cold and hot properties of TCM from the traditional temperature-based methods (e.g. cold/hot plate differentiating and infrared thermography technologies) to modern elucidation that relies on the material basis-oriented strategies (multi-omics and gut microbiomics). The analytical techniques that are appliable to the in vitro/in vivo characterization of TCM decoction, analysis of effects on endogenous substances, and use of machine learning models for predicting properties, are systematically summarized. In addition, a review on the principles, characteristics, and applications of these analytical methods is conducted, to highlight the important research ideas and key results. It is thus expected to provide valuable reference for the in-depth analysis and better understanding of the theory of TCM properties.