Hot and Cold Theory: Evidence in Pharmacology.

Traditional and folk medicine from different countries are valuable sources of new ideas to design novel natural products for health and diseases. In this field, the classification of medicinal plants and other natural medicinal materials into hot or cold categories is a common concept within different doctrines of complementary and alternative medicine such as Persian medicine, traditional Chinese medicine, and Indian medicine. Today, a growing body of evidence is being provided to support different pathophysiologic bases of this categorization, as well as the pharmacological targets affected by natural products from each of the two categories. Different body systems such as endocrine and nervous systems are influenced by the hot/cold materials, some of which have been studied in animals or humans. This chapter focuses on the pharmacological evidence supporting the hot/cold nature of medicinal plants.