Ethnopharmacology of Hypericum species in China: A comprehensive review on ethnobotany, phytochemistry and pharmacology

Ethnopharmacological relevance: Hypericum species have been used traditionally as astringent, antipyretic, diuretic, antiphlogistic, analgesic, and antidepressant in Europe, America, Africa, and Asia. One of the most extensively investigated medicinal herbs, H. perforatum L. (St. John's wort), is widely used in many countries to treat mild to moderate mental depression. Hypericum species are abundant throughout China, including 30 used as ethnomedicines. There are limited publications describing the ethnobotanical uses and biological activities associated with Hypericum species in China. Some reported activities include the treatment of wounds and bruises, irregular menstruation, dysentery, hepatitis, mastitis, jaundice, hemoptysis, and epistaxis. Aim of the review: This review aims to critically examine how Hypericum species are used ethnomedicinally in China, to see if the ethnobotanical data may be useful to help prioritize Hypericum species and certain phytochemical constituents that may be new drug leads, and consider the focus and lack of the phytopharmacological study on Hypericum species in China. Materials and methods: Classic medicinal books and ethnomedicinal publications were reviewed for the genus Hypericum (called jin si tao in Chinese). In addition, relevant information about ethnobotany, phytochemistry, and pharmacology were from online databases including SciFinder, Science Direct, PubMed, Google Scholar, and China National Knowledge Infrastructure (CNKI). "Hypericum", "", "ethnobotany", "traditional use", "ethnomedicine", "phytochemistry", "pharmacology" and "bioactivity" were used as keywords when searching the databases. Thus, available articles from 1959 to 2019 were collected and analyzed. Results: Among 64 Hypericum species recorded in China, 30 have been used as ethnomedicines by 15 linguistic groups such as Dai, Dong, Han, Miao, and Mongolian people. Hypericum species in China possess traditional uses which are also mirrored in Europe, America, Africa, and other countries in Asia. However, there are some unique ethnomedicinal uses in China. For example, several Hypericum species are used as a local remedy in southwest China, and H. attenuatum Fisch. ex Choisy is used to treat cardiac disorders in northeast China. Antitumor, anti-inflammatory, antimicrobial, neuroprotective, antidepressant, hepatoprotective, cardioprotective, and antiviral activities have been reported in numerous biological studies. The main phytochemical constituents in Hypericum consist of phloroglucinols, naphthodianthrones, xanthones, flavonoids, and terpenoids. Conclusions: There is a rich traditional knowledge regarding the ethnomedicinal uses of Hypericum species in China. Through phytochemical and pharmacological studies, several medicinal Hypericum from China have yielded many bioactive phytochemicals, possessing antitumor, anti-inflammatory, antimicrobial, and neuroprotective properties. Hypericum species from China are potential sources of drugs to fight cancer and other chronic diseases. Remarkably, nearly half of Hypericum species in China have rarely been studied, and their ethnomedicinal potential have not been scientifically evaluated. Thus, in vitro mechanistic studies, in vivo pharmacology, and clinical efficacy are all needed, prioritizing those studies that relate most closely with their traditional uses. In addition, a comprehensive plant-resource evaluation, quality control, and toxicology studies are needed.