Traditional uses, Clinical studies, and Ten-years Research Progress in Phytochemistry and Pharmacology of the Genus Scutellaria

Ethnopharmacological relevance: Scutellaria (Lamiaceae), which includes 536 accepted species, is widespread in Europe, North America, East Asia, and South America. Several species are used as traditional medicines for a long history to treat diarrhea, dysentery, inflammation, respiratory infections. The phytochemistry and pharmacology of the genus Scutellaria have developed dramatically in the past ten years, and the traditional uses and clinical studies of the genus have not been systematically summarized. Therefore, it is especially valuable to exhibit its current progress to provide the bases for further exploration of medicinal potential.

Aim of the review: The aim of the review is to provide updated information on the ethnopharmacology and clinical studies, the ten-years research progress of phytochemistry and pharmacology of Scutellaria, and to explore the potential medicinal values and further studies of Scutellaria.

Materials and methods: This review is based on the literature studies and books from the library and electronic sources, including SciFinder, Scopus, PubMed, Web of Science, Baidu Scholar, CNKI, online ethnobotanical database, and ethnobotanical monographs. These literature are related to ethnopharmacology, clinical studies, the ten-years research progress of phytochemistry, and pharmacology of Scutellaria.

Results: A total of 52 species and 20 varieties of the genus Scutellaria are used as traditional medicine with various biological activities. In the past ten years, 208 chemical constituents have been identified from 16 species and 1 variety of the genus Scutellaria, such as neo-clerodane diterpenoids, sesterterpenoids, terpenoid, flavonoids. Currently, pharmacological researches have demonstrated that the extract and compound identified from this genus exhibited extensive biological activities, including anticancer, antioxidant, anti-inflammatory, antiviral activities, anti-bacterial, effects on cardiovascular and cerebrovascular diseases, hepatoprotective and effects on neurodegenerative disease. The species of S. baicalensis, S. barbata, and S. lateriflora and the main compounds baicalein, baicalin and wogonin are involved in clinical trials, which point the way for us to conduct further study including anticancer, lower blood pressure, anti-infective, anti-inflammatory, protect the central nervous system and other effects on Scutellaria.

Conclusions: The species in Scutellaria can be used to treat cancer, infection, hepatic disorders, cardiovascular and cerebrovascular diseases, neurodegenerative diseases and other diseases. Some indications in traditional medicines have been confirmed by modern pharmacological activities, such as anticancer, anti-inflammatory, anti-infective, hepatoprotective, and neuroprotection. The available literature exhibited that most of the bioactivities could be attributed to flavonoids and neo-clerodane diterpenoids. Though there are some in clinical practice of Scutellaria, the existing researches on this genus is still limited. For more profound studies of Scutellaria, in-depth study of more concerned species, which possess great bioactivities to treat diseases in vitro/vivo and as well as in clinical are suggested to be carried out to complete the studies on their effective substances, pharmacology mechanism, quality control, clinical use, and new drug research. Also, in order to expand the development of medicinal resources of Scutellaria, the once used as local herbal medicine but unexploited species are needed more concern.

Keywords: Scutellaria; clinical studies; pharmacology; phytochemistry; traditional uses.