Botany, Traditional Use, Phytochemistry, Pharmacology and Clinical Applications of Rhubarb (Rhei Radix et Rhizome): A Systematic Review

Rhubarb, the Rhei radix et rhizoma (Da huang) is a member of the Polygonaceae family, included in the 2020 edition of the Chinese Pharmacopoeia, and is mainly distributed in Gansu, Sichuan, Qinghai, northwestern Yunnan, and eastern Tibet. Rhei radix et rhizoma is one of the most commonly used traditional Chinese medicines, processed into drinkable tablets in different concoctions for clinical use. Phytochemical studies showed that more than 170 compounds were isolated and identified from Rhei radix et rhizoma, including anthraquinones/anthrones (major constituents), stilbenes, chromones, flavonoids, tannins, and other compounds, etc. Rhei radix et rhizoma is an herb with a long history of traditional use and many potential therapeutic benefits. It can play the role of diarrhea, clearing heat in response to different combinations and concoctions. It is mainly used for the treatment of constipation, gastrointestinal function impairment, and other diseases. In addition, Rhei radix et rhizoma has significant antitumor, anti-inflammatory, antibacterial, hepato-renal protective, neuroprotective, hypolipidemic, and immunomodulatory activities. Its active constituents have anti-tumor, anti-inflammatory, anti-inflammatory and hepato-kidney protective properties. Although it is primarily used for gastrointestinal disorders, it may also have wider applications in various inflammatory and liver disorders. Therefore, further studies are needed to explore its full potential and mechanism of action. This paper reviews the research progress of Rhei radix et rhizoma in terms of botany, traditional use, chemistry, pharmacology, and clinical studies. It aims to provide a scientific basis for in-depth research and development of Rhei radix et rhizome resources.