Genus Helleborus: a comprehensive review of phytochemistry, pharmacology and clinical applications

The genus Helleborus belongs to the Ranunculaceae family, distributed in southeastern Europe and western Asia. In folk medicine, it is commonly used as an anti-inflammatory and analgesic medicine for rheumatoid arthritis and bruises. Through reviewing recent articles, it was found that two hundred and twenty-six compounds have been isolated and identified from the genus Helleborus. These compounds include steroids, flavonoids, phenylpropanoids, lignans, anthraquinones, phenolics and others. Among them, the main chemical constituents are steroids. Pharmacological studies show Helleborus has anti-cancer, immunomodulatory, anti-inflammatory, analgesic, anti-hyperglycaemic, antioxidant and antibacterial properties. This article reviews the botany, phytochemistry, pharmacological effects and clinical applications of the genus Helleborus. Hopefully, it will provide a reference for in-depth research and exploitation of the genus Helleborus.