Herba Siegesbeckiae: A review on its traditional uses, chemical constituents, pharmacological activities and clinical studies

Herba Siegesbeckiae, mainly includes Sigesbeckia orientalis L, Sigesbeckiae pubescens Makino and Sigesbeckiae glabrescens Makino. Herba Siegesbeckiae, also known as 'Xi-Xian Cao' (Chinese: ), has been regarded as an important traditional Chinese medicine since Tang dynasty. The dried aerial parts of Herba Siegesbeckiae are also being used as a herbal medicine in many countries such as Japan, Korea and Vietnam. In China, Herba Siegesbeckiae has been used for the treatment of rheumatic arthralgia with aching and weakness of loins and knees, as well as numbness of limbs.The aim of this review was to provide critical analysis on the scientific evidence to support the traditional uses of Herba Siegesbeckiae. The information available on its in botanical characteristics, traditional uses, chemical constituents, pharmacological activities, clinical studies, toxicity and quality control was summarized to understand the current research and provided the leas for future study.The search terms "Herba Siegesbeckiae", "Sigesbeckia orientalis", "Sigesbeckia pubscens" and "Sigesbeckia glabrescens" were used to obtain the information from electronic databases such as Web of Science, China National Knowledge Infrastructure, PubMed, Google Scholar and SciFinder Scholar and other web search instruments (Springer, Yahoo search). The information provided in this review was based on peer-reviewed papers in English and Chinese. Besides, information was also collected from ancient documents.The studies showed that Herba Siegesbeckiae contains sesquiterpenoids, diterpenoids, flavonoids and organic acids, etc. Due to these constituents, it displayed numerous pharmacological activities, such as anti-inflammatory, antitumor, antiallergic, antioxidant, antithrombotic and antibacterial activities. In addition, it showed effects in protecting myocardial and cerebral ischemia injury.According to its traditional uses, chemical constituents, pharmacological activities and clinic studies, Herba Siegesbeckiae is regarded as a promising medical plant with various chemical compounds and numerous pharmacological activities. However, fewer experimental studies were focused on toxicity and quantitative study of 3 species. It suggested that further in-depth study of toxicity and quality control were critical for future evaluation of drug efficacy and safety.