Pharmacological and Chemical Potential of Spiranthes sinensis (Orchidaceae): A Narrative Review

Orchidaceae is one of the largest families of flowering plants with more than 27,000 accepted species, and more than 31,000–35,000 species are estimated to exist in total. The orchid Spiranthes sinensis (Pers.) Ames, having ornamental and medicinal value, is widely distributed throughout Asia and Oceania. S. sinensis (Shou Tsao) is also known as Panlongshen among the common folk herbs. It has a fleshy root similar to ginseng, and the entire plant is widely used in traditional Chinese medicine. Owing to overexploitation and habitat destruction in recent years, the wild population has become scarce. The traits of this species show obvious differences in different countries. In the Taiwanese climate, it flowers during the Ching Ming Festival, also called the ching ming tsao. Previous investigations into S. sinensis have revealed the presence of flavonoids, homocyclotirucallane, dihydrophenanthrenes, ferulic acid, and 3,4-dihydroxybenzaldehyde. Phenolic constituents of structural and biological interest, including phenanthrenes and flavonoids, have been isolated and identified from S. sinensis. This natural product possesses extensive bioactivity, including anti-tumor, anti-inflammatory, and antioxidant effects. In this review, we outline the herbal medicine formulations and plant-derived natural products of S. sinensis.