Medicinal plants of the genus Gelsemium (Gelsemiaceae, Gentianales)--a review of their phytochemistry, pharmacology, toxicology and traditional use

Abstract

Ethnopharmacological relevance: In the genus Gelsemium, Gelsemium elegans (Gardn. & Champ.) Benth. has been recognized as a toxic plant that is widely distributed in Southeast Asia and has been used as traditional Chinese medicine for the treatment of rheumatoid pain, neuropathic pain, spasticity, skin ulcers and cancers for many years. Gelsemium sempervirens (L.) J.St.-Hil. has been used since the nineteenth century in homeopathy for treating anxiety, neuralgia, migraine and spasmodic disorders, such as asthma and whooping cough in North America. This review aims to provide comprehensive information on the botany, traditional uses, phytochemistry, pharmacological research and toxicology of medicinal plants in the genus Gelsemium. The overall objective is to explore the evidence supporting its ethnopharmacological effectiveness.

Materials and methods: A literature survey was performed by searching the scientific databases Pubmed, Google Scholar, SciFinder, Scopus, Web of Science and the Chinese CNKI, in addition to traditional Chinese medicine and homeopathic texts for information on Gelsemium.

Results: Plants of the genus Gelsemium have been used in traditional medicine for the treatment of migraines, neuralgia, sciatica, cancer and various types of sores. Studies into the phytochemical composition of this genus have shown that all of the species are rich sources of monoterpene indole alkaloids and that they have attracted the attention of many researchers due to their markedly diverse and complex architecture. To date, a total of 121 alkaloids have been isolated and identified from the genus. The crude extracts, as well as the monomeric compounds, from the genus possess anti-tumor, analgesic, anxiolytic, anti-inflammatory and immunomodulating pharmacological activities.

Conclusion: It is evident from the available literature that Gelsemium species possess potential for use as a beneficial therapeutic remedy. However, the analysis of previous pharmacological research suggests that a clear assignment of active molecules and mechanisms of action is remain lacking. Due to their high toxicity, the studies available on toxicity and safety are inadequate for providing information on clinical utilization.

Keywords: Alkaloids; Gelsemium; Iridoids; Pharmacology; Phytochemistry; Toxicology.