The genus Clematis (Ranunculaceae): Chemical and pharmacological perspectives

Ethnopharmacological relevance: Twenty six species of the genus Clematis (Ranunculaceae) have been traditionally used in various systems of medicine for the treatment of ailments such as nervous disorders, syphilis, gout, malaria, dysentry, rheumatism, asthma, and as analgesic, anti-inflammatory, diuretic, antitumour, antibacterial and anticancer. Aim of the review: To emphasize on ethnopharmacology, chemical constituents, pharmacology, toxicology and clinical studies of various species of the genus Clematis. Materials and methods: The available information on Clematis species was collected through electronic search of major scientific databases. Results: A survey of literature revealed that triterpene saponins, alkaloids, flavonoids, lignans, steroids, coumarins, macrocyclic compounds, phenolic glycosides, anemonin and volatile oils constitute major classes of chemical constituents in the genus Clematis. Preliminary analgesic, anticancer, anti-inflammatory, diuretic, antiarthritis, hepatoprotective, hypotensive and HIV-1 protease inhibitor activity studies have been carried out on crude extracts of 26 traditionally used and medicinally promising species of Clematis genus. Conclusions: The species of the genus Clematis emerged as good source of traditional medicine for the treatment of various ailments. Although few experimental studies validated their traditional claims, but employed uncharacterized crude extracts. Such Clematis species need to be explored properly following bioactivity-directed fractionation with a view to isolate bioactive constituents, and to evaluate their possible mode of actions. These species hold great potential for detailed clinical studies so that these could be exploited as potential drugs. The review will help researchers to select medicinally potential species of Clematis genus for future research. (C) 2012 Elsevier Ireland Ltd. All rights reserved.