Orchids : A review of uses in traditional medicine, its phytochemistry and pharmacology

Many of the epiphytic orchids are used as traditional medicine. Chemical components and pharmacology have been studied in recent 15 years. Medicinal orchids, in general, are not subjected to detailed pharmacological studies. A wide range of chemical compounds are presented including alkaloids, bibenzyl derivatives, flavonoids, phenanthrenes and terpenoids which have been isolated recently from this species. Extracts and metabolites of these plants, particularly those from flowers and leaves, possess useful pharmacological activities. Particular attention has been given to diuretic, anti-rheumatic, anti-inflammatory, anti-carcinogenic, hypoglycemic activities, antimicrobial, anticonvulsive, relaxation, neuroprotective, and antivirus, activities. A comprehensive account of chemical constituents and biological activities is presented and a critical appraisal of the ethnopharmacological issues is included in view of the many recent findings of importance of these orchids. A large number of orchids have been empirically used for treatment of different diseases, thus, several studies have been undertaken to provide scientific proof to justify the medicinal use of various plants in treatment of diseases. The aim of this review is to up-date and to present a comprehensive analysis of traditional and folklore uses, pharmacological reports and phyto-constituents isolated from the orchids family.   Key words: Orchids, medicinal plant, traditional uses, chemical constituents, biological activities.