Medicinal plants and herbal drugs: An overview

Abstract

Medicinal plants, which represent one of the greatest assets of ecosystem, have found their utilization in human life and healthcare system since early days of mankind and have still maintained their importance in modern times by virtue of maintaining their basic therapeutic curative role. Numerically constituting a large group of world flora, medicinal plants form the source for large variety of herbal drugs used for medicinal purposes. Cultivation of medicinal plants being a promising alternative to wild collection enables not only conservation of natural genetic variability and survival of critically endangered, vulnerable, endangered, endemic and rare species but also symbolizes a potent economy branch for pharmaceutical industry as source of their quality raw material. Medicinal plants owe their curative value to naturally occurring biologically active ingredients in them, i.e. the primary and secondary metabolites which obtained either in pure or combined form with other molecules form a pivotal source of drug lead compounds. Growth and development of medicinal plants and medicinally active chemical metabolites found in them are influenced by the abiotic factors and biotic factors. The resurgence in recognizing medicinal plants as a source of drugs and other products is mainly due to their effectiveness, with no to little side effects associated with their application and as an alternate to high-cost synthetic drugs. Though herbal medicine has become more mainstream world over during the last few decades, their safety, quality and effectiveness still remain a key issue. The renewed interest in medicinal plants expanded their market demand which however coupled with their already rather limited availability and potential overharvesting have brought about alarming biodiversity problems sounding the need to evaluate and conserve our old prized natural germplasm. This chapter deals with stocking of knowledge regarding use of medicinal plants, their correct identification, their chemical constitution, factors involved in their quality production and also that of naturally occurring bioactive principles, as well concerns with regard to their quality and control parameters thereof. The chapter also gives insight into their conservation aspect especially from the viewpoint of sustainability as they represent the substantial proportion of the global drug market.