A review of antimycobacterial natural products

Tuberculosis is a chronic infectious disease caused by several species of mycobacteria. Due to multi-drug resistant strains of mycobacteria and to a high prevalence of tuberculosis in patients who have acquired human immunodeficiency syndrome (AIDS), the number of patients infected with the disease is increasing worldwide. Thus there is an urgent need for new effective antimycobacterial agents to replace those currently in use. In this instance, the plant kingdom is undoubtedly a valuable source for new anti-tuberculosis agents. The present review article reports the findings from an extensive literature search of all plants that have been assessed for antimycobacterial/antitubercular activity over the past 20-30 years. An attempt has been made to summarize the information in order to highlight those promising plant species which are worthy of further investigation as leads for drug development. Over 350 plant species from a wide range of families and origins, containing various chemical classes of compounds, have been screened for such activity. A review of the relevant in vitro assays using different species of pathogenic and non-pathogenic mycobacteria is also included.