Anti- mycobacterial effect of plant essential oil and its chemical components

Worldwide, the number of  tuberculosis (TB) patients is very high. Increasing number of Mycobacterium tuberculosis organisms are reported to be multi-drug resistant. Even 50 years after the introduction of effective specific chemotherapy against tuberculosis, the number of tuberculosis cases is higher worldwide, and there are an increasing number of cases of infections with organisms resistant to the major anti- tuberculosis agents. Furthermore,  side-effects from current medications, increased cost of developing new drugs, the limited commercial potential for drugs for TB and decreasing funds for research from pharmaceutical companies make a negative impact on anti-microbial research. Recently essential oils from plants have been investigated and found to have anti-bacterial and anti-mycobacterial effects. Recent developments in technology have helped in identifying individual chemical constituents in Essential oils.  Apart from the essential oil as a whole, these individual chemical constituents also have been found to have anti-mycobacterial effect. Furthermore, few of the individual chemical constituents have been chemically modified to create newer molecules and these newer molecules also have anti-mycobacterial effect. This review emphasizes the importance of continuing research on plant essential oils for newer drug molecules against tuberculosis.