A systematic review on the anti­ mycobacterial activities of essential oils

Tuberculosis is a chronic infectious disease caused by Mycobacterium species bacteria. With the emergence of multi-drug resistant (MDR) bacterial strains, this issue has become a major concern for global public health. The scientists are still in search of new anti-tubercular agent that is less likely to get resistant and with less adverse effect. Amongst complementary medicine treatments, essential oil is gaining popularity in our community. Essential oil is the extraction product of natural plants which the anti-infective properties have been proven in many studies. It has shown good inhibitory activities against bacterial strain such as Escherichia coli and Staphylococcus aureus, but less is known on its anti­ tubercular activities. Therefore, this study aims to conduct a systematic review of published literature on the anti-rnycobacterial activities of plant essential oils. An extensive literature search on the use of plant essential oils for anti-mycobacterial activities from year 2000 to 2016 was conducted. Available in vitro studies published in National Center for Biotechnology Information (NCBI) in English language were reviewed and screened for inclusion. Data were extracted by two independent researchers and evaluated using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) tool. A total of 129 literature have been identified through the databases, but only 10 studies were included after screening with inclusion criteria. Over 20 plant essential oils have been tested for anti-rnycobacterial properties, from various range of families and origin such as Citrus sinensis, Cymbopogon species and Hyptis suaveolens. This systematic review explores the potential of essential oils in preventing drug resistant bacterial strains to encourage further research on the safety and effectiveness of essential oil therapy in the clinical setting.