The leishmanicidal activity of essential oils: A systematic review

Leishmaniasis is the neglected disease among parasitic diseases with an increasing rate of infections. Recently, numerous studies have been conducted on the leishmanicidal properties of various essential oils (EOs). In this research, literature have been systematically reviewed, from ۲۰ years ago, and required information have been extracted. Overally, leishmanicidal effects of ~۱۸۰ EOs against promastigotes of nine species of Leishmania havebeen documented. Inhibitory concentrations ۵۰% (IC۵۰) of around ۳۰ EOs were less than ۱۰ μg.mL-۱. EOs of Tetradenia riparia, Nectandra hihua, and Thymus hirtus with IC۵۰s of ۰.۰۱,۰.۲۰, and ۰.۲۵ μg.mL-۱ against Leishmania amazonensis, Leishmania infantum, and Leishmania major respectively, were identified as the most effective EOs. Furthermore, IC۵۰ of Thymus hirtus on Leishmania infantum was ۰.۴۳ μg.mL-۱. Frequently, substantial differences were found between the observed IC۵۰s of one EO against promastigotes of different species of Leishmania. It can be concluded that the leishmanicidal activity of EOs is selective. Turning to the results,the combination of EOs for the design of multifunctional drugs can lead to excellent outcomes.Interestingly, the results have been classified by promastigote species, so this would be a valuablebenchmark for researchers.