Chemical Composition and Biological Activities of the Essential Oils from the Fresh Leaves of Citrus limonia Osbeck and Citrus latifolia Tanaka (Rutaceae)

This study aimed at determining, for the first time, the chemical composition of the essential oils from fresh leaves of Citrus limonia and Citrus latifolia and evaluating its in vitro antibacterial, trypanocidal, leishmanicidal and cytotoxic effects. The essential oils from fresh leaves of C. latifolia and C. limonia were extracted by hydro distillation and analyzed by GC-MS. The oil yield was 0.8% for C. latifolia and 0.5% for C. limonia, whereas 17 and 18 chemical components were identified for C. latifolia and for C. limonia, respectively. Major components were limonene (46.3 %), nerol (10.0 %) and 1,8-cineole (13.4 %). In vitro antibacterial activity was evaluated against the bacteria Streptococcus mitis, Streptococcus mutans, Streptococcus sanguinis, Streptococcus sobrinus and Bacteroides fragilis by the broth dilution method. Protozoa of the Trypanosomatidae family cause neglected tropical diseases, such as trypanosomiasis, whose treatment has depended on few available drugs. Therefore, the essential oils from fresh leaves of C. limonia and C. latifolia were also evaluated against the Y strain of Trypanosoma cruzi trypomastigotes, resulting in IC50 = 88.2 g/mL and 51.7 g/mL, respectively. Regarding the evaluation of the cytotoxic activity against fibroblasts LLCMK2 line, the essential oil from C. limonia (CC50 = 422.9 g/mL) and C. latifolia (CC50 = 502.9 g/mL) showed moderate cytotoxicity. The leishmanicidal activity of the essential oils from fresh leaves of C. limonia and C. latifolia were evaluated against promastigote forms of Leishmania amazonensis, resulting in IC50 = 2.63 g/mL and 2.03 g/mL, respectively. Thus, the essential oils from fresh leaves of Citrus limonia and Citrus latifolia had moderate antibacterial and trypanocidal activities and significant leishmanicidal activity.