Cytotoxic effects of the essential oil from leaves of Casearia sylvestris Sw. (Salicaceae) and its nanoemulsion on A549 tumor cell line

Abstract

Extracts from leaves of C. sylvestris have cytotoxic effect in different tumor cell lines, possibly due to clerodane type diterpenes (casearins). On the other hand, there are few studies related to the antitumor activity of the essential oils from this species. This work evaluated for the first time the cytotoxicity effects of the pure essential oil and its nanoemulsion against A549 tumor cell line (human lung carcinoma). The essential oil was obtained from fresh leaves by hydrodistillation in a Clevenger-type apparatus and analyzed by GC/MS and GC/FID. Cytotoxicity evaluation was performed using the WST-1 test. The chemical analysis of the essential oil revealed a volatile fraction composed mainly of non-oxygenated sesquiterpenes (72.1%). The essential oil and its nanoemulsion exhibited cytotoxic activity against A549 tumor cells with EC50 of 4.0 μg/mL and EC50 of 1.0 μg/mL, respectively. Both samples displayed a dose dependent pattern (r = -0.79, p = 0.03) as determined by linear regression test.