Chemical composition of the Brazilian native Cinnamomum stenophyllum (Meisn.) Vattimo-Gil essential oil by GC-qMS and GC × GC-TOFMS, and its cytotoxic activity

Cinnamomum stenophyllum (Meisn.) Vattimo-Gil (Lauraceae) is a native and vulnerable Brazilian species restricted to the Atlantic Forest. The leaf essential oil obtained by hydrodistillation was characterized for the first time by two-dimensional gas chromatography with time-of-flight mass spectrometry (GC × GC-TOFMS). This analysis resulted in the tentatively identification of 80 compounds, showing the superior performance of this method in comparison to the seven compounds identified by GC–MS. The identified compounds included 8 ketones, 7 monoterpene hydrocarbons, 30 oxygenated monoterpenes, 4 sesquiterpene hydrocarbons and 23 oxygenated sesquiterpenes, showing that the C. stenophyllum oil contained mostly oxygenated mono and sesquiterpenes. The oil cytotoxicity was tested against two human cancer cell lines, colon adenocarcinoma (HCT-116) and breast cancer carcinoma (MCF-7), and the non-tumor retinal pigment epithelial cells (RPE) using the colorimetric MTT assay. Both cancer cell lines were sensible to leaf essential oil, with IC50 < 20 μg/mL (HCT, IC50 = 9.95 μg/mL and MCF-7, IC50 = 16.65 μg/mL), while there was no cytotoxicity against the non-tumor cells at tested concentrations (IC50 > 50 μg/mL), suggesting selectivity to cancer cells. The results showed that the C. stenophyllum leaf essential oil has a cytotoxic potential, presenting several compounds already known as biologically active against tumor cells.