In vitro cytotoxic activity of essential oil from khaya species flowers

The essential oil from fresh flowers of Khaya grandifoliola C.DC and. Khaya senegalensis A. Juss were obtained by hydro distillation method, in a modified Likens and Nickerson apparatus which allowed the distillation and simultaneous extraction of the volatile components in an organic solvent (n-pentane). The n-pentane layer was collected, filtered over anhydrous sodium sulfate, cautiously evaporated. A content of 0.09 – 0.1% essential oil was established. The chemical composition of the essential oil was analyzed by gas-chromatography coupled with mass spectrometry. Sesquiterpenes represents (88%) of the identified compounds. The main compounds identified in essential oil were: caryophyllene-oxide (23.01%), isocaryophyllene, (Z) (21.99%), α- Humulene (13.46%) in K. grandifoliola. while: caryophyllene-oxide (14.85%), trans-Caryophyllene (43.59%), α- Humulene (15.72%) in K. senegalensis. The oils were tested for cytotoxic activity against HepG-2, MCF-7 and HCT-116 cell lines. Cell viability was assessed by the mitochondrial dependent reduction of yellow MTT using Doxorubicin as reference drug. K. grandifoliola and K. senegalensis oil displayed cytotoxic activity with LC₅₀ (21.6, 26.1, 37.6 ppm) and (61.1, 79.7, 61 ppm) respectively. Sesquiterpene content of the oils may contribute to their cytotoxic activity. This is the first study for oil from khaya species.