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VOL. 76 (3), 343-356, 2010 CYTOTOXIC ACTIVITY OF a-HUMELENE AND...

3. RESULTS

3.1. Essential oil, active fractions, subfractions and sub-subfractions
compositions

In order to identify active compounds present within the essential
oil and its active subfractions, gas chromatography systems were
applied. The chemical composition of the essential oil and its fractions,
subfractions and sub-subfractions is shown in Table 1. S. officinalis es-
sential oil was characterized by 23 compounds (98% of the total oil)
of which 18 were monoterpenes, 4 sesquiterpenes and diterpene. The
GC-MS analysis revealed the presence of camphor (21.23%), a-thujone
(21.22%), 1,8-cineole (17.52%), ß-thujone (13.45%), trans-caryophyl-
lene (1.67%) and a-humulene (1.45%). The fractions F1, F2 and F3 rep-
resent respectively 92.67%, 96.67% and 91% of the total compounds
identified. In the fraction F1, the main compounds were a-pinene
(18.56%), trans-caryophyllene (18.32%), camphene (14.81%) and a-hu-
mulene (12.38%). In the F2 and F3 fractions the main compounds were
a-thujone and 1,8-cineole with 67.05%, 10.88% and 49.06%, 20.72%
respectively.

3.2. Cytotoxicity

The cytotoxicity of the essential oil of S. officinalis and its frac-
tions in the three cancer cell lines is shown in Figures 1, 2 and 3,
and the IC50 values are given in Table 2. The first fraction F1 was the
most active on the murine macrophage cells RAW264.7 (IC50 118.4
µg/ml). Less activity was found when the fraction F1 was applied to
both cell cultures (279.3 and 265.5 µg/ml for HCT-116 and MCF-7,
respectively). The sub-subfraction (ssf) F1.1.1 obtained from subfrac-
tion (sf) F1.1 was more active on the RAW264.7 cells (IC50 41.9 µg/ml)
than on the HCT-116 cells (IC50 77.3 µg/ml). Less activity was found
when the ssf F1.1.1 was applied to MCF-7 cells (IC50 125.7 µg/ml).
The ssf F1.2.1 selected from sf F1.2 was less cytotoxic in RAW264.7
(IC50 90.5 µg/ml), HCT-116 (IC50 145.8 µg/ml) and MCF-7 (IC50 144.7
µg/ml). Commercially available samples of some of the identified
main compounds (1,8-cineole, ß-thujone, trans-caryophyllene and a-
humulene) were tested for their cytotoxic activity in vitro on the three

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