Niaouli oils from different sources: Analysis and influence on cutaneous permeation of estradiol in vitro

Figures & data

Table 1.  Terpene components (% w/w) of NEOs 1–4.

Terpenes	NEO1	NEO2	NEO3	NEO4
1,8-cineol	53.0	55.1	57.5	70.4
α-pinene	18.3	6.0	4.0	6.9
α-terpineol	12.0	7.9	15.8	5.5
d-limonene	3.9	8.6	4.9	7.4
γ-terpineol	5.1	3.1	6.1	0.7
p-cymene	3.8	6.7	2.1	2.1
β-terpineol	2.2	1.2	1.3	0.2
β-pinene	0.4	1.2	1.7	1.8
β-myrcene	0.3	0.6	—	0.6
(E)-β-ocimene	0.2	0.9	< 0.1	0.6
sabinene	< 0.1	< 0.1	4.1	< 0.1
terpinolene	< 0.1	1.9	< 0.1	0.3
γ-terpinene	< 0.1	1.4	< 0.1	0.25
linalool	—	1.8	2.1	0.5
terpinen-4-ol	< 0.1	0.4	< 0.1	0.8
aromadendrene	< 0.1	0.3	< 0.1	< 0.1
γ-cubebene	< 0.1	0.7	< 0.1	0.5
Total	> 99.2	> 97.8	> 99.6	> 98.55

Table 2.  Composition (% w/w ) of the terpene mixtures used as enhancers.

Artificial mixtures
Denomination	MIX1	MIX2	MIX3	MIX4
Corresponding NEO	NEO1	NEO2	NEO3	NEO4
1,8-cineol	58.31	65.36	68.21	76.27
α-pinene	20.13	7.12	4.74	7.48
α-terpineol	13.20	9.37	18.75	5.96
d-limonene	4.18	10.20	5.81	8.02
p-cymene	4.18	7.95	2.49	2.27
Total	100.00	100.00	100.00	100.00

Table 3.  Skin permeation data of ES from vehicles containing NEOs from different sources (means ± standard error, SE).

Vehicle^a	NEO type	J (μg/cm^2.h)	Lag time (h)	ES permeated × 10^2 (% w/w)	EF^b
V0	None	0.2 ± 0.041	6.17 ± 1.66	0.24 ± 0.036	1.00
V1	NEO1	15.00 ± 0.79*	1.17 ± 0.26*	5.22 ± 1.65*	75.0 ± 3.97
V2	NEO2	16.93 ± 2.21*	1.23 ± 0.02*	5.78 ± 1.96*	84.63 ± 11.05
V3	NEO3	8.30 ± 0.37*	0.50 ± 0.05*	4.70 ± 0.13*	41.50 ± 1.86
V4	NEO4	13.33 ± 1.03*	1.19 ± 0.22*	5.24 ± 0.64*	66.63 ± 5.15

^a Each vehicle (except V0) consisted of propylene glycol (PG) containing 1.0% w/w ES and 10.0 % w/w NEO.

^b Enhancement factor: * Significantly different from V0 (p < 0.05).

Table 4.  Skin permeation data of ES from vehicles containing artificial terpene mixtures (means ± SE).

Vehicle	Corresponding essential oil	J (μg/cm^2·h)	Lag time (h)	ES permeated × 10^2 (% w/w)	EF
MIX1	NEO1	10.63 ± 0.49	1.60 ± 0.34	4.18 ± 0.33	53.13 ± 2.45
MIX2	NEO2	15.05 ± 1.58	0.33 ± 0.093	7.70 ± 0.81	75.25 ± 7.88
MIX3	NEO3	4.37 ± 0.68	0.42 ± 0.13	2.63 ± 0.37	21.88 ± 3.42
MIX4	NEO4	17.23 ± 0.26	0.45 ± 0.16	9.27 ± 0.91	78.73 ± 7.68

Figure 1.  ES transdermal fluxes produced by NEO1–4 shown in comparison with fluxes produced by the corresponding artificial mixtures MIX1–4. Vertical lines over bars indicate ± SE. * Significantly different from the corresponding artificial mixture.