The real UVB photoprotective efficacy of vegetable oils: in vitro and in vivo studies

Table 4 UVB photoprotection performance of the seven virgin vegetable oils and the standard HMS sunscreen determined in vitro and in vivo

Sample	Standard HMS sunscreen	Argan oil	Avocado oil	Black cumin seed oil	Carrot seed oil*	Chaulmo ogra oil	Coconut oil	Hazelnut oil
In vitro SPF determination
Solution at the reference concentration (mg mL⁻¹)	0.2	0.2	0.2	0.2	0.2	0.2	0.2	0.2
Solution at the sample concentration (mg mL⁻¹)	0.2	10.0	10.0	10.0	10.0	10.0	10.0	10.0
Dilution factor	1.0	0.02	0.02	0.02	0.02	0.02	0.02	0.02
Absorbance at 290 nm	0.2470	0.6320	0.4693	0.5123	0.6390	0.2910	0.0381	0.3070
Absorbance at 295 nm	0.3065	0.4720	0.3947	0.4373	0.4757	0.1620	0.0312	0.1483
Absorbance at 300 nm	0.3585	0.4707	0.3477	0.3650	0.4083	0.1153	0.0246	0.0970
Absorbance at 305 nm	0.3885	0.3930	0.3147	0.2770	0.3237	0.0833	0.0190	0.0533
Absorbance at 310 nm	0.3740	0.2740	0.2913	0.1900	0.2727	0.0577	0.0162	0.0223
Absorbance at 315 nm	0.3235	0.2943	0.2787	0.1520	0.2783	0.0507	0.0144	0.0163
Absorbance at 320 nm	0.2360	0.2287	0.2570	0.1303	0.2853	0.0393	0.0133	0.0083
Found SPF in vitro ± SD, CF = 10, n = 3	3.60 ± 0.47
Found SPF in vitro modified ± SD, CFa = 12.4, n = 3	4.43	0.097 ± 0.001	0.081 ± 0.002	0.072 ± 0.001	0.087 ± 0.002	0.023 ± 0.002	0.004 ± 0.001	0.017 ± 0.003
In vivo SPF determination
Found SPF in vivo ± SD, n = 10, SPF 95% CI		3.2 ± 0.7	2.7 ± 0.4	2.7 ± 0.6	2.5 ± 0.6	3.0 ± 0.4	1.2 ± 0.1	2.5 ± 0.6
SPF 95% CI		2.7–3.7	2.4–3.0	2.3–3.3	2.1–2.9	2.7–3.3	1.1–1.3	2.1–2.9

The final values in vitro and in vivo SPF are indicated in bold. The SPF values are stated for concentrated oils. The absorbance values (the arithmetic mean of “n” measurements) are shown here for illustration purposes only. *Not to be confused with essential oil obtained by distillation from carrot seed