Clinical data collected so far suggest support of olive polyphenols for skin healthby reducing oxidative stress.
Opextan® and UV protection from within
The skin response to sun irradiation can be assessed by measuring the erythemal dose, that is the lowest UV dose that causes enough superficial vasodilatation to be visually perceived as reddness. The lowest erythema-inducing UV dose is defined MED (Minimal Erythemal Dose), and can be visually judged by trained evaluators.
In order to evaluate the effect of orally administered polyphenols from olive (olive fruit extract) on skin sensitivity to UV irradiation, 13 male subjects with high sensitivity to UV light were selected(1). A dose of 160 mg/day of olive fruit extract was administered orally for four weeks. The subjects were then irradiated with increasing doses of ultraviolet light (UVA+UVB 0.45 mW/cm2; from 0.054 J/cm2 to 0.135 J/cm2) in the dorsal area, and MED was evaluated. The results showed an averaged 16.45% increase of MED compared to before the treatment, suggesting support of olive polyphenols for sun-exposed skin health.
Other investigations(2) indicate that daily topical use of super virgin olive oil after sun bathing may delay and reduce UV-induced skin cancer development in human skin, possibly by decreasing ROS induced gene mutations.
Lipid peroxidation is a well known example of oxidative damage in lipid containing structures(3). Unsaturated phospholipids, glycolipids and cholesterol present in cell membranes are all targets for oxidation. Lipid peroxidation is a degenerative process that affects both the structure and the function of the target system, and that has been linked to a variety of disorders(3).
The protective effect of the olive fruit extract against oxidative stress and lipid peroxidation has been assessed experimentally in order to detect its biological activity when applied topically against oxidative damage. Thus, a formulation containing olive fruit extract was applied topically and evaluated on a group of 6 healthy volunteers, who were asked to wash their face and apply the formulation under investigation and the placebo formulation on each half face. Three hours later, they were irradiated with sunlight for about 20 minutes, and sebum was sampled by Sebutape, extracted and measured by dosing luminescence, a direct measurement of lipid peroxidation, in 0.1 μg/mL recovered sebum. The area treated with the olive fruit extract showed a 27.1% (statistically significant, p<0.001 Dunnett’s test) decrease of fluorescence compared to the placebo(1).Expand Bibliography
- Maramaldi G, Artaria C, Ikemoto T, Haratake A, “Estratto standardizzato di frutti di Olea europaea”, L’ integratore Nutrizionale 9 (3), (2006), 23-2
- Ichihashi M, Ahmed NU, Budyianto A, Wu A, Bito T, Ueda M, Osawa T, “Preventive effect of antioxidant on ultraviolet-induced skin cancer in mice”, J Dermat Sci 23, Suppl 1 (2000), S45-S50
- Girotti AW, “Lipid peroxide generation, turnover and effector action in biological systems”, J. Lipid Research 39, (1998), 1529-1542