The relevance of skin care is based on its ability to respond to specific needs. The issue of pigmentation is particularly worthy of consideration as it may reflect certain skin problems.
Skin pigmentation: definition
The skin has a natural colour, one that is not dependent on sun exposure. This is called “pigmentation”. This colour results from melanocytes. These are the cells responsible for the production of melanin, in other words the pigments that give the skin its natural colour.
Two types of melanin are found in all skins, the proportion varying from one individual to another. Eumelanins are pigments whose colour varies from dark brown to black. This is the type of melanin that defines the colour of dark skin and provides protection against UV radiation from the sun. Pheomelanins are dominant in fair-skinned people as well as in redheads. This melanin offers no protection against UV radiation.
How does skin pigmentation work?
The pigmentation process is stimulated both by UV radiation and by various substances naturally present in the skin cells. This causes the production of melanocytes.
In turn, the melanocytes produce melanin (eumelanin and pheomelanin).
The melanin spreads through the different layers of the epidermis.
Finally, the melanin rises to the surface thanks to the phenomenon of epidermal cell renewal.
These 4 stages therefore ensure the pigmentation of the skin.
When the skin is exposed to the sun, ultraviolet rays pass through the epidermis, which can disturb the functioning of the melanocytes. As a result, these pigment cells continually secrete large quantities of melanin. This overproduction causes an inhomogeneous diffusion of melanin and therefore the formation of round, flat brown spots which appear in different places. These are called “lentigos”.
In most cases, brown spots are the result of excessive exposure to UV rays. People who work outdoors (e.g. construction workers) are therefore the most affected.
This hyperpigmentation can also be caused by cellular ageing of the areas of the skin most frequently/long-term exposed to UV rays. This concerns in particular the face and neck, but also the hands. Light-skinned people over the age of 50 are more affected by senile lentigo or sun lentigo.
In other cases, brown spots are caused by hormonal changes during pregnancy or after taking hormone-based contraceptive treatments. The hyperpigmentation then disappears naturally as soon as hormone production returns to balance.
It should be noted that certain plants contained in cosmetic products and medicines react to sun exposure by stimulating hyperpigmentation. The skin then suffers the effects of photosensitisation, also known as phototoxicity.
Lesions and scars also predispose the skin to the formation of pigment spots. This is without forgetting friction, mechanical rubbing of textiles (clothing) and the effects of hair removal.
The market for active ingredients acting on skin pigmentation is growing rapidly and will reach up to 8 billion euros by 2026. The active ingredients developed are increasingly aimed at combating pigmentation defects (hypo- and hyper-pigmentation), and not the complexion in general.
Discover the company Phenocell
Phenocell is a CRO (contract research organisation) that dedicates its know-how to the fields of dermatology and ophthalmology. Tailor-made in-vitro tests are carried out with the aim of offering solutions adapted to the most specific needs, thanks to state-of-the-art analytical equipment.
What role can Phenocell’s technology play in skin pigmentation?
Thanks to its technology, Phenocell is able to reproduce in vitro the cells that play a central role in skin pigmentation: the melanocytes. These can be obtained for Caucasian, Asian and African skin types.
A set of in vitro tests for the development of pro- or de-pigmenting actives is available via our testing platform.
Because beauty is also about respecting pigmentation, it is relevant to rely on the research results of an ethnic dermatological project.