The skin and chronobiology

The skin goes through different phases in 24 hours. During the day, it defends itself against external aggressions like the wind, the sun, the cold, or pollution. At night, it regenerates. It was evidenced that the highest number of cell divisions occurs between midnight and 1am, and the lowest between 12pm and 1pm. The skin’s blood flow is at its maximum between 11pm and 4am, which makes it possible to provide nutrients and remove toxins. And it is between 7pm and 11pm that desquamation on the superficial stratum corneum is the most important. In addition, the skin has receptors for melatonin which, on top of their role as circadian synchronizers, are excellent at trapping free radicals. In the late 1990s, researchers highlighted the existence of the ‘Clock’ gene as a central regulator for monitoring the circadian clock.

According to Neil Astles, Marketing Manager for biofunctional actives at Ashland Specialty Ingredients, “more than 20% of the expression of a tissue’s genes depends on circadian regulation”.

Actives in line with circadian rhythms

Given these observations, cosmetic active suppliers have been developing various types of molecules.

Some of them target circadian genes and help them resynchronize, like Chronocyclin®, by Exsymol, which can partially reproduce the effect of sun radiation in relation to the expression of circadian genes. The chrono-peptide studied on reconstructed epidermises kept in the dark shows an activation of the Clock and Period1 genes according to a circadian rhythm similar to the activation initiated by UV radiation. The Chronocyclin® product is an anti-aging active that stimulates defence and cell regeneration physiological activities. As for Nocturshape™, by Lipotec, it focuses on circadian genes Clock and Bmal1 and on the regulation of the production of nocturnin, a protein that acts at night and enhances both the accumulation of lipids in the cells and lipogenesis. Nocturshape™ has firming and slimming properties. Silab’s Circagenyl® is rich in lindera oligo-alpha-glucans and helps fight against the desynchronization of the human fibroblasts circadian clock by acting on the expression of the Clock circadian gene. The effects measured are comparable to those obtained with a light therapy treatment and boosted if the two routes of administration are combined: application of a topical product with 3% of Circagenyl® associated with light therapy sessions. The results show increased skin hydration, tone and elasticity, smoother microrelief, and a more radiant complexion.

Boosted melatonin

Another way to tackle chronocosmetology is to act on the synthesis of melatonin. With Prodizia®, Sederma manages to rebalance the synthesis of this hormone by glycation-stressed fibroblasts. Prodizia® contributes to visibly reducing the signs of fatigue by repairing and protecting the skin from the damages caused by glycation, leaving the skin rested, just like after a good night’s sleep.

Cell vitality and protection against daily aggressions

Lastly, another method consists in helping the cells keep their energy so they can better resist against daily aggressions. Active molecules mainly act on mitochondria. Seppic’s Sepitonic M3 is a combination of minerals essential for the balance of cells and organic anions, for a chrono-energizing, anti-free radical, intercellular communication-boosting effect.

Specific cosmetic products

The will to develop chronocosmetology is gaining more and more importance, especially with the emergence of Sleeping packs. These products from Korea offer the perfect solution to counter the effects of lack of sleep on the skin, and promise to reproduce the virtues of a good night’s sleep, even if it only lasted a few hours.

In Asia, it is said that the first three hours of sleep, called ‘Golden Time’, are the most important for the skin. In Korea, there is also an expression, meaning ‘well-slept face’, to refer to a beautiful face. It is conveyed by the face of a sleeping woman”, explains Florence Bernardin, expert in Asian cosmetics trends and founder of the Information & Inspiration marketing intelligence firm.

Vichy and Garnier have developed sleeping packs, respectively with Idealia Skin Sleep and Miracle Sleeping Cream. But other sectors like the slimming segment are also targeting the sleeping body, more sensitive to fat storage, as can be seen in particular with Phytocéane’s Chrono Night Express Contouring Bi-Gel.

With these products, no one will ever worry about the consequences of the legal time change on the skin, and even less about short nights!