ANTI-AGEING
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100 80 60 40 20 0
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0.1% G+Complex CLR
damage also stands at the basis of skin ageing.9 Skin is the outermost barrier for our body and, as such, exposed to external stresses, the so- called exposome.10 Consequentially, skin is the tissue which
accumulates most DNA damage of all tissues in the human body. Indeed, the skin of some people ages more slowly than others, due to its endogenous ability to repair DNA more efficiently, but external stresses easily ‘overwhelm’ this ability, especially UV light originating from the sun. It is elegantly described in a paper by
Ichihashi that the mean daily sun exposure time to maintain healthy skin until 80 years of age in the summer was calculated to be just 2.54 minutes per day, comprising about 0.14 MED (Minimal Erythemal Dose), during the whole lifetime.11
Maximum 2.54 minutes
of sun exposure daily is something which is virtually impossible to comply to, at least partly explaining the consumer interest in using anti- ageing skincare products. A paper by Guyuron et al, ‘Factors
contributing to the facial aging of identical twins’, gives interesting insights.12
Indeed, the
ability to repair DNA is an inherent quality of ‘good agers’ such as described above, but the effect of sun exposure being able to inundate this quality is dramatic. This study describes identical twins, i.e., two
people with the same genetic make-up and, therefore, genetically, identical ability to repair DNA. The twin which is exposed to UV light more than the other twin clearly looks older. Skin shows uneven coloration, sagging and wrinkling, making the person look 11.25 years older than her twin sister.
Towards effective anti-ageing skincare Anti-ageing skincare products, ideally, should support the skin cells in maintaining the quality of their nuclear DNA. Of all the factors in the exposome, UV radiation from the sun is the most important factor in accelerating the ageing process due to its inherent ability to ‘overwhelm’ the endogenous DNA repair mechanisms in skin cells. Hence the term
www.personalcaremagazine.com 0.5% 1.5% Figure 1: G+C Complex CLR reduces UV-induced immunosuppression
-10 -20 -30 -40 -50
G+Complex CLR (1%) vs. UV incl. UV irradiation ■ Increase UV vs. non-UV ■ Figure 2: G+C Complex CLR regulates the skin’s circadian rhythm
‘photoageing.’ This merits different questions that need to
be asked when wanting to provide an effective solution with a cosmetic skincare product. On the one hand, UV radiation induces DNA damage. On the other hand, exposure to UV radiation
negatively affects the DNA repair mechanisms. Such questions are: What is the nature of the DNA mutations? What negative effects does exposure to UV radiation have on the ability of skin cells to repair their DNA? UV radiation can lead to different types of
lesions in the nuclear DNA of skin cells, such as cyclobutane pyrimidine dimers (CPDs), 6-4 photoproducts, 8-oxo-7,8-dihydro-2- deoxyguanosine, strand breaks etc. These mutations have different
consequences and are repaired with varying efficiency. Scientific literature shows that CPD’s are the predominant lesions in exposed to UVA and UVB radiation, though, which merits a focus on these for anti-ageing skincare. As described above, mutations in DNA are
a given. It is the ability to repair damaged DNA which enables good and healthy ageing for any human being. Exposure to UV radiation has some negative implications to this feature for skin cells, though. UV radiation, especially UVB radiation, has immunosuppressive effects.14, 15 Realising that DNA repair, in its essence, is an immunological process, UV-induced immunosuppression is therefore clearly unwanted. Two main cell biological players can be considered to stand at the basis of this: interleukin-10 (IL-10) and IL-12. IL-10 is an immunosuppressive cytokine of which expression is increased after UV radiation.16 IL-12 stands in competition with IL-10. IL-12 is immune-stimulating and induces DNA repair.17 Consequentially, the maintenance of a healthy balance between IL-10 and IL-12, allowing for DNA repair, overruling UV radiation-induced immunosuppression is a key goal for anti- ageing skincare. Skin cells have a molecular clock that lead
to oscillations in their physiology and behaviour with a period, which is close to 24 hours. This so-called circadian clock is finely and complexly
regulated by regulatory feedback loops, where different activators regulate DNA transcription. This transcriptional circuitry generates daily fluctuation of output genes for the regulation of cell-specific physiology, which maintains the homeostasis of the skin.18
Maintaining the
balance in the circadian clock is described to be essential for maintaining skin cells’ ability to repair DNA.19,20 Two main players in the regulatory feedback
loops in the circadian rhythm of skin cells are Per1 (Period 1) and Clock (circadian locomotor output cycles kaput protein). Maintaining a balance between Per1 and Clock is essential to maintain the ability to repair nuclear DNA effectively.19,21
Experimental CLR has developed G+C Complex CLR™ (INCI: Bifida Ferment Lysate) as a cosmetic active ingredient to provide effective support to the skin cells in increasing the ability to repair UV-induced DNA damage. Hereafter known as CPDna, it represents the latest innovation of Bifida Ferment Lysate. Earlier scientific publications from 1982 and 2008 already showed the effectiveness of Bifida Ferment Lysate for anti-ageing skincare.22,23
As such, postbiotics such as
Bifida Ferment Lysate might be a trend at the moment, but, in reality, are a type of active ingredients with a strong and proven track record in the cosmetic industry. Several cell biological and ex vivo studies
show that CPDna counteracts all most important cell biological features which accelerate skin ageing. Its effect on UV-induced immunosuppression could convincingly be shown in cell biological experiments where CPDna was able to reduce UV-induced IL-10 expression (Figure 1) and induce UV-reduced IL-12 expression (not shown). Human keratinocytes were incubated with
CPDna, after which they were irradiated with UV irradiation with 3 J/cm2
UVA + 0.3 J/cm2
UVB. Expression of IL-10 by control cells (non- treated, but irradiated) is set at 100%. Ex vivo experiments on a human skin explant were performed to assess the effect
January 2024 PERSONAL CARE
Expression of IL-10 (%)
PER 1 expression (%)
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