Free radicals and ageing: a new look at anti-oxidant use in cosmetics formulations

Free radicals and ageing: a new look at anti-oxidant use in cosmetics formulations

02 April 2019, 09:30 - 13:00

Workshop Room 1

Anti-oxidants in cosmetic products: what are they good for? The number of articles found in Medline data bases claiming “potential anti-age” activity of plant extracts and/or specific metabolites, continues to grow. However almost all these publications present data obtained only in vitro on various cellular components and biomarkers. What is the evidence of their benefits on human skin ageing?

A review of the most recent theories of Free Radical (ROS) research will introduce the topics of the workshop:

  • The discovery that ROS correlate more with tissue - and organ frailty than with age, opening a new path to study and claim anti-oxidant benefits in vivo
  • The detailed story of how to develop efficient anti-oxidants
  • The story of a new bi-functional anti-oxidant, the evidence that ROS may also have unsuspected beneficial sides, e.g. extending (rather than shortening) cellular life span, making the indiscriminate use of antioxidants a question of dosage (the hormesis concept)…

Expected take home messages
: While the idea of preventing ROS-induced skin damages is a reasonable approach to skin health maintenance, claiming significant benefits of “anti-oxidants” without relevant, vehicle controlled long term clinical studies can no longer be considered state of the art. The field requires greater investment in evidence based research.

09:30 - 10:00     Introduction
Dr. Karl Lintner, Presient, KAL'IDEES

1962: A.J. Norins (J. Inv. Dermatol.): “The purpose of this investigation is to determine whether free radicals are produced when the skin is irradiated with ultraviolet light. […].Melanin has a strange property of acting as a free radical trap. Both the sulfhydryl and melanin compounds are known to protect against irradiation damage. The mechanism of the protection may be due to this property of effectively diminishing the free radical pool”

2018: E.V. Silina et al. (J. Clin. Cosmet Invest. Dermatol): “The purpose of this study was to examine the role of free radical oxygen and peroxide-lipid processes along with conducting the study of blood flow level and oxygen saturation of facial tissues in patients of different ages with varying degrees of involutional changes in the skin of the face and neck.[…]. The tissue metabolism and microcirculation parameters naturally regress with aging, which is associated with the increase of ROS. The excess of species leads to the intensification of peroxide processes. This, in turn, is reflected in the aesthetic appearance manifested by aging.”

The big question thus is, as always: So what’s new in the field, if anything? From the 1962 paper and similar studies emerged the ‘Free radical theory of ageing” first mentioned in 1977. Is it still valid? Presenters will explain their different points of view. I will attempt a somewhat provocative mathematical approach to the question: how to reduce the noxious effect of stress-induced ROS for extending life span, with cosmetic means?

10:00 - 10:45     Anti-oxidant/anti-pollution protective skin benefits of an original H. procumbens stem cell extract.
Dr. Alain Mavon, Senior Director of Science & Innovation, Oriflame

Recent research shows an increased role of pollution is skin-induced oxidative stress, well-known as being one of the main factors affecting skin health and accelerating aging. With the rise in the demand of natural bioactive compounds, we developed an enriched antioxidant -plant stem cell- extract from Harpagophytum procumbens. After challenging steps to ensure a constant proliferative rate, a stable phenotypic characteristics and reproducible secondary metabolite profile, a stable cell line has been established with an enriched phenylethanoids secondary metabolites content.

The enriched antioxidant extract shows strong biological activities on skin cells and reconstituted epidermis, such as inhibition of pollution induced MMP-1, UV-induced melanin and anti-glycation, making it as a highly promising multifunctional & antipollution active [1]. The following steps aim at defining appropriate formulations, explore delivery routes and validate clinical efficacy.
1. The Roles of Vitamin C in Skin Health, Juliet M. Pullar, Nutrients 2017, 9, 866.

10:45 - 11:20     A new strategy to combine antioxidants and enhance synergy
Prof. Dominique Vichard, Professor - Researcher, University of Versailles

Additives are commonly used to protect both actives and formulas. Among them, butylhydroxytoluene BHT is one of the major synthetic antioxidants which is used to preserve cosmetics and fragrances. However the question of its substitution is highly debated and the main alternative is focused on mixtures of natural or synthetic antioxidants. A combination of these ingredients often works synergistically better than the isolated components. But these "cocktails", involving several compounds, are submitted to more and more regulations, as well as negative views from clients and customers. Thus, the search of new innovative and more environmentally-friendly raw materials is very challenging.

The objective of our research was the identification and synthesis of new plurifunctional molecules with variable solubility that can act on several stabilization pathways. A series of products was obtained and characterized, whereas the solubility and efficiency of the molecules have been studied in the main solvents used in Fine Fragrance and Personal Care.  The results showed that this innovative strategy was able to tune antioxidant structure to modulate their properties, leading to "multifunctional antioxidants". This concept could be enlarged to further functional additives.

11:20 - 11:40     Coffee & networking break

11:40 - 12:15     A free radical theory of frailty
Dr. Consuelo Borras, Lecturer, University of Valencia

The free radical theory of ageing provided an intellectual framework for many laboratories working on ageing. However, experimental and clinical evidence showing that high doses of antioxidants do not have an effect on ageing or on age-associated diseases, cast doubts on the validity of this theory.

Data from our own laboratory show that oxidative damage does not correlate with age, especially in the geriatric population, but rather with the frailty state. This has led us to postulate the free radical theory of frailty that proposes that oxidative damage is associated with frailty, but not with chronological age itself. Superoxide dismutase deficient mice are more frail than controls. But more importantly, we have observed that animals that are protected against oxidative damage by overexpression of antioxidant enzymes, delay the onset of frailty and are more vigorous than controls.

It will be described results from both, experimental animals and human cohorts, that lead us to the formulate this free radical theory of frailty.

12:45 - 12:50     Measurement of skin antioxidant activity by the PAOT-Skin® Technology. Relationship with various biomarkers of oxidative stress.
Dr. Joël Pincemail, Scientific Collaborator, CHU Liège

Oxidative stress (OS) has been defined as an imbalance between reactive oxygen species or ROS (including free radical and non-free radical species) and antioxidants in favor of the formers, leading to a disruption of the redox signaling and/or molecular damage to lipids, proteins and DNA. A promising but always under- explored way to evidence OS is to use skin as a matrix. Having the largest surface area in the body, skin is a major target for oxidative stress, as it is continually exposed to external aggressions.

The present talk is devoted to the potential use of the PAOT-Skin® technology based on electrochemical application for evidencing OS in a non-invasive way in the skin matrix. Data related to robustness and validation of the method will be examined and a study on 30 healthy subjects will be presented. Significant negative correlations (PAOT-skin score® vs. blood lipid peroxides, copper, the Cu / Zn ratio, oxidized DNA/creatinine ratio) and positive correlations (-tocopherol/-tocopherol ratio, polyphenol/creatinine) were found.

Further studies are under investigation to test PAOT-skin score® in populations known to be submitted to high OS such as smokers or patients having type II diabetes, cardiovascular diseases or cancer.

12:50 - 13:00     Discussion & Conclusion


  • Dr. Karl Lintner




    Dr. Karl LINTNER obtained a Degree in Chemical Engineering from Vienna University (Austria) and a PhD in Biochemistry from the same University. After...

  • Dr. Alain Mavon


    Senior Director of Science & Innovation


    Alain owns a MSc. in Biochemistry and Physico-chemistry and a Ph.D degree from Dermatology Unit at University Hospital, Besancon, FR. Prior to join...

  • Prof. Dominique Vichard


    Professor - Researcher

    University of Versailles

    Dr. Dominique VICHARD obtained a Chemical Engineer Degree from Chimie Paris Tech (ENSCP) and a PhD in Organic Chemistry from the Pierre and Marie...

  • Dr. Consuelo Borras



    University of Valencia

    Lecturer of the Department of Physiology of the University of Valencia 80 indexed publications, index h 34, Principal investigator of several...

  • Dr. Joël Pincemail


    Scientific Collaborator

    CHU Liège

    Joël Pincemail has a PhD in Biomedical Sciences from the University of Liège, Belgium. Presently, he works as scientific collaborator in the...

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