The press release was published in late 2015: ‘Scientifically-tested Heuliad products show no oestrogenic action, which means there is no need for their users to fear any disruption! The natural cosmetics brand based in Brittany, France, is proud to announce the results of scientific tests performed (voluntarily) on two of its products’…
Everyone knows it: disruptors are everywhere and can often be found in our daily cosmetics. Their harmful potential, in particular for foetuses and young children have already been demonstrated, but they are still very little regulated because of a lack of scientific data and/or political courage.
As a matter of fact, Heuliad chose to focus on two skincare products commonly used by pregnant women: the Crème talentueuse, a multifunctional face and hand repair cream that can also be applied on the areas affected by stretch marks, and the Soin épatant anti-taches, an anti-dark spot cream.
Yet, how can it be claimed that a product has no endocrine action today? How is it possible to search for the hundred or so molecules likely to have this type of effect, and possibly assess their interactions, commonly named the cocktail effect? What type of test enables to do that?
When asked these questions, Élise Le Pallabre, the founder of Heuliad, refers to the laboratory that performed the test at stake.
OEDT, a test for measuring oestrogenic-type endocrine disruption
Vincent Bourgeteau is at the head of Ephyla, a French laboratory dedicated to the development of actives derived from green chemistry and new formulation concepts for the cosmetics industry. And he is also the one that explained to us the history and test protocol at the root of the ‘free from endocrine disruptors’ claim.
The OEDT, or Oestrogenic Endocrine Disruptor Test, was developed in partnership with the LimatB, at the Yves Coppens Research Centre of the University of South Brittany, France. It is a biological test that required several years of research.
The principle is not to try and detect all the substances that might act as an endocrine disruptor in a product, one by one, but to target the activation of oestrogen receptors.
Why oestrogens? They lie at the core of the endocrine disruption phenomena that induce the feminization of species and reproductive disorders today, among other troubles.
The OEDT protocol involves two particular steps.
It is performed in vitro, on microtanks, and soon on microplates. It makes it possible to test a ‘pool of molecules’, which can be a cosmetic formulation or foodstuffs, a packaging or a coffee capsule… or any material or substance that can be diluted in a solvent (water, oil, or other). This ‘blind’ test can be carried out without even knowing the details of the tested product’s composition.
At this stage, scientists observe whether any bond is created on the endocrine receptors and if, in the presence of an oestrogen control, the substance tested prevents the hormone to settle on its receptor as it usually does, which would create another endocrine disruption effect.
• If none of these two phenomena occurs, the product is not likely to act as a disruptor
• Otherwise, scientists first quantify the importance of the phenomenon with the percentage of receptors affected, before they go on with the second part of the test
NB: As this test was validated by two scientific publications*, it can be used in the cosmetic Product Information File to justify the ‘free from endocrine disruptors’ claim, if the results obtained in Step 1 are satisfactory. However, Vincent Bourgeteau recommends to validate them for good, but also to make the diagnosis more accurate by performing Step 2.
It focuses on cell culture. At that stage, it is the genes of the endocrine receptors that are studied. In case of a bond between a substance and an endocrine receptor, its coding gene is activated, so it is possible to measure the activation risk or risk of path blockage and to qualify the agonist (acts like a hormone) or antagonist (paralyses the receptor) phenomenon. This step helps accurately measure the potential hazard and define risk thresholds.
OEDT, a cutting-edge test
The problem with endocrine disruptors and the concerns it raises are such that this test will no doubt attract a lot of brands willing to reassure their consumers about their products’ safety…
… especially since it is not that expensive: today, it costs about €350 per product for step 1 only, and €500 for a result confirmation with step 2. Vincent Bourgeteau hopes to be able to reduce these costs to €180 if the demand for tests allows for it.
But the test also enables to consider other possibilities of application, much beyond the ‘mere’ justification of a claim, as interesting as it is.
*Consulting in formulation**
The various results already obtained by Ephyla are also integrated to an internal database at the laboratory, with all the substances that can be characterized as endocrine disruptors. And as the OEDT makes it possible to measure the risk and concentration thresholds representing a risk, it can also be used as a basis for making safe dosage recommendations, since the renowned cocktail effect is not systematic, Vincent Bourgeteau affirms, and lower doses can sometimes reduce the risk, as it was demonstrated with parabens.
*The search for antidotes**
If cinnamon essential oil is not an endocrine disruptor, the cinnamal it contains when it is isolated is. Would it not be possible to use it, after determining appropriate doses, for example to offset an excess of oestrogens in men, when it provokes hair loss? Ephyla is also working on a similar test, but which targets androgens to better explore this possibility of development.
Besides, Vincent Bourgeteau also evokes specific molecules that are believed to prevent the endocrine disruption action of certain UV-filters, and which might be added to sun product formulas…
Or how could the public health issue of endocrine disruptors become the basis of a constructive approach to innovate and improve cosmetics formulas and their safety?
*The scientific publications
• A. Le Grand, A. Bouter, A. Couturier, O. Mulner-Lorillon, X. Le Goff, F. Cesnel , ^^ O. Sire, V. Le Tilly - Investigation of the functional properties and subcellular localization of alpha human and rainbow trout estrogen receptors within a unique yeast cellular context - Journal of Steroid Biochemistry & Molecular Biology, 149 (2015) 17–26
Adélaïde Le Grand, Gwenaëlle André-Leroux, Gaëlle Marteil, Hélène Duval, Olivier Sire, and Véronique Le Tilly - Investigating the in Vitro Thermal Stability and Conformational Flexibility of Estrogen Receptors as Potential Key Factors of Their in Vivo Activity - Biochemistry, 2015, 54 (25), pp 3890–3900