ANTI-POLLUTION 51 a b c


d


e


f


Figure 5: Expression of cytokeratins under pollutants. a) non-treated keratinocytes (control), b) keratinocytes +sulfuric acid (1mg/1ml), c) keratinocytes +sulfuric acid (1mg/1ml) +4% Padina active, d) Skin at D0 (control), e) Skin with cream + 1% Sulfuric acid D8, f) Skin with cream + 1% Sulfuric acid + 4% Padina active D8.


junction structures that allow keratinocytes to adhere to one another and resist mechanical tractions: they ensure the epidermis resistance. With age, their number lessens, which is one factor of the skin ageing process. A first evaluation was made in vitro on


keratinocytes treated or not with Padina active at 0.4% by ELISA immunoenzymatic technique (Fig 2). The second test in using several concentrations of Padina active incubated during 72 hours at 37°C, and rinsed, cells are then fixed and kept at 4°C. Desmosomial proteins are made visual with the indirect immunofluorescence technique by using an anti-desmosome antibody (Fig 3). The tests show an increase of 85% in the


synthesis of keratins in presence of Padina active compared to the control and a dose- dependent increase in the expression of desmosomes under the effect of Padina active.


Efficient skin barrier even in pollution conditions (ex vivo & in vitro tests) Epidermis is the only physical barrier to the external environment and must therefore be particularly resistant to protect the skin against the deleterious effects of urban pollutants


a


(industrial smokes, acid rain, tobacco, exhaust gases, etc.). Under such conditions, the skin needs to be actively protected through the maintenance of essential proteins ensuring the cohesion and the resistance of the epidermis to keep a good cell metabolism and to fight against skin destructuring. In order to reconstitute environmental


pollution conditions, cells and skin explants are treated with a cream containing 1% of polluting agents (sulphuric acid or nicotine) alone or with 4% of Padina active. Sulphuric acid is a polluting agent contained in exhaust gas and industrial smoke. A number of scientists connects it to the premature ageing of the skin in cities. Nicotine is a component of the tobacco pollution. It would have a deleterious effect on the skin by activating enzymes responsible for the degradation of the intercellular cement and by damaging the junction structures of keratinocytes. The expression of desmosomes was


studied on skin explants under nicotine pollutant (Fig 4). The test shows an increase in desmosomes synthesis compared to the control even under pollution. The expression of cytokeratins by


b


keratinocytes was studied ex vivo andin vitro to highlight the action of Padina active on cell architecture in presence of pollutants (sulphuric acid). Cytokeratins are made visual by the indirect immunofluorescence technique, using an anti-cytokeratin antibody (Fig 5). When keratinocytes are treated with


sulphuric acid, the fluorescence intensity weakens, meaning a lesser expression of cytokeratins. The presence of Padina active restores the fluorescence intensity, proving that it efficiently fights the deleterious effect of the polluting agent (Fig 5). Observation of skin explants highlights that in presence of sulphuric acid, the fluorescence is only observed in the deepest layers of the epidermis. On the contrary, when the skin explants are treated with the cream containing Padina active, the fluorescence is more intense and distributed in the whole thickness of the epidermis. When skin explants are treated with the


cream containing nicotine only, the epidermis is considerably thinner than the control and presents only 2 to 3 cell layers in some places. When the explants are treated with the cream containing Padina active, the


c


Figure 6: Epidermis global structure.a) Skin at D0 - control, b) Cream with 1% nicotine D8, c) Cream with 1% nicotine + 4% Padina active. November 2020 PERSONAL CARE ASIA PACIFIC


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