Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our ...Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9<sup>th</sup> edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. .展开更多
Background: Sugar moiety of macromolecules is today very well known for its implications in many biological recognition mechanisms including cell-cell, extracellular matrix-cell and/or bacteria-cell interactions. In t...Background: Sugar moiety of macromolecules is today very well known for its implications in many biological recognition mechanisms including cell-cell, extracellular matrix-cell and/or bacteria-cell interactions. In this context lectins, which are carbohydrate-binding proteins displaying a high affinity for sugar groups of other molecules, are of a great importance, notably in immune response involving bacteria, viruses and fungi. As protein-carbohydrate interactions are often mediated by ions such as calcium, zinc or magnesium, we were prompted to study the effect of a thermal spring water (which contains this type of component) on interactions existing between: 1) osidic receptors of human normal keratinocytes and 2) two lectins greatly implicated in the immune response mechanisms (i.e. the dectin-1 and the langerin), and their ligands. Materials and Methods: In a first series of experiments, we studied the effect of increasing concentrations of a thermal spring water on interactions existing between glycosylated molecules and the osidic receptors expressed at the normal human keratinocytes surface. In a second step, and in order to better understand the putative effect of our thermal spring water on the immune response, we analyzed its effect on the interactions existing between the dectin-1 (implicated in the recognition of bacteria, viruses and fungi) and the langerin (expressed by Langerhans cells, the immune cells of the cutaneous tissue), and their ligands in a model using recombinant human lectins and appropriate binding molecules. Results: We showed here that our thermal spring water was able to reinforce interactions between keratinocytes osidic receptors and some of their ligands, in a dose-related manner: From 8% to 55% of increase with 10% to 30% (v/v) of thermal spring water. In the second part of our studies, we also showed that our thermal spring water was able to modulate interactions between dectin-1 and langerin and their ligands through a biphasic effect: Interactions were enhanced by more than 40% and 20% respectively with 10% of thermal spring water, and return to their basal level or lower for higher concentrations. Conclusion: The tested thermal spring water, probably due to its ionic composition, could significantly affect interactions of osidic receptors with their ligands. This property could be of a great interest to help immune system to maintain an appropriate “vigilance state” by using the thermal water at up to a concentration of 10%, and by avoiding any runaway reaction in case of aggression, by using concentrations higher than 10%. .展开更多
<strong>Background:</strong> Dexpanthenol containing formula (BEPANTHEN<sup>®</sup>), formulated as a water in oil preparation, is currently widely marketed as a diaper care product aiming...<strong>Background:</strong> Dexpanthenol containing formula (BEPANTHEN<sup>®</sup>), formulated as a water in oil preparation, is currently widely marketed as a diaper care product aiming to protect baby’s buttocks and repair diaper dermatitis. Dexpanthenol is a well-known moisturizer with barrier-improving properties and the oily phase of the water in oil preparation forms a lipophilic film on the skin surface that isolates the skin from irritants (feces and urine). Prolonged contact with irritants triggers a local inflammation cascade responsible for the cutaneous erythema. To further investigate the protective properties of skin barrier preparations, we took advantage of an <i>ex vivo</i> model of healthy human skin discs especially designed to evaluate protective and/or repairing effects of topical preparations recommended for baby’s buttocks through the measurement of interleukin-1 alpha release (a cytokine considered as the <em>Primum movens</em> of the skin inflammatory reaction), following the application of different irritants. <strong>Methods: </strong>Healthy human skin discs have been incubated in the absence (control) or in the presence of two irritants,<em> i.e.</em> a “urine like + urease” preparation and sodium dodecyl sulfate, and in the presence of three ointments, one containing dexpanthenol, but not the other two. At the end of the incubation period, interleukin-1 alpha (IL-1<em>α</em>) was quantified in the explants culture media.<strong> Results: </strong>“Urine like + urease” preparation (ULU) and sodium dodecyl sulfate (SDS) both increased IL-1<em>α</em> production of skin explants by 181.1% (p < 0.001) and 88.3% (p < 0.001), respectively. The dexpanthenol containing formula significantly inhibited the ULU- and the SDS-induced IL-1<em>α</em> release by 67.42% (p < 0.001) and 46.55% (p < 0.001), respectively. Under the same experimental conditions, one of the formulas without dexpanthenol significantly inhibited the ULU-induced IL-1<em>α</em> release by 45.94% (p < 0.01) but not the SDS-induced one, and the other tested formulation displayed no significant effect on the IL-1<em>α</em> production regardless of the irritant applied. Moreover, the effect of the dexpanthenol containing formula on the ULU-induced IL-1<em>α</em> release was significantly higher than the effect of the other formula;a difference of 19.6 % (p < 0.05) was observed.<strong> Conclusion: </strong>Dexpanthenol containing formula (BEPANTHEN<sup>®</sup>) provides good protection of baby’s buttocks against irritants. Its protective effect seems to be superior compared with other products, which did not contain this ingredient. Moreover, the results obtained in the present study suggest that dexpanthenol displays <i>per se</i> a real IL-1<em>α</em> production inhibitory effect. This work, however, consists of preliminary studies and additional investigations involving more formulas and end-points such as the quantification of other pro- or anti-inflammatory cytokines and/or resolvins for example, are needed to better understand the cutaneous protective effect of dexpanthenol.展开更多
<strong>Background:</strong> Titanium dioxide and zinc oxide were often criticized over the last decade because of their supposed noxious effects on human health. Moreover, these compounds which are freque...<strong>Background:</strong> Titanium dioxide and zinc oxide were often criticized over the last decade because of their supposed noxious effects on human health. Moreover, these compounds which are frequently introduced in sunscreen products as UV filter, are sometimes associated with poor UVA protection factors. So, in order to clarify the real efficacy and safety status of these products, we provide here some bibliographic and experimental data regarding 1) their “real” protective effect against UVA rays and 2) their real harmful effects on human skin notably by studying their capability to penetrate through the human cutaneous tissue. <strong>Materials and Methods:</strong> We studied here 4 sunscreen products containing titanium dioxide and zinc oxide for 3 of them. First, because the UVA-PF values obtained for these compounds by using the “classical” <em>in vitro</em> ISO 24443 procedure seem to be significantly different from to those obtained by using the <em>in vivo</em> method ISO 24442, we chose to develop a new <em>in vitro</em> methodology in order to more precisely define the UVA-PF of titanium and zinc oxides. This new methodology was then used to lead UVA-PF studies with the 4 selected solar products. We also provide here an evaluation of the toxicological effects of titanium and zinc oxides on human skin based on the SCCS reports and analysis of recent and relevant bibliographic studies. Moreover, as the harmful effects of this type of products are closely linked to their ability to penetrate cutaneous tissue, we tested 7 sunscreen products to precise the skin penetration profiles of titanium dioxide and zinc oxide by using human skin explants mounted on Franz cells. <strong>Results:</strong> We here demonstrated that our new <em>in vitro</em> methodology gave some UVA-PF values very close to those obtained with <em>in vivo</em> methods and we took advantage of it to define more realistic UVA-PF for titanium dioxide and zinc oxide. Additionally, we here evaluated the human skin permeation and resorption capacities of titanium dioxide and zinc oxide incorporated in the 7 tested products. As it was defined by World Health Organization (WHO) in 2005, permeation consists in the ability for a compound to penetrate into different layers of a tissue, and the resorption consists in the absorption of this compound into the vascular system. In our experimental conditions, we showed 1) that zinc oxide and titanium dioxide permeations did not exceed 8.5 and 5.5 μg/cm<sup>2</sup> of skin respectively (<em>i.e.</em> 0.89% and 0.26% of the applied product, respectively), and 2) that their resorptions were not significantly different from zero. As a consequence, we can assume that the supposed harmful effects of titanium dioxide and zinc oxide on cutaneous tissue could not be observed following the use of the tested solar products. <strong>Conclusion:</strong> Regarding their efficacy, we here provide, by using a new <em>in vitro</em> methodology for UVA-PF measurements (which is also very efficient to determine SPF), new evidence showing that titanium dioxide and zinc oxide could constitute “good” UV filters. In addition, our work with Franz cells reinforces the fact these compounds can be safely used for human skin solar protection.展开更多
文摘Background: Cosmetic formulations, and particularly solar products which contain mineral and chemical UV-filters, are often suspected of causing harmful effects on marine fauna and flora. After the publication of our work in 2019 concerning the ecotoxicological effects of such formulations on corals (Seriatopora hystrix), we here provide some new information about the biodegradability and the ecotoxicological effects of these products on marine zoo- and phytoplankton. Therefore, we choose to realize in silico and in vitro studies of the biodegradability of several solar products but also to evaluate the ecotoxicological effects of these products on one phytoplankton, i.e. Phaeodactylum tricornutum, and one zooplankton, i.e. Acartia tonsa, of a great importance for sea species survival (notably as sources of food). Materials and methods: Two different approaches were used to study the biodegradability of the tested products: One in silico method and an in vitro one. 2 solar products were involved in the in silico study which consisted in the determination of the degradation factor (DF) of each ingredient of the tested formulas in order to finally obtain their estimated biodegradability percentage. Already available data concerning each ingredient coupled to a computer model developed with one of our partners were used to achieve this study. The in vitro study involved 8 formulas containing UV-filters and was led by following the OECD 301 F guidelines. Ecotoxicological studies of 7 of the formulas containing UV-filters were for their part realized by following the ISO 10253 guidelines for the experiments led with Phaeodactylum tricornutum, and the ISO 14669 guidelines for the experiments led with Acartia tonsa. In these studies, the effect of each tested product on crustaceans’ mortality and algal growth inhibition was assessed. Results: The in silico study predicted that formulas containing chemical UV-filters display a high biodegradability (superior to the threshold value of 60% given by the OECD 301 F guidelines). In the in vitro part of our work, the 8 tested formulas showed a biodegradability slightly inferior to the one predicted in the in silico experiments. Therefore, in order to evaluate if these calculated biodegradability value could have significant harmful effects on zoo- or phytoplankton, we studied the effect of our products regarding the growth inhibition on Phaeodactylum tricornutum and the mortality on Acartia tonsa. In this last part of the study, all the tested products were classified as “non ecotoxic” following an internal classification based on Part 4 entitled “Environmental Hazards” of Globally Harmonized System of Classification and Labelling of Chemicals (GHS), 9<sup>th</sup> edition (2021). Conclusions: These results are notably in line with those published by our teams in 2019 on the effects of solar cosmetic products on corals and seem to confirm that formulas containing mineral and chemical UV-filters can be daily used without displaying significant noxious effects on marine fauna and flora. .
文摘Background: Sugar moiety of macromolecules is today very well known for its implications in many biological recognition mechanisms including cell-cell, extracellular matrix-cell and/or bacteria-cell interactions. In this context lectins, which are carbohydrate-binding proteins displaying a high affinity for sugar groups of other molecules, are of a great importance, notably in immune response involving bacteria, viruses and fungi. As protein-carbohydrate interactions are often mediated by ions such as calcium, zinc or magnesium, we were prompted to study the effect of a thermal spring water (which contains this type of component) on interactions existing between: 1) osidic receptors of human normal keratinocytes and 2) two lectins greatly implicated in the immune response mechanisms (i.e. the dectin-1 and the langerin), and their ligands. Materials and Methods: In a first series of experiments, we studied the effect of increasing concentrations of a thermal spring water on interactions existing between glycosylated molecules and the osidic receptors expressed at the normal human keratinocytes surface. In a second step, and in order to better understand the putative effect of our thermal spring water on the immune response, we analyzed its effect on the interactions existing between the dectin-1 (implicated in the recognition of bacteria, viruses and fungi) and the langerin (expressed by Langerhans cells, the immune cells of the cutaneous tissue), and their ligands in a model using recombinant human lectins and appropriate binding molecules. Results: We showed here that our thermal spring water was able to reinforce interactions between keratinocytes osidic receptors and some of their ligands, in a dose-related manner: From 8% to 55% of increase with 10% to 30% (v/v) of thermal spring water. In the second part of our studies, we also showed that our thermal spring water was able to modulate interactions between dectin-1 and langerin and their ligands through a biphasic effect: Interactions were enhanced by more than 40% and 20% respectively with 10% of thermal spring water, and return to their basal level or lower for higher concentrations. Conclusion: The tested thermal spring water, probably due to its ionic composition, could significantly affect interactions of osidic receptors with their ligands. This property could be of a great interest to help immune system to maintain an appropriate “vigilance state” by using the thermal water at up to a concentration of 10%, and by avoiding any runaway reaction in case of aggression, by using concentrations higher than 10%. .
文摘<strong>Background:</strong> Dexpanthenol containing formula (BEPANTHEN<sup>®</sup>), formulated as a water in oil preparation, is currently widely marketed as a diaper care product aiming to protect baby’s buttocks and repair diaper dermatitis. Dexpanthenol is a well-known moisturizer with barrier-improving properties and the oily phase of the water in oil preparation forms a lipophilic film on the skin surface that isolates the skin from irritants (feces and urine). Prolonged contact with irritants triggers a local inflammation cascade responsible for the cutaneous erythema. To further investigate the protective properties of skin barrier preparations, we took advantage of an <i>ex vivo</i> model of healthy human skin discs especially designed to evaluate protective and/or repairing effects of topical preparations recommended for baby’s buttocks through the measurement of interleukin-1 alpha release (a cytokine considered as the <em>Primum movens</em> of the skin inflammatory reaction), following the application of different irritants. <strong>Methods: </strong>Healthy human skin discs have been incubated in the absence (control) or in the presence of two irritants,<em> i.e.</em> a “urine like + urease” preparation and sodium dodecyl sulfate, and in the presence of three ointments, one containing dexpanthenol, but not the other two. At the end of the incubation period, interleukin-1 alpha (IL-1<em>α</em>) was quantified in the explants culture media.<strong> Results: </strong>“Urine like + urease” preparation (ULU) and sodium dodecyl sulfate (SDS) both increased IL-1<em>α</em> production of skin explants by 181.1% (p < 0.001) and 88.3% (p < 0.001), respectively. The dexpanthenol containing formula significantly inhibited the ULU- and the SDS-induced IL-1<em>α</em> release by 67.42% (p < 0.001) and 46.55% (p < 0.001), respectively. Under the same experimental conditions, one of the formulas without dexpanthenol significantly inhibited the ULU-induced IL-1<em>α</em> release by 45.94% (p < 0.01) but not the SDS-induced one, and the other tested formulation displayed no significant effect on the IL-1<em>α</em> production regardless of the irritant applied. Moreover, the effect of the dexpanthenol containing formula on the ULU-induced IL-1<em>α</em> release was significantly higher than the effect of the other formula;a difference of 19.6 % (p < 0.05) was observed.<strong> Conclusion: </strong>Dexpanthenol containing formula (BEPANTHEN<sup>®</sup>) provides good protection of baby’s buttocks against irritants. Its protective effect seems to be superior compared with other products, which did not contain this ingredient. Moreover, the results obtained in the present study suggest that dexpanthenol displays <i>per se</i> a real IL-1<em>α</em> production inhibitory effect. This work, however, consists of preliminary studies and additional investigations involving more formulas and end-points such as the quantification of other pro- or anti-inflammatory cytokines and/or resolvins for example, are needed to better understand the cutaneous protective effect of dexpanthenol.
文摘<strong>Background:</strong> Titanium dioxide and zinc oxide were often criticized over the last decade because of their supposed noxious effects on human health. Moreover, these compounds which are frequently introduced in sunscreen products as UV filter, are sometimes associated with poor UVA protection factors. So, in order to clarify the real efficacy and safety status of these products, we provide here some bibliographic and experimental data regarding 1) their “real” protective effect against UVA rays and 2) their real harmful effects on human skin notably by studying their capability to penetrate through the human cutaneous tissue. <strong>Materials and Methods:</strong> We studied here 4 sunscreen products containing titanium dioxide and zinc oxide for 3 of them. First, because the UVA-PF values obtained for these compounds by using the “classical” <em>in vitro</em> ISO 24443 procedure seem to be significantly different from to those obtained by using the <em>in vivo</em> method ISO 24442, we chose to develop a new <em>in vitro</em> methodology in order to more precisely define the UVA-PF of titanium and zinc oxides. This new methodology was then used to lead UVA-PF studies with the 4 selected solar products. We also provide here an evaluation of the toxicological effects of titanium and zinc oxides on human skin based on the SCCS reports and analysis of recent and relevant bibliographic studies. Moreover, as the harmful effects of this type of products are closely linked to their ability to penetrate cutaneous tissue, we tested 7 sunscreen products to precise the skin penetration profiles of titanium dioxide and zinc oxide by using human skin explants mounted on Franz cells. <strong>Results:</strong> We here demonstrated that our new <em>in vitro</em> methodology gave some UVA-PF values very close to those obtained with <em>in vivo</em> methods and we took advantage of it to define more realistic UVA-PF for titanium dioxide and zinc oxide. Additionally, we here evaluated the human skin permeation and resorption capacities of titanium dioxide and zinc oxide incorporated in the 7 tested products. As it was defined by World Health Organization (WHO) in 2005, permeation consists in the ability for a compound to penetrate into different layers of a tissue, and the resorption consists in the absorption of this compound into the vascular system. In our experimental conditions, we showed 1) that zinc oxide and titanium dioxide permeations did not exceed 8.5 and 5.5 μg/cm<sup>2</sup> of skin respectively (<em>i.e.</em> 0.89% and 0.26% of the applied product, respectively), and 2) that their resorptions were not significantly different from zero. As a consequence, we can assume that the supposed harmful effects of titanium dioxide and zinc oxide on cutaneous tissue could not be observed following the use of the tested solar products. <strong>Conclusion:</strong> Regarding their efficacy, we here provide, by using a new <em>in vitro</em> methodology for UVA-PF measurements (which is also very efficient to determine SPF), new evidence showing that titanium dioxide and zinc oxide could constitute “good” UV filters. In addition, our work with Franz cells reinforces the fact these compounds can be safely used for human skin solar protection.
