New Converted Ingredient for Skin Moisturizing

Novel Postbiotic-Based Ingredient for Skin Moisturisation  

Abstract

Based on probiotic fermentation technology, Symrise has developed a new postbiotic ingredient for skin care applications. The fermented ingredient has been shown to moisturise skin while simultaneously improving skin tissue quality. In addition to standard corneometric measurements, changes to the skin surface caused by this new ingredient were evaluated using a high-quality digital imaging system, and smart visualisation of product performance for skin moisturisation on hands was achieved.

Introduction

Moisturisation has long been an important cosmetic concern at the centre of marketing claims. Hand skin dehydration in particular is a common source of concern for many women, men and children, especially during winter months or when aggressive hygiene procedures are applied. Here, a new and sustainable cosmetic ingredient created through the recovery of valuable by-streams from Lactobacillus probiotic production was investigated for hand moisturisation. Moisturisation assessment is typically limited to measurement of water content in the stratum corneum. However, the objective moisturising benefit should be addressed with a more holistic approach. Indeed, changes to the skin surface that occur after using a moisturising product are of major importance from a user satisfaction perspective (increased elasticity, reduced roughness, soothing sensation and less discomfort). To add value to research into the moisturising properties of the postbiotic ingredient, a combined protocol was developed that linked standard corneometric measurement of the stratum corneum with capture and analysis of digital macro images of the same areas using a new camera providing high-resolution images, three-dimensional (3D) reconstruction of skin surface shape and objective parameters to be monitored under the moisturising effect. Skin microrelief pattern develops with intrinsic (age, dryness1,2) and extrinsic factors (UV exposure, relative humidity)3-5 and reflects the functional condition of skin.6-8 Here, we present results on hand and forearm skin with such research combined with corneometric measurements. Furthermore, the moisturising effect of the product on hands was modelled using a continuous colour mapping method that helped to objectively and successfully demonstrate differences between the formula containing the research ingredient and placebo.  

Materials and Method

An in-vivo study was conducted in winter in Paris with a panel of 13 healthy male and female subjects aged 22 to 53 years. O/W cosmetic emulsions containing 5%, 10% and 20% of the cosmetic ingredient studied (INCI: Lactobacillus Ferment, Lactic acid, Pentylene Glycol, Sodium Benzoate, 1,2-Hexanediol, Capryly Glycol) were evaluated against placebo. The ingredient is a postbiotic derived from an advanced transformation process beginning with fermentation of selected Lactobacillus strains determined to be beneficial for skin and already used in the food and health industries (Symrise AG, Holzminden, Germany and Probi AB, Lund, Sweden) (Figure 1). This process yields biomass (probiotics) and supernatant (fermentation water). The biomass is used in consumer health and food industries, but the supernatant is typically discarded. It contains both factors that enable the growth of health-related bacterial strains and micronutrients produced by Lactobacilli (amino acids, proteins, minerals and organic acids). The potential of this supernatant for skin care applications has been identified for its strong moisturising benefit and is now being evaluated in this new ingredient. [caption id="attachment_145045" align="aligncenter"] Fig. 1: Postbiotic ingredient, advanced transformation production process[/caption] In the first part of the study, the formula containing 20% of the ingredient studied and placebo were randomly applied to two defined areas on the back of the hands of volunteers. In the second part of the study, formulas containing 5% and 10% of the ingredient studied and placebo were randomly applied to a defined area on the inner forearm of subjects. Stratum corneum capacitance was measured from different defined locations on hands and forearms before and 1 hour after application of the cosmetic formulas. Image acquisition with a macro camera (SkinCam®, Newtone Technologies, Lyon, France) was performed in the same areas before application and 4 hours after capacitance measurements. To measure skin surface characteristics, 3D depth maps were calculated from 2D images of the skin surface (Fig. 2).9-11 [caption id="attachment_145046" align="aligncenter"] Fig. 2: Roughness analysis images obtained from SkinCam®; A: 2D image; B: Applied 3D image[/caption] The roughness parameter Ra, the arithmetic mean variation of surface amplitudes over the entire surface, was examined. Other roughness parameters such as average groove depth, average groove area and average peak height and peak area were also examined.

Results

Corneometric measurements confirmed the moisturising effect of the postbiotic ingredient versus placebo 1 hour after application. The increase in moisture on the hand was found to be statistically 44% higher than the hand treated with placebo. On the forearms, when emulsions containing 5% and 10% were applied, the ingredient's moisturising effect was also demonstrated with increases of 19.45% and 21.9% respectively (Fig. 3). [caption id="attachment_145048" align="aligncenter"] Fig. 3: In-vivo study, immediate improvement of skin moisturisation by corneometric measurements; A: Study on hands; B: Study on forearms.
**statistically significant versus placebo (p<0.01)
## statistically significant versus untreated (p<0.01)[/caption] Furthermore, based on roughness and microrelief pattern parameters, a statistically significant benefit of the ingredient on the skin surface was recorded 4 hours after application versus placebo (Figures 4 and 5). Notably, the Ra parameter, reflecting roughness, showed a reduction demonstrating a smoothing effect, while in placebo-treated skin this parameter increased conversely. While placebo did not counteract the natural progression of skin roughness, the formula containing the ingredient did. The benefit of the fermented ingredient was also statistically proven in the average peak height parameter versus placebo. This result confirms the effect measured across the entire analysed skin surface and brings an element to understanding the intrinsic structure of the micro-relief pattern under the effect of the ingredient. Here placebo again showed an inverse value over time. [caption id="attachment_144979" align="aligncenter"] Fig. 4: In-vivo study, improvement of skin moisturisation by skin surface texture measurements; A: Study on hands; B: Study on forearms.
** statistically significant versus placebo (p<0.01)
# statistically significant versus untreated (p<0.01)[/caption] [caption id="attachment_144980" align="aligncenter"] Fig. 5: In-vivo study, skin surface on hand, improvement of skin moisturisation with grid pattern parameter measurements; A: Average peak height; B: Average wrinkle area.
** statistically significant versus placebo (p<0.01)
μ statistically significant versus placebo (p=0.05)[/caption] These results demonstrate complementary information obtained by each of the research methods. Corneometric measurement helped to emphasise that the formula containing the fermented ingredient rapidly increased stratum corneum water content within one hour. Image analysis in turn contributed to demonstrating the persistent effect of the formula containing the new ingredient on skin surface texture quality versus placebo. To visualise corneometric values, a unique advanced algorithm was used that allowed for projection of moisturising results onto a 3D hand model. The average corneometric values obtained are an indication of the transformation of moisture at determined points on both hands based on a colour scale from grey to blue (from the lowest measured capacitance values to the highest measured values). These colour levels were mapped onto a 3D hand model for each of the measured areas and were then interpolated to cover the entire hand and reflect a holistic interpretation of these results (Fig. 6). [caption id="attachment_144982" align="aligncenter"] Fig. 6: Moisturisation results evaluated by colour mapping[/caption]  

Conclusion

Through this new integrated approach, the performance of the postbiotic ingredient on skin moisture has been demonstrated both in stratum corneum water content and in skin microrelief patterns. Interestingly, each approach generated beneficial, complementary information for skin and also demonstrated efficacy at different time points. The postbiotic ingredient has been shown to provide immediate skin moisturisation while simultaneously smoothing skin and improving its texture. This study demonstrates the positive effect of postbiotics on skin moisturisation and the importance of such ingredients for skin care. The collaborative research between Symrise and Probi focusing on probiotic Lactobacillus strains enables Symrise to determine how best to integrate new scientific data into innovative cosmetic products. Symrise benefits from the Swedish manufacturer's extensive database of bacterial strains and its ability to continuously supply high-quality probiotics in large quantities.   References 1 Corcuff P, de Rigal J, Lévêque JL, Makki S, Agache P. Skin relief and ageing. J Soc Cosmet Sci. 1983; 34: 177-190. 2 Vörös E, Robert C, Godeau G, RobertAM. Morphometric study of the evolution of the skin surface relief with age. Acta Stereol. 1989; 8: 379-380. 3 Corcuff P, Francois AM, Lévêque JL, Porte G. Microrelief changes in chronically sun-exposed human skin. Photodermatol Photoimmunol Photomed. 1988; 5: 92-95. 32 / 43 19. 4 De Paepe K, Lagarde JM, Gall Y, Roseeuw D, Rogiers V. Microrelief of the skin using a light transmission method. Arch Dermatol Res. 2000; 292: 500- 510. 5 Egawa M, Oguri M, Kuwahara T, Takahashi M. Effect of exposure of human skin to a dry environment. Skin Res Technol. 2002; 8: 212-218 6 Piérard GE, Franchimont C, Lapierre CM. Le vieillissement, son expression au niveau de la microanatomie et des propriétés physiques de la peau. Int J Cosmet Sci. 1980; 2(4), 209-214. 7 Stamatas GN, Nikolovski J, Luedtke MA, Kollias N, Wiegand BC. Infant skin microstructure assessed in vivo differs from adult skin in organization and at the cellular level. Pediatr Dermatol. 2010; 27(2),125-131. 8 Fischer TW, Wigger-Alberti W, Elsner P. Direct and non-direct measurement techniques for analysis of skin surface topography. Skin Pharmacol Appl Skin Physiol. 1999; 12(1-2): 1-11. 9 Hertzmann A, Seitz SM. Shape and Materials by Example: A Photometric Stereo Approach. Proc. 2003 IEEE Computer Society Conference on Computer Vision and Pattern Recognition.2003; 1: 533-540 10 Hertzmann A, Seitz SM. Example-Based Photometric Stereo: Shape Reconstruction with General, Varying BRDFs. IEEE Trans Pattern Anal Mach Intell. 2005; 27: 1254-1264 11 Santo H, Samejima M, Matsushita Y. Numerical shape-from-shading revisited. IPSJ Trans. Comput Vis. Appl. 2018; 10: 8       Translator and Compiler Tuğba Bayazıt Technical Application Specialist / Africa, Middle East, Turkey Team Leader Symrise   Authors Léa Schmidt, Mickael Larnicol - Symrise SAS, France Joachim Hans - Symrise AG, Germany