COSMETIC USE OF A SHORT CHAIN FATTY ACID (SCFA) FOR PREVENTING AND/OR TREATING DRY SKIN AND/OR AGED SKIN

Abstract

The present invention relates to the cosmetic use of at least one short chain fatty acid (SCFA) comprising from 3 to 8 carbon atoms, salts thereof, esters thereof and mixtures thereof, for preventing and/or treating dry skin and/or aged skin, in particular hyposeborrheic dry skin and/or aged skin. The present invention also relates to the cosmetic use of a conditioned culture medium obtained from at least one microorganism of the species Propionibacterium acnes, the said medium comprising at least one short chain fatty acid comprising from 3 to 8 carbon atoms, salts thereof, esters thereof and mixtures thereof, for preventing and/or treating dry skin and/or aged skin, in particular hyposeborrheic dry skin and/or aged skin.

Claims

1. A cosmetic method for preventing and/or treating dry skin and/or aged skin, which comprises applying to the skin at least one short chain fatty acid comprising from 3 to 8 carbon atoms, salts thereof, esters thereof and mixtures thereof.

2. The cosmetic method according to claim 1, wherein the short chain fatty acid is comprised in a cosmetic composition.

3. The cosmetic method according to claim 1, wherein the short chain fatty acid comprises a straight and saturated aliphatic chain containing 3 to 5 carbon atoms.

4. The cosmetic method according to claim 1, wherein the said short chain fatty acid is chosen from propionic acid, butyric acid, valeric acid, salts thereof, esters thereof and mixtures thereof.

5. The cosmetic method according to claim 1, wherein the short chain fatty acid is obtained from at least one microorganism of the species Propionibacterium acnes.

6. The cosmetic method according to claim 1, wherein the short chain fatty acid is used in an amount representing from 0.01% to 5% by weight relative to the total weight of the composition.

7. A cosmetic method for preventing and/or treating dry skin and/or aged skin, which comprises applying to the skin a conditioned culture medium obtained from at least one microorganism of the species Propionibacterium acnes, the said culture medium comprising at least one short chain fatty acid comprising from 3 to 8 carbon atoms, salts thereof, esters thereof and mixtures thereof.

8. The cosmetic method according to claim 7, wherein the conditioned culture medium is obtained by the process comprising the following steps: i) culturing at least one microorganism of the species Propionibacterium acnes such as Propionibacterium acnes ATCC 6919; ii) separating the culture supernatant from the biomass; iii) recovering the culture supernatant; and iv) optionally stabilizing the culture supernantant.

9. The cosmetic method according to claim 1 or which comprises applying to the skin a conditioned culture medium obtained from at least one microorganism of the species Propionibacterium acnes, the culture medium comprising at least one short chain fatty acid comprising from 3 to 8 carbon atoms, salts thereof, esters thereof and mixtures thereof, wherein the short chain fatty acid or the conditioned culture medium is used in combination with at least one long chain fatty acid comprising at least 10 carbon atoms, non-glyceryl esters thereof, and mixtures thereof.

10. The cosmetic method according to claim 1, wherein the dry skin is characterized by presenting a feeling of discomforts rough to the touch and/or squames.

11. A cosmetic method for preventing and/or treating hyposeborrheic dry skin and/or aged skin, comprising the application of a cosmetic composition on the skin, wherein the composition comprises at least one short chain fatty acid as defined in claim 1.

12. A cosmetic method for preventing and/or treating hyposeborrheic dry skin and/or aged skin, comprising the application of a cosmetic composition on the skin, wherein the said composition comprises a conditioned culture medium as defined in claim 7.

13. The cosmetic method according to claim 2, wherein the short chain fatty acid comprises a straight and saturated aliphatic chain containing 3 to 5 carbon atoms.

14. The cosmetic method according to claim 2, wherein the short chain fatty acid is chosen from propionic acid, butyric acid, valeric acid, salts thereof, esters thereof and mixtures thereof.

15. The cosmetic method according to claim 2, wherein the short chain fatty acid is obtained from at least one microorganism of the species Propionibacterium acnes.

16. The cosmetic method according to claim 3, wherein the short chain fatty acid is obtained from at least one microorganism of the species Propionibacterium acnes.

17. The cosmetic method according to claim 4, wherein the short chain fatty acid is obtained from at least one microorganism of the species Propionibacterium acnes.

18. The cosmetic method according to claim 2, wherein the short chain fatty acid is used in an amount representing from 0.01% to 5% by weight relative to the total weight of the composition.

19. The cosmetic method according to claim 3, wherein the short chain fatty acid is used in an amount representing from 0.01% to 5% by weight relative to the total weight of the composition.

20. The cosmetic method according to claim 4, wherein the short chain fatty acid is used in an amount representing from 0.01% to 5% by weight relative to the total weight of the composition.

Description

FIGURES

[0125] FIG. 1: Overview of SCFAs (C3, C4, and C5) which induce de-novo production of lipid droplets & mediate holocrine secretion (top scheme). This phenomenon is maintained during co-treatment with LCFAs aimed at boosting the sebogenic response (bottom scheme).

[0126] FIG. 2: Effect of SOFA propionate on lipid droplets per cell.

[0127] FIG. 3: Effect of SOFA butyrate on lipid droplets per cell.

[0128] FIG. 4: Effect of SOFA valerate on lipid droplets per cell.

[0129] FIG. 5: Effect of SOFA propionate on size of LDs.

[0130] FIG. 6: Effect of SOFA butyrate on size of LDs.

[0131] FIG. 7: Effect of SOFA valerate on size of LDs.

[0132] FIG. 8: Effect of SOFA propionate on intensity of LDs.

[0133] FIG. 9: Effect of SOFA butyrate on intensity of LDs.

[0134] FIG. 10: Effect of SOFA valerate on intensity of LDs.

[0135] FIG. 11: Effect of SOFA propionate on the number of nuclei.

[0136] FIG. 12: Effect of SOFA butyrate on the number of nuclei.

[0137] FIG. 13: Effect of SOFA valerate on the number of nuclei.

[0138] FIG. 14: Effect of SOFA propionate on size of the nucleus.

[0139] FIG. 15: Effect of SOFA butyrate on size of the nucleus.

[0140] FIG. 16: Effect of SOFA valerate on size of the nucleus.

[0141] FIG. 17: Growth curves of Propionibacterium acnes: (Optical Density (OD) and Colony Forming Units (CFU).

[0142] FIG. 18: Quantification of propionate in bacterial culture supernatants.

[0143] FIG. 19: Effect of bacterial supernatants on lipid droplets per cell.

[0144] FIG. 20: Effect of bacterial supernatants on number and size of the nucleus.

[0145] FIG. 21: Fold change of triglycerides (TGs) produced and secreted in cell culture media by non-treated sebocytes (Control: Ctrl.) and sebocytes treated with propionate (P) at 5 (P5) and 15 mmol.Math.l−1 (P15), butyrate (B) at 5 and 15 mmol.Math.l−1 and valerate (V) at 5 and 15 mmol.Math.l−1, after 24 h of incubation.

[0146] FIG. 22: The additive effect of combining one SOFA, valerate (V) with palmitic acid (PA) on size of lipid droplets (LDs).

[0147] FIG. 23: The additive effect of combining one SOFA, valerate (V) with linoleic acid (LA) on size of lipid droplets (LDs).

[0148] FIG. 24: The additive effect of combining one SOFA, valerate (V) with palmitic acid (PA) on intensity of lipid droplets (LDs).

[0149] FIG. 25: The additive effect of combining one SOFA, valerate (V) with linoleic acid (LA) on intensity of lipid droplets (LDs).

EXAMPLES

Example 1—Demonstration of the Lipids Production and Sebum Secretion Effects of SCFA According to the Invention and Comparative Test with Sodium Acetate (Outside of the Invention)

[0150] A) Material and Methods

[0151] Bacteria culture. Stored at −80° C., Strains of Propionibacterium acnes ATCC 6919 were pre-cultured on agar plate (Trypcase Soy Agar, bioMérieux, cat. 41466) incubated in anaerobic bag (GENbag, bioMérieux, cat. 45534, controlled with Anaerotest strip, Merck, cat. 1.15112) for 5 days at 33° C. Single isolated colonies were sampled and pre-cultured in liquid medium in triplicate in 9 ml of Trypcase Soy Broth (bioMérieux, cat. 42100) and incubated under anaerobic conditions (anaerobic bag controlled with Anaerotest strip) for 5 days at 33° C. Each replicate of liquid pre-culture was used to inoculate three flasks of Trypcase Soy Broth supplemented with 2% glycerol (Promega, cat. H5433) at OD 0.05±0.002 (Dabs=600 nm, Shimadzu UV-1800) and then aliquoted in snap cap tubes (Greiner, cat. 187262) and incubated at 33° C. under anaerobic condition. Growth curves were determined by measuring optical density and CFU (Colony Forming Units: serial dilutions plated on trypcase soy agar plate incubated 48 hours at 33° C. under anaerobic condition).

[0152] Quantification of propionate in supernatants. Propionate of supernatants from bacterial culture was extracted using an aliquot of 500 μl acidified with 1% formic acid (Merck, cat. 1.00264) following a ratio of 1:10 (formic acid:supernatant), vortexed for 1 min and stored at 4° C. Supernatants were analyzed by GC-FID using an Agilent DB-FFAP column.

[0153] Cell culture. Vials containing 3T3 mitomycine treated cells stored in 20% DMSO (Dimethylsulf oxide, Sigma Ref. D2650) in liquid nitrogen have been thawed in a water bath at 37° C. and directly washed with prewarmed G7F culture media (Table 1). 3T3m cells were plated at 40.10.sup.3 cells.Math.cm.sup.2 in a 175 cm.sup.2 flask (Thermoscientific Ref. 159910) and incubated 2 hours at 37° C., 5% CO.sub.2. Sebocytes were obtained from primary cell line and stored in 10% DMSO in liquid nitrogen. Vials containing sebocytes were thawed in a water bath at 37° C. and directly washed with prewarmed G7F culture media. Sebocytes were plated at 2600 cells.Math.cm.sup.2 in a 175 cm.sup.2 flask containing attached 3T3m cells and incubated (37° C., 5% CO.sub.2) to reach 70-80% confluence. After 5 days, cells were harvested using trypsin (Gibco Ref. 25300) and transferred in 96 well plates (10×10.sup.3 cells per well, Greiner Bio-one Ref. 655956) and incubated (37° C., 5% CO.sub.2).

[0154] After sampling of aliquots for OD and CFU measurements, tubes were closed and immediately centrifuged (6400 g, 5 min) at room temperature (centrifuge Eppendorf 5810R). Supernatants were then aspirated in a 10 ml syringe (Thermo Ref. SS+10l), filtered through a 0.45 μm, 25 mm (Pall Ref. 4614) filter and stored directly at −20° C.

TABLE-US-00001 TABLE 1 Composition of G7F media. Compounds Commercial reference Concentration DMEM Gibco Ref. 10569     ~67% Ham's F-12 Nutrient Mix Gibco Ref. 31765     22% FetalClone II Serum HyClone Ref.     10% SH30066.03 Antibiotic-Antimycotic (100x) Gibco Ref. 15240062      1% Supplemented with: Insulin solution human Sigma Ref. I9278  0.00025% 3,3′,5-Triiodo-L-thyronine Sigma Ref. T2752    0.05% sodium salt Hydrocortisone 21- Sigma Ref. H4881 2 × 10.sup.−8% hemisuccinate sodium salt apo-Transferrin human Sigma Ref. T2252   0.0001% (−)-Isoproterenol hydrochloride Sigma Ref. I6504    0.05% Adenine hydrochloride hydrate Sigma Ref. A9795   0.0001% Epidermal Growth factor Sigma Ref. GF144   0.004%

[0155] Cell treatment. After 24 hours, cell media was replaced by modified cell media (G7F w/o hydrocortisone and w/o antibiotic-antimycotic) supplemented with: modified cell media (control), sodium acetate (CH.sub.3COONa, Sigma Ref. 32319), sodium propionate (CH.sub.3CH.sub.2COONa, Sigma Ref. P1880), sodium butyrate (CH.sub.3(CH.sub.2).sub.2COONa Sigma Ref. 303410), valeric acid (CH.sub.3(CH.sub.2).sub.3COOH, Sigma Ref. 75054). For valeric acid, the pH in modified cell media was neutralized with NaOH (Sodium hydroxide, Sigma 283060). Palmitic acid (C16:0, Cayman Ref. 10006627) and linoleic acid (C18:2 cis 9.12, Sigma Ref. L1376) were both dissolved in pure ethanol (Merck Ref. 1.00983) for a final concentration per well of 60 μmar′. For these treatments, modified cell media supplemented with pure ethanol was used as controls. Supernatants (25%) sampled in exponential and stationary phases were neutralized with NaOH and were controlled with modified cell media supplemented at 25% with pure bacterial culture media. All conditions were repeated 8 times (n=8) for SOFA experiments and 24 times (n=24) for supernatants assays. Microplates were incubated 48 hours (37° C., 5% CO2) and directly sampled and/or stained and analyzed.

[0156] Triglycerides quantification. Assays have been realized using Triglycerides Assays Kit—Quantification (Abcam, ref. Ab65336) following manufacturer's instructions. Each supernatant of the 8 replicates have been sampled (50 μl) and analyzed following the colorimetric detection method of the kit (OD 570 nm) using a plate reader Infinite 200PRO (Tecan).

[0157] Cell staining. Wells were washed with DPBS solution (Dulbecco's Phosphate-Buffered Saline, Gibco Ref. 14040) and were fixed with 10% Formalin (Leica Ref. 3800598). Lipid droplets were stained with BODIPY (Invitrogen Ref. D3922) diluted in DPBS solution supplemented with delipidated BSA (Bovin Serum Albumin, Sigma Ref. A7906). Nuclei were stained with Hoechst (Invitrogen, Ref. H3570) diluted in DPBS solution.

[0158] High content imaging, images analysis and statistics. An inverted automated epifluorescent microscope (ImageXpress Micro 4, Molecular Devices) was used to acquire 16 images of each well with a 10× objective (well coverage=80%) controlled by MetaXpress software (version 6.2.3.733, Molecular Devices). Images were analyzed using the MetaXpress image based module Transfluor (Molecular Devices). Results were exported into GraphPad Prism (version 7.01) to determine statistical significance using One-way ANOVA and expressed on bar graph as mean±SD or on box plot±min and max. *: P-value<0.05, **: P-value<0.01, ***: P-value<0.001, ****: P-value<0.0001.

[0159] B) Results

[0160] a. Effect of SCFA on Lipid Droplets (Lipids Production) and Holocrine Secretion (Sebum Secretion) by High Content Screening (HCS)

[0161] Sebocytes were seeded in 96 well plates, followed by treatment with SOFA and/or LCFAs with at least 8 replicate wells (1 column) for each condition. Sebogenesis (lipid formation) and holocrine secretion (release of lipids) have been analyzed by imaging the cell layer using a high content screening (HCS) system in all 8 wells (ensuring 80% coverage of the cell layer in each well) by characterization of 5 different parameters: number of nucleus, size of nucleus, average number of Lipid Droplets (LDs) per cell, average size of LDs and average intensity of LDs. 3 SOFA as sodium salts: propionate (CH.sub.3CH.sub.2COOH), butyrate (CH.sub.3(CH.sub.2).sub.2COOH) and valerate (CH.sub.3(CH.sub.2).sub.3COOH) were tested at 4 different concentrations (2.5, 5, 10 and 15 mmol.Math.l.sup.−1). Results are presented in FIGS. 2 to 16.

[0162] a.1 Effect of SCFA on Lipids Droplets (Lipids Production)

[0163] a.1.i Effect of SCFA on Number of Lipid Droplets (LDs)

[0164] Compared to the control, number of LDs per cell is significantly higher and equivalent for all the conditions tested. Interestingly, the maximum de novo synthesis of LDs was the same for all of the conditions tested (see FIGS. 2 to 4).

[0165] a.1.ii Effect of SCFA on Size of Lipid Droplets (LDs)

[0166] Compared to controls, the size of LDs is higher for all of the conditions tested. LDs in cells treated with propionate are the smallest but LDs increased in size as the concentration of propionate increased. This trend is enhanced with butyrate and valerate (e.g. size of LDs for valerate treated cells with 15 mmol.Math.l.sup.−1>10>5>2.5 mmol.Math.l.sup.−1, P-value<0.001) (see FIGS. 5 to 7).

[0167] a.1.iii Effect of SCFA on Intensity of Lipid Droplets (LDs)

[0168] Based on the principle of BODIPY staining (hydrophobic-hydrophobic interactions), fluorescence intensity of lipid droplets can be related to the quantity of lipid embedded within the droplets. Fluorescence of LDs in cells treated with SOFA is more intense compared to the control (see FIGS. 8 to 10).

[0169] a.2 Effect of SCFA on Holocrine Secretion (Sebum Secretion)

[0170] a.2.i Effect of SCFA on Nuclear Count

[0171] Holocrine secretion is the final step of sebogenic process wherein the mature cells burst to release the lipid contents (Schneider and Paus, 2010). Holocrine secretion is thus associated with a decrease in the nuclear count per well. This trend is clearly observable for cells treated with propionate, butyrate and valerate. (see FIGS. 11 to 13).

[0172] In order to demonstrate that the decrease of cell number is due to holocrine secretion and not toxicity, we correlated these observations with the size of nucleus and also estimated the triglycerides in the supernatant (see below).

[0173] a.2.ii Effect of SCFA on Size of Nucleus

[0174] Holocrine secretion involves maturation of sebocyte cells to a terminal bursting stage. This process involves enlargement of the nuclei during the expansion phase and final shrinkage just before the sebocyte cells burst to release the lipid content (Tosti, 1974). This trend is clearly observed in cells treated with the 3 SOFA. (see FIGS. 14 to 16).

[0175] a.3 Effect of the Conditioned Culture Medium (Supernatants) of P. acnes ATCC 6919 Containing SCFA on Lipids Droplets (Lipids Production) and Holocrine Secretion (Sebum Secretion)

[0176] a.3.i Effect of P. acnes Supernatants Containing SCFA on Number of Lipid Droplets (LDs) (Lipids Production)

[0177] Treated cells with bacterial supernatants (sampled during exponential (Sup. Exp.) and stationary (Sup. Stat.) phases) and containing propionate as the SOFA (see FIGS. 17 and 18) have been compared to cells treated with the media used to grow bacteria (Bacterial Culture Media, Bact. CM). Compared to the control, number of LDs per cell is significantly higher for all the conditions tested. Moreover, number of LDs per cell increases with concentration of propionate produced by bacteria (Sup. Stat.>Sup. Exp.). Interestingly number of LDs per cell of sebocytes treated with the supernatants sampled in stationary phase (4.2 mmol.Math.l.sup.−1 of propionate, about 11 LDs/cell) is very close to the number of LDs measured for approximately the same concentration of pure propionate (5 mmol.Math.l.sup.−1) used to treat the sebocytes in sections a1 and a2 (about 12 LDs/cell, FIG. 19). Treating cells with bacterial supernatants containing SCFAs induces de novo production of LDs (see FIG. 19).

[0178] a.3.ii Effect of P. acnes Supernatants Containing SCFA on Nuclear Size and Nuclear Count (Sebum Secretion)

[0179] The number of nuclei in the wells treated with bacterial supernatants decreases. (see FIG. 20).

[0180] This diminution is even more important for cells treated with Sup. Stat. and is comparable to the nuclear count measured for approximately the same concentration of pure propionate (5 mmol.Math.l.sup.−1) used to treat the sebocytes in FIG. 11.

[0181] This is correlated with the clear trend of nuclear size enlargement for sebocytes treated with bacterial supernatants (see FIG. 20).

[0182] We conclude that supernatants containing at least one SOFA have a positive effect on holocrine secretion in sebocytes (see FIG. 20).

[0183] Conclusion: treatment of sebocytes with SOFA or supernatants containing SOFA has multiple effects: [0184] 1) SOFA lead to de novo production of lipid droplets (FIGS. 2 to 16). [0185] 2) Butyrate as well as valerate treatment has a positive effect on the size of lipid droplets (FIGS. 6 and 7). [0186] 3) Propionate, butyrate as well as valerate treatment boost sebum production process by promoting holocrine secretion (FIGS. 11 to 16). [0187] 4) Treatment of sebocytes with bacterial supernatants containing SOFA has similar effects on de novo production of LDs/sebum production (FIG. 19), and holocrine secretion (FIG. 20).

[0188] b. Effect of SCFA on Holocrine Secretion (Sebum Secretion) by Quantifying Secreted Triglycerides (TGs) and Comparison with Acetate (SCFA that does not Mediate Holocrine Secretion)

[0189] Holocrine secretion is the final step of sebogenic process wherein the mature cells burst to release the lipid contents. Promotion of holocrine secretion by SOFA was based on observations and interpretations of a lower number of cells in association with an enlargement of nuclear area. In order to demonstrate the induction of holocrine secretion on treatment with SOFA, the secreted triglycerides (TGs, the major lipid class of sebum) in sebocyte supernatants treated with 5 and 15 mmol.sup.−1 of SOFA was quantified. Results are presented in FIG. 21.

[0190] In the supernatants of the sebocytes treated with SCFAs, the fold change (FC) is significantly higher for all the conditions tested (min. FC˜1.2 (P5): +20% of TGs excreted by cells treated with P5, max. FC˜2 (V15): +100% of TGs excreted by cells treated with V15). Moreover, the quantity of TGs produced and excreted is systematically higher when concentration increases (e.g. FC of TGs in B15>FC of TGs in B5, P-value=0.02). This clearly establishes that SCFAs mediate holocrine secretion in sebocyte cells.

[0191] b.1 Comparative Outside of the Invention (SCFA=Acetate)

[0192] TGs secreted in supernatants of propionate and acetate treated sebocytes was compared: while both acetate and propionate lead to similar sebogenic response (based on lipid induction parameters), no apparent change in nuclear parameters was observed for acetate treated cells. These results are presented Table 2 below.

[0193] Compared to the control, the effect of acetate on de novo lipid induction is significant and, similar to propionate (same number of LDs per cell, similar size, similar intensity).

[0194] However, no effect of acetate is observed on the nuclear count (same number of cells compared to the control), and the size of nucleus (similar size as compared to the control), which is in sharp contrast with propionate treated cells. This would indicate that while same quantity of lipids is produced by cells treated with both acetate and propionate, only sebocytes treated with propionate would mediate holocrine secretion and release the produced sebum in the supernatant. Interestingly, TG estimation from supernatants of acetate and propionate treated cells clearly supported these observations, further establishing a unique role of propionate, holocrine secretion in sebocyte cells.

TABLE-US-00002 TABLE 2 Comparison between acetate and propionate on lipid induction and holocrine secretion effect. Proprionate (5 Acetate (5 mmol.L.sup.−1) mmoL.sup.−1) (P5) (A5) outside of according to the Ctrl. the invention invention Lipid LDs per cell 6.85 ± 1.68  11.97 ± 2.08 (****)  12.04 ± 1.92 (***)   induction Size of LDs 5.06 ± 0.20  5.86 ± 0.31 (****)  6.08 ± 0.38 (****) Intensity of LDs 6962 ± 1193  10251 ± 1295 (****)   9656 ± 798 (***) Holocrine Nuclear count 18905 ± 1745   18574 ± 2148 =  11921 ± 1080 (***) secretion Size of nucleus 216 ± 3    215 ± 5 =   238 ± 7 (****) FC 1 FC = 0.90, = FC = 1.2, (compared to control) % of excreted — −10% = +20% (**) TGs (compared to control) Results are presented as mean ± SD and fold change (FC) plus % for excreted TGs. : significantly higher than the control, : significantly lower than the control, =: no significant difference with the control.

[0195] Conclusion: The significant increase of TGs secreted by sebocytes cultured during 24 h. in media supplemented with SOFA, correlated with the trend seen for nuclear parameters, and demonstrates that SOFA boost the sebum production process by mediating both lipid production and promoting holocrine secretion.

[0196] c. Effect of LCFA in Combination with SCFA on Lipids Droplets (Lipids Production)

[0197] One SOFA, valerate, V (CH.sub.3(CH.sub.2).sub.3COOH), was tested in association with two LCFA: palmitic acid, PA (C16:0) and linoleic acid, LA (C18:2 cis 9.12) in two experiments to demonstrate an additive effect on sebum production. Results are presented in FIGS. 22 to 25.

[0198] c.1 Effect of LCFA in Combination with SCFA on Size of Lipids Droplets (LDs)

[0199] When palmitic acid was combined with valerate, the LDs were bigger than when palmitic acid was used alone. This boost effect is even more noticeable with valerate and linoleic acid (FIGS. 22 and 23).

[0200] c.2 Effect of LCFA in Combination with SCFA on Intensity of Lipids Droplets (LDs)

[0201] The fluorescence of LDs in cells treated with valerate and/or the two LCFA follows the same conclusion, that there is a better effect on intensity of lipid droplets when LCFA is added in combination with valerate (see FIGS. 24 and 25).

Conclusion: The combination of SOFA and LCFA has an additive effect on the size of lipid droplets (FIGS. 24 and 25).

Example 2—Skin Care Composition

[0202] The composition as described below is prepared.

TABLE-US-00003 Compounds Concentration (w/w) Sodium propionate 0.01 Palmitic acid 1 Sodium methyl stearoyl taurate 0.23 Xanthan gum 0.05 carbomer 0.2 water qs 100
The composition is applied on the skin and provides a decrease of signs of skin dryness.