Active ingredient from Bombax costatum (kapok tree) to preserve skin microbiota equilibrium
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Presented by: Sophie Leclere-Bienfait
Background
Skin is colonized by a wide variety of microbes. Preserving skin microbiota homeostasis is of crucial importance for maintaining healthy skin. We have developed a new active ingredient from Bombax costatum flowers, this polysaccharide-rich extract was evaluated in vitro on different microbiota models.
Methods
Bacterial growth study: A mixture of different bacterial strains, representative of cutaneous microbiota, has been cultivated in a liquid medium for 48 hours in presence of the extract. The growth of each bacterium has been evaluated after subculture on specific agar.
Biofilm study: Biofilm formation of diverse bacterial strains was studied using crystal violet dye.
Adhesion study: Reconstructed human epidermis (RHE) have been topically treated by the extract prior to the deposition of different bacterial strains. After incubation, bacteria adhering to the RHE have been quantified by colony forming unit counting after seeding on specific agar.
Epidermal response studies: Normal human keratinocytes have been incubated for 48h in presence of the extract. The expression level of innate immunity markers TLR2 (Toll-Like Receptor 2) and hBD2 (human beta-Defensin 2) were evaluated by ELISA assay. RHE, topically pre-treated for 24h by the extract, were incubated in presence of S. aureus secretum. Histological analysis were performed after barrier markers immunostaining.
Results
The polysaccharide-rich extract tended to inhibit the growth of the pathogenic strain S. aureus, without significantly affecting the growth of commensal bacteria (S. epidermidis, S. hominis, C. acnes). This effect was even more significant as S. aureus was present in high proportions compared to other strains, suggesting a preventive effect toward S. aureus pathogenicity by limiting its overgrowth.
The extract significantly inhibited S. aureus biofilm formation, when it increased that of S. epidermidis. Moreover, it was able to inhibit S. aureus adhesion on RHE without affecting S. epidermis adhesion.
The extract significantly increased keratinocyte production of TLR2 and anti-microbial peptide hBD2. Finally, the extract protected the expression of filaggrin, desmoglein-1 and corneodesmosin that were alterered in RHE by S. aureus secretum.
Conclusion
We have demonstrated that a natural and plant polysaccharide-rich extract obtained from Bombax costatum is able to limit growth, adhesion and biofilm forming properties of a pathogenic strain (S. aureus), without affecting commensal bacteria. Moreover, it stimulates immune defenses and helps to preserve epidermal barrier from alteration due to S. aureus. These results show the beneficial properties of the extract to preserve skin microbiota homesostasis by promoting commensal against pathogenic bacterial strains and by preserving from the deleterious effects of S. aureus.
Skin is colonized by a wide variety of microbes. Preserving skin microbiota homeostasis is of crucial importance for maintaining healthy skin. We have developed a new active ingredient from Bombax costatum flowers, this polysaccharide-rich extract was evaluated in vitro on different microbiota models.
Methods
Bacterial growth study: A mixture of different bacterial strains, representative of cutaneous microbiota, has been cultivated in a liquid medium for 48 hours in presence of the extract. The growth of each bacterium has been evaluated after subculture on specific agar.
Biofilm study: Biofilm formation of diverse bacterial strains was studied using crystal violet dye.
Adhesion study: Reconstructed human epidermis (RHE) have been topically treated by the extract prior to the deposition of different bacterial strains. After incubation, bacteria adhering to the RHE have been quantified by colony forming unit counting after seeding on specific agar.
Epidermal response studies: Normal human keratinocytes have been incubated for 48h in presence of the extract. The expression level of innate immunity markers TLR2 (Toll-Like Receptor 2) and hBD2 (human beta-Defensin 2) were evaluated by ELISA assay. RHE, topically pre-treated for 24h by the extract, were incubated in presence of S. aureus secretum. Histological analysis were performed after barrier markers immunostaining.
Results
The polysaccharide-rich extract tended to inhibit the growth of the pathogenic strain S. aureus, without significantly affecting the growth of commensal bacteria (S. epidermidis, S. hominis, C. acnes). This effect was even more significant as S. aureus was present in high proportions compared to other strains, suggesting a preventive effect toward S. aureus pathogenicity by limiting its overgrowth.
The extract significantly inhibited S. aureus biofilm formation, when it increased that of S. epidermidis. Moreover, it was able to inhibit S. aureus adhesion on RHE without affecting S. epidermis adhesion.
The extract significantly increased keratinocyte production of TLR2 and anti-microbial peptide hBD2. Finally, the extract protected the expression of filaggrin, desmoglein-1 and corneodesmosin that were alterered in RHE by S. aureus secretum.
Conclusion
We have demonstrated that a natural and plant polysaccharide-rich extract obtained from Bombax costatum is able to limit growth, adhesion and biofilm forming properties of a pathogenic strain (S. aureus), without affecting commensal bacteria. Moreover, it stimulates immune defenses and helps to preserve epidermal barrier from alteration due to S. aureus. These results show the beneficial properties of the extract to preserve skin microbiota homesostasis by promoting commensal against pathogenic bacterial strains and by preserving from the deleterious effects of S. aureus.