GREENTECH présent à l'ASCC 2019

Abstract

Objective

Intrinsic skin ageing is mainly caused by cellular senescence. p16 and p21 are two important tumour suppressor proteins that play essential roles during cell proliferation and ageing through regulating the expression of several genes. Moreover, physical changes between the ages of 55 and 60 years affect one’s physical and disrupt self‐esteem. The cosmetics industry has focused on bioactive substances derived from natural products such as plants, mushrooms and marine algae to counteract the deleterious effect on skin senescence. Besides these products, compounds produced by bacteria may decelerate individual senescence.

Methods

In order to evaluate the potential benefits of bacteria extract over skin ageing, we investigated whether a Sphingomonas hydrophobicum (SH) extract is able to protect our skin against senescence mechanisms. We used an ageing full‐thickness skin equivalent model, which was treated or not with the bacteria extract in a systemic way for 42 days. p21 and p16 and senescence‐associated galactosidase activity were used to detect cellular senescence with immunohistology. Using a psychobiological approach, we evaluated in vivo the effect of SH extract on self‐esteem, isotropy and suppleness.

Results

Sphingomonas extract significantly suppressed senescence associated with β‐galactosidase activation. It also significantly inhibited the expression of cell cycle inhibitors (p21 and p16). At the same time, the bacteria extract has a significant positive impact on the issue by increasing the expression of versican and fibrillin‐1. Significant improvements of self‐esteem were reported after 56 days of SH extract application. These psychological benefits were accompanied by a significant improvement in skin suppleness and isotropy.

Conclusion

Sphingomonas extract delays intrinsic skin ageing process by inhibiting cellular senescence, and has also the capability to restructure the skin. These beneficial physiological effects induced by SH extract have a positive influence on self‐esteem. Because skin ageing causes emotional distress, SH extract can serve as an anti‐ageing cosmeceutical agent and help to build a better psychological health, and help individuals to assume ageing.