TAGS: Sustainability / Natural Cosmetics Skin Care
Shiseido discovered that the extract of lemon ironwood leaf extract has an effect on inhibiting the senescence of epidermal stem cells.
Moreover, this extract was found to increase the quantity of epidermal stem cells and improve the ability to produce cells. These findings suggest that the extract may help maintain healthy epidermal stem cells that serve as the source of turnover of the skin, leading to solutions for skin problems caused by aging.
This study applied the findings from Shiseido's collaborative research with the Cutaneous Biology Research Center (CBRC) at Massachusetts General Hospital, which revealed that senescence of epidermal stem cells may be controllable.
Maintaining Healthy Epidermal Stem Cells is Crucial for Skin
Moving forward, Shiseido will continue to advance epidermal stem cell research with the aim of addressing various skin problems caused by aging. The results of this study were partly presented at the International Societies of Investigative Dermatology (ISID) meeting, held in Tokyo on May 10–13, 2023.
Skin turnover occurs as a result of cells in the epidermis constantly proliferating and differentiating, helping the skin to stay healthy. Epidermal stem cells that are present in the basal layer serve as the source of these cells. Based on the idea that maintaining healthy epidermal stem cells is crucial for achieving beautiful skin, Shiseido has discovered that supporting the maintenance of the quantity of epidermal stem cells through the basement membrane under the basal layer of the epidermis contributes to skin hydration, barrier function, and even collagen production in the dermis.
Moreover, a joint study with the CBRC focusing not only on the quantity of epidermal stem cells but also on their quality revealed that phosphorylation of YBX1, the RNA binding protein that inhibits the senescence of epidermal stem cells, decreases the function of YBX1 and thereby causes cellular aging. The present study applied these findings and aimed to improve the quality of epidermal stem cells with cosmetic ingredients.
The function of YBX1, which inhibits the senescence of epidermal stem cells, has been shown to decrease by phosphorylation. Among more than 100 cosmetic ingredients, they identified the leaf extract of lemon ironwood, a plant native to Australia, to have the effect of inhibiting the phosphorylation of YBX1 and preventing the senescence of epidermal stem cells in cultured cells containing epidermal stem cells.
As for the mechanism to prevent epidermal stem cell senescence by YBX1, it has been known that YBX1 inhibits the production of SASP factors, which are secreted from aged cells and trigger the propagation of aging. In the present study, they observed that the production of IL-8, a SASP factor, is suppressed in cultured cells containing the lemon ironwood leaf extract. In addition, the lemon ironwood leaf extract increased the expression of MCSP, a marker gene of epidermal stem cells, and also increased the proliferation of cells. These results suggested the effect of the lemon ironwood leaf extract to inhibit the senescence of epidermal stem cells while also increasing the quantity of epidermal stem cells and improving the ability to produce cells.
Shiseido will apply these findings as a solution to maintain healthy epidermal stem cells, which serve as the source of skin turnover, in solving the various
skin problems that emerge with aging.
Source: Shiseido
