The 24-hour skin hydration and barrier function effects of a hyaluronic 1%, glycerin 5%, and <em>Centella asiatica</em> stem cells extract moisturizing fluid: an intra-subject, randomized, assessor-blinded study

A new trend in cosmetic formulations is the use of biotechnological raw materials as the polysaccharides from Klebsiella pneumoniae, which are supposed to enhance cell renewal, improve skin hydration and micro-relief. Botanical extracts of Myrtus communis leaves contain different sugars, which may provide the same benefits. Thus, the objective of this study was to evaluate through objective and subjective analysis the immediate and long-term effects of cosmetic formulations containing polysaccharides biotechnologically-originated and / or the ones contained in Myrtus communis extracts. Three polysaccharide-based and placebo formulations were applied on the forearm skin of 40 volunteers. Skin hydration, transepidermal water loss (TEWL), viscoelasticity and skin micro-relief measurements were made before and 2 hours after a single application and after 15 and 30 day-periods of daily applications. Answers to a questionnaire about perceptions of formulation cosmetic features constituted the subjective analysis. All polysaccharide-based formulations enhanced skin hydration. Formulations with isolated or combined active substances improved skin barrier function as compared to placebo, in the short and long term studies. Formulations containing Myrtus communis extracts had the highest acceptance. Results suggest that daily use of formulations containing these substances is important for protection of the skin barrier function.

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Improvement of intestinal stem cells and barrier function via energy restriction in middle-aged C57BL/6 mice

Nutrition Research ◽

10.1016/j.nutres.2020.06.015 ◽

2020 ◽

Vol 81 ◽

pp. 47-57

Author(s):

Wenjuan Di ◽

Yifan Lv ◽

Fan Xia ◽

Yunlu Sheng ◽

Juan Liu ◽

...

Keyword(s):

Stem Cells ◽

Barrier Function ◽

Energy Restriction ◽

Intestinal Stem Cells ◽

Middle Aged

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The Junctional Epithelium Is Maintained by a Stem Cell Population

Journal of Dental Research ◽

10.1177/0022034520960125 ◽

2020 ◽

pp. 002203452096012

Author(s):

X. Yuan ◽

J. Chen ◽

J.A. Grauer ◽

Q. Xu ◽

L.A. Van Brunt ◽

...

Keyword(s):

Stem Cells ◽

Stem Cell ◽

Bone Resorption ◽

Cell Population ◽

Barrier Function ◽

The Body ◽

Stem Cell Population ◽

Oral Epithelium ◽

Junctional Epithelium ◽

Slow Cycling

The most fundamental function of an epithelial tissue is to act as a barrier, regulating interactions between the external environment and the body. This barrier function typically requires a contiguous cell layer but since teeth penetrate the oral epithelium, a modified barrier has evolved, called the junctional epithelium (JE). In health, the JE attaches to the tooth, sealing the inside of the body against oral micro-organisms. Breakdown of the JE barrier results in periodontal ligament (PDL) disintegration, alveolar bone resorption, and ultimately tooth loss. Using lineage tracing and DNA pulse-chase analyses, we identified an anatomical location in the JE that supported both fast- and slow-cycling Wnt-responsive stem cells that contributed to self-renewal of the tissue. Stem cells produced daughter cells with an extraordinarily high rate of turnover that maintained JE integrity for 1.4 y in mice. Blocking cell proliferation via a chemotherapeutic agent 5-fluorouracil (5-Fu) eliminated fast-cycling stem cells, which caused JE degeneration, PDL destruction, and bone resorption. Upon removal of 5-Fu, slow-cycling stem cells regenerated both the structure and barrier function of the JE. Taken together, our studies identified a stem cell population in the JE and have potential clinical implications for prevention and treatment of periodontitis.

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