Royal Jelly Maintains Epidermal Stem Cell Properties by Repressing Senescence

Area of Science:

• Dermatology
• Cell Biology
• Biochemistry

Background:

• Royal jelly (RJ) is a bee product used in skincare for its homeostatic properties.
• The precise mechanisms of RJ's effects on skin remain unclear.
• Understanding RJ's impact on skin cells is crucial for its application in cosmetics.

Purpose of the Study:

• To investigate the effects of RJ on human primary epidermal keratinocytes (HPEKs).
• To explore RJ's influence on HPEK proliferation and cellular senescence.
• To elucidate the molecular mechanisms underlying RJ's skincare benefits.

Main Methods:

• Culturing human primary epidermal keratinocytes (HPEKs).
• Assessing cell proliferation in 2D and epidermal equivalent models.
• Analyzing the expression of senescence markers (p16, p21, ΔNp63).
• Identifying key fatty acids in RJ, including 10-hydroxy-2-decenoic acid.

Main Results:

• RJ addition increased epidermal thickness and p63-expressing cells in epidermal equivalents.
• Short-term RJ treatment showed minimal impact on HPEK proliferation.
• Long-term RJ treatment enhanced cell population doubling, indicating senescence inhibition.
• RJ modulated ΔNp63, p16, and p21 expression, suppressing cellular senescence.

Conclusions:

• Royal jelly inhibits cellular senescence in epidermal cells.
• RJ maintains epidermal stem cell properties by repressing senescence.
• Findings provide mechanistic insights into RJ's efficacy in skincare products.