Akihiro Aioi
Development Laboratory, SEPTEM-SOKEN Co., Ltd.,

[Abstract]
In the previous decade, various benefits and biological activities of royal jelly, applied in alternative and modern medicine, and cosmetics, have been reported. However, the effects of royal jelly extract (RJ) on keratinocytes have not been fully elucidated. The primary objectives of this study were to reveal the effects of RJ on keratinocytes and explore the underlying mechanism. HaCaT cells, were used in this study. RJ treatment upregulated LAMA3, ITGB1 and HIF-1α mRNA expression, and accelerated HaCaT cell proliferation. Akt and mTOR inhibitors suppressed the RJ-induced HIF-1α expression and cell proliferation. HIF-1α silencing abrogated RJ-induced LAMA3 and ITGB1 mRNA expression and cell proliferation, whereas LAMA3 silencing and antibody-mediated ITGB1 blockade did not affect the effects of RJ. Conclusively, RJ upregulates LAMA3 and ITGB1 mRNA expression levels by HIF-1α expression enhancement, and accelerates keratinocyte proliferation via Akt/mTOR/HIF-1α/NF-κB signaling pathway, indicating that RJ is beneficial for anti-aging, as a skin care product ingredient.