α-Ionone Protects Against UVB-Induced Photoaging in Human Dermal Fibroblasts

Ultraviolet (UV) light-induced wrinkle formation is a major dermatological problem and is associated with alteration in collagen. Here, we investigated the potential of &alpha
ionone, a naturally occurring aromatic compound, in regulation of UVB-induced photoaging in human Hs68 dermal fibroblasts and identified the mechanisms involved. We found that in human dermal fibroblasts, &alpha
ionone inhibited UVB-induced loss of collagen. &alpha
Ionone upregulated the molecules participating in the TGF-&beta
&ndash
SMAD pathway (TGF-&beta
1, phospho-SMAD2/3, Col1A1, and Col1A2), but downregulated the molecules involved in the MAPK&ndash
AP-1 signaling pathway (phospho-p38, phospho-JNK, phospho-ERK, phospho-c-Fos, phospho-c-Jun, MMP1, MMP3, and MMP9), in human dermal fibroblasts. &alpha
Ionone treatment also increased hyaluronic acid contents, and this effect was accompanied by an upregulation of mRNA expression of genes (HAS1 and HAS2) involved in hyaluronic acid synthesis. Thus, &alpha
ionone is effective in the prevention of UVB-induced decrease of collagen and hyaluronic acid in human dermal fibroblasts. We propose that &alpha
ionone may prove beneficial for the prevention of UV-induced wrinkle formation and skin damage.