Zerumbone blocks the activation of two proteins (c-Fos and c-Jun) that tell skin cells to break down collagen when exposed to UVA light.
Scientific Claim
Zerumbone at 2–8 μM inhibits UVA-induced phosphorylation and nuclear translocation of c-Fos and c-Jun in human skin fibroblasts, thereby suppressing AP-1 activation, a key driver of matrix metalloproteinase expression in photoaging.
Original Statement
“UVA radiation alone tends to elevate the phosphorylations of c-Fos and c-Jun proteins in HSF cells. However, this effect was dose-dependently and significantly downregulated due to ZER pretreatment (Figures 3(a) and 3(b)).”
Evidence Quality Assessment
Claim Status
appropriately stated
Study Design Support
Design supports claim
Appropriate Language Strength
definitive
Can make definitive causal claims
Assessment Explanation
The study directly measured protein phosphorylation and localization using validated methods; the mechanistic claim is fully supported by the data without overreach.
Evidence from Studies
Supporting (1)
The study found that zerumbone, at the same doses mentioned in the claim, blocks harmful proteins (c-Fos and c-Jun) from moving into the cell nucleus after UV exposure, which stops a process that breaks down skin collagen—exactly what the claim says.