Quercetin, a flavonol, is a functional compound that is abundant in onions and is
known to have antioxidant and anti-inflammatory effects. Quercetin and its glucoside
are known to function as peroxisome proliferator-activated receptor (PPAR) ligands
and showed high PPAR-α transactivation activity but little PPAR-γ transactivation activity in some reports. In this study, we demonstrated that an
aqueous extract of a quercetin-rich onion cultivar increased transactivation activities
not only of PPAR-α but also of PPAR-γ. We isolated (9S,12S,13S)-(10E)-9,12,13-trihydroxyoctadec-10-enoic acid (pinellic acid) obtained from the aqueous
extract using PPAR-γ transactivation as an index. Furthermore, it was revealed that pinellic acid could
transactivate PPAR-α. Our findings are the first report mentioned showing that trihydroxyoctadec-10-enoic
acids showed PPAR-α/γ transactivation activities.
Key words
Allium cepa
- Amaryllidaceae - (9
S,12
S,13
S)-(10
E)-9,12,13-Trihydroxyoctadec-10-enoic acid (Pinellic acid) - (
S) configuration - peroxisome proliferator-activated receptor - nuclear factor-
κB