Kaempferol is a
flavonoid present in Kaempferia galanga and Opuntia ficus indica var. saboten. Recent studies have suggested that it has
anti-oxidant, anti-inflammatory, anti-
cancer, and anti-
obesity effects. In this study, we focused on the anti-adipogenic effects of
kaempferol during adipocyte differentiation. The results showed that
kaempferol inhibits
lipid accumulation in adipocytes and zebrafish.
Oil Red O and
Nile Red staining showed that the number of intracellular lipid droplets decreased in adipocytes and zebrafish treated with
kaempferol. LPAATθ (
lysophosphatidic acid acyltransferase), lipin1, and DGAT1 (
triglyceride synthetic
enzymes) and FASN and
SREBP-1C (
fatty acid synthetic
proteins) showed decreased expression levels in the presence of
kaempferol. In addition, treatment of
kaempferol showed an inhibitory activity on cell cycle progression.
Kaempferol delayed cell cycle progression from the S to G2/M phase through the regulation of
cyclins in a dose-dependent manner.
Kaempferol blocked the phosphorylation of AKT (
protein kinase B) and
mammalian target of rapamycin (mTOR) signaling pathway during the early stages of adipogenesis. In addition,
kaempferol down-regulated pro-early adipogenic factors such as
CCAAT-enhancer binding proteins β (C/EBPβ), and Krüppel-like factors (KLFs) 4 and 5, while anti-early adipogenic factors, such as KLF2 and pref-1(preadipocyte factor-1), were upregulated. These
kaempferol-mediated regulations of early adipogenic factors resulted in the attenuation of late adipogenic factors such as C/EBPα and
peroxisome proliferator-activated receptor γ (PPARγ). These results were supported in zebrafish based on the decrease in
lipid accumulation and expression of adipogenic factors. Our results indicated that
kaempferol might have an anti-
obesity effect by regulating lipid metabolism.