茶花（Camellia polyodonta）花中酚类化合物的分离与鉴定：诺博汀D（Nobotanin D）通过PI3K/AKT介导的调控机制抑制脂质积累

Abstract

Nobotanin D was first isolated from C. polyodonta flowers. • Nobotanin D reduced lipid accumulation in oleic acid-induced HepG2 cells. • Nobotanin D modulated PI3K/AKT signaling and lipid-related proteins. • Nobotanin D attenuated oxidative stress and apoptosis in HepG2 cells. Camellia polyodonta (Oil-tea Camellia) flowers are rich in polyphenols but remain underexploited. Although previous studies indicated their hypolipidemic activity, the active compounds and mechanisms were unclear. Seven phenolic compounds were isolated from the 20% ethanol fraction, among which nobotanin D was first reported from this species. In oleic acid-induced steatotic HepG2 cells, all seven compounds reduced lipid accumulation, with nobotanin D exhibiting the strongest effect. Mechanistically, nobotanin D activated the PI3K/AKT pathway and modulated the expression of FOXO1, SREBP-1c, ApoC-III, and MTP, which was associated with reduced intracellular triglyceride accumulation and altered lipoprotein metabolism. It also attenuated oxidative stress (increased SOD, CAT, GSH; decreased MDA) and suppressed apoptosis (upregulated Bcl-2, downregulated Bax). These findings identify nobotanin D as a novel hypolipidemic agent from C. polyodonta flowers for functional food applications. Download: Download high-res image (224KB) Download: Download full-size image