素馨花水提物及其主要成分对3T3-L1细胞成脂分化的影响

Effects of a Water Extract of Jasminum grandiflorum L. and its Main Components on the Adipogenic Differentiation of 3T3-L1 Cells

摘要:

该研究探讨素馨花水提物（WE）及其化学成分在3T3-L1前脂肪细胞上的降脂作用。通过将3T3-L1细胞诱导为成熟脂肪细胞，油红Ｏ染色定量和检测甘油三酯（TG）含量判断素馨花样品对脂滴的抑制作用；液质联用仪分析WE中化学成分；MTT检测素馨花及其成分对3T3-L1细胞增殖的影响；Western Blot检测AMPK、C/EBPα、FAS、ACC、CPT1、Bax、Bcl-2等蛋白表达。结果发现，WE能剂量依赖性抑制脂滴形成，其中高浓度WE（500 µg/mL）能降低中性脂质含量23.59%，降低TG含量30.20%，在脂肪积累早期作用最显著，并证明其活性成分主要是橄榄苦苷，含量为13.77%。WE及橄榄苦苷能激活AMPK（123.19%和115.98%）和其下游靶点ACC（451.06%和1 050.0%）的磷酸化、下调其下游靶点FAS（81.72%和60.50%）的蛋白表达，减少脂肪形成，提高CPT1（164.84%和292.19%）蛋白的表达，加快脂肪酸氧化；抑制C/EBPα（68.97%和34.57%）的表达，影响3T3-L1细胞分化；上调Bax（154.60%和139.37%）、下调Bcl-2（41.10%和45.62%）蛋白的表达，诱导脂肪细胞凋亡。结果提示，WE能在3T3-L1细胞分化过程早期抑制细胞生长、分化和脂肪合成并促进脂肪酸氧化从而有效抑制脂质积累，机制上可能通过调控AMPK和Bax/Bcl-2通路。

Abstract:

The lipid-lowering effects of a water extract of Jasminum grandiflorum L. (WE) and its chemical components on 3T3-L1 preadipocytes was investigated. To determine the inhibitory effects of J. grandiflorum samples on lipid droplet development, oil red O staining was used to quantify and detect triglyceride (TG) contents following the induction of 3T3-L1 preadipocytes to produce mature adipocytes. Liquid chromatography-mass spectrometry was used to analyze the chemical components in the water extract of J. grandiflorum, an MTT assay was used to determine the effects of J. grandiflorum and its components on the proliferation of 3T3-L1 preadipocytes, and western blotting was performed to determine the expression of AMPK, C/EBPα, FAS, ACC, CPT1, Bax, and Bcl-2 proteins. The results revealed that the WE can significantly inhibit the formation of lipid droplets in a dose-dependent manner. A high concentration of WE (500 µg/mL) was found to reduce the contents of neutral lipids and TG by 23.59% and 30.20%, respectively. These effects were found to be most significant during the early stage of fat accumulation, and it was established that the active constituent contributing most to this lipid-lowering effect was oleuropein, with a content of 13.77%. Furthermore, WE and oleuropein were shown to activate the phosphorylation of AMPK (123.19% and 115.98%, respectively) and its downstream target ACC (451.06% and 1 050.0%), and to downregulate the protein expression of its downstream target FAS (81.72% and 60.50%). This had the effect of reducing adipogenesis and increasing the expression of CPT1 (164.84% and 292.19%), and accelerating fatty acid oxidation. Moreover, it inhibited the expression of C/EBPα (68.97% and 34.57%), thereby affecting the differentiation of 3T3-L1 cells, and also upregulated the expression of Bax (154.60% and 139.37%) and downregulated the expression of Bcl-2 (41.10% and 45.62%), thus inducing 3T3-L1 cell apoptosis. These findings indicate that a WE of J. grandiflorum can inhibit cell growth, differentiation, and lipid synthesis, and promote fatty acid oxidation during the early stage of 3T3-L1 cell differentiation, thereby effectively inhibiting lipid accumulation, the underlying mechanism of which may involve the regulation of AMPK and Bax/Bcl-2 pathways.