研究乳酸菌发酵大麦提取物（LFBE）对3T3-L1前脂肪细胞分化及其脂代谢的影响与作用途径。利用植物乳杆菌（Lactobacillus plantarum dy-1）发酵大麦获得LFBE，采用Folin-Ciocalteu法测定总酚含量；凯氏定氮法测定蛋白质含量与苯酚硫酸法测定多糖含量；采用CCK-8法检测细胞增殖能力和油红O染色法分析前脂肪细胞的分化程度；采用Realtime PCR法检测LFBE对脂代谢关键基因转录水平的调控作用。结果表明，与未发酵大麦提取物相比，LFBE中总酚含量增加了20.88%；LFBE中蛋白质含量从发酵前的13.93%增加至34.94%；多糖含量从未发酵时的64.94%下降至35.43%。与未发酵大麦提取物组相比，LFBE能够有效地抑制3T3-L1前脂肪细胞的生长，其IC50约为560 μg/mL；与模型组和未发酵大麦提取物组相比，400 μg/mL LFBE能够显著抑制3T3-L1前脂肪细胞分化，抑制率达到58.85%。与模型组相比，LFBE能显著抑制脂代谢关键基因C/EBPα、PPAR-γ、SREBP-1c、PTP1B和aP2的mRNA表达水平，上调GLUT4的mRNA表达水平（p<0.05）。LFBE可有效抑制3T3-L1前脂肪细胞的增殖，并通过调节脂代谢相关基因的转录水平抑制其分化，表明其可能具有预防肥胖的作用。

Lactobacillus plantarum dy-1 isolated from pickles was used for barley fermentation to obtain Lactobacillus-fermented barley extract (LFBE), and the effect of this extract on 3T3-L1 preadipocyte differentiation and lipid metabolism was investigated. The protein content in the extract was determined by the Kjeldahl method, the total phenol content was measured by the Folin-Ciocalteu method, and the polysaccharide content was determined by the phenol-sulfuric acid method. The proliferation of 3T3-L1 preadipocytes was estimated using the CCK-8 assay and their differentiation was determined using oil red O staining. Furthermore, the regulatory effect of LFBE on the mRNA expression levels of adipogenic genes was measured using real time-polymerase chain reaction (RT-PCR). The total phenol content in the LFBE was higher by 20.88% than the unfermented extract, while the protein content increased from 13.93% to 34.94% after fermentation. However, fermentation caused the polysaccharide content to decrease from 64.94% to 35.43%. Hence, LFBE effectively inhibited the growth of 3T3-L1 preadipocytes in a dose-dependent manner, with an IC50 value of approximately 560 μg/mL. We found that 400 μg/mL of LFBE effectively inhibited the differentiation of 3T3-L1 preadipocytes, and the inhibitory rate achieved was 58.85% higher than that in the positive control. Apart from up-regulating the mRNA level of glucose transporter-4 (GLUT4), LFBE significantly inhibited the mRNA expression of key adipogenic genes including peroxisome proliferator-activated receptor-gamma (PPAR-γ), ccaat-enhancer-binding protein-alpha (C/EBPα), sterol regulatory element-binding protein-1c (SREBP-1c), protein tyrosine phosphatase-1B (PTP1B), and adipocyte protein 2 (aP2). These results indicated that LFBE significantly suppressed adipocyte differentiation and lipid accumulation by inhibiting the transcription of genes related to lipid metabolism. Hence, LFBE has potential applications in the prevention and control of obesity.

江苏高校优势学科建设工程项目；江苏省产学研前瞻性联合研究项目（BY2012172）