Kim Young Sook, Lee Yun Mi, Kim Joo Hwan, Kim Jin Sook
Korean Medicine-Based Herbal Drug Development Group, Herbal Medicine Research Division, Korea Institute of Oriental Medicine (KIOM), Daejeon 305-811, Republic of Korea.
BMC Complement Altern Med. 2013 Oct 25;13:282. doi: 10.1186/1472-6882-13-282.
Obesity causes metabolic disease and is a serious health problem around the world. Polygonum cuspidatum (POCU1b) has been used clinically for the treatment of constipation, gallstones, hepatitis, and inflammation in East Asian countries. The principal aim of this study was to investigate for the first time whether the extract of Polygonum cuspidatum (POCU) biologically affects adipogenesis in 3 T3-L1 preadipocytes.
Fractions (n-hexan, ethyl acetate, n-butanol, and water) of POCU ethanol extract were evaluated in vitro for their inhibitory activities on pancreatic lipase. Of the fractions, the n-butanol of POCU ethanol extract (POCU1b) was examined anti-obesity activity in 3 T3-L1 preadipocytes. To examine the inhibitory effect of POCU1b on adipogenesis, 3 T3-L1 preadipocytes were treated every the other day with POCU1b at various concentrations (0 ~ 25 μg/mL) for twelve days. Oil-red O staining and triglyceride content assay were performed to determine the lipid accumulation. The expression of mRNA and proteins associated lipid accumulation was measured using RT-PCR and Western blotting analysis. We also examined the effect of POCU1b on level of phosphorylated AMP-activated protein kinase (pAMPK) in 3 T3-L1 preadipocytes with POCU1b at various concentrations during adipocyte differentiation.
POCU1b exhibited the most pronounced inhibitory effects on pancreatic lipase activity. We found that POCU1b inhibited adipocyte differentiation in 3 T3-L1 preadipocytes in a dose-dependent manner, as evidenced by the reduced formation of lipid droplets and decreased glycerol-3-phosphate dehydrogenase (GPDH) activity. We also showed that the expression levels of adipocyte differentiation-related protein (ADRP) and perilipin (a protein that coats lipid droplets in adipocytes) were both reduced after POCU1b treatment. Peroxisome proliferator-activated receptor-gamma (PPAR-γ) and CCAAT/enhancer-binding protein-alpha (C/EBP-α) proteins, both major adipogenic transcription factors, were markedly reduced by POCU1b. Moreover, ADRP, perilipin, C/EBP-α, and PPAR-γ mRNA levels were also reduced by POCU1b. Levels of phosphorylated AMP-activated protein kinase (pAMPK) were elevated after POCU1b treatment (5, 10, and 25) in a dose-dependent manner.
Taken together, these results suggest that the anti-obesity effects of POCU1b involve the inhibition of pancreatic lipase activity and adipogenesis via the down-regulation of lipid accumulation.
肥胖会引发代谢性疾病，是全球范围内严重的健康问题。在东亚国家，虎杖已被临床用于治疗便秘、胆结石、肝炎及炎症。本研究的主要目的是首次探究虎杖提取物（POCU）对3T3-L1前脂肪细胞脂肪生成是否具有生物学影响。
体外评估POCU乙醇提取物的各馏分（正己烷、乙酸乙酯、正丁醇和水）对胰脂肪酶的抑制活性。在这些馏分中，检测POCU乙醇提取物的正丁醇馏分（POCU1b）对3T3-L1前脂肪细胞的抗肥胖活性。为检测POCU1b对脂肪生成的抑制作用，每隔一天用不同浓度（0~25μg/mL）的POCU1b处理3T3-L1前脂肪细胞，持续12天。进行油红O染色和甘油三酯含量测定以确定脂质蓄积情况。使用逆转录聚合酶链反应（RT-PCR）和蛋白质免疫印迹分析来检测与脂质蓄积相关的mRNA和蛋白质表达。我们还检测了在脂肪细胞分化过程中，不同浓度的POCU1b对3T3-L1前脂肪细胞中磷酸化腺苷酸活化蛋白激酶（pAMPK）水平的影响。
POCU1b对胰脂肪酶活性表现出最显著的抑制作用。我们发现POCU1b以剂量依赖性方式抑制3T3-L1前脂肪细胞的脂肪细胞分化，脂滴形成减少和甘油-3-磷酸脱氢酶（GPDH）活性降低证明了这一点。我们还表明，POCU1b处理后，脂肪细胞分化相关蛋白（ADRP）和围脂滴蛋白（一种包裹脂肪细胞中脂滴的蛋白质）的表达水平均降低。过氧化物酶体增殖物激活受体γ（PPAR-γ）和CCAAT/增强子结合蛋白α（C/EBP-α）这两种主要的脂肪生成转录因子蛋白均被POCU1b显著降低。此外，POCU1b还降低了ADRP、围脂滴蛋白、C/EBP-α和PPAR-γ的mRNA水平。POCU1b处理（5、10和25μg/mL）后，磷酸化腺苷酸活化蛋白激酶（pAMPK）水平呈剂量依赖性升高。
综上所述，这些结果表明POCU1b的抗肥胖作用涉及通过下调脂质蓄积来抑制胰脂肪酶活性和脂肪生成。
