Pakalapati Geeta, Li Li, Gretz Norbert, Koch Egon, Wink Michael
Institute of Pharmacy and Molecular Biotechnology, University of Heidelberg, INF 364, Heidelberg, Germany.
Phytomedicine. 2009 Sep;16(9):845-55. doi: 10.1016/j.phymed.2009.03.003. Epub 2009 May 5.
Isoflavones such as genistein, biochanin A, formononetin, and glycetin are fairly abundant in red clover (Trifolium pratense, Fabaceae) and show estrogenic, antioxidant and hypolipidemic activities. To explore these effects mediated by red clover extract at the gene and protein levels, female ovariectomized rats were treated with an isoflavone rich extract of T. pratense. The experimental rats were divided into 2 groups of five animals each: a) control b) experimental group (red clover extract treated with 450mg/kg/day for four days). The treatment influenced the plasma lipid levels differentially. Plasma LDL concentrations were significantly reduced (p<0.05), whereas triglycerides increased (p<0.05). Plasma HDL and total cholesterol remained unchanged. The rat livers were examined for their differential gene expression by Affymetrix Rae230 DNA microarrays. In addition, the total liver proteins were separated by 2D PAGE and proteins, which showed differences in their intensities were identified by MALDI-TOF-MS. The extract influenced the transcript levels of many novel estrogen and non-estrogen responsive genes as well as other regulatory genes. Functional annotations indicate that genes involved in metabolic pathways, information processing, membrane transport regulation, signal transduction and other cellular processes were regulated. Quantitative reverse transcription analysis with real-time PCR confirmed that red clover extract regulates genes involved in lipid metabolism and antioxidation mechanisms. Proteomic analysis support the potential of red clover extract to modulate the lipid metabolism. In summary isoflavone rich red clover extract mediates numerous genomic and non-genomic effects, which influence besides the lipid metabolism a broad range of cellular functions, including metabolic actions, cell cycle regulation and antioxidant activity.
染料木黄酮、鹰嘴豆芽素A、芒柄花黄素和大豆黄素等异黄酮在红车轴草（豆科车轴草属）中含量相当丰富，并具有雌激素活性、抗氧化活性和降血脂活性。为了在基因和蛋白质水平上探究红车轴草提取物介导的这些作用，对雌性去卵巢大鼠给予富含异黄酮的红车轴草提取物进行处理。将实验大鼠分为两组，每组五只：a）对照组；b）实验组（用450mg/kg/天的红车轴草提取物处理四天）。该处理对血浆脂质水平产生了不同影响。血浆低密度脂蛋白（LDL）浓度显著降低（p<0.05），而甘油三酯升高（p<0.05）。血浆高密度脂蛋白（HDL）和总胆固醇保持不变。通过Affymetrix Rae230 DNA微阵列检测大鼠肝脏的差异基因表达。此外，通过二维聚丙烯酰胺凝胶电泳（2D PAGE）分离肝脏总蛋白，并用基质辅助激光解吸电离飞行时间质谱（MALDI-TOF-MS）鉴定强度有差异的蛋白质。该提取物影响了许多新的雌激素和非雌激素反应基因以及其他调控基因的转录水平。功能注释表明，参与代谢途径、信息处理、膜转运调节、信号转导和其他细胞过程的基因受到了调控。实时定量逆转录聚合酶链反应（qRT-PCR）分析证实，红车轴草提取物可调节参与脂质代谢和抗氧化机制的基因。蛋白质组学分析支持红车轴草提取物调节脂质代谢的潜力。总之，富含异黄酮的红车轴草提取物介导了许多基因组和非基因组效应，除了脂质代谢外，还影响广泛的细胞功能，包括代谢作用、细胞周期调节和抗氧化活性。
