Department of Nutrition and Health Sciences, Chinese Culture University, Taipei 11114, Taiwan.
Graduate Institute of Biotechnology, Chinese Culture University, Taipei 11114, Taiwan.
Evid Based Complement Alternat Med. 2013;2013:267217. doi: 10.1155/2013/267217. Epub 2013 Nov 28.
Effects of mulberry leaf-related extracts (MLREs) on hydrogen peroxide-induced DNA damage in human lymphocytes and on inflammatory signaling pathways in human aortic endothelial cells (HAECs) were studied. The tested MLREs were rich in flavonols, especially bombyx faces tea (BT) in quercetin and kaempferol. Polyphenols, flavonoids, and anthocyanidin also abounded in BT. The best trolox equivalent antioxidant capacity (TEAC) was generated from the acidic methanolic extracts of BT. Acidic methanolic and water extracts of mulberry leaf tea (MT), mulberry leaf (M), and BT significantly inhibited DNA oxidative damage to lymphocytes based on the comet assay as compared to the H2O2-treated group. TNF- α -induced monocyte-endothelial cell adhesion was significantly suppressed by MLREs. Additionally, nuclear factor kappa B (NF- κ B) expression was significantly reduced by BT and MT. Significant reductions were also observed in both NF- κ B and activator protein (AP)-1 DNA binding by MLREs. Significant increases in peroxisome proliferator-activated receptor (PPAR) α and γ DNA binding by MLREs were also detected in M and MT extracts, but no evidence for PPAR α DNA binding in 50 μ g/mL MT extract was found. Apparently, MLREs can provide distinct cytoprotective mechanisms that may contribute to its putative beneficial effects on suppressing endothelial responses to cytokines during inflammation.
研究了桑叶相关提取物（MLREs）对人淋巴细胞中过氧化氢诱导的 DNA 损伤和人主动脉内皮细胞（HAECs）中炎症信号通路的影响。测试的 MLREs 富含类黄酮，尤其是桑茶（BT）中的槲皮素和山奈酚。多酚、类黄酮和花青素在 BT 中也很丰富。BT 的酸性甲醇提取物产生了最佳 Trolox 等效抗氧化能力（TEAC）。与 H2O2 处理组相比，基于彗星试验，桑茶（MT）、桑叶（M）和 BT 的酸性甲醇和水提取物显著抑制了淋巴细胞的 DNA 氧化损伤。MLREs 显著抑制了 TNF-α诱导的单核细胞-内皮细胞黏附。此外，BT 和 MT 还显著降低了核因子 kappa B（NF-κB）的表达。MLREs 还显著降低了 NF-κB 和激活蛋白（AP）-1 的 DNA 结合。还检测到 MLREs 使 M 和 MT 提取物中的过氧化物酶体增殖物激活受体（PPAR）α和γ的 DNA 结合显著增加，但在 50μg/mL MT 提取物中未发现 PPARα DNA 结合的证据。显然，MLREs 可以提供不同的细胞保护机制，这可能有助于其对抑制炎症期间细胞因子诱导的内皮反应的潜在有益作用。
