Institute of Environmental Science for Human Life, Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
Endowed Research Department "Food for Health," Ochanomizu University, 2-1-1 Otsuka, Bunkyo-ku, Tokyo 112-8610, Japan.
Nutr Res. 2015 Jan;35(1):56-64. doi: 10.1016/j.nutres.2014.10.010. Epub 2014 Oct 20.
Polyphenols are widely distributed in leaves, seeds, bark, and flowers and considered to have beneficial effects on cardiovascular health. We hypothesized that the potent antioxidant properties of pine bark extract (PBE) are exerted by its ability to scavenge free radicals and induce antioxidant enzymes. Therefore, we investigated the effects of PBE on low-density lipoprotein (LDL) oxidation and the antioxidant defense system in monocytes. Oxidative susceptibility of LDL was determined by lag time assay in vitro and by using a human umbilical vein endothelial cell-mediated oxidation model. THP-1 monocytic cells were treated with PBE, and the expression of antioxidant enzymes was measured by real-time polymerase chain reaction and Western blot. Pine bark extract showed radical scavenging ability and significantly inhibited free radical-induced and endothelial cell-mediated LDL oxidation in vitro. Pine bark extract treatment resulted in increases in the expressions of antioxidant enzymes, glutathione peroxidase-1, catalase, and heme oxygenase-1 in THP-1 cells. In addition, PBE induced nuclear factor-erythroid-2-related factor 2 activation, which was accompanied by the activation of extracellular signal-regulated kinase and Akt despite a down-regulation of reactive oxygen species. After the monocyte investigations, we further examined the antioxidant effect after the intake of PBE by 10 healthy male volunteers. Pine bark extract significantly prolonged the lag time of LDL oxidation. Based on our findings, it appears that PBE enhances the antioxidant defense capacity of LDL and monocytes and may play a preventive role in atherosclerosis progression.
多酚广泛存在于叶片、种子、树皮和花朵中，被认为对心血管健康有益。我们假设松树皮提取物（PBE）的强大抗氧化特性是通过其清除自由基和诱导抗氧化酶的能力发挥作用的。因此，我们研究了 PBE 对低密度脂蛋白（LDL）氧化和单核细胞抗氧化防御系统的影响。通过体外迟滞时间测定和人脐静脉内皮细胞介导的氧化模型来确定 LDL 的氧化易感性。用 PBE 处理 THP-1 单核细胞，并通过实时聚合酶链反应和 Western blot 测量抗氧化酶的表达。松树皮提取物显示出自由基清除能力，并显著抑制了体外自由基诱导和内皮细胞介导的 LDL 氧化。松树皮提取物处理导致 THP-1 细胞中抗氧化酶、谷胱甘肽过氧化物酶-1、过氧化氢酶和血红素加氧酶-1 的表达增加。此外，PBE 诱导核因子-红细胞 2 相关因子 2 的激活，尽管活性氧的下调，但伴随着细胞外信号调节激酶和 Akt 的激活。在单核细胞研究之后，我们进一步检查了 10 名健康男性志愿者摄入 PBE 后的抗氧化作用。松树皮提取物显著延长了 LDL 氧化的迟滞时间。根据我们的发现，PBE 似乎增强了 LDL 和单核细胞的抗氧化防御能力，并可能在动脉粥样硬化进展中发挥预防作用。
