Woo Yunju, Lim Ji Sun, Oh Jisun, Lee Jeong Soon, Kim Jong-Sang
School of Food Science and Biotechnology (BK21 plus) and Institute of Agricultural Science and Technology, Kyungpook National University, Daegu 41566, Korea.
Forest Resources Development Institute of Gyeongsangbuk-do, Andong 36605, Korea.
Antioxidants (Basel). 2020 May 22;9(5):449. doi: 10.3390/antiox9050449.
is considered to elicit various beneficial effects against cancer, hyperglycemia, menstrual discomfort, diabetic complications, and detoxification. The young leaves of this plant are exploited as food and also utilized for traditional medicine in East Asian countries, including Korea and China. Our preliminary study demonstrated that ethanolic extract from the leaf (EAE) exhibited the strongest antioxidant enzyme-inducing activity among more than 100 kinds of edible tree leaf extracts. This study investigated whether EAE could attenuate the cognitive deficits caused by oxidative stress in mice. Oral intubation of EAE at 100 mg/kg bw or higher resulted in significant improvements to the memory and behavioral impairment induced via i.p. injection of scopolamine. Furthermore, EAE enhanced the expression levels of hippocampal neurotrophic factors such as brain-derived neurotrophic factor (BDNF) and glial cell-derived neurotrophic factor in mice, activated the Nrf2, and the downstream heme oxygenase-1 (HO-1) a quintessential antioxidant enzyme. As rutin (quercetin-3--rutinose) was abundantly present in EAE and free quercetin was able to induce defensive antioxidant enzymes in an Nrf2-dependent manner, our findings suggested that quercetin derived from rutin via the intestinal microflora played a significant role in the protection of the mouse hippocampus from scopolamine-induced damage through BDNF-mediated Nrf2 activation, thereby dampening cognitive decline.
被认为对癌症、高血糖、月经不适、糖尿病并发症和解毒有多种有益作用。这种植物的嫩叶在包括韩国和中国在内的东亚国家被用作食物，也用于传统医学。我们的初步研究表明，在100多种可食用树叶提取物中，该树叶的乙醇提取物（EAE）表现出最强的抗氧化酶诱导活性。本研究调查了EAE是否能减轻小鼠氧化应激引起的认知缺陷。以100mg/kg体重或更高剂量口服EAE可显著改善腹腔注射东莨菪碱引起的记忆和行为障碍。此外，EAE提高了小鼠海马神经营养因子如脑源性神经营养因子（BDNF）和胶质细胞源性神经营养因子的表达水平，激活了Nrf2及其下游的血红素加氧酶-1（HO-1），一种典型的抗氧化酶。由于EAE中富含芦丁（槲皮素-3-芸香糖），游离槲皮素能够以Nrf2依赖的方式诱导防御性抗氧化酶，我们的研究结果表明，通过肠道微生物群从芦丁衍生而来的槲皮素在保护小鼠海马免受东莨菪碱诱导的损伤中发挥了重要作用，通过BDNF介导的Nrf2激活，从而减轻认知衰退。
