School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, 510006, China.
School of Traditional Chinese Medicine, Guangdong Pharmaceutical University, Guangzhou, 510006, China; Guangdong Provincial Engineering Center of Topical Precise Drug Delivery System, Guangdong Pharmaceutical University, Guangzhou, 510006, Guangdong, China.
J Ethnopharmacol. 2022 Oct 5;296:115361. doi: 10.1016/j.jep.2022.115361. Epub 2022 May 21.
Anoectochilus roxburghii (A. roxburghii) is a precious herb and folk medicine in many Asian countries. It has been used traditionally to treat diabetes, etc., and also used as a dietary therapy to delay senescence.
This study was to evaluate the neuroprotective effects of A. roxburghii flavonoids extract (ARF) and whether its effects were due to the regulation of SIRT1 signaling pathway in senescent mice and in D-galactose (D-gal) induced aging in SH-SY5Y cells.
18-month-old mice were randomly divided into senescent model, low-dose ARF, high-dose ARF and vitamin E group. 2-Month-old mice were as a control group. After 8 weeks treatment, Morris water maze (MWM) was performed. The levels of reactive oxygen species (ROS), malondialdehyde (MDA), superoxide dismutase (SOD), monoamine oxidase (MAO) and acetylcholinesterase (ACh-E) in the cortex were determined. Hippocampus morphologic changes were observed with haematoxylin and eosin (H&E), Nissl, senescence-associated-galactosidase (SA-β-gal) and terminal deoxynucleotidyl transferase nick-end labeling (TUNEL) staining. Apoptosis-related molecular expressions in the hippocampus were performed by western blotting. Furthermore, after stimulated by EX527 (a SIRT1 inhibitor), the SIRT1-dependent neuroprotective effects of ARF were determined by measuring SRIT1 and p53 expression in SH-SY5Y aging cells induced by D-gal.
ARF could significantly ameliorate memory decline in senescent mice and reduce the generations of ROS, MDA and the activities of MAO and ACh-E, while increasing SOD activities in the cortex of aging mice. ARF obviously improved hippocampus pathological alterations, increased the number of Nissl bodies, while reducing senescent and apoptotic cells in senescent mice hippocampus. Further, ARF positively regulated SIRT1 expression, and reduced apoptosis-related molecules p53, p21 and Caspase-3 expression, while increasing the ratio of Bcl-2/Bax. In D-gal-induced SH-SY5Y cells, the effects of ARF on SIRT1 and p53, and the ability of scavenging ROS were mostly abolished after incubation with the EX527.
ARF, in a SIRT1-dependent manner, exerted neuroprotection via modulating SIRT1/p53 signaling pathway against memory decline and apoptosis due to age-induced oxidative stress damage in senescent mice.
铁皮石斛（A. roxburghii）是许多亚洲国家的一种珍贵草药和民间药物。传统上，它被用于治疗糖尿病等疾病，也被用作延缓衰老的饮食疗法。
本研究旨在评估铁皮石斛黄酮提取物（ARF）的神经保护作用，以及其作用是否是由于 SIRT1 信号通路在衰老小鼠和 D-半乳糖（D-gal）诱导的 SH-SY5Y 细胞衰老中的调节。
将 18 个月大的小鼠随机分为衰老模型组、低剂量 ARF 组、高剂量 ARF 组和维生素 E 组。2 个月大的小鼠作为对照组。8 周治疗后，进行 Morris 水迷宫（MWM）测试。测定皮质中活性氧（ROS）、丙二醛（MDA）、超氧化物歧化酶（SOD）、单胺氧化酶（MAO）和乙酰胆碱酯酶（ACh-E）的水平。用苏木精和伊红（H&E）、尼氏染色、衰老相关-β-半乳糖苷酶（SA-β-gal）和末端脱氧核苷酸转移酶缺口末端标记（TUNEL）染色观察海马形态变化。通过蛋白质印迹法检测海马中与细胞凋亡相关的分子表达。此外，在 EX527（一种 SIRT1 抑制剂）刺激后，通过测量 D-gal 诱导的 SH-SY5Y 衰老细胞中 SIRT1 和 p53 的表达，确定 ARF 的 SIRT1 依赖性神经保护作用。
ARF 可显著改善衰老小鼠的记忆减退，并降低皮质中 ROS、MDA 和 MAO 和 ACh-E 的产生，同时增加衰老小鼠 SOD 活性。ARF 明显改善海马病理改变，增加尼氏小体数量，同时减少衰老和凋亡细胞在衰老小鼠海马中的数量。此外，ARF 正向调节 SIRT1 表达，降低凋亡相关分子 p53、p21 和 Caspase-3 表达，同时增加 Bcl-2/Bax 比值。在 D-gal 诱导的 SH-SY5Y 细胞中，用 EX527 孵育后，ARF 对 SIRT1 和 p53 的作用以及清除 ROS 的能力大部分被消除。
ARF 通过调节 SIRT1/p53 信号通路，在衰老小鼠中发挥神经保护作用，对抗因年龄引起的氧化应激损伤导致的记忆减退和细胞凋亡，这种作用依赖于 SIRT1。
