Yang Zhong-Bao, Tan Bin, Li Ting-Bo, Lou Zheng, Jiang Jun-Lin, Zhou Ying-Jun, Yang Jie, Luo Xiu-Ju, Peng Jun
Department of Pharmacology, School of Pharmaceutical Sciences, Central South University, No. 110 Xiang-Ya Road, Changsha, 410078, China.
Naunyn Schmiedebergs Arch Pharmacol. 2014 Sep;387(9):861-71. doi: 10.1007/s00210-014-1006-0. Epub 2014 Jun 20.
Vitexin compound B-1 (VB-1) is a novel member of the vitexins family isolated from the seeds of the Chinese herb Vitex negundo. This study aims to investigate whether VB-1 is able to protect nerve cells against oxidative injury and whether the antioxidative effects of VB-1 occur through a mechanism involving the inhibition of NADPH oxidase (NOX) in a manner of hypoxia-inducible factor 1α (HIF-1α)-dependent. To establish a neuronal in vitro model of oxidative stress, the differentiated PC12 cells were subjected to 5 h of hypoxia followed by 20 h of reoxygenation (H/R). Three dosages of VB-1 (10(-8), 10(-7), and 10(-6) M) were chosen to evaluate the effect of VB-1 on H/R-induced injury and the underlying mechanisms. At the end of the experiments, culture mediums and cells were collected for analysis of cellular apoptosis, lactate dehydrogenase (LDH) and caspase 3/7-like activities, reactive oxygen species (ROS) levels, 4-hydroxynonenal (4-HNE) and malondialdehye (MDA) contents, and HIF-1α and NOX expression, respectively. Our results showed that cell injury (indicated by apoptosis ratio, caspase 3/7-like activity, and LDH release), oxidative stress (indicated by ROS production, 4-HNE, and MDA contents), NOX activity, and NOX expression (NOX2 and NOX4 isoforms) were dramatically increased in PC12 cells following H/R, which were attenuated in the presence of VB-1 at dosage of 10(-7) or 10(-6) M. There was no significant change in HIF-1α expression in all experimental groups. These results provide evidence that VB-1 is able to protect the PC12 cells against H/R-induced injury through a mechanism involving the suppression of NOX expression and subsequent reduction of ROS production. The effect of VB-1 on H/R-induced NOX expression is independent on HIF-1α inhibition.
牡荆素化合物B-1（VB-1）是从中药黄荆种子中分离出的牡荆素家族的一个新成员。本研究旨在探讨VB-1是否能够保护神经细胞免受氧化损伤，以及VB-1的抗氧化作用是否通过一种涉及以缺氧诱导因子1α（HIF-1α）依赖性方式抑制NADPH氧化酶（NOX）的机制发生。为建立氧化应激的神经元体外模型，将分化的PC12细胞进行5小时缺氧，随后再进行20小时复氧（H/R）。选择三种剂量的VB-1（10^(-8)、10^(-7)和10^(-6) M）来评估VB-1对H/R诱导损伤的影响及其潜在机制。在实验结束时，分别收集培养基和细胞，用于分析细胞凋亡、乳酸脱氢酶（LDH）和半胱天冬酶3/7样活性、活性氧（ROS）水平、4-羟基壬烯醛（4-HNE）和丙二醛（MDA）含量以及HIF-1α和NOX表达。我们的结果表明，H/R后PC12细胞中的细胞损伤（以凋亡率、半胱天冬酶3/7样活性和LDH释放表示）、氧化应激（以ROS产生、4-HNE和MDA含量表示）、NOX活性和NOX表达（NOX2和NOX4亚型）显著增加，而在10^(-7)或10^(-6) M剂量的VB-1存在下这些指标减弱。所有实验组中HIF-1α表达均无显著变化。这些结果证明，VB-1能够通过一种涉及抑制NOX表达并随后减少ROS产生的机制保护PC12细胞免受H/R诱导的损伤。VB-1对H/R诱导的NOX表达的影响不依赖于HIF-1α抑制。
