Oxidative Stress Research Centre, Institute of Biomedical and Microbial Biotechnology, Cape Peninsula University of Technology, Bellville Campus, Bellville 7535, South Africa.
Department of Medical Biosciences, Faculty of Natural Sciences, University of Western Cape, Bellville, 7535, South Africa.
Phytomedicine. 2019 Jun;59:152898. doi: 10.1016/j.phymed.2019.152898. Epub 2019 Mar 20.
Previous evidence show foods and beverages rich in polyphenolic compounds to have favourable effects on the cardiovascular system.
The current study assessed the modulation of oxidative stress and associated inflammation induced by diesel exhaust particles (DEP - SRM 2975) by pre-treatment of human umbilical vein endothelial cells (HUVECs) with aqueous extracts of rooibos [fermented (FR) as well as green form (GR)] and honeybush [fermented form (FH)].
HUVEC are either exposed to DEP (10 µg/ml) for 4 h or pre-treated with 40 and 60 µg/ml of FR or GH or FR, or 50 µg/ml orientin (OR) for 6 h prior to DEP exposure.
In vitro antioxidant capacity of the extracts was assessed and the polyphenol contents were also assessed by HPLC. ROS, cell viability, lactate dehydrogenase leakage, lipid peroxidation, GSH:GSSG ratios, conjugated diene and protein carbonyl levels were determined as indices of oxidative stress and cytotoxicity. RT-qPCR and western blot were used to assess inflammatory cytokines and antioxidant genes expression.
DEP caused a dose and time-dependent increase in ROS production, significant (p < 0.001) increase in protein carbonyl (PC) formation, thiobarbituric acid reactive substances and conjugated dienes levels (p < 0.01) and a significant reduction in glutathione (GSH) redox status. Pre-incubation with either the herbal extracts or orientin attenuated these effects. The significant increase in IL-1α, IL-6, IL-8, VCAM-1 and ATF4 gene expression caused by DEP (10 µg/ml) were also attenuated by the presence of the FR, GR and FH extracts, and OR . Pre-treatment with the rooibos extracts or flavone orientin enhanced cell viability, reduced LDH leakage, enhanced mRNA expression of NQO1 and Nrf2, but repressed CYP1B1 mRNA induced by DEP. Western blot showed both the herbal tea extracts and orientin to enhance NQO1 and γGSC protein induction by DEP.
Taken together, the herbal extracts offer protection against DEP-induced oxidative stress and inflammatory response.
先前的证据表明，富含多酚化合物的食物和饮料对心血管系统有有益影响。
本研究评估了罗布斯塔茶（发酵（FR）和绿色形式（GR））和霍比布什茶（发酵形式（FH））的水提物预处理对人脐静脉内皮细胞（HUVEC）中由柴油废气颗粒（DEP-SRM 2975）诱导的氧化应激和相关炎症的调节作用。
HUVEC 要么暴露于 DEP（10μg/ml）4 小时，要么用 40 和 60μg/ml 的 FR 或 GH 或 FR，或 50μg/ml 的 orientin（OR）预处理 6 小时，然后暴露于 DEP。
通过 HPLC 评估提取物的体外抗氧化能力，并评估多酚含量。通过测定 ROS、细胞活力、乳酸脱氢酶漏出、脂质过氧化、GSH：GSSG 比、共轭二烯和蛋白质羰基水平来确定氧化应激和细胞毒性的指标。使用 RT-qPCR 和 Western blot 来评估炎症细胞因子和抗氧化基因的表达。
DEP 导致 ROS 产生呈剂量和时间依赖性增加，显著（p<0.001）增加了蛋白质羰基（PC）形成、硫代巴比妥酸反应物质和共轭二烯水平（p<0.01），并显著降低了谷胱甘肽（GSH）氧化还原状态。用草药提取物或 orientin 预先孵育可减弱这些作用。DEP（10μg/ml）引起的 IL-1α、IL-6、IL-8、VCAM-1 和 ATF4 基因表达的显著增加也被 FR、GR 和 FH 提取物和 OR 减弱。用罗布斯塔茶提取物或黄酮 orientin 预处理可增强细胞活力，减少 LDH 漏出，增强 NQO1 和 Nrf2 的 mRNA 表达，但抑制 DEP 诱导的 CYP1B1 mRNA。Western blot 显示，两种草药茶提取物和 orientin 均可增强 DEP 诱导的 NQO1 和γGSC 蛋白诱导。
综上所述，这些草药提取物可防止 DEP 诱导的氧化应激和炎症反应。
