Nephroprotective effects of Lippia sidoides ethanolic extract against ischemia/reperfusion-induced acute kidney injury

Abstract Ischemia/reperfusion injury (I/R) is commonly related to acute kidney injury (AKI) and oxidative stress. Antioxidant agents are used to treat this condition. Lippia sidoides is a brazillian shrub with anti-inflammatory and anti-oxidative properties. Thus, the aim of this study is to evaluate the effect of Lippia sidoides ethanolic extract (LSEE) on in vivo and in vitro models of AKI induced by I/R. Male Wistar rats were submitted to unilateral nephrectomy and ischemia on contralateral kidney for 60 min via clamping followed by reperfusion for 48 h. They were divided into four groups: Sham, LSEE (sham-operated rats pre-treated with LSEE), I/R (rats submitted to ischemia) and I/R-LSEE (rats treated with LSEE before ischemia). Kidney tissues homogenates were used to determine stress parameters and nephrin expression. Plasma and urine samples were collected for biochemical analysis. I/R in vitro assays were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide (MTT) and flow cytometry assays in Rhesus Monkey Kidney Epithelial Cells (LLC-MK2). The LSEE treatment prevented biochemical and nephrin expression alterations, as well as oxidative stress parameters. In the in vitro assay, LSEE protected against cell death, reduced the reactive oxygen species and increased mitochondrial transmembrane potential. LSEE showed biotechnological potential for a new phytomedicine as a nephroprotective agent.

摘要 缺血再灌注损伤（Ischemia/reperfusion injury, I/R）常与急性肾损伤（acute kidney injury, AKI）及氧化应激密切相关。抗氧化剂被用于该病症的临床治疗。Lippia sidoides是一种巴西灌木，具备抗炎与抗氧化活性。本研究旨在评估Lippia sidoides乙醇提取物（Lippia sidoides ethanolic extract, LSEE）对缺血再灌注诱导的急性肾损伤体内及体外模型的干预效果。雄性Wistar大鼠先行单侧肾切除术，随后通过夹闭对侧肾脏血流60分钟构建缺血模型，再灌注48小时。将大鼠分为四组：假手术组、LSEE预处理假手术组（假手术大鼠术前给予LSEE干预）、缺血再灌注组（仅行缺血再灌注造模的大鼠）以及缺血再灌注-LSEE干预组（缺血术前给予LSEE治疗的大鼠）。采集肾脏组织匀浆以检测应激相关指标及肾病蛋白（nephrin）的表达水平；采集血浆与尿液样本用于生化指标检测。体外缺血再灌注损伤实验采用恒河猴肾上皮细胞（LLC-MK2），通过3-(4,5-二甲基噻唑-2-基)-2,5-二苯基四氮唑溴盐（3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide, MTT）法及流式细胞术进行评估。结果显示，LSEE干预可阻断缺血再灌注导致的生化指标异常与肾病蛋白表达紊乱，同时改善氧化应激相关指标。体外实验中，LSEE可抑制细胞死亡、减少活性氧生成并提升线粒体跨膜电位。综上，LSEE具备开发为新型植物源性肾保护药物的生物技术潜力。