Modification of Caffeic Acid with Pyrrolidine Enhances Antioxidant Ability by Activating AKT/HO-1 Pathway in Heart
作者:Hui-Chun Ku、Shih-Yi Lee、Kai-Chien Yang、Yueh-Hsiung Kuo、Ming-Jai Su
DOI:10.1371/journal.pone.0148545
日期:——
Overproduction of free radicals during ischemia/reperfusion (I/R) injury leads to an interest in using antioxidant therapy. Activating an endogenous antioxidant signaling pathway is more important due to the fact that the free radical scavenging behavior in vitro does not always correlate with a cytoprotection effect in vivo. Caffeic acid (CA), an antioxidant, is a major phenolic constituent in nature. Pyrrolidinyl caffeamide (PLCA), a derivative of CA, was compared with CA for their antioxidant and cytoprotective effects. Our results indicate that CA and PLCA exert the same ability to scavenge DPPH in vitro. In response to myocardial I/R stress, PLCA was shown to attenuate lipid peroxydation and troponin release more than CA. These responses were accompanied with a prominent elevation in AKT and HO-1 expression and a preservation of mnSOD expression and catalase activity. PLCA also improved cell viability and alleviated the intracellular ROS level more than CA in cardiomyocytes exposed to H2O2. When inhibiting the AKT or HO-1 pathways, PLCA lost its ability to recover mnSOD expression and catalase activity to counteract with oxidative stress, suggesting AKT/HO-1 pathway activation by PLCA plays an important role. In addition, inhibition of AKT signaling further abolished HO-1 activity, while inhibition of HO-1 signaling attenuated AKT expression, indicating cross-talk between the AKT and HO-1 pathways. These protective effects may contribute to the cardiac function improvement by PLCA. These findings provide new insight into therapeutic approaches using a modified natural compound against oxidative stress from myocardial injuries.
缺血/再灌注(I/R)损伤过程中自由基的过度产生导致人们对使用抗氧化疗法产生了兴趣。激活内源性抗氧化信号通路更为重要,因为体外清除自由基的行为并不总是与体内的细胞保护效应相关联。抗氧化剂咖啡酸(CA)是自然界中的一种主要酚类成分。研究人员将 CA 的衍生物吡咯烷基咖啡酰胺(PLCA)与 CA 的抗氧化和细胞保护作用进行了比较。结果表明,CA 和 PLCA 在体外清除 DPPH 的能力相同。在心肌I/R应激反应中,PLCA比CA更能减轻脂质过氧化反应和肌钙蛋白的释放。这些反应伴随着 AKT 和 HO-1 表达的显著增加,以及 mnSOD 表达和过氧化氢酶活性的保持。在暴露于 H2O2 的心肌细胞中,PLCA 也比 CA 更能提高细胞活力和缓解细胞内 ROS 水平。当抑制 AKT 或 HO-1 通路时,PLCA 失去了恢复 mnSOD 表达和过氧化氢酶活性以对抗氧化应激的能力,这表明 PLCA 激活 AKT/HO-1 通路发挥了重要作用。此外,抑制 AKT 信号传导会进一步削弱 HO-1 的活性,而抑制 HO-1 信号传导会减弱 AKT 的表达,这表明 AKT 和 HO-1 通路之间存在交叉作用。这些保护作用可能是 PLCA 改善心脏功能的原因。这些发现为利用改性天然化合物对抗心肌损伤氧化应激的治疗方法提供了新的视角。