Kazinol B protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced cardiac injury by modulating the AKT/AMPK/Nrf2 signalling pathway

Qian Zhang; Yuan-Ye Dang; Xiu Luo; Ji-Jun Fu; Zhi-Cong Zou; Xue-Jing Jia; Guo-Dong Zheng; Chu-Wen Li

doi:10.1080/13880209.2023.2173247

Kazinol B protects H9c2 cardiomyocytes from hypoxia/reoxygenation-induced cardiac injury by modulating the AKT/AMPK/Nrf2 signalling pathway

Pharm Biol. 2023 Dec;61(1):362-371. doi: 10.1080/13880209.2023.2173247.

Authors

Qian Zhang¹, Yuan-Ye Dang¹, Xiu Luo¹, Ji-Jun Fu¹, Zhi-Cong Zou¹, Xue-Jing Jia², Guo-Dong Zheng¹, Chu-Wen Li¹

Affiliations

¹ The Fifth Affiliated Hospital, Key Laboratory of Molecular Target & Clinical Pharmacology and the State & NMPA Key Laboratory of Respiratory Disease, School of Pharmaceutical Sciences, Guangzhou Medical University, Guangzhou, China.
² College of Food Science and Technology, Guangdong Ocean University, Zhanjiang, China.

Abstract

Context: Kazinol B (KB), an isoprenylated flavan derived from Broussonetia kazinoki Sieb. (Moraceae) root, has long been used in folk medicine.

Objective: This study examines the protective effects of KB and its underlying mechanisms in hypoxia and reoxygenation (H/R)-induced cardiac injury in H9c2 rat cardiac myoblasts.

Materials and methods: H9c2 cells were incubated with various concentrations of KB (0, 0.3, 1, 3, 10 and 30 μM) for 2 h and then subjected to H/R insults. The protective effects of KB and its underlying mechanisms were explored.

Results: KB significantly elevated cell viability (1 μM, 1.21-fold; 3 μM, 1.36-fold, and 10 μM, 1.47-fold) and suppressed LDH release (1 μM, 0.77-fold; 3 μM, 0.68-fold, and 10 μM, 0.59-fold) in H/R-induced H9c2 cells. Further, 10 μM KB blocked apoptotic cascades, as shown by the Annexin-V/PI (0.41-fold), DNA fragmentation (0.51-fold), caspase-3 (0.52-fold), PARP activation (0.27-fold) and Bax/Bcl-2 expression (0.28-fold) assays. KB (10 μM) downregulated reactive oxygen species production (0.51-fold) and lipid peroxidation (0.48-fold); it upregulated the activities of GSH-Px (2.08-fold) and SOD (1.72-fold). KB (10 μM) induced Nrf2 nuclear accumulation (1.94-fold) and increased ARE promoter activity (2.15-fold), HO-1 expression (3.07-fold), AKT (3.07-fold) and AMPK (3.07-fold) phosphorylation. Nrf2 knockdown via using Nrf2 siRNA abrogated KB-mediated protective effects against H/R insults. Moreover, pharmacological inhibitors of AKT and AMPK also abrogated KB-induced Nrf2 activation and its protective function.

Discussion and conclusions: KB prevented H/R-induced cardiomyocyte injury via modulating the AKT and AMPK-mediated Nrf2 induction. KB might be a promising drug candidate for managing ischemic cardiac disorders.

Keywords: Broussonetia kazinoki; apoptosis; mitochondrial dysfunction; myocardial ischemia; oxidative stress.

MeSH terms

AMP-Activated Protein Kinases / metabolism
Animals
Apoptosis
Hypoxia / drug therapy
Hypoxia / metabolism
Myocytes, Cardiac*
NF-E2-Related Factor 2 / metabolism
Oxidative Stress
Proto-Oncogene Proteins c-akt* / metabolism
Rats

Substances

kazinol B
Proto-Oncogene Proteins c-akt
NF-E2-Related Factor 2
AMP-Activated Protein Kinases

Grants and funding

This work was supported by grants from Guangdong Basic and Applied Basic Research Foundation (2020A1515110899), Science and Technology Projects in Guangzhou (202102020972), Guangzhou Education Bureau Yangcheng Scholars Project (202032774), College Student Laboratory Opening Project of Guangzhou Medical University (PX-1020420) and College Students’ Innovation Training Program of Guangzhou Medical University (2020A081).