Liufang Hu1, Jianhui Sun2, Hongmei Li3, Lifang Wang4, Yuna Wei5, Ying Wang6, Yaying Zhu7, Hairu Huo8, Yuqing Tan9. 1. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: cacms2014@163.com. 2. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: sjh121858@sina.com. 3. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: sinomd@sina.com. 4. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: wanglifang73@163.com. 5. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: weiyuna0914@163.com. 6. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: 15189802005@163.com. 7. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: zhuysml75@sina.com. 8. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: hrhuo@sohu.com. 9. Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing 100700, China. Electronic address: yqtan@icmm.ac.cn.
Abstract
BACKGROUND AND PURPOSE: The clinical use of arsenic trioxide (As2O3) for treating acute promyelocytic leukemia (APL) is limited due to its severe cardiotoxicity. The possible mechanisms of As2O3-induced cardiotoxicity include DNA fragmentation, reactive oxygen species (ROS) generation, cardiac ion channel changes and apoptosis. The present study is designed to investigate the protective effects of imperatorin and sec-O-glucosylhamaudol and to explore their mechanistic involvement in As2O3-induced cytotoxicity. EXPERIMENTAL METHODS: Cell viability assay, Lactate dehydrogenase (LDH) release, Acridine orange/ethidium bromide (AO/EB) double staining, Caspase-3 activity assay, ROS generation, cellular calcium levels, mRNA expression levels by qRT-PCR and protein expression levels by Western blotting were measured in H9c2 cells in combination with As2O3 and imperatorin or sec-O-glucosylhamaudol. KEY RESULTS: We observed that H9c2 cells treated with imperatorin or sec-O-glucosylhamaudol were more resistant to As2O3-induced cell death. Both imperatorin and sec-O-glucosylhamaudol reduced H9c2 cell apoptosis, but both imperatorin and sec-O-glucosylhamaudol had no effects on Caspase-3 activity and intracellular calcium accumulation. Furthermore, imperatorin was capable of suppressing ROS generation, while sec-O-glucosylhamaudol did not show this effect. Moreover, imperatorin and sec-O-glucosylhamaudol triggered Nrf2 activation, which resulted in upregulation of downstream phase II metabolic enzymes and antioxidant protein/enzyme, probably offering cellular protection to As2O3-induced cardiotoxicity via the Nrf2 signal pathway. CONCLUSIONS AND IMPLICATIONS: Imperatorin and sec-O-glucosylhamaudol can ameliorate As2O3-induced cytotoxicity and apoptosis in H9c2 cells, the mechanisms probably related to antioxidation. As2O3 in combination with imperatorin or sec-O-glucosylhamaudol could be considered as a novel strategy to expand the clinical application of As2O3.
BACKGROUND AND PURPOSE: The clinical use of arsenic trioxide (As2O3) for treating acute promyelocytic leukemia (APL) is limited due to its severe cardiotoxicity. The possible mechanisms of As2O3-induced cardiotoxicity include DNA fragmentation, reactive oxygen species (ROS) generation, cardiac ion channel changes and apoptosis. The present study is designed to investigate the protective effects of imperatorin and sec-O-glucosylhamaudol and to explore their mechanistic involvement in As2O3-induced cytotoxicity. EXPERIMENTAL METHODS: Cell viability assay, Lactate dehydrogenase (LDH) release, Acridine orange/ethidium bromide (AO/EB) double staining, Caspase-3 activity assay, ROS generation, cellular calcium levels, mRNA expression levels by qRT-PCR and protein expression levels by Western blotting were measured in H9c2 cells in combination with As2O3 and imperatorin or sec-O-glucosylhamaudol. KEY RESULTS: We observed that H9c2 cells treated with imperatorin or sec-O-glucosylhamaudol were more resistant to As2O3-induced cell death. Both imperatorin and sec-O-glucosylhamaudol reduced H9c2 cell apoptosis, but both imperatorin and sec-O-glucosylhamaudol had no effects on Caspase-3 activity and intracellular calcium accumulation. Furthermore, imperatorin was capable of suppressing ROS generation, while sec-O-glucosylhamaudol did not show this effect. Moreover, imperatorin and sec-O-glucosylhamaudol triggered Nrf2 activation, which resulted in upregulation of downstream phase II metabolic enzymes and antioxidant protein/enzyme, probably offering cellular protection to As2O3-induced cardiotoxicity via the Nrf2 signal pathway. CONCLUSIONS AND IMPLICATIONS: Imperatorin and sec-O-glucosylhamaudol can ameliorate As2O3-induced cytotoxicity and apoptosis in H9c2 cells, the mechanisms probably related to antioxidation. As2O3 in combination with imperatorin or sec-O-glucosylhamaudol could be considered as a novel strategy to expand the clinical application of As2O3.