The Metabolic Effects of Traditional Chinese Medication Qiliqiangxin on H9C2 Cardiomyocytes

Background/aims: A traditional Chinese medicine, Qiliqiangxin (QLQX) has been identified to perform protective effects on myocardium energy metabolism in mice with acute myocardial infarction, though the effects of QLQX on myocardial mitochondrial biogenesis under physiological condition is still largely elusive.

Methods: H9C2 cells were treated with different concentrations of QLQX (0.25, 0.5, and 1.0 µg/mL) from 6 to 48 hours. Oxidative metabolism and glycolysis were measured by oxygen consumption and extracellular acidification with XF96 analyzer (SeaHorse). Mitochondrial content and ultrastructure were assessed by Mitotracker staining, confocal microscopy, flow cytometry, and transmission electron microscopy. Mitochondrial biogenesis-related genes were measured by qRT-PCR and Western blot.

Results: H9C2 cells treated with QLQX exhibited increased glycolysis at earlier time points (6, 12, and 24 hours), while QLQX could enhance oxidative metabolism and mitochondrial uncoupling in H9C2 cells with longer duration of treatment (48 hours). QLQX also increased mitochondrial content and mitochondrial biogenesis-related gene expression levels, including 16sRNA, SSBP1, TWINKLE, TOP1MT and PLOG, with an activation of peroxisome proliferator-activated receptor coactivator 1 alpha (PGC-1α) and its downstream effectors. Silencing PGC-1α could abolish the increased mitochondrial content in H9C2 cells treated with QLQX.

Conclusion: Our study is the first to document enhanced metabolism in cardiomyocytes treated with QLQX, which is linked to increased mitochondrial content and mitochondrial biogenesis via activation of PGC-1α.