Luteolin improves myocardial cell glucolipid metabolism by inhibiting hypoxia inducible factor-1α expression in angiotensin II/hypoxia-induced hypertrophic H9c2 cells.

Luteolin, a natural flavonoid, can attenuate hepatic lipid accumulation and insulin resistance in obese mice. Therefore, we hypothesized that luteolin may also improve the abnormal glucolipid metabolism of hypertrophic myocardial cells. This study aimed to investigate the effect and possible molecular mechanisms of luteolin. Hypertrophic H9c2 cells were induced by angiotensin II/hypoxia and simultaneously treated with 2 to 8 μg/mL luteolin for 24 h. Luteolin might dose-dependently decrease intracellular total protein, atrial natriuretic peptide, and free fatty acid levels, and increase supernatant glucose levels. Western blot assay showed that luteolin could inhibit the expressions of intracellular hypoxia inducible factor-1α (HIF-1α) and glucose transporter-4 (GLUT-4) proteins, and increase the expressions of intracellular peroxisome proliferator-activated receptor α (PPARα), carnitine palmitoyltransferase-1A (CPT-1A), and pyruvate dehydrogenase kinase-4 (PDK-4) proteins. These findings demonstrate that luteolin can improve abnormal glucolipid metabolism in angiotensin II/hypoxia-induced hypertrophic H9c2 cells, and its mechanisms are related to the inhibition of HIF-1α expression and subsequent modulation of PPARα-mediated target genes, including CPT-1A, PDK-4, and GLUT-4.