PDK4 and cardiac hypertrophy: In vivo and in vitro experimental data suggest that apigenin alleviates cardiac hypertrophy via suppression of HIF-1α, thereby reversing the expression of PPARα/γ and target genes including glycerol-3-phosphate acyltransferase (GPAT), glucose transporter 4 (GLUT-4), carnitine palmitoyltransferase 1 (CPT-1) and pyruvate dehydrogenase kinase 4 (PDK-4).