To explore the effect of acacetin on myocardial mitochondrial dysfunction in spontaneously hypertensive rats (SHR) with insulin resistance (IR), and the possible mechanism. Rapid IR was first induced in fructose-fed SHR, and they were then treated with acacetin (25, 50 mg/kg). After 7 weeks, the rats were tested for hypertension, IR, cardiac function, and mitochondrial damage status. Potential mechanisms of action were explored in terms of oxidative stress, mitochondrial fission and division, apoptosis, and the insulin signaling pathway. Subsequently, the PI3K gene was silenced, after intervention with acacetin (5 μM) for 24 h, and H