HDAC1 and Myocardial fibrosis: Furthermore, molecular docking and dynamics simulations indicated that protocatechuic acid stably binds to a key target, HDAC1.<h4>Conclusions</h4>Protocatechuic acid alleviates inflammation and EndMT by inhibiting the HDAC1/GATA4 signaling pathway, thereby preserving cardiac function and retarding the progression of myocardial fibrosis.