Ethyl 3, 4-dihydroxybenzoate

Ethyl 3, 4-dihydroxybenzoate (Protocatechuic acid ethyl ester) is an orally effective, blood-brain permeable, competitive prolyl hydroxylase (PHD) inhibitor that prevents HIF hydroxylation. It stabilizes HIF-1α by inhibiting PHD, activating downstream pathways to induce tumor cell autophagy and apoptosis. It also regulates inflammatory responses, inhibits NF-κB, improves vascular permeability, and promotes osteoblast differentiation. Ethyl 3, 4-dihydroxybenzoate has antitumor, anti-hypoxic injury, and bone metabolism regulation effects, with potential for cardiovascular protection (e.g., reducing myocardial ischemic damage), bone tissue engineering (promoting osteogenesis/inhibiting osteoclast differentiation), and high-altitude cerebral edema prevention.