Ethyl 3,4-Dihydroxybenzoate is an antioxidant compound. It also exhibits anti-inflammatory, anti-parasitic, antibacterial, anti-metastatic, and anticancer activities. Protocatechuic acid inhibits TNF-induced expression and release of adhesion molecules and pro-inflammatory cytokines as well as ADP-induced expression of platelet P-selectin. This compound increases quinone reductase activity and acts as a radical scavenger. Protocatechuic acid ethyl ester inhibits RhoB activation, decreasing expression of matrix metalloproteinase 2 (MMP2) and inactivating NF-κB and also inhibits human topoisomerase II.