Bisphenol-A Can Inhibit the Enzymatic Activity of Human Superoxide Dismutase

Bisphenol-A (BPA), a synthetic xenoestrogen, is currently being used to produce a wide variety of consumer products. Humans as well as animals are exposed to this ubiquitous compound through ingestion, inhalation, and dermal exposure. The effect of this compound on superoxide dismutase (SOD), an antioxidant enzyme, isolated from human blood was studied using an enzyme inhibition assay. The mode of interaction of BPA on SOD was investigated using modeling and docking studies. Purified human SOD from erythrocytes was used to study the enzyme inhibition assay of BPA. Molecular level interactions of BPA on SOD were also analyzed by modeling and docking studies. Our study demonstrates that BPA has an inhibitory effect on SOD. The docking results showed that it could bind to the active site residues of SOD and could interfere with the catalytic activity of the enzyme. Our study reveals for the first time that BPA can directly inhibit the enzymatic activity of human SOD and thus impairs the free radical scavenging mechanism.