Inhibition of lipoxygenase-1 by tetrahydrocurcumin

Tetrahydrocurcumin (THC)—the reduced form of curcumin—is more hydrophilic than its parent compound. It possesses higher stability in aqueous medium compared to curcumin. Lipoxygenase (LOX) enzyme is implicated in inflammatory conditions. THC was investigated for the inhibition of soy LOX-1. THC-inhibited LOX-1 with an IC50 value of 44.6 ± 0.6 μM. Kinetics of inhibition revealed mixed linear type with a Ki value of 46 μM. THC-inhibited LOX-1 by preventing the activation of LOX-1 as evidenced from spectroscopic studies. Molecular docking simulations suggested the binding of THC near the iron cofactor. This study helps in further understanding of the anti-inflammatory property of curcumin derivatives and provides valuable leads as an alternative of curcumin with better solubility and stability at physiological pH.