title: Curcumin differs from tetrahydrocurcumin for molecular targets, signaling pathways and cellular responses.
abstract: Curcumin (diferuloylmethane), a golden pigment from turmeric, has been linked with antioxidant, anti-inflammatory, anticancer, antiviral, antibacterial, and antidiabetic properties. Most of the these activities have been assigned to methoxy, hydroxyl, α,β-unsaturated carbonyl moiety or to diketone groups present in curcumin. One of the major metabolites of curcumin is tetrahydrocurcumin (THC), which lacks α,β-unsaturated carbonyl moiety and is white in color. Whether THC is superior to curcumin on a molecular level is unclear and thus is the focus of this review. Various studies suggest that curcumin is a more potent antioxidant than THC; curcumin (but not THC) can bind and inhibit numerous targets including DNA (cytosine-5)-methyltransferase-1, heme oxygenase-1, Nrf2, β-catenin, cyclooxygenase-2, NF-kappaB, inducible nitric oxide synthase, nitric oxide, amyloid plaques, reactive oxygen species, vascular endothelial growth factor, cyclin D1, glutathione, P300/CBP, 5-lipoxygenase, cytosolic phospholipase A2, prostaglandin E2, inhibitor of NF-kappaB kinase-1, -2, P38MAPK, p-Tau, tumor necrosis factor-α, forkhead box O3a, CRAC; curcumin can inhibit tumor cell growth and suppress cellular entry of viruses such as influenza A virus and hepatitis C virus much more effectively than THC; curcumin affects membrane mobility; and curcumin is also more effective than THC in suppressing phorbol-ester-induced tumor promotion. Other studies, however, suggest that THC is superior to curcumin for induction of GSH peroxidase, glutathione-S-transferase, NADPH: quinone reductase, and quenching of free radicals. Most studies have indicated that THC exhibits higher antioxidant activity, but curcumin exhibits both pro-oxidant and antioxidant properties.
authors.affiliation: Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston 77054, TX, USA. aggarwal@mdanderson.org.
authors.forename: Bharat B
authors.initials: BB
authors.lastname: Aggarwal
authors.affiliation: Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston 77054, TX, USA. lokeshdeb@gmail.com.
authors.forename: Lokesh
authors.initials: L
authors.lastname: Deb
authors.affiliation: Cytokine Research Laboratory, Department of Experimental Therapeutics, The University of Texas MD Anderson Cancer Center, Houston 77054, TX, USA. spbiotech@gmail.com.
authors.forename: Sahdeo
authors.initials: S
authors.lastname: Prasad
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000737:chemistry / Q000494:pharmacology; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D000975:Antioxidants / Q000737:chemistry / Q000494:pharmacology; D000998:Antiviral Agents / Q000737:chemistry / Q000494:pharmacology; D003474:Curcumin / Q000031:analogs & derivatives* / Q000737:chemistry / Q000494:pharmacology*; D006801:Humans; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D000893:Anti-Inflammatory Agents; D000970:Antineoplastic Agents; D000975:Antioxidants; D000998:Antiviral Agents; C096277:tetrahydrocurcumin; D003474:Curcumin