Concentration of curcuminoids and metabolites in plasma (uM) and brain (nmol/g) after i.v. injection. (A) Time course of total curcuminoids (◊), reduction products (hexa- + octacurcuminoids, ▼), and monoconjugates (sulfates + glucuronides, ▲) in plasma. (B) Time course of individual metabolite concentrations in plasma: hexahydrocurcuminoids (○), octahydrocurcuminoids (□), curcuminoid monoglucuronides (■), and curcuminoid monosulfates (●). (C) Time course of total curcuminoids (◊) and reduction products (▼) in brain. (D) Time course of hexahydro- (○) and octahydrocurcuminoids (□) in brain.