Fig. 2.

Concentration of curcumin and its glucuronide and sulfate conjugates in plasma before and after hydrolysis with β-glucuronidase or sulfatase. Turmeric was administered to human volunteers (A-C), and plasma was obtained after 2 h, Mice (D-F) received turmeric extract by oral gavage or i.p. injection and serum was obtained after 30 or 20 min, respectively. Plasma or serum samples were left untreated or hydrolyzed with β-glucuronidase (β-gluc.) or sulfatase (Sulfat.) prior to extraction, and concentration of curcumin (A,D), curcumin-glucuronide (B,E), and curcumin-sulfate (C, F) was quantified using LC-SRM-MS. All values in A-C are different from each other at p<0.05 (n = 6). In D-F all values are different from each other within the oral and i.p. series, respectively, at p<0.05 (n = 5). Statistical analysis was performed using one-way ANOVA followed by Tukey multiple comparison tests of every pair. Error bars indicate SEM.