Background: Curcumin has diverse biological activities such as anti-cancer, antioxidant, and anti-inflammatory properties and is assumed to exhibit beneficial effects in the prevention and treatment of various diseases. Although curcumin is known to be safe in humans, its therapeutic efficacy is limited owing to its poor bioavailability. To overcome this problem, we prepared a novel curcumin preparation curcuRougeTM using the amorphous solid dispersion method. In this study, we aimed to investigate the oral absorption efficiency of curcuRougeTM and compare its efficiency with that of Theracurmin®, a highly absorptive curcumin preparation dispersed with colloidal submicron-particles exhibiting improved bioavailability, in rats and healthy volunteers.
Methods: In the animal experiment, male Sprague–Dawley rats were orally administered curcuRougeTM or Theracurmin® (10 mg/kg of curcumin). The plasma curcumin levels were measured at 0.25, 0.5, 1, 2, 4, and 6 h after administration. In addition, we performed a single-dose, double-blind, two-way crossover study to compare plasma curcumin levels after the administration of curcuRougeTM or Theracurmin® in humans. Twelve healthy volunteers were administered curcuRougeTM or Theracurmin® containing 30 mg curcumin. The plasma curcumin concentrations at 0.5, 1, 2, 4, and 8 h after ingestion were determined.
Results: The area under plasma concentration–time curve (AUC0-6 h) and maximum plasma concentration (Cmax) of curcuRougeTM in rats were 3.7- and 9.6-fold higher than those of Theracurmin®, respectively. Twelve healthy volunteers were orally administered 90 mg of curcuRougeTM or Theracurmin® in a randomized double-blind crossover study. In these volunteers, the AUC0-8 h and Cmax of curcuRougeTM were 3.4-fold and 5.4-fold higher than those of Theracurmin®, respectively.
Conclusion: These findings indicate that curcuRougeTM shows better bioavailability than other highly absorptive curcumin preparations, such as Theracurmin®. Hence, curcuRougeTM is assumed to exhibit clinical efficacy for managing various diseases at a low dose.
Trial registration: The trial was registered with the UMIN Clinical Trials Registry (January 8, 2020, UMIN000039083, https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000044573).