Urine and serum analysis of consumed curcuminoids using an IkappaB-luciferase surrogate marker assay.

ABSTRACT

BACKGROUND: curcumin metabolites are detectable in body fluids such as serum and urine. We have developed a novel assay that can detect metabolites in such body fluids by measuring their effect on the nuclear factor kappa B/inhibitor of kappa B (NF-κB/IκB) pathway. PATIENTS AND METHODS: fifteen healthy individuals were enrolled in the study and randomly assigned to two groups control group (five) and curcumin group (ten). The test group ingested 8 g of the curcuminoids (C(3)-Complex) with 16 oz of bottled water. Blood and urine were collected at 0, 4, 8, and 24 h after ingestion. Degradation of the NF-κB/IκB complex was detected by the Genetic Expression and Measurement (GEM) assay using HCT116 cells stably transfected with PGL3-IκB firefly luciferase. RESULTS: using our novel GEM assay, the five controls who had not taken curcumin were identified. CONCLUSION: the GEM assay is a very sensitive and accurate non-invasive assay that could be utilized to detect metabolites in body fluids. It could also serve as a tool to determine participants' compliance during clinical research studies.