Study Design for CAP-e Testing
The CAP-e assay utilizes red blood cells to assess the antioxidant capacity by absorbing antioxidants from a physiological liquid containing soluble products. All compounds that are not absorbed into the cell are removed, after which the cell is subjected to oxidative stress. An indicator dye reveals the degree of intracellular damage to the cell, allowing for the evaluation of cellular bioavailability in the presence versus absence of serial dilutions of the test product, which is essential for effective clinical trial designs.
Example of Study Design for Bioavailability Testing
Below is a diagram illustrating the involvement of each human subject in evaluating the antioxidant capacity and cellular bioavailability, as well as the various clinical trial designs employed.
When a cross-over study design is implemented, the relative difference in antioxidant capacity can be calculated as the difference between "no product" and "product", i.e. the difference between grey and green data sets for each time point. This value, Delta, measures improved antioxidant status and cellular bioavailability after consumption, illustrated by the red arrows below in the context of various clinical trial designs.
