Experiments were designed to assess the ability of AC to
effectively remove peanut protein allergens from solution in the
gastrointestinal tract under physiological conditions in vivo. The
porcine system has been shown to be a valid approximation of the
analogous system in humans and has been used extensively to
model human digestion and immune response (24-27). The
results in Figure 5 indicate that the administration of 2 g of AC
following a 0.25 g dose of chopped peanut results in the removal
of much, but not all, of the soluble protein in a gastric sample.
Under these conditions, approximately 10% of the initial weight
of the peanut is released as soluble protein. This would result in an
80:1 AC/protein ratio in the stomach. Because there are likely to
be residual proteins, enzymes, and other peptides even in a fasted
porcine stomach, and the gastric volume is much greater than in
the in vitro situation, it is not unreasonable that the 80:1 ratio was
insufficient for complete adsorption of all soluble peanut protein.
However, by increasing the amount of AC administered, complete
adsorption of the soluble protein was obtained. After the
administration of 6 g of AC, no remaining peanut protein could
be detected by quantitative protein assay, SDS-PAGE, or immunoblotting.
This suggests that the ability of AC to effectively
bind protein in vitro is valid under physiological conditions.