Inflammatory processes are also characterized by an increase in microvascular permeability to macromolecules.
Leakage of Evans blue dye into the peritoneal cavity indicated the formation of gaps or pores in the wall of the
peritoneal microvessels, large enough for a significant portion of macromolecules to pass through. The administration
of AEBO resulted in the retention of the normal endothelial barrier function during histamine challenge, having prevented the leakage of approximately 99% of the Evans blue dye into the peritoneal cavity. Based on these outcomes, it was demonstrated that AEBO displayed significant antihistamine activity, through inhibition of the vascular permeability processes. This could also be related to the suppression of other permeability-regulating molecules that lead to inflammation.