Abstract
The bioavailability of ivermectin is modulated by lipid-based formulations and membrane
efflux transporters such as Breast Cancer Resistance Protein and P-glycoprotein (BCRP
and P-gp). We have investigated the effect of oleic acid on the uptake of ivermectin
in vitro using Caco-2 cells and in vivo in the intestines of wild-type mice. Complex
micelles (M) with oleic acid induced a significant increase (e. g. for M3 was 7-fold,
p≤0.001) in the uptake of the drug in a time-dependent manner with no involvement
of cholesterol in the mechanism. In vivo results showed a significant increase in
the concentration of plasma and intestinal mucosa ivermectin (p≤0.01) in mice receiving
oleic acid-based drug formulation. We also examined the expression of the drug efflux
transporter, BCRP and P-gp in Caco-2 cells and found a significant decrease (p≤0.001)
in their level in the presence of 5 mM oleic acid. Treatment of mice with oleic acid-based
formulation showed a significant decrease in the activity of P-gp in the intestinal
mucosa (p≤0.01). This study highlighted the effect of oleic acid in decreasing the
expression and the activity of P-gp-mediated ivermectin efflux and in limiting the
drug absorption by increasing its uptake and bioavailability in Caco-2 cells and intestine,
respectively.
Key words
Oleic acid - ivermectin - P-glycoprotein - BCRP