Construction of a simple evaluation system for the intestinal absorption of an orally administered medicine using Bombyx mori larvae.

Human intestinal absorption is estimated using a human colon carcinoma cell line (Caco-2) cells from human colorectal adenocarcinoma, intestinal perfusion, or a mammalian model. These current evaluation systems are limited in their ability to estimate human intestinal absorption. In addition, in vivo evaluation systems using laboratory animals such as mice and rats entail animal ethics problems, and it is difficult to screen compounds on a large scale at the drug discovery stage. Thus, we propose the use of Bombyx mori larvae for evaluation of intestinal absorption of compounds as an alternative system in this study. First, to compare the characteristics among Caco-2 cells, human intestine, and B. mori larval midgut, we analyzed their RNA-seq data, and we found 26 drug transporters common to humans and B. mori. Next, we quantitatively developed an oral administration technique in B. mori and established a method using silkworm B. mori larvae that can easily estimate the intestinal permeability of compounds. Consequently, we could determine the dose and technique for oral administration in B. mori larvae. We also developed a B. mori model to evaluate the intestinal permeability of orally administered. Our constructed evaluation system will be useful for evaluating intestinal permeability in medical drug development.