Studies on the uptake of tomato lectin nanoparticles in everted gut sacs

Int J Pharm. 1999 Jun 10;183(1):7-11. doi: 10.1016/s0378-5173(99)00050-2.


Tomato lectin (TL) is a bioadhesive glycoprotein that has been shown to bind selectively to the small intestine epithelium. When bound to polystyrene microspheres, intestinal uptake occurs not only through the gut associated lymphoid tissue (GALT) but also through normal enterocytes. In this study, the everted gut sac model was used to compare the rates and quantities of intestinal uptake of tomato lectin and that of TL coupled to microspheres. Using bovine serum albumin (BSA) and BSA coupled to microspheres as comparators. Uptake is time and concentration dependent. Transfer of TL from the lumen to the serosa was 3.9 ng/mg per h whereas that of BSA was 0.5 ng/mg per h. Hence uptake of tomato lectin was 7-fold higher than BSA. The rate of uptake of TL coupled microspheres was 41.5 ng/mg per h, which was 4-fold higher than microspheres coupled to BSA (11.8 ng/mg per h). The uptake of TL conjugated microspheres was shown to be inhibited by N-acetyl-d-glucosamine tetramer [GlcNac]4.

MeSH terms

  • Animals
  • Intestinal Mucosa / metabolism*
  • Lectins / administration & dosage*
  • Lectins / pharmacokinetics
  • Microspheres
  • Plant Lectins*
  • Rats
  • Serum Albumin, Bovine / pharmacokinetics


  • Lectins
  • Plant Lectins
  • tomato lectin
  • Serum Albumin, Bovine