[Enhancing effect of Ulex europaeus agglutinin I modified liposomes on oral insulin absorption in mice].
OBJECTIVE
To investigate the enhancing effect on insulin absorption through GI. tract in mice by using the Ulex europaeus agglutinin I (UEA1) modified liposomes as the carrier.


METHODS
UEA1 modified phosphatidylethanolamine (PE) was prepared by conjugating method of 1-ethyl-3-(3'-dimethylaminopropyl) carbodiimide (EDC), then the modified compound (PE-UEA1) was incorporated into the conventional liposomes of insulin to obtain UEA1 modified liposomes. The agglutination test was performed to examine the UEA1 biological activities after synthesis and modification. When liposomes were applied to healthy mice or diabetic mice at insulin dose of 350 u x kg(-1) orally, the hypoglycemic effect was investigated according to the blood glucose level determination.


RESULTS
The blood glucose levels of the healthy mice reduced by UEA1 modified liposomes were (84 +/- 15)% at 4 h, (78 +/- 11)% at 8 h and (90 +/- 12)% at 12 h after oral administration. The conventional liposomes and saline showed no effect. The blood glucose levels of the diabetic mice reduced by UEA1 modified liposomes were (73 +/- 7)% at 4 h, (74 +/- 9)% at 8 h, (86 +/- 9)% at 12 h after oral administration.


CONCLUSIONS
The UEA1 modified liposomes promote the oral absorption of insulin due to the specific-site combination on M cell membrane.
Zhang
Na
N
China Pharmaceutical University, Nanjing 210009, China.
Ping
Qi-neng
QN
Xu
Wen-fang
WF
D000284:Administration, Oral; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D003921:Diabetes Mellitus, Experimental / Q000097:blood; D004337:Drug Carriers; D016503:Drug Delivery Systems; D007004:Hypoglycemic Agents / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D007328:Insulin / Q000008:administration & dosage* / Q000493:pharmacokinetics*; D007408:Intestinal Absorption / Q000187:drug effects; D008081:Liposomes; D051379:Mice; D010714:Phosphatidylethanolamines / Q000737:chemistry; D037121:Plant Lectins / Q000737:chemistry* / Q000302:isolation & purification / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry; D039762:Ulex / Q000737:chemistry
D001786:Blood Glucose; D004337:Drug Carriers; D007004:Hypoglycemic Agents; D007328:Insulin; D008081:Liposomes; D010714:Phosphatidylethanolamines; D037121:Plant Lectins; C036850:Ulex europaeus lectins; C483858:phosphatidylethanolamine