Aim To investigate the enhancing effect on insulin absorption through GI. tract in mice by
using
tomato lectin (TL)
modified liposomes as the carrier. Methods TL-phosphatidylethanolamine (PE)
conjugate (TL-PE) was synthesized by using carbodiimide cross-linking method, then the compound was
incorporated into the conventional liposomes of insulin. The agglutination test was performed to examine TL
biological activities after synthesis and incorporation. When TL modified liposomes were administrated orally to
the normal mice or diabetic mice at insulin dose of 350 u·kg~(-1), the hypoglycemic effect was determinated
according to the
blood glucose level. Results The blood glucose levels of the normal mice were reduced by
modified liposomes. The glucose levels were (85±5)% at 4 h, (54±11)% at 8 h, (57±6)% at 12 h
postdose compared with the glucose levels prior to oral administration respectively. However, the conventional
liposomes and saline have no hypoglycemic effect. The blood glucose levels of the diabetic mice were obviously
reduced by TL modified liposomes, the glucose levels were (38±13)% at 4 h, (50±15)% at 8 h, (50±
16)% at 12 h respectively. Conclusion TL modified liposomes promote the oral absorption of insulin due to
the specific-site combination on GI cell membrane.