JTT-130, a microsomal triglyceride transfer protein (MTP) inhibitor lowers plasma triglycerides and LDL cholesterol concentrations without increasing hepatic triglycerides in guinea pigs.
BACKGROUND
Microsomal transfer protein inhibitors (MTPi) have the potential to be used as a drug to lower plasma lipids, mainly plasma triglycerides (TG). However, studies with animal models have indicated that MTPi treatment results in the accumulation of hepatic TG. The purpose of this study was to evaluate whether JTT-130, a unique MTPi, targeted to the intestine, would effectively reduce plasma lipids without inducing a fatty liver.


METHODS
Male guinea pigs (n = 10 per group) were used for this experiment. Initially all guinea pigs were fed a hypercholesterolemic diet containing 0.08 g/100 g dietary cholesterol for 3 wk. After this period, animals were randomly assigned to diets containing 0 (control), 0.0005 or 0.0015 g/100 g of MTPi for 4 wk. A diet containing 0.05 g/100 g of atorvastatin, an HMG-CoA reductase inhibitor was used as the positive control. At the end of the 7th week, guinea pigs were sacrificed to assess drug effects on plasma and hepatic lipids, composition of LDL and VLDL, hepatic cholesterol and lipoprotein metabolism.


RESULTS
Plasma LDL cholesterol and TG were 25 and 30% lower in guinea pigs treated with MTPi compared to controls (P < 0.05). Atorvastatin had the most pronounced hypolipidemic effects with a 35% reduction in LDL cholesterol and 40% reduction in TG. JTT-130 did not induce hepatic lipid accumulation compared to controls. Cholesteryl ester transfer protein (CETP) activity was reduced in a dose dependent manner by increasing doses of MTPi and guinea pigs treated with atorvastatin had the lowest CETP activity (P < 0.01). In addition the number of molecules of cholesteryl ester in LDL and LDL diameter were lower in guinea pigs treated with atorvastatin. In contrast, hepatic enzymes involved in maintaining cholesterol homeostasis were not affected by drug treatment.


CONCLUSIONS
These results suggest that JTT-130 could have potential clinical applications due to its plasma lipid lowering effects with no alterations in hepatic lipid concentrations.
Aggarwal
Dimple
D
Department of Nutritional Sciences, University of Connecticut, Storrs, CT, USA. dimple.aggarwal@uconn.edu
West
Kristy L
KL
Zern
Tosca L
TL
Shrestha
Sudeep
S
Vergara-Jimenez
Marcela
M
Fernandez
Maria Luz
ML
D000818:Animals; D000069059:Atorvastatin; D002352:Carrier Proteins / Q000037:antagonists & inhibitors* / Q000378:metabolism; D053480:Cholesterol Ester Transfer Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D002791:Cholesterol, Dietary / Q000008:administration & dosage; D008078:Cholesterol, LDL / Q000097:blood* / Q000737:chemistry; D004305:Dose-Response Relationship, Drug; D006168:Guinea Pigs; D006538:Heptanoic Acids / Q000008:administration & dosage / Q000494:pharmacology; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents / Q000008:administration & dosage / Q000494:pharmacology*; D050356:Lipid Metabolism; D008099:Liver / Q000378:metabolism; D008297:Male; D023421:Models, Animal; D010316:Particle Size; D011758:Pyrroles / Q000008:administration & dosage / Q000494:pharmacology; D014280:Triglycerides / Q000097:blood*
D002352:Carrier Proteins; D053480:Cholesterol Ester Transfer Proteins; D002791:Cholesterol, Dietary; D008078:Cholesterol, LDL; D006538:Heptanoic Acids; D019161:Hydroxymethylglutaryl-CoA Reductase Inhibitors; D000960:Hypolipidemic Agents; D011758:Pyrroles; D014280:Triglycerides; C106092:microsomal triglyceride transfer protein; D000069059:Atorvastatin