Medium-chain triglycerides reduce glomerulosclerosis and induce expression of redox genes in NSY mice with diabetic nephropathy

Abstract

Background

Nephropathy is a type of complication of type 2 diabetes, and medium chain triglycerides (MCTs) potentially improve metabolic abnormalities. This study examined whether MCT intake inhibits nephropathy development in a type 2 diabetic mouse model.

Methods

Six-week-old control non-diabetic ICR mice and type 2 diabetic Nagoya Shibata Yasuda (NSY) mice were fed a diet enriched with long-chain saturated/mono-unsaturated triglycerides, including palmitic-, stearic-, and oleic acids (C16/C18-rich group). NSY mice were fed a diet containing medium-chain triglycerides with either caprylic acid (C8-rich group) or capric acid (C10-rich group). Feeding was performed for 20 weeks. Plasma biomarker levels were measured using ELISA or enzymatic methods. Kidney pathology was evaluated using periodic acid–Schiff staining, and the expression of redox genes and proteins were determined using qRT-PCR and western blotting.

Results

The C16/C18-rich group of NSY mice exhibited expansion of the mesangial region in the kidney. Plasma cystatin C and creatinine concentrations were not different between ICR mice and C16/C18-rich group of NSY mice and between C16/C18-rich and C8- or C10-rich groups of NSY mice. The C8- and C10-rich groups had suppressed mesangial region than the C16/C18-rich groups. The mRNA expression of Sod1, Prdx1, and Gpx2, and SOD1 protein levels were higher in the C8- and/or C10-rich groups than in the C16/C18-rich group of NSY mice.

Conclusions

MCT intake in NSY mice at the stage without increased markers indicating glomerular filtration decrease, reduces glomerulosclerosis, with induction of redox gene expression, in the kidney.