Assessment of Lipid Metabolism Biomarkers in a Type-2 Diabetes Rodent Model Following an Intervention With Corn-Resistant Starch Feed and Intake of ACE Inhibitor, Captopril

Objectives: Determine the impact of a nutritional intervention, during which captopril-treated rats were fed different dietary high-amylose maize (RS) levels, on lipid metabolism biomarkers in a type-2 diabetes rodent model. Methods: Six-week-old, Zucker diabetic fatty rats-ZDF and lean rats (n=56) were randomly assigned to experimental and control groups were kept in individual plastic cages under a 12-h-light/-dark cycle for 8 wks, consuming feed and water ad libitum. Groups (n=8) established as follows: three ZDF-groups were fed with 0%, 5%, or 10% RS, all receiving captopril injections (25mg/kg i.p.); three ZDF-groups were fed the same RS diets, but were administered vehicle (saline); one group of lean rats, provided with 0% RS, received vehicle. Animals were placed in metabolic cages 12 h before being anesthetized by intraperitoneal injection with a cocktail of ketamine: xylazine; whole blood was obtained by cardiac puncture, and livers were then collected, weighted, and snap frozen in liquid nitrogen. Adiponectin, serum, and liver triglycerides (TG's) were analyzed using commercial assays. Protein expression of PPARγ and UCP2 was determined by western blotting. Descriptive statistics and 2-way ANOVA were conducted for the data. Results: Adjusted liver weights decreased for the groups consuming 5-10% RS + captopril. Adiponectin levels in serum were reduced for all ZDF groups except for the 10%RS + captopril group, which showed statistical similarities with the lean group. Groups receiving captopril injections showed reduced serum TG values, 12 to 34% lower than those of their 0%RS + placebo ZDF counterparts, as for liver TG results showed a reduction of 41% for the 10%RS + captopril group. Conclusions: Increased adiponectin levels were reported for the 10%RS + captopril group. Captopril groups also showed decreasing serum TG's levels when compared with their counterparts who did not receive captopril injections. RS and Captopril seem to act synergistically in improving the biomarkers of lipid metabolism evaluated in this study. Funding Sources: USDA-NIFA Award to M.J. Rowling.