Caprenin 2. Short-Term Safety and Metabolism in Rats and Hamsters

Abstract

A series of short-term feeding studies was undertaken to evaluate the biological effects of three behenic medium-chain triglycerides (BMCTs), including caprenin (CAP). All three triglycerides were composed primarily of caprylic (C8:0), capric (C10:0), and behenic (C22:0) acids, although total fatty acids compositions differed slightly. In the first experiment, adult male rats were maintained for 23 days on semipurifled diets containing 26% (w/w) of a BMCT, medium-chain triglyceride (MCT) oil or corn oil. Each triglyceride was assessed for its effects on growth, feed efficiency, calcium and iron balance, fat balance, and carcass fatty acid composition. A 28-day study of similar design evaluated the nutritive properties of chow diets that were supplemented with 15% of a BMCT or MCT when consumed by adult male golden Syrian hamsters. Finally, a 28-day feeding study in weanling male and female rats was conducted to assess the potential oral toxicity of CAP. CAP was administered in semipurifled diet at 0, 5, 10, and 15%. Corn oil was added at 18, 13, 8, and 3%, respectively, to maintain total dietary fat content at 18% and provide a source of essential fatty acids. The overall results of these experiments demonstrated that (1) BMCTs, including CAP, provided usable energy to sustain growth in rats and hamsters, although these triglycerides had lower calorie values than typical fats and oils, (2) up to 75–82% of the behenic acid content of BMCTs was unabsorbed by both species and excreted in the feces, (3) increased fecal excretion of BMCT-derived behenic acid did not significantly affect calcium and iron balance in rats, (4) behenic acid was metabolized readily by both rats and hamsters as indicated by recovery of only 3–15 % of the absorbed fatty acid in total carcass fat at the end of the studies, and (5) CAP was nontoxic to rats when consumed for 28 consecutive days at levels of up to 15% in the diet (83% of total dietary fat).