We have previously shown that anacardic acid has an uncoupling effect on oxidative phosphorylation in rat liver mitochondria using succinate as a substrate (Toyomizu et al. 2000). In the present study, in order to clarify whether or not anacardic acid could be used advantageously as a special feed/food supplement to reduce fat deposition through the uncoupling action, two sets of experiments were conducted to determine quantitatively the effect of dietary anacardic acid (0.1% w/w) supplementation. More specifically, effects on growth, feed efficiency, fattening, and levels of several constituents of blood serum in rats fed normal and low protein-high carbohydrate (CHO) diets were examined. There were no significant differences in bodyweight gain, feed consumption and feed efficiency among the experimental groups. For the total fat pad content, including inguinal and epididymal fat, significant interaction was shown between both treatments: dietary anacardic acid at 0.1% w/w significantly decreased the total fat pad content in rats fed the CHO diet, but not in rats fed the normal diet. Weights of heart, spleen and brown adipose tissue were not affected by either the dietary treatment or anacardic acid, while both liver and kidney weights decreased with feeding of anacardic acid at 0.1% w/w, but were not affected by the CHO diet. Anacardic acid supplementation in the diet had no effect on serum glutamic oxaloacetic transaminase, alkaline phosphatase or lactate dehydrogenase levels, suggesting that the dysfunction of liver or kidney may not be induced by dietary anacardic acid. The results of the present study reveal a unique function of anacardic acid in that, for dietary conditions enhancing body fat deposition, that is consumption of a diet high in carbohydrates, dietary anacardic acid has the potential to decrease body fat deposition. A possible mechanism for differences observed in anacardic acid-induced regulation of body fat pad content between rats fed the normal and CHO diets, based on uncoupling action of anacardic acid on the mitochondrial oxidative phosphorylation, is discussed.
- Anacardic acid
- Natural uncoupler
ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)