Anti-obesity efficacy of nanoemulsion oleoresin capsicum in obese rats fed a high-fat diet

Purpose: This study determined the effects of oleoresin capsicum (OC) and nanoemulsion OC (NOC) on obesity in obese rats fed a high-fat diet. Methods: The rats were randomly separated into three groups: a high-fat (HF) diet group, HF + OC diet group, and HF + NOC diet group. All groups were fed the diet and water ad libitum for 14 weeks. Results: NOC reduced the body weight and adipose tissue mass, whereas OC did not. OC and NOC reduced mRNA levels of adipogenic genes, including peroxisome proliferator-alpha ctivated receptor (PPAR)-gamma, sterol regulatory element-binding protein-1c, and fatty acid-binding protein in white adipose tissue. The mRNA levels of genes related to beta-oxidation or thermogenesis including PPAR-alpha, palmitoyltransferase-1 alpha, and uncoupling protein-2 were increased by the OC and NOC relative to the HF group. Both OC and NOC clearly stimulated AMP-alpha ctivated protein kinase (AMPK) activity. In particular, PPAR-alpha, palmitoyltransferase-1 alpha, uncoupling protein-2 expression, and AMPK activity were significantly increased in the NOC group compared to in the OC group. NOC decreased glycerol-3-phosphate dehydrogenase activity whereas OC did not. Conclusion: From these results, NOC could be suggested as a potential anti-obesity agent in obese rats fed a HF diet. The effects of the NOC on obesity were associated with changes of multiple gene expression, activation of AMPK, and inhibition of glycerol-3-phosphate dehydrogenase in white adipose tissue.