Cinnamon extract improves the body composition and attenuates lipogenic processes in the liver and adipose tissue of rats

Abstract

In models of metabolic disorders, cinnamon improves glucose and lipid metabolism. This study explores the effect of chronic supplementation with aqueous cinnamon extract (CE) on the lipid metabolism of rats. Male adult Wistar rats were separated into a control group (CTR) receiving water and a CE Group receiving aqueous cinnamon extract (400 mg of cinnamon per kg body mass per day) by gavage for 25 consecutive days. Cinnamon supplementation did not change the food intake or the serum lipid profile but promoted the following changes: lower body mass gain (P = 0.008), lower relative mass of white adipose tissue (WAT) compartments (P = 0.045) and higher protein content (percentage of the carcass) (P = 0.049). The CE group showed lower leptin mRNA expression in the WAT (P = 0.0017) and an important tendency for reduced serum leptin levels (P = 0.059). Cinnamon supplementation induced lower mRNA expression of SREBP1c (sterol regulatory element-binding protein 1c) in the WAT (P = 0.001) and liver (P = 0.013) and lower mRNA expression of SREBP2 (P = 0.002), HMGCoA reductase (3-hydroxy-3-methylglutaryl-CoA reductase) (P = 0.0003), ACAT1 (acetyl-CoA acetyltransferase 1) (P = 0.032) and DGAT2 (diacylglycerol O-acyltransferase 2) (P = 0.03) in the liver. These changes could be associated with the reduced esterified cholesterol and triacylglycerol content detected in this tissue. Our results suggest that chronic ingestion of aqueous cinnamon extract attenuates lipogenic processes, regulating the expression of key enzymes and transcriptional factors and their target genes, which are directly involved in lipogenesis. These molecular changes possibly promote adaptations that would prevent an increase in circulating cholesterol and triacylglycerol levels and prevent lipid accumulation in tissues, such as liver and WAT. Therefore, we speculate that cinnamon may also be useful for preventing or retarding the development of lipid disorders.