Curcumin attenuates insulin resistance and hepatic lipid accumulation in a rat model of intra-uterine growth restriction through insulin signalling pathway and sterol regulatory element binding proteins

Abstract

AbstractThe objective of the present study was to investigate the effect of curcumin on insulin resistance (IR) and hepatic lipid accumulation in intra-uterine growth restriction (IUGR). Rats with a normal birth weight (NBW) or IUGR were fed basic diets (NBW and IUGR groups) or basic diets supplemented with curcumin (NBW-C and IUGR-C groups) from 6 to 12 weeks. Rats in the IUGR group showed higher levels of glucose and homeostasis model assessment for insulin resistance index (HOMA-IR) (P< 0·05) than in the NBW group. The livers of IUGR rats exhibited higher (P< 0·05) concentration of TAG and lower (P< 0·05) activities of lipolysis enzymes compared with the normal rats. In response to dietary curcumin supplementation, concentrations of serum insulin, glucose and HOMA-IR, pyruvate, TAG, total cholesterol and NEFA in the liver were decreased (P< 0·05). The concentrations of glycogen and activities of lipolysis enzymes in the liver were increased (P< 0·05) in the IUGR-C group compared with the IUGR group. These results were associated with lower (P< 0·05) phosphorylated insulin receptor substrate 1, protein kinase B or Akt, glycogen synthase kinase 3β and expressions of sterol regulatory element binding protein 1 and fatty acid synthase (FASN); decreased expressions forCd36, sterol regulatory element binding protein 1c (Srebf1) andFasn; increased (P< 0·05) expression of PPARα; and expressions forPparaand hormone-sensitive lipase in the liver of IUGR-C rats than the IUGR rats. Maternal malnutrition caused IR and lipid accumulation in the liver. Curcumin supplementation prevented IR by regulating insulin signalling pathways and attenuated hepatic lipid accumulation.