Effects of (-)-hydroxycitric acid on lipid droplet accumulation in chicken embryos

This study was conducted to determine the impact of (-)-hydroxycitric acid ((-)-HCA) on biochemical indices and lipid metabolism parameters in chicken embryos. Two hundred and forty fertilized eggs were divided into six groups and injected with (-)-HCA at concentrations of 0, 0.1, 0.5, 1.0, 10.0 and 50 mg/kg (n = 40). After 19 days of incubation, serum and liver were collected for analysis of biochemical indices and lipid metabolism parameters. Results showed no significant differences on serum biochemical indices: 1-50 mg/kg (-)-HCA significantly increased serum glucose and hepatic glycogen contents (P < 0.05). Oil Red O staining analysis showed total area, counts of lipid droplets and hepatic triglyceride content were significantly decreased (P < 0.01), meanwhile hepatic lipase and lipoprotein lipase activity were significantly increased (P < 0.05). ACLY, ME1, SREBP-1c messenger RNA (mRNA) levels in 0.5-10 mg/kg groups and FAS mRNA level in 1-10 mg/kg groups were significantly decreased (P < 0.05), while PPARα mRNA level, serum adiponectin content and AdipoR1 mRNA level were significantly increased in 0.5-50 mg/kg groups (P < 0.05). These results indicated (-)-HCA treatment inhibited triglyceride synthesis via decreasing lipogenesis-related factors, mRNA expression level and accelerated lipolysis by enhancing lipoprotein lipase and hepatic lipase activity, which finally reduced lipid droplet accumulation, and this action may be associated with activating the adiponectin signaling pathway.