ABSTRACT
The purpose of this study was to investigate whether dietary nuciferine affects lipid metabolism in broiler chickens. Four treatment groups were made from 120 1-day-old broiler chickens including the base diet group (normal control [NC], supplemented with 0 mg/kg of nuciferine) and groups treated with 25 mg/kg, 100 mg/kg, and 400 mg/kg of dietary nuciferine, which was supplemented for 42 d. The results showed that body weight, average daily weight gain, and absolute and relative fat and liver weight were significantly decreased with nuciferine supplementation. The plasma concentration of triiodothyronine, free triiodothyronine, thyroxine, and free thyroxine was significantly decreased in the nuciferine-supplemented group, but the plasma glucagon concentration was significantly increased. The plasma and hepatic triglyceride (TG) and total cholesterol (TC) concentrations were significantly decreased in the nuciferine group, but plasma and hepatic nonesterified fatty acid concentration, hepatic lipase activity, and hepatic glycogen content were significantly increased. Hepatic histological examination showed that fat cell volume and size in the 100 and 400 mg/kg group were smaller than those in the NC group. The fatty degeneration in the liver was decreased with nuciferine supplementation. The fat cell volume and size were shrunk in the nuciferine group. Dietary nuciferine supplementation significantly decreased the gene expression level of HMGCR, SREBP2, ACC, and SPEBP-1C, but significantly increased the gene expression level of LXR-α, CYP7A1, and CPT-I. The results indicated that nuciferine exhibited strong reduced fat deposition activities and reflected not only by decrease of the concentration of TG and TC but also by reduction in the key gene expression level of HMGCR, SREBP2, ACC, and SPEBP-1c and elevation of the key gene expression level of LXR-α, CYP7A1, and CPT-I. Taken together, our results suggested that the ability of nuciferine on reducing fat deposition in broiler chickens by regulating lipid metabolism was associated with the balance of TG and TC concentration.
