Figure 1.
Growth and feed/caloric intake of Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) Body weight time course over the 30-day experiment; (B) Daily feed intake over the course of the 30-day experiment and average daily feed and total caloric intake (insert). *, denotes a significant difference (p<0.05); n = 8/group.
Figure 2.
Blood lipid, lipoprotein, glucose and insulin responses in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) Plasma lipids including total cholesterol (TC), non-HDL cholesterol (n-HDL-C), direct low density lipoprotein cholesterol (d-LDL-C), high density lipoprotein cholesterol (HDL-C), and triglycerides (TG); (B) LDL particle number; (C) HDL particle number; (D) VLDL particle number; (E) lipoprotein particle size; and (F) glucose and insulin. *, denotes a significant difference (p<0.05); n = 8/group.
Table 1.
Formulation of high fat and LA-supplemented diets fed to Zucker rats.
Table 2.
Hepatic fatty acid composition (% total fatty acids), triglyceride (mmol/g tissue), and cholesterol concentration (mg/g tissue) in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
Figure 3.
Hepatic expression of cholesterol responsive genes and blood PCSK9 in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) low density lipoprotein receptor (LDLr) mRNA; (B) (B) low density lipoprotein receptor protein abundance; (C) 3-hydroxy-3-methyl-glutaryl-CoA reductase mRNA (HMG-CoAr); (D) Nuclear sterol regulatory element binding protein abundance (SREBP2); (E) Proprotein convertase subtilisin/kexin type 9 mRNA (PCSK9); and (F) Serum PCSK9 concentrations (ng/mL). *, denotes a significant difference (p<0.05). All data normalized to β-actin and expressed relative to HF group; n = 8/group.
Figure 4.
Hepatic expression of lipogenic regulators in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) Acetyl-CoA carboxylase (ACC) mRNA expression and protein abundance; (B) Fatty acid synthase mRNA expression and protein abundance (FAS); (C) cytoplasmic and nuclear sterol regulatory element binding protein 1c (SREBP1C) mRNA and protein. *, denotes a significant difference (p<0.05). All data normalized to β-actin and expressed relative to HF group; n = 8/group.
Figure 5.
Targets of hepatic triglyceride synthesis/VLDL production regulators in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
Diacylglycerol acyltransferase (DGAT) mRNA expression; (D) Microsomal triglyceride transfer protein (MTP) mRNA expression; n = 8/group.
Figure 6.
Expression of hepatic fat oxidative targets in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) Carnitine palmitoyltransferase I (CPT1α) mRNA expression and protein abundance; (B) PPARα mRNA expression and protein abundance; and (C) P-AMPK, total AMPK, and total:P-AMPK. *, denotes a significant difference (p<0.05). All data normalized to β-actin and expressed relative to HF group; n = 8/group.
Figure 7.
Expression of skeletal muscle fatty acid uptake and oxidation markers in Zucker rats fed a high fat (HF) diet or the HF diet supplemented with 0.25% α-lipoic acid (HF-LA) for 30 days.
(A) Total lipase activity in serum and muscle total protein tissue extracts (n = 6 HF; 5 LA); (B) carnitine palmitoyltransferase I (CPT1β). *, denotes a significant difference (p<0.05). All data normalized to β-actin and expressed relative to HF group; n = 8/group.