ABSTRACT
Hyperlipidemia and oxidation play major roles upon cardiovascular diseases (CVDs). C-phycocyanin (CPC), the major component in blue-green algae, possesses antiinflammatory and radical scavenging properties. Herein we aimed to investigate the effect of CPC upon lipid metabolism and its antioxidant effects. Golden Syrian hamsters were randomly assigned to five groups: (1) control; (2) 0.2% cholesterol; (3) 0.2% cholesterol+ 1% lopid; (4) 0.2% cholesterol+ 0.25% CPC; and (5) 0.2% cholesterol+ 1.25% CPC. All animals were sacrificed after 8-week feeding. Serum cholesterol, triglyceride (TG), low-density lipoprotein (LDL), glutamate-oxaloacetate transaminase (GOT), and glutamate-pyruvate transaminase (GPT) were examined. The diene conjugation in the Cu(2+)-mediated oxidation of LDL was measured. The protein levels of several antioxidative enzymes including catalase (CAT), superoxide dismutases (SOD), and glutathione peroxidase (GPx) of liver were assayed. HepG2 cells were cultured in medium containing various concentrations of CPC (0, 1, 15, and 30 µM). The mRNA concentrations of LDL receptor, 3-hydroxy-3-methylglutaryl-coenzyme A (HMG CoA) reductase, SOD-1 and GPx of HepG2 cells in each group were analyzed. CPC was effective in lowering serum cholesterol, total cholesterol (TC), TG, LDL, GOT, and GPT. CPC was found to decrease the malondialdehyde (MDA) equivalents and delay the diene conjugation in the Cu(2+)-mediated oxidation of LDL. CPC increase the enzyme expressions of CAT, SOD, and GPx. CPC concentrations were positively correlated with the mRNA level of LDL receptor while the mRNA levels of HMG CoA reductase, SOD-1, and GPx in HepG2 cells were not affected. The lipid-lowering and antioxidation effects of CPC suggest its roles in prevention of CVD and atherosclerotic formation.
ABSTRACT
Lycopene is known to decrease cardiovascular risks. The objective of this study was to investigate the molecular mechanisms of tomato paste containing approximately 0.1% lycopene in regulating lipid metabolism and oxidation. Hamsters fed 3% or 9% tomato paste containing 0.2% cholesterol were subjected to total cholesterol (TC), low density lipoprotein (LDL), high density lipoprotein (HDL), and triglyceride (TG) measurements. Our results showed reduced rates of serum TC and LDL levels due to 9% tomato paste were 14.3% and 11.3% respectively. Concentrations of 3% and 9% of tomato paste after 8 weeks of feeding significantly increased serum HDL levels, by 19.4% and 28.8% respectively. After ingestion of tomato paste for 8 weeks, the plasma malondialdehyde (MDA) levels significantly decreased, by 80.18% and 89.33% respectively, as compared to the cholesterol group. MDA and diene conjugation assays indicated the potent antioxidant activity of the tomato paste. The increased activities of superoxide dismutases (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px), further supported the antioxidant effects of the tomato paste. Two dimension-gel electrophoresis (2-DE) analysis revealed that carbonic anhydrase III (CAIII) and adenylate kinase 2 (AK2) may be two important regulators involved in the anti-lipid and antioxidant effects of tomato paste, opening new insight into the nutritional value of tomato in public health promotion.
