The traditional Japanese diet with its high intake of fruits and vegetables that are rich in antioxidants is believed to effectively ward off cardiovascular disease. Oxidative stress, related to reactive oxygen and nitrogen species produced by aerobic organisms, is responsible for the pathogenesis of most chronic diseases. Oxidative low density lipoprotein (LDL) is thought to play a key role in the pathogenesis of early atherosclerosis. There has been increasing interest in antioxidant substances derived from edible plants. It has been suggested that the measurement of LDL antioxidant activity is physiopathologically more important and informative for screening antioxidant activity to prevent atherosclerosis than other methods. We assessed by LDL oxidation assay the antioxidant characteristics of various edible plants from rural areas. The mulberry (Morus alba L.) leaf showed comparatively high antioxidant activity. We identified the antioxidant compounds and investigated compound levels in the mulberry leaf and found the antioxidant activity of mulberry leaves to be mainly attributable to quercetin 3-(6-malonylglucoside) (Q3MG). Dietary consumption of mulberry leaves and/or Q3MG may enhance resistance to oxidative modification of LDL and attenuated atherosclerotic lesion development. However, the outcome of intervention trials suggested that a single antioxidant had little effect on the risk of developing cardiovascular disease. The synergic effect of certain combinations may determine outcome. We need to widen our understanding of the synergic effect of diets and nutrient-gene interactions related to nutrient/disease risk.
Antioxidants ; seconds ; Low density lipoprotein cholesterol measurement ; Pathogenesis ; Oxidative Dietary Supplements

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-alpha, related to beta-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing beta-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake (0.4 x 10(-5) vs 0.4 x 10(-5) mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.
Adipose Tissue, White ; Animals ; Biochemistry ; Blood Glucose ; Catechin ; Cholesterol ; Diet, High-Fat ; Fatty Acids, Nonesterified ; Gene Expression* ; Glucose* ; Lipid Metabolism ; Liver ; Metabolism* ; Mice* ; Morus* ; NADPH Oxidase ; Obesity ; Oxidative Stress ; Plasma ; Quercetin* ; Triglycerides ; Weights and Measures

BACKGROUND/OBJECTIVES: Mulberry leaves contain quercetin derivatives, which have the effects of reducing obesity and improving lipid and glucose metabolism in mice with obesity. It is not clear whether or not mulberry leaves can directly affect metabolic disorders, in the presence of obesity, because of the interaction between obesity and metabolic disorders. The aim of the current study was to assess the direct action of quercetin derivatives on metabolic disorders in non-obese conditions in short-term high-fat diet fed mice. MATERIALS/METHODS: C57BL/6N mice were fed a high-fat diet, supplemented with either 0% (control), 1%, or 3% mulberry leaf powder (Mul) or 1% catechin powder for five days. Anthropometric parameters and blood biochemistry were determined, and hepatic gene expression associated with lipid and glucose metabolism was analyzed. RESULTS: Body and white fat weights did not differ among the four groups. Plasma triglycerides, total cholesterol, and free fatty acids in the 1%, 3% Mul and catechin groups did not differ significantly from those of the controls, however, plasma glucose and 8-isoprostane levels were significantly reduced. Liver gene expression of gp91phox, a main component of NADPH oxidase, was significantly down-regulated, and PPAR-alpha, related to beta-oxidation, was significantly up-regulated. FAS and GPAT, involved in lipid metabolism, were significantly down-regulated, and Ehhadh was significantly up-regulated. Glucose-metabolism related genes, L-PK and G6Pase, were significantly down-regulated, while GK was significantly up-regulated in the two Mul groups compared to the control group. CONCLUSIONS: Our results suggest that the Mul quercetin derivatives can directly improve lipid and glucose metabolism by reducing oxidative stress and enhancing beta-oxidation. The 1% Mul and 1% catechin groups had similar levels of polyphenol compound intake (0.4 x 10(-5) vs 0.4 x 10(-5) mole/5 days) and exhibited similar effects, but neither showed dose-dependent effects on lipid and glucose metabolism or oxidative stress.
Adipose Tissue, White ; Animals ; Biochemistry ; Blood Glucose ; Catechin ; Cholesterol ; Diet, High-Fat ; Fatty Acids, Nonesterified ; Gene Expression* ; Glucose* ; Lipid Metabolism ; Liver ; Metabolism* ; Mice* ; Morus* ; NADPH Oxidase ; Obesity ; Oxidative Stress ; Plasma ; Quercetin* ; Triglycerides ; Weights and Measures

The anti-obesity effects of a hot water extract from wasabi (Wasabia japonica Matsum.) leaves (WLE), without its specific pungent constituents, such as allyl-isothiocyanate, were investigated in high fat-diet induced mice. C57J/BL mice were fed a high-fat diet (control group) or a high-fat diet supplemented with 5% WLE (WLE group). Physical parameters and blood profiles were determined. Gene expression associated with lipid metabolism in liver and white adipose tissue were analyzed. After 120 days of feeding, significantly lower body weight gain, liver weight and epididymal white adipose tissue weight was observed in the WLE group compared to the control group. In liver gene expression within the WLE group, PPARalpha was significantly enhanced and SREBP-1c was significantly suppressed. Subsequent downstream genes controlled by these regulators were significantly suppressed. In epididymal white adipose tissue of the WLE group, expression of leptin, PPARgamma, and C/EBPalpha were significantly suppressed and adiponectin was significantly enhanced. Acox, related to fatty acid oxidization in adipocytes, was also enhanced. Our results demonstrate that the WLE dietary supplement induces mild suppression of obesity in a high-fat diet induced mice, possibly due to suppression of lipid accumulation in liver and white adipose tissue.
Adipocytes ; Adiponectin ; Adipose Tissue, White ; Animals ; Body Weight ; Diet, High-Fat ; Dietary Supplements ; Gene Expression ; Leptin ; Lipid Metabolism ; Liver ; Mice ; Obesity ; PPAR alpha ; PPAR gamma ; Sterol Regulatory Element Binding Protein 1 ; Water