Catherine W. Rico

Influence of Oryzanol and Ferulic Acid on the Lipid Metabolism and Antioxidative Status in High Fat-Fed Mice

The comparative effects of oryzanol and ferulic acid on the lipid metabolism and antioxidative status of high fat-fed mice were investigated. The mice were given a diet containing 17% fat (HF), supplemented with oryzanol (HF-O) or ferulic acid for 7 weeks. The control mice (NC) were fed with normal diet. The HF mice exhibited increased body weight gain, plasma and hepatic total cholesterol and triglyceride concentrations, and lipid peroxidation rate, and reduced high-density lipoprotein cholesterol level. In general, they also showed lower hepatic antioxidant and higher lipid-regulating enzymes activities relative to that of NC group. Addition of oryzanol or ferulic acid in the diet counteracted these high fat-induced hyperlipidemia and oxidative stress via increased faecal lipid excretion and regulation of antioxidant and lipogenic enzymes activities. This study illustrates that oryzanol and ferulic acid have relatively similar hypolipidemic actions and could be effective in lowering the risk of high fat diet-induced obesity.

Effect of oryzanol and ferulic acid on the glucose metabolism of mice fed with a high-fat diet.

The effects of oryzanol and ferulic acid on the glucose metabolism of high-fat-fed mice were investigated. Male C57BL/6N mice were randomly divided into 4 groups: NC group fed with normal control diet; HF group fed with high-fat (17%) diet; HF-O group fed with high-fat diet supplemented with 0.5% oryzanol; and HF-FA group fed with high-fat diet supplemented with 0.5% ferulic acid. All animals were allowed free access to the experimental diets and water for 7 wk. At the end of the experimental period, the HF-O and HF-FA groups exhibited significantly lower blood glucose level and glucose-6-phosphatase (G6pase) and phosphoenolpyruvate carboxykinase (PEPCK) activities, and higher glycogen and insulin concentrations and glucokinase (GK) activity compared with NC and HF groups. The results of this study illustrate that both oryzanol and ferulic acid could reduce the risk of high-fat diet-induced hyperglycemia via regulation of insulin secretion and hepatic glucose-regulating enzyme activities.

Modulatory Effect of Rice Bran and Phytic Acid on Glucose Metabolism in High Fat-Fed C57BL/6N Mice

The effect of dietary feeding of rice bran and phytic acid on the glucose metabolism in high fat-fed C57BL/6N mice fed was investigated. The mice were given with either a high fat diet only (HF group) or a high fat diet supplemented with rice bran (HF-RB group) or phytic acid (HF-PA group) for 7 weeks. The control mice (NC group) received a normal diet. At the end of the experimental period, the HF group exhibited substantially higher blood glucose level than the NC group. However, the HF-RB and HF-PA groups showed a marked decrease in the blood glucose level relative to HF mice. Furthermore, significantly higher glucokinase (GK) activity and lower phosphoenolpyruvate carboxykinase (PEPCK) activity were observed in HF-RB and HF-PA mice compared with that of the NC and HF ones. It was also found that the glucose-6-phosphatase (G6pase) activity and hepatic glycogen concentration were considerably higher in HF-RB and HF-PA groups, respectively, than that of the HF mice. These findings demonstrate that both rice bran and phytic acid could reduce the risk of high fat diet-induced hyperglycemia via regulation of hepatic glucose-regulating enzyme activities.

Antihyperlipidemic and body fat-lowering effects of silk proteins with different fibroin/sericin compositions in mice fed with high fat diet.

The effect of silk protein with different fibroin/sericin compositions on body weight and lipid metabolism in high fat-fed mice was investigated. The animals were given experimental diets for 6 weeks: normal control (NC), high fat (HF) and high fat diet supplemented with F100 (pure fibroin, HF-F100), F81 (81:19 fibroin/sericin, w/w, HF-F81) or F50 (50:50 fibroin/sericin, w/w, HF-F50). The silk protein-fed mice showed markedly reduced body weight and enhanced lipid profile relative to the HF group. In general, the amount of body fat, triglyceride and total plasma cholesterol levels, atherogenic index and free fatty acid level tended to decrease, while the HDL-cholesterol level increased, with increased amount of sericin in the diet. This hypolipidemic effect was partly due to increased fecal lipid excretion, inhibition of lipogenesis and regulation of adipokine production. These findings illustrate that silk protein, particularly sericin, may be beneficial in the prevention of high fat diet-induced hyperlipidemia and obesity.

Hypolipidemic and antioxidative effects of rice bran and phytic acid in high fat-fed mice

The influence of rice bran and phytic acid on lipid metabolism and antioxidative status in high fat-fed mice was investigated. The mice were given high fat diet (HF) or high fat diet supplemented with rice bran (HF-RB) or phytic acid (HF-PA) for 7 weeks. The control mice (NC) received normal diet. The HF mice showed marked increase in body weight, total cholesterol levels, hepatic triglyceride concentration, and lipid peroxidation rate compared with NC group. Also, a significant decrease in antioxidant enzyme activities was observed in HF animals. Addition of rice bran and phytic acid in the diet counteracted this high fatinduced hyperlipidemia and oxidative stress, mainly by increasing fecal lipid excretion and regulation of antioxidant and lipogenic enzyme activities. These findings illustrate that rice bran and phytic acid possess antihyperlipidemic action and antioxidant status-improving ability, and may be beneficial as dietary supplements in the management of high fat diet-induced hyperlipidemia.

Comparative study on the hypoglycemic and antioxidative effects of fermented paste (doenjang) prepared from soybean and brown rice mixed with rice bran or red ginseng marc in mice fed with high fat diet.

The effects of fermented paste made from soybean, brown rice, or brown rice in combination with rice bran or red ginseng marc on the glucose metabolism and antioxidative defense system in high fat-fed mice were investigated. The mice were given experimental diets for eight weeks: Normal control, high fat, and high fat supplemented with soybean fermented paste, brown rice fermented paste, brown rice-rice bran fermented paste, or brown rice-red ginseng marc fermented paste. The high fat group showed markedly higher blood glucose level and erythrocyte lipid peroxidation than the normal control group. Diet supplementation of fermented paste inhibited the high fat-induced hyperglycemia and oxidative stress via regulation of the glucose-regulating and antioxidant enzymes activities. The soybean and brown rice-red ginseng marc fermented pastes were the most effective in improving the glucose metabolism and antioxidant defense status in mice under high fat diet condition. These findings illustrate that brown rice, in combination with red ginseng marc, may be useful in the development of fermented paste with strong hypoglycemic and antioxidative activities.

In vitro antioxidative and antimutagenic activities of oak mushroom (Lentinus edodes) and king oyster mushroom (Pleurotus eryngii) byproducts

The in vitro antioxidative and antimutagenic activities of ethanolic extracts from oak mushroom (Lentinus edodes) and king oyster mushroom (Pleurotus eryngii) byproducts were investigated. The antioxidant capacity of the extracts was assessed by determining the ferricyanide reducing power, scavenging activity on nitrite, DPPH radical, superoxide anions and hydroxyl radicals, ferrous ion chelating ability, and inhibitory effect on linoleic acid peroxidation and xanthine oxidase. The antimutagenic activity, on the other hand, was based on the suppression of mitomycin C-induced mutagenesis in Escherichia coli cells. Both the mushroom extracts showed strong antioxidative and antimutagenic effects at higher concentrations. In general, extracts from the oak mushroom byproduct had greater antioxidative and antimutagenic abilities than that of the king oyster extract. Results of this study demonstrate that the mushroom byproducts possess strong antioxidant capacity in vitro and may be useful as a functional biomaterial in the preparation of health-promoting food products and animal feeds.

Comparative effects of doenjang prepared from soybean and brown rice on the body weight and lipid metabolism in high fat-fed mice

The comparative effects of doenjang prepared from fermented soybean or brown rice on the body weight and lipid metabolism in C57BL/6N mice fed with high fat diet were investigated. The animals were randomly divided and given experimental diets for eight weeks: normal control diet, high fat diet, and high fat diet supplemented with soybean doenjang, brown rice doenjang, brown rice-rice bran doenjang, or brown rice-red ginseng marc doenjang. At the end of the experimental period, the HF group exhibited a marked increase in body weight, body fat, plasma triglyceride concentration, and atherogenic index relative to the normal control diet group. However, diet supplementation of doenjang counteracted this high fat-induced hyperlipidemia through modulation of lipogenesis and adipokine production. In general, compared with soybean doenjang, the brown rice-rice bran doenjang and brown rice-red ginseng marc doenjang were similarly effective in improving the lipid metabolism under high fat diet condition. These findings demonstrate that brown rice, in combination with rice bran or red ginseng marc, may be useful as a functional biomaterial for the preparation of doenjang with strong anti-obesity effect and hypolipidemic action.

Comparative evaluation of the hypolipidemic effects of hydroxyethyl methylcellulose (HEMC) and hydroxypropyl methylcellulose (HPMC) in high fat-fed mice

The effect of hydroxyethyl methylcellulose (HEMC), in comparison with hydroxypropyl methylcellulose (HPMC), on the body weight and lipid metabolism in mice fed with high fat diet was investigated. The animals were given normal control diet (NC group), high fat diet (HF group), or high fat diet supplemented with either HEMC (HF+HEMC group) or HPMC (HF+HPMC group) for 6weeks. At the end of the experimental period, both HF+HEMC and HF+HPMC groups showed reduced body weight, body fat, plasma triglyceride and total cholesterol contents, atherogenic index and free fatty acid level, and increased HDL-cholesterol concentration relative to the HF group. The hypolipidemic effect was partly due to the inhibition of lipogenesis and regulation of adipokine production. These findings demonstrate that compared with HPMC, HEMC was similarly effective in improving the lipid metabolism under high fat diet condition and may be useful in the prevention and treatment of high fat diet-induced hyperlipidemia.

Effect of Instant Cooked Giant Embryonic Rice on Body Fat Weight and Plasma Lipid Profile in High Fat-Fed Mice

The comparative effects of instant cooked rice made from giant embryo mutant or ordinary normal rice on body weight and lipid profile in high fat-fed mice were investigated. The animals were given experimental diets for seven weeks: normal control (NC), high fat (HF), and HF supplemented with instant normal white (HF-NW), normal brown (HF-NB), giant embryonic white (HF-GW), or giant embryonic brown (HF-GB) rice. The HF group showed markedly higher body weight, body fat, plasma and hepatic triglyceride and cholesterol concentrations, and atherogenic index relative to NC group. However, instant rice supplementation counteracted this high fat-induced hyperlipidemia through regulation of lipogenesis and adipokine production. The GB rice exhibited greater hypolipidemic and body fat-lowering effects than the GW or NB rice. These findings illustrate that the giant embryo mutant may be useful as functional biomaterial for the development of instant rice with strong preventive action against high fat diet-induced hyperlipidemia and obesity.