Protective effect of dietary chitosan on cadmium accumulation in rats

BACKGROUND/OBJECTIVES: Cadmium is a toxic metal that is an occupational and environmental concern especially because of its human carcinogenicity; it induces serious adverse effects in various organs and tissues. Even low levels of exposure to cadmium could be harmful owing to its extremely long half-life in the body. Cadmium intoxication may be prevented by the consumption of dietary components that potentially reduce its accumulation in the body. Dietary chitosan is a polysaccharide derived from animal sources; it has been known for its ability to bind to divalent cations including cadmium, in addition to other beneficial effects including hypocholesterolemic and anticancer effects. Therefore, we aimed to investigate the role of dietary chitosan in reducing cadmium accumulation using an in vivo system. MATERIALS/METHODS: Cadmium was administered orally at 2 mg (three times per week) to three groups of Sprague-Dawley rats: control, low-dose, and high-dose (0, 3, and 5%, respectively) chitosan diet groups for eight weeks. Cadmium accumulation, as well as tissue functional and histological changes, was determined. RESULTS: Compared to the control group, rats fed the chitosan diet showed significantly lower levels of cadmium in blood and tissues including the kidneys, liver, and femur. Biochemical analysis of liver function including the determination of aspartate aminotransferase and total bilirubin levels showed that dietary chitosan reduced hepatic tissue damage caused by cadmium intoxication and prevented the associated bone disorder. CONCLUSIONS: These results suggest that dietary chitosan has the potential to reduce cadmium accumulation in the body as well as protect liver function and bone health against cadmium intoxication.

Effects of Iron Overload during Pregnancy on Oxidative Stress in Maternal Rats

Although iron is an essential mineral, excess iron intake during pregnancy may increase oxidative stress in tissues. This study was conducted to investigate the effects of iron overload during pregnancy on iron status and oxidative stress in maternal rats. Ten week-old female Sprague-Dawley rats were mated with male rats. Non-pregnant (control) and pregnant rats were fed diets containing normal Fe (35 mg/kg diet), high Fe (350 mg/kg diet), or excess Fe (1,050 mg/kg diet) during pregnancy. Rats were sacrificed on pregnancy day 19. No significant difference in weight gain, diet intake, or litter size was observed according to iron intake levels. Furthermore, serum iron, hemoglobin, and hematocrit were not different among the rats administered the three levels of Fe both in the control and pregnant groups. However, the iron levels were lower in pregnant rats than those in the control. The liver and spleen iron contents increased significantly in the excess Fe group. An increase in liver ferritin levels with increasing iron intake was observed. Protein carbonyl content, as a marker of oxidative stress, increased significantly in liver with increasing iron intake but not malondialdehyde. Glutathione peroxidase activity in the liver of pregnant rats fed excess iron decreased significantly. Bcl-2 protein expression in the liver declined remarkably with increasing maternal iron intake in pregnant rats. Taken together, iron overload during pregnancy had little effect on hematology. However, the deposits of iron in the liver and the decline in antioxidant enzyme activity implied increased oxidative stress in tissues of the excess Fe group. These results suggest that excess iron intake during pregnancy increases oxidative stress in maternal tissues and may also affect fetal tissues.

Effects of a Low Calcium Diet and Oxalate Intake on Calcium Deposits in Soft Tissues and Bone Metabolism in Ovariectomized Rats

It is controversial whether low calcium intake, commonly associated with osteoporosis, results in calcium accumulation in soft tissues. This study was conducted to investigate the effects of low calcium (Ca) and oxalate (ox) intake on soft-tissue Ca deposits and bone metabolism in ovariectomized (ovx) rats. Eight week old female Sprague-Dawley rats were ovariectomized and divided into four groups. The rats were fed experimental diets containing low (0.1%, w/w) or normal (0.5%, w/w) Ca with or without sodium oxalate (1%, w/w); Sham/NCa, Ovx/NCa, Ovx/LCa, Ovx/NCa-ox, Ovx/LCa-ox for 6 weeks. All ovx rats showed a remarkable increase in body and tissue weight, glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, blood urea nitrogen, alkaline phosphatase, and decreases in weight, ash, and Ca contents, as well as bone breaking force compared to those in sham rats. Serum Ca concentration was not significantly affected by dietary Ca levels or ox intake. Kidney Ca, ox acid content, and microscopic Ca deposition increased remarkably in the Ovx/LCa-ox group compared to those in the other groups. Ca content in the spleen and aorta also increased significantly, but the weight contents, Ca, bone breaking force, and Ca and oxalic acid in feces decreased significantly in the Ovx/LCa-ox group. Serum parathyroid hormone levels were not significantly different among the groups. These results indicate that low Ca intake decreased bone mineral content and increased Ca deposits in soft tissues, which was aggravated by ox intake in ovx rats. Thus, high ox intake may result in a kidney disorder in patients with osteoporosis who eat a low Ca diet.

Secular Trend in Dietary Patterns in a Korean Adult Population, Using the 1998, 2001, and 2005 Korean National Health and Nutrition Examination Survey

Koreans have undergone many changes in dietary patterns with economic growth. The purpose of this research was to examine changes in dietary patterns using data from the 1998, 2001, and 2005 Korean National Health and Nutrition Examination Survey. The study included 21,525 subjects (8,295 from 1998, 6,880 from 2001, and 6,350 from 2005) who were 20 years or older and who participated in a 24-h diet recall. The percentage energy intake from 22 food groups was calculated, and a cluster analysis was applied to identify dietary patterns. Two dietary patterns emerged; the first pattern was characterized by high intake of white rice, legumes, vegetables, kimchi, and seaweeds, the so-called "traditional" pattern (53%), whereas the other pattern was characterized by high intake of other grains, noodle dumplings, floured bread, pizza, hamburgers, cereals and snacks, potatoes, sugared sweets, nuts, fruits, meat.its products, eggs, fish, milk and dairy products, oils, beverages and seasoning, or the so-called "modified" pattern. The modified pattern comprised a higher proportion of younger aged, metropolitan residents with more education and higher incomes. However, the gender distribution was not significantly different. The modified pattern had a significantly higher intake of all nutrients except carbohydrates and had a higher proportion of energy from fat and protein. No association with a risk for metabolic syndrome was found for either dietary pattern. After age was standardized, the traditional pattern included 52% of the respondents in 1998, 54% in 2001, and 50% in 2005. However, the modified pattern was significantly more prevalent in the younger age group (20-29 yr), whereas the traditional pattern increased significantly in the older age group (> or = 65 yr). In conclusion, a secular trend was found for dietary pattern by age group, suggesting that it is necessary to monitor the changes in dietary pattern by age group and to develop appropriate dietary education and guidelines.

Effects of Different Types of Dietary Fat on Muscle Atrophy According to Muscle Fiber Types and PPARdelta Expression in Hindlimb-Immobilized Rats

This study investigated how dietary fat affects muscle atrophy and lipid metabolism in various muscles during hindlimb immobilization in rats. Twenty-four male Sprague-Dawley rats had their left hindlimb immobilized and were divided into four groups by dietary fat content and composition. The contralateral hindlimb (control) was compared with the immobilized limb in all dietary groups. Rats (n = 6/group) were fed a 4% corn oil diet (CO), 2.6% corn oil + 1.4% fish oil diet (FO), 30% corn oil diet (HCO), or a 30% beef tallow diet (HBT)after their hind limbs were immobilized for 10 days. Data were collected for the gastrocnemius, plantaris and soleus muscles. Muscle atrophy was induced significantly after 10 days of hindlimb immobilization, resulting in significantly decreased muscle mass and total muscle protein content. The protein levels of peroxisome proliferator activated receptor delta (PPARdelta) in the plantaris, gastrocnemius, and soleus increased following hindlimb immobilization irrespective of dietary fat intake. Interestingly, the PPARdelta mRNA level in the plantaris decreased significantly in all groups and that in the FO group was lower than that in the other groups. The soleus PPARdelta mRNA level decreased significantly following hindlimb immobilization in the FO group only. Muscle carnitine palmitoyl transferase 1 (mCPT1) mRNA level was not affected by hindlimb immobilization. However, the mCPT1 mRNA level in the FO group was significantly lower in the plantaris but higher in the soleus than that in the other groups. The pyruvate dehydrogenase kinase 4 (PDK4) mRNA level in the plantaris decreased significantly, whereas that in the soleus increased significantly following hindlimb immobilization. The plantaris, but not soleus, PDK4 mRNA level was significantly higher in the FO group than that in the CO group. The increased PPARdelta protein level following hindlimb immobilization may have suppressed triglyceride accumulation in muscles and different types of dietary fat may have differentially affected muscle atrophy according to muscle type. Our results suggest that omega-3 polyunsaturated fatty acids may suppress muscle atrophy and lipid accumulation by positively affecting the expression level and activity of PPARdelta and PPARdelta-related enzymes, which are supposed to play an important role in muscle lipid metabolism.

Association between Dietary Patterns and Blood Lipid Profiles in Korean Adults with Type 2 Diabetes

We aimed to explore the associations of dietary patterns with blood lipid profiles and obesity in adults with type 2 diabetes. The data were obtained from the Forth Korean National Health and Nutrition Examination Survey, 2007-2008. Adults 30 yr or older, from which had both biochemical and dietary data were obtained. Among them, 680 subjects were defined as having diabetes based on criteria of fasting glucose > or = 126 mg/dL, anti-diabetic treatment, or previously diagnosed diabetes. Dietary data from a 24-hr recall were used to derive dietary patterns by factor analysis. Four dietary patterns by factor analysis were identified: 'Bread & Meat & Alcohol', 'Noodles & Seafood', 'Rice & Vegetables', and 'Korean Healthy' patterns. Serum cholesterol levels in the highest quartile of the 'Bread & Meat & Alcohol' pattern were significantly higher compared with those in the lowest quartile. In addition, total cholesterol and triglyceride levels in the highest quartile of the 'Korean Healthy' pattern were significantly lower after adjusting for potential confounders. Dietary patterns of adults with diabetes were found to be associated with blood lipid profiles. 'Korean Healthy' pattern including whole grains, legumes, vegetables, and fruits could thus improve lipid profiles among those with type 2 diabetes.

Effect of aldosterone on the amplification of oncolytic vaccinia virus in human cancer lines / 대한간학회지

BACKGROUND/AIMS: JX-594 is an oncolytic virus derived from the Wyeth vaccinia strain that causes replication-dependent cytolysis and antitumor immunity. Starting with a cross-examination of clinical-trial samples from advanced hepatocellular carcinoma patients having high levels of aldosterone and virus amplification in JX-594 treatment, we investigated the association between virus amplification and aldosterone in human cancer cell lines. METHODS: Cell proliferation was determined by a cell-counting-kit-based colorimetric assay, and vaccinia virus quantitation was performed by quantitative polymerase chain reaction (qPCR) and a viral plaque assay. Also, the intracellular pH was measured using a pH-sensitive dye. RESULTS: Simultaneous treatment with JX-594 and aldosterone significantly increased viral replication in A2780, PC-3, and HepG2 cell lines, but not in U2OS cell lines. Furthermore, the aldosterone treatment time altered the JX-594 replication according to the cell line. The JX-594 replication peaked after 48 and 24 hours of treatment in PC-3 and HepG2 cells, respectively. qPCR showed that JX-594 entry across the plasma membrane was increased, however, the changes are not significant by the treatment. This was inhibited by treatment with spironolactone (an aldosterone-receptor inhibitor). JX-594 entry was significantly decreased by treatment with EIPA [5-(N-ethyl-N-isopropyl)amiloride; a Na+/H+-exchange inhibitor], but aldosterone significantly restored JX-594 entry even in the presence of EIPA. Intracellular alkalization was observed after aldosterone treatment but was acidified by EIPA treatment. CONCLUSIONS: Aldosterone stimulates JX-594 amplification via increased virus entry by affecting the H+ gradient.

Effects of Soy Protein, its Hydrolysate and Peptide Fraction on Lipid Metabolism and Appetite-Related Hormones in Rats

This study was aimed to investigate whether soy protein hydrolysates had beneficial effects on serum and tissue lipid contents and appetite-related hormones as compared with intact soy protein. Four-week-old male Sprague-Dawley rats were fed AIN-93M diet containing high fat (18% w/w) with low protein (10% w/w). After four weeks, the rats were divided into four groups (n = 8/group) and fed experimental diets with different nitrogen sources and levels, respectively; 10% soy protein isolate (10SPI), 25% soy protein isolate (25SPI), 25% soy protein hydrolysates (25SPH) and 25% soy macro-peptide fractions (25SPP, MW > or = 10,000) for six weeks. Weight gain was significantly higher in 25% nitrogen sources-fed groups than in 10% group (10SPI). In 25SPP, perirenal fat mass and serum total lipid were significantly lower than in other groups. As for appetite-related hormones, serum ghrelin concentration was not shown to be different among groups but leptin concentration was significantly decreased in 25SPP. It can be concluded that soy macro-peptide fractions as compared with intact soy protein may have beneficial effects on reducing fat mass and serum lipid.

Effects of sn-2 palmitic acid-fortified vegetable oil and fructooligosaccharide on calcium metabolism in growing rats fed casein based diet

This study was carried out to investigate the efficacy of sn-2 palmitic acid-fortified vegetable oil (Sn2PA) on calcium absorption and to confirm the synergistic effects of fructooligosaccharide on calcium absorption. Male SD rats were fed 6 kinds of casein based diets containing vegetable oil (control), sn-2 palmitic acid-fortified vegetable oil (Sn2PA) and Sn2PA with fructooligosaccharide(Sn2PAFO) in two levels of calcium (normal 0.5% and high 1.0%) for 3 weeks. Total lipids, cholesterol, triglyceride and calcium in blood were measured. Feces were collected using cages for 4 days. Serum concentrations of total lipids and calcium were not significantly different among groups. However, serum triglyceride was significantly decreased by fructooligosaccharide supplementation regardless of dietary calcium level. The lipid absorption was not significantly different among experimental groups. Calcium absorption was significantly higher in Sn2PAFO group than other groups. Calcium solubility of intestine was increased by sn-2 palmitic acid supplementation. These results suggest that sn-2 palmitic acid and fructooligosaccharide supplementation could be beneficial for baby foods including infant formula, with regard to increasing absorption of calcium by more soluble calcium in the small intestinal content.

Effects of Genistein Supplementation on Fatty Liver and Lipid Metabolism in Rats Fed High Fat Diet

This study was performed to investigate the effects of genistein, a kind of soy isoflavones, on fatty liver and lipid metabolism in rats fed high fat diet. Twenty four male Sprague-Dawley rats were divided into four groups by dietary fat and genistein contents then raised for six weeks. The rats (n = 6 / group) were fed normal fat diet (NOR), high fat diet (HF), high fat with 0.1% genistein (HF + 0.1%G) or high fat with 0.2% genistein (HF + 0.2%G). Hepatic total lipid, triglyceride, total cholesterol and Serum GPT, as a marker for fatty liver, were significantly increased by high fat diet. Also, serum total lipid, triglyceride, total cholesterol, glucose and insulin concentration, hepatic lipogenic enzyme (fatty acid synthase and malic enzyme) activities were significantly increased by high fat diet. However, hepatic total lipid, triglyceride, total cholesterol and Serum GPT were significantly decreased by genistein intake. Also, genistein supplementation decreased serum total lipid, triglyceride, glucose and insulin concentration, hepatic lipogenic enzyme (fatty acid synthase and malic enzyme) activities. There were no differences by genistein level except for serum insulin. These results suggest that fatty liver induced by high fat diet was caused by increased serum lipid profiles and hepatic lipogenesis, whereas, genistein may be useful in inhibiting of fatty liver by reducing serum lipid profiles and hepatic lipogenesis.

Status of Early Childhood and Maternal Nutrition in South Korea and North Korea / 대한지역사회영양학회지

The purpose of this study was to compare the nutritional status of children aged 5 or under and women aged 20 to 34 years between the Republic of Korea (South Korea) and the Democratic Peoples' Republic of Korea (DPRK: North Korea). For the source of nutritional status of North Koreans, the DPRK 2004 Nutrition Assessment-Report of Survey Results was used. As the comparable data of South Koreans, the anthropometric data for children and women were obtained from the reports of the Korean Pediatric Society and the Korean Agency for Technology and Standards, respectively. The blood hemoglobin data of South Korean women were obtained from the data file of the 2001 National Health and Nutrition Survey and analyzed. In regard to the North Korea, the prevalence of underweight (weight for age Z-score <-2.0) in children under 12 months was about 10~15%, and thereafter progressively increased until 30 to 35 months reaching 30%. In South Korea, the prevalence of underweight was less than 3% in most age groups both in boys and girls. In North Korea, the prevalence of stunting (height for age Z-score <-2.0) reached 20% in children under 12 months and increased with age over the level of 50% in children aged 54 to 59 months. In South Korea, the prevalence of stunting was less than 3% in children under 12 months and was less than 10% throughout the age groups. Maternal protein-energy malnutrition and anemia were assessed for the women aged 20 to 34 years using mid-upper arm circumference (< 22.5 cm) and blood hemoglobin level (< 12 g/DL), respectively. The prevalence of protein-energy malnutrition was 39.6%, 30.7%, 31.7% in North Korea and 12.5%, 5.0%, 1.5% in South Korea for the women in 20~24, 25~29, 30~34 years, respectively. The prevalence of anemia in the North Korean women was about 34~36% while that in the South Korean women was 15~18%. In conclusion, the disparity of nutritional status in early childhood and maternity between South Korea and North Korea is so huge that active and well-planned nutrition support policy and programs for women and children in North Korea is imperative to prepare for the future unified nation.

Effects of Deer Antler Extract on Serum IGF-I, Bone Growth and Splenocyte Proliferation in Growing Rats

Although it has traditionally known that deer antler and medicinal herbs extract contain some functional components for health promotion, the nutritional significance remains to be elucidated. This study examined the efficacy of deer antler extract (DA) , medicinal herbs extract (MH) and their mixture (DAMH) on serum IGF-I, bone growth with growing rats in vivo and splenocyte proliferation with spleen cells in vitro. Three week-old young female rats (Sprague-Dawley) were divided into 4 groups and then fed basal diet (AIN-93G) or experimental diets containing DA, MH, DAMH, respectively, for 7 weeks. We collected blood, liver, kidney, spleen, femur and tibia from rats. There was no significant difference in weight gain, but food intake increased in DA- and MH-fed groups. There were no signs of liver and kidney damage in the DA, MH and DAMH-fed groups compared to basal diet group. In femur and tibia, wet weights, breaking forces and bone minerals (Ca, Mg and Zn) were significantly higher in the DA-fed group than in the other groups. Serum alkaline phosphatase (ALP) , bone-specific alkaline phosphatase (BALP) activities were significantly lower in the DA, MH, DAMH-fed groups than in basal diet group. Also, serum insulin-like growth factor-I (IGF-I) concentrations were significantly increased in DA-fed group compared to the other groups. Therefore DA was shown to have an activity of bone growth promotion by increasing the IGF-I, a major bone growth factor. The deer antler extract showed an enhanced immune action on the primary cultured-cells from spleen of rats, representing that splenocytes were proliferated by lipopolysaccharide (LPS) , but not by concanavalin A (Con A) . These results indicate that deer antler extract has beneficial effects on bone growth via IGF-I and on splenocyte activation.

Effect of Dietary Fat and Genistein on Lipid Metabolism and Antioxidant Activity in Hyperlipidemic Male Rats induced High Fat Diet

This study was conducted to investigate whether dietary factors, normal fat and genistein leads to beneficial improvement of lipid metabolism and oxidative stress in adult hyperlipidemic male rats. Seven wk-old male SD rats were fed high fat diet (15% fat, 1% cholesterol) for 4 wks for induction of hyperlipidemic model rat. Weight-matched rats were then assigned to four groups according to dietary fat level (7% or 15% fat) and genistein contents (0 or 320 mg/kg diet). Food intake was significantly decreased by both high fat intake and genistein supplementation compared with normal fat intake and genistein no supplementaion. But weight gain was significantly decreased by genistein supplementation in normal fat intake compared with the other groups. Total lipid, total cholesterol and triglyceride in serum and liver were significantly decreased by normal fat intake compared with high fat intake. But total cholesterol in liver was significantly increased by genistein supplementation in both high fat and normal fat intake. TBARS in serum and liver was less produced by normal fat intake compared with high fat intake but TBARS in liver was significantly increased by genistein supplementation compared with genistein no supplementation in normal fat intake. Glutathione reductase activity in erythrocytes was significantly reduced by genistein supplementation in normal fat intake compared with the other groups. Glutathione peroxidase and glutathione reductase activities in liver were significantly inhibited by normal fat intake compared with high fat intake. Catalase activity in liver was significantly increased by genistein supplementation compared with genistein no supplementation in high fat intake. Nitrite was significantly decreased by normal fat intake compared with high fat intake. These results suggest that normal fat intake has the treatment effect against risk factors related with cardiovascular disease by reducing lipid profiles, lipid peroxidation. And genistein shows action as a antioxidant replacing antioxidant enzymes but also may act as prooxidant causing the production of TBARS.

Effects of Calcium and Genistein on Body Fat and Lipid Metabolism in High Fat-induced Obese Mice

The study was conducted to investigate the effects of dietary calcium and soy isoflavone on body fat and lipid metabolism in high fat-induced obesity. Four week old female C57/BL6J mice, known as a good model of diet-induced obesity, were fed low Ca and high fat diet for 6 weeks. After induced obesity, mice were divided into six groups according to diets varying calcium contents (0.1 or 1.5%) and genistein contents (0 or 500 or 1,000 ppm). Body weight, fat pad (perirenal fat and parameterial fat), adipocyte size, serum total lipid and total cholesterol were significantly decreased by both high Ca intake and genistein supplementation. However, the effect of genistein supplementation showed in low Ca-fed groups. Serum LDL-cholesterol and TG were significantly decreased by high Ca intake and genistein supplementation, respectively. In liver, lipogenic enzymes (fatty acid synthase and malic enzyme) activity and TG were significantly decreased by both high Ca intake and genistein supplementation. This inhibitory effect of genistein on lipogenic enzymes showed in low Ca-fed groups. But liver total cholesterol and total lipid were significantly decreased by high Ca intake and genistein supplementation, respectively. Fecal excretion of total lipid, total cholesterol and TG were significantly increased by high Ca intake, not by genistein supplementation. In conclusion, high calcium intake and genistein supplement may be beneficial for suppression of obesity through direct anti-adipogenesis by decreasing fat weight and size and indirect anti-lipogenesis by inhibiting lipogenic enzymes activity and improving lipid profile.

Effect of Genistein and Soy Protein on Lipids Metabolism in Ovariectomized Rats

Postmenopausal women or ovariectomized rats are associated with increased cholesterol levels, which are risk factors of metabolic syndrome and cardiovascular diseases. Increased prevalence of metabolic syndrome after menopause might be associated with estradiol deficiency. Harmful effect of estradiol hampers the casual usage of hormone to prevent the metabolic syndrome. Soy protein has been reported to show several beneficial effects on health, however it is unclear which components of soy protein is responsible for anti-obesity and hypocholesterolemic effects. Soy isoflavones, genistein and daizein, are suggested to have anti-obesity and hypocholesterolemic effects but with inconsistency. The present study investigated the effect of supplementation of genistein (experiment I) and soy protein containing isoflavones (experiment II) to high fat diet on body weight gain, food intake, liver and fat tissue weight and the lipid levels in ovariectomized rats. Plasma and hepatic lipid contents and the mRNA levels of genes encoding lipid metabolism related proteins, such as CPT1 and HMGR were measured. Ovariectomy increased body weight, fat tissue weight and plasma and hepatic lipid levels which increase the risk of metabolic syndrome. Soy protein could improve plasma and hepatic lipids levels. Soy protein also increased hepatic CPT1 and HMGR mRNA levels. Plasma and hepatic lipids levels could not be decreased by dietary genistein alone. In contrast, lipids levels could be decreased by isoflavone-fortified soy protein, suggesting that the ingestion of soy protein enriched with isoflavone gives more benefit for protecting postmenopausal women from metabolic syndrome.

Effects of Soy Isoflavone Intake on Nitrite Content and Antioxidant Enzyme Activities in Male Rats Fed High-Fat Diet

This study was performed to investigate the effect of soy isoflavone on plasma nitrite concentration and the antioxidant enzyme activities of erythrocyte and the liver using adult male rats fed high fat diet. Seven-week old male Sprague Dawley rats were divided into three groups and fed high fat diet (15% beef tallow, 1% cholesterol; control: IF0) or high fat diets containing isoflavone 80 ppm (IF80) or 320 ppm (IF320) for 10 weeks. Plasma nitrite concentration as a vasodilator, and antioxidant enzyme activities in erythrocytes and the liver were measured. Plasma nitrite concentration was increased by 45% and 35%, respectively, in IF80 and IF320 than in IF0 group. Erythrocyte catalase, glutathione peroxidase (GPx) and glutathione reductase (GR) activities increased by 31%, 30% and 40% in IF320 compared to IF0 group. Especially, erythrocyte GR activity increased by 61% in IF80 group. However, catalase activity in the liver was decreased in IF80 group. GPx and GR activities in the liver were not differ among groups. The results suggest that soy isoflavone have the protective effect against risk factors related with cardiovascular disease by improving vasodilator factor, nitrite, and antioxidant enzyme activities in blood.

Preventive Effects of Chitosan on the Disorders of Hepatic Functions and Lipid Metabolism in Rats Treated with 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)

This study was conducted to fine out the preventive effects of chitosan and chitosan oligomer on the disorders of hepatic functions and lipid metabolism induced by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD), using adult male rats (SD) for four weeks. Rats were fed chitosan (4%) or chitosan oligomer (4%) diets respectively before 3weeks of TCDD treatment (50 ug/kg BW) by intraperitoneal injection and then continually supplied these diets for one week until being sacrificed. The elevation of serum total and LDL cholesterol levels induced by TCDD treatment was significantly reduced in the rats fed chitosan diets. The increment of liver triglyceride levels caused by TCDD treatment was tended to suppress in all rats fed chitosan and chitosan oligomer diets. Fecal total lipid and cholesterol excretion were high levels in the rats fed chitosan diets. The hepatic cytosolic catalase activities significantly decreased by TCDD treatment appeared recovering trend by chitosan diets. In hepatic microsomal cytochrome p-450, NADPH cytochrome p-450 reductase, ethoxycoumarin-o-deethylase (ECOD) and benzphetamin N-demethylase (BPND), chitosan than chitosan oligomer diets apparently decreased the increasing levels by TCDD treatment. In histochemical observation, the fat droplets and apoptosis of hepatocytes by TCDD treatment were markedly alleviated by chitosan and chitosan oligomer diets. These results indicate that chitosan, more than chitosan oligomer can exert preventive effects on some disorders of hepatic functions and lipids accumulation by TCDD.

Effects of Chitosan on the Lead Level and Histological Changes in Rats Exposed to Various Levels of Lead

Chitosan, which is a biopolymer, composed of glucosamine units linked by beta-1, 4 glycoside bonds, is rich in shells of crustacean such as crabs and shrimps. Consumption of chitosan has been rapidly increased as a functional food. We examined effects of chitosan on the damages caused by lead (Pb) exposure in rats. Male Sprague-Dawley rats were divided into 8 groups (n = 64), then fed diets containing 3% cellulose (control) or 3% chitosan, each with 4 different lead doses (0 mg/d, 20 mg/d, 50 mg/d, and 100 mg/d) for 4 wks. Lead doses were given 3 times per week by oral administration. Blood lead levels in rats increased depending on the administered doses of lead. Rats fed chitosan diets showed lower blood lead concentration than did their respective controls. Effect of chitosan on the blood lead was more beneficial in rats exposed to lower lead (20 mg/d) than in rats exposed to higher lead (50 mg/d and 100 mg/d). Histological changes in erythrocytes and liver were also examined. Chitosan tended to reduce numbers of basophilic stippling erythrocytes and improve the histological liver changes in rats given various lead doses. The preventive effects of chitosan on liver damages were stronger in rats with higher lead than those with lower lead. These results indicate that chitosan has beneficial effects on both blood toxicological responses and histological damages of erythrocytes and liver induced by the administration of various lead doses.

Supplementary Effect of the High Dietary Fiber Rice on Blood Glucose in Diabetic KK Mice

This study was carried out to investigate the supplementary effects of Suwon 464, which has over two times of dietary fiber content compared with normal rice (Ilpum), on blood glucose in diabetic mice. We supplied 5 kinds of experimental diets (corn starch diet as a control (CO), Ilpum polished rice diet (IP), Ilpum brown rice diet (IB), polished rice diet (SP) and brown rice diet (SB) of Suwon 464) to diabetic mice for 8 weeks, after analyzing dietary fiber contents of 5 experimental diets. Diet intake, body weight and contents of blood glucose, hemoglobin A(1c) and insulin were measured. The dietary fiber contents in CO, IP, IB, SP, and SB diets were 1.0, 1.2, 1.4, 1.4, and 2.0% respectively. Body weight was lower in SB group than the other groups though there was no significant difference in diet intake among experimental groups. The concentration of blood glucose in diabetic mice was lower in SB group than the other groups during the supplementary period of experimental diets. The hemoglobin A(1c) and serum insulin levels were lower in SP and SB groups. These results suggested that the brown rice of Suwon 464 with high dietary fiber can control diabetes in diabetic mice by reducing the blood glucose and hemoglobin A(1c).

Effect of Ovariectomy and Genistein on Hepatic Mitochondrial Function

Women with menopause or rats with ovariectomy is associated with increased body weight, body fat and insulin resistance, which are components of metabolic syndrome. Increased prevalence of metabolic syndrome after menopause might be associated with mitochondrial dysfunction, since mitochondrial oxidative and phosphorylation activity is strongly correlated with insulin sensitivity. Although estradiol replacement prevents the metabolic syndrome, harmful effect of estradiol hampers the casual usage to prevent the metabolic syndrome. It has been reported that genistein has a mild estrogenic activity, decreases fat mass in mice and has an antidiabetic role in diabetic rats. Although insulin resistance is closely related to mitochondrial functions, there has not been yet any study in regard to the effect of dietary genistein on mitochondrial function in the insulin resistant female subjects induced by ovariectomy or similar situation. The present study investigated whether the supplementation of genistein in the high fat diet affected the mitochondrial function of high fat fed ovariectomized rats. Female Sprague Dawley rats (8 weeks old) were assigned to the following groups: sham-operated + high fat diet (S, n = 6); sham-operated + high fat diet with 0.1% genistein (S + G, n = 7); ovariectomized + high fat diet (OVX, n = 8); ovariectomized + high fat diet with 0.1% genistein (OVX + G, n = 8). Ovariectomy significantly increased body weight compared with S group. Genistein consumption in ovariectomized (OVX + G) rats decreased body weight gain compared with OVX rats. Liver weights were increased by ovariectomy. The hepatic mitochondrial protein density expressed as mg per g liver was lower in the OVX group than in the S group. However, OVX + G group showed the increased mitochondrial protein density similar to the level of S group. When mRNA levels of genes related to mitochondria such as peroxisome proliferator-activated receptor gamma coactivator 1 (PGC-1) and cytochrome c oxidase subunit III (COX III) were measured, there were decreases in the mRNA levels of PGC-1 and COX III in S + G, OVX and OVX + G group. The activity of cytochrome c oxidase was not different between groups. We could observe the decrease in succinate dehydrogenase (SDH) activity per g liver in OVX rats. Genistein supplement increased SDH activity. In conclusion, genistein supplementation to the OVX rats enhanced mitochondrial function by increasing mitochondrial protein density and SDH activity. The improvement in mitochondrial function by genistein can contribute to the improvement in metabolic syndrome.