Effects of different ratios of monounsaturated and polyunsaturated fatty acids to saturated fatty acids on regulating body fat deposition in hamsters.

OBJECTIVE: Effects of monounsaturated fatty acid (MUFA) and polyunsaturated fatty acid consumption on regulating body fat accumulation and body weight gain are controversial between animal and human studies. METHODS: We designed a 2 x 2 factorial study, with two levels of MUFAs (60% and 30%) and two levels of polyunsaturated-to-saturated fatty acid (P/S) ratio (5 and 3) to prepare four kinds of experimental oils consisting of 60% MUFAs with a high or low P/S ratio (HMHR or HMLR, respectively) or 30% MUFAs with a high or low P/S ratio (LMHR or LMLR, respectively). Thirty-two male golden Syrian hamsters were randomly divided into four groups and fed the experimental diets containing 15% (w/w) fat for 12 wk. RESULTS: No difference was observed in the mean daily food intake. Hamsters fed the LMLR diet had increased weight gain, epididymal and retroperitoneal white adipose tissues, plasma non-esterified fatty acids, insulin, hepatic acetyl coenzyme A carboxylase and malic enzyme activities, and mRNA expressions of peroxisome proliferator-activated receptor-alpha and sterol regulatory element-binding protein-1c among all groups (P < 0.05). Hamsters fed the HMHR diet had lower plasma insulin levels and hepatic acetyl coenzyme A carboxylase activities among groups (P < 0.05) and elevated hepatic acyl coenzyme A oxidase and carnitine palmitoyltransferase-I activities compared with those fed the LMLR diet (P < 0.05). CONCLUSION: Hamsters fed the LMLR diet had increased weight gain and body fat accumulation, whereas the HMHR diet appeared to be beneficial in preventing white adipose tissue accumulation by decreasing plasma insulin levels and increasing hepatic lipolytic enzyme activities involved in beta-oxidation.

Effects of beta-carotene on antioxidant status in rats with chronic alcohol consumption.

This study examined the effects of beta-carotene on antioxidant status in rats with chronic alcohol consumption. At the beginning of experiment (week 0), according to both the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, rats (n = 24) were divided into 3 groups and fed with a standard diet (group C), a diet containing ethanol (group E), or a diet containing ethanol and beta-carotene (group E+B). After 10 weeks, plasma AST and ALT, fat accumulation in the liver, antioxidant enzyme activities in erythrocytes and the liver, malondialdehyde (MDA), and alpha-tocopherol and retinol in plasma and hepatic samples were analyzed. The chronic alcohol diet significantly increased AST and ALT levels in plasma, and these changes were prevented by supplementing the diet with beta-carotene. Glutathione (GSH) in erythrocytes and in the liver was significantly elevated in rats fed with a diet containing beta-carotene. The results indicate that beta-carotene supplementation can prevent ethanol-induced liver damage and increase GSH concentrations in erythrocytes and the liver.

Consumption of purple sweet potato leaves decreases lipid peroxidation and DNA damage in humans.

Consumption of polyphenols is associated with reduced risk of chronic diseases, possibly via a variety of bio-mechanisms, including antioxidation and anti-inflammation. Purple sweet potato leaves (PSPL) commonly consumed in Asia possess polyphenols. In this study, we aim to investigate antioxidant effect of 200 g/d PSPL containing 902 mg polyphenols in a clinical trial. This randomized, crossover clinical study included 16 healthy adults (7 M, 9 F; aged 20-22 y). After a 1-wk run period, subjects were assigned randomly to receive either PSPL or low polyphenol diet (LPD) for 2 wks, followed by a 2-wk washout period before crossing over to the alternate diet. Fasting blood and 24-h urine samples were collected from each subject at day 0, 7 and 14 of each phase. Our data showed PSPL consumption enhanced urinary total phenol excretion by 24.5% at day 14 as compared to day 0, while the LPD decreased total phenol content in plasma and urine by 3.3 and 16.3%, respectively (p< or =0.05). Low-density lipoprotein lag time and glutathione concentration in erythrocytes at day 14 was significantly enhanced by 15.0 and 33.3% by PSPL as compared to day 0, respectively, while their values were not altered by the LPD. Urinary 8-hydoxy-deoxyguanosine (8-OHdG) excretion decreased significantly by PSPL consumptoin by 36.7% at day 7 as compared to day 0, yet unchanged by the LPD (p< or =0.05). In conclusion, our results suggest that polyphenols in 200 g PSPL were bioavailable and could enhance antioxidant defense and decrease oxidative stress in young healthy people.

Effectiveness of a soy-based compared with a traditional low-calorie diet on weight loss and lipid levels in overweight adults.

OBJECTIVE: This study investigated the effects of a soy-based low-calorie diet on weight control, body composition, and blood lipid profiles compared with a traditional low-calorie diet. METHODS: Thirty obese adults (mean body mass index 29-30 kg/m(2)) were randomized to two groups. The soy-based low-calorie group consumed soy protein as the only protein source, and the traditional low-calorie group consumed two-thirds animal protein and the rest plant protein in a 1200 kcal/d diet for 8 wk. A diet record was kept everyday throughout the study. Food intake was analyzed before and after the study. Anthropometric data were acquired every week, and biochemical data from before and after the 8-wk experiment were compared. RESULTS: Body weight, body mass index, body fat percentage, and waist circumference significantly decreased in both groups (P < 0.05). The decrease in body fat percentage in the soy group (2.2%, 95% confidence interval 1.6-2.8) was greater than that in the traditional group (1.4%, 95% confidence interval -0.1 to 2.8). Serum total cholesterol concentrations, low-density lipoprotein cholesterol concentrations, and liver function parameters decreased in the soy-based group and were significantly different from measurements in the traditional group (P < 0.05). No significant change in serum triacylglycerol levels, serum high-density lipoprotein cholesterol levels, and fasting glucose levels was found in the soy or traditional group. CONCLUSION: Soy-based low-calorie diets significantly decreased serum total cholesterol and low-density lipoprotein cholesterol concentrations and had a greater effect on reducing body fat percentage than traditional low-calorie diets. Thus, soy-based diets have health benefits in reducing weight and blood lipids.

Leptin, superoxide dismutase, and weight loss: initial leptin predicts weight loss.

OBJECTIVE: Our goal was to study how plasma leptin concentration, superoxide dismutase (SOD) activity, and weight loss are related in obese adults. RESEARCH METHODS AND PROCEDURES: Serum leptin concentration, SOD activities, general biochemical data, and body composition measurements were obtained for 62 overweight and obese subjects before and after an 8-week body weight reduction (BWR) regimen. The subjects were on dietary control, performed moderate aerobic and strength training exercises, and attended educational lectures. RESULTS: The measurement results indicated that the following criteria were significantly reduced: body weight [84.4 +/- 17.0 vs. 79.3 +/- 16.1 (standard error) kg, p < 0.001]; BMI (31.5 +/- 4.3 vs. 29.4 +/- 4.2 kg/m(2), p < 0.001), and fat mass (33.3 +/- 10.0 vs. 29.8 +/- 10.4 kg, p < 0.001). Plasma leptin levels also significantly decreased from 31.5 +/- 17.6 to 26.5 +/- 17.2 ng/mL (p < 0.001). Additionally, SOD activity was significantly increased from 261.4 +/- 66.0 to 302.7 +/- 30.9 U/mL (p < 0.001). Based on linear regression analysis results, a 3.78- to 8.13-kg reduction in weight can be expected after the 8-week BWR regimen when initial leptin concentration was 5 to 30 ng/mL. DISCUSSION: We found that an 8-week exercise and diet program was effective in reducing weight and fat mass and, notably, had further beneficial effects on leptin resistance and SOD activity. Additionally, this study demonstrated that initial plasma leptin concentration may be used as a predictor for weight loss outcome.

One-year soy isoflavone supplementation prevents early postmenopausal bone loss but without a dose-dependent effect.

It is believed that soy isoflavone has much potential effectiveness on the postmenopausal status; however, the optimal dose for preventing postmenopausal bone loss still remains unclear. This open-labeled, self-controlled pilot study was undertaken to determine the effect of 1-year supplementation of different high dosages of soy isoflavone in postmenopausal Taiwanese women. Forty-three women aged 45-67 years were enrolled and randomly assigned into a control (C), 100 mg/day isoflavone (IF100) and 200 mg/day isoflavone (IF200) groups for 1 year. Dual-energy X-ray absorptiometry and other related biochemical markers of bone metabolism were measured. Results indicated that the decrease in bone mineral density (BMD) was significant for lumbar vertebrae L1-3, L1-4 and the femur neck in the C group; surprisingly, the BMD of L1-3 was significantly elevated in the IF100 group; however, there were no consistent responses in the IF200 group. No significant change except loss of the bone mineral content of Ward's triangle (P=.003) was found in the IF200 group after treatment. The percentage change at L1-3 was less (P=.04) in the IF200 group when compared to the IF100 group. A relatively uniform direction of bone formation in expanding the weight and area with different rates of change resulted in different BMD changes. Both indicated a change of bone formation patterns with the higher-dose supplement. A protective effect of IF100 on estrogen-related bone loss was observed. A lack of a benefit such as high safety in the IF200 group for 1-year administration was ensured and lacked undesirable side effects.

Analysis of the health risk of exposure to breast milk mercury in infants in Taiwan.

The aim of this study was to assess the total concentration and health risk to infants of breast milk mercury in urban mothers and mothers married to fishermen in relation to fish intake in Taiwan. A total of sixty-eight healthy mothers were recruited for the study. The breast milk mercury geometric mean concentration was 2.02 microgl(-1) (n=56, range: 0.24-9.45 microgl(-1)) for the city group and 2.04 microgl(-1) (n=12, range: 0.26-8.62 microgl(-1)) for the fishermen's group. Of the three sources of mercury exposure (i.e., ingestion (breast milk), inhalation (ambient air), and dermal exposure (shower)), breast-feeding was found to be the largest (96.3-99.6% of the total). From a Monte Carlo simulation, in which methyl mercury accounted for about 50% of total mercury, the hazard quotient (exposure estimate/oral minimal risk level or target organ toxicity dose) exceeded 1.0 for 12.9% of urban babies and 18.8% of fishermen's babies (chronic oral minimal risk level and target organ toxicity dose: 3 x 10(-4)mgkg(-1)d(-1)). The calculated mercury exposure was 3.02 x 10(-1) microgkg(-1)d(-1) for a 3.49 kg urban baby boy and 3.06 x 10(-1) microgkg(-1)d(-1) for a 3.44 kg urban baby girl. These results suggest the life style of mothers (eating raw fish and shellfish such as used in "Sashimi" and "Sushi," and vitamin supplementation) may influence the mercury concentration in breast milk.

Effect of the mother's consumption of traditional Chinese herbs on estimated infant daily intake of lead from breast milk.

Infant exposure to lead through breast milk is of special concern because breast milk is considered the best food source for infants under 6 months. In this study, a total of the mothers provided colostrum samples once in the early postpartum period, but only 16 of them provided breast milk weekly at 1-60 days postpartum. The geometric mean of lead concentrations in all colostrum samples (n=72) was 7.68+/-8.24 microg/L. The concentration of lead in the breast milk of the consumption group (the mothers who consumed traditional Chinese herbs) was 8.59+/-10.95 microg/L, a level significantly higher than the level of 6.84+/-2.68 microg/L found in the control group (mothers who did not consume traditional Chinese herbs). In the consumption group (n=9), the mean concentration of lead in the breast milk decreased with days postpartum, from 9.94 microg/L in colostrum to 2.34 microg/L in mature milk. We found the highest daily lead intake in infants at birth, and the level gradually decreased after the first month. We used an estimation of the hazard index (HI) to analyze the health risk of infants. In total, 5.7% (2 out of 35) of the HI estimates exceed 1.0 for the consumption group. In conclusion, the consumptions of traditional Chinese herbs by the mothers in this study significantly affected the body burden of lead in their infants.

Consumption of purple sweet potato leaves modulates human immune response: T-lymphocyte functions, lytic activity of natural killer cell and antibody production.

AIM: To study the immunological effects of physiological doses of purple sweet potato leaves (PSPL). METHODS: The randomized crossover study (two periods, each lasting for 2 wk) involved 16 healthy non-smoking adults of normal weight. The 6-wk study consisted of a run-in (wk 1) PSPL diet (daily consumption of 200 g PSPL) or a control diet (low polyphenols, with the amount of carotenoids adjusted to the same level as that of PSPL) (wk 2-3), washout diet (wk 4), and switched diet (wk 5-6). Fasting blood was collected weekly in the morning. T-lymphocyte function was assessed via the proliferation and secretion of immunoreactive cytokines. Salivary IgA secretion and the specific cytotoxic activities of cytotoxic T lymphocytes and natural killer (NK) cells were determined. RESULTS: The plasma beta-carotene level increased with time in both groups, while the plasma polyphenol level decreased in the control group, and no significant difference was detected between the two groups. Although plasma polyphenol levels did not significantly increase in the PSPL group at the end of the study, they were significantly elevated in urine. PSPL consumption produced a significant increase in proliferation responsiveness of peripheral blood mononuclear cells (PBMC) and their secretion of immunoreactive IL-2 and IL-4. As well, lytic activity in NK cells was elevated in a time-dependent fashion. Salivary IgA secretion significantly decreased in control group after 2 wk, and returned to baseline following dietary switch to PSPL. CONCLUSION: Consumption of PSPL modulates various immune functions including increased proliferation responsiveness of PBMC, secretion of cytokines IL-2 and IL-4, and the lytic activity of NK cells. The responsible determinants of PSPL remain to be elucidated, as does the biological significance of the present observations.

Effects of gonadotrophin-releasing hormone agonists on apoptosis of granulosa cells.

Granulosa cells are known to contribute to maturation of oocytes, and most of the growth factors exert their action via granulosa cells. It has been established that granulosa cell death during follicular atresia and luteolysis results from apoptosis. However, the precise mechanistic pathways of granulosa cell apoptosis have not yet been defined. In this study, we determined the proportions of apoptosis in granulosa cells treated with two kinds of gonadotrophin-releasing hormone agonists (GnRHa): buserelin and leuprorelin depot. The incidences of DNA fragmentation of human granulosa cells treated with buserelin and leuprorelin were 54.33% and 39.02%, respectively. The proportions of apoptotic bodies were 6.04% and 4.29%, respectively. There was a significant difference in the proportions of DNA fragmentation between the two kinds of GnRHa-treated granulosa cells. The apoptosis pathway and associated protein expression in granulosa cells treated with GnRHa were also determined. The Bax molecule, a pro-apoptosis protein, was expressed in granulosa cells undergoing apoptosis. In contrast, Bcl-2, an anti-apoptosis protein, could not be detected in the same group of granulosa cells. The distribution of cytochrome c determined via immunostaining showed a diffuse pattern, which most likely indicated that cytochrome c was translocated from mitochondria into the cytoplasm. Western blotting showed the expressions of caspase-9 and caspase-3 in patients' granulosa cells. The GnRHa effects on granulosa cells indicated a higher incidence of DNA fragmentation and apoptotic bodies in the buserelin-treated than in the leuprorelin depot-treated group. The granulosa cells go through the mitochondria-dependent apoptosis pathway; the indicated pro-apoptosis protein Bax was expressed and induced cytochrome c release from mitochondria, which then activated caspase-9 and caspase-3 until cell death occurred.

Effects of long-term ethanol consumption on jejunal lipase and disaccharidase activities in male and female rats.

AIM: To study the effect of long-term ethanol consumption on jejunal lipase and disaccharidase (sucrase, maltase, and lactase) activities in rats and its gender difference. METHODS: Age-matched male and female Wistar rats were fed control or ethanol-containing liquid diets for 12 wk following the Lieber-DeCarli model. According to both the plasma aspartate aminotransferase (AST) and alanine aminotransferase (ALT) activities, 40 rats were divided into four groups as follows: male control group (MC), male ethanol group (ME), female control group (FC), and female ethanol group (FE). RESULTS: After ethanol feeding for 12 wk, the results revealed that plasma AST and ALT activities of group ME were significantly increased by 58% and 92%, respectively, than those of group MC (P<0.05). Similarly, plasma AST and ALT activities of group FE were also significantly increased by 61% and 188%, respectively, than those of group FC (P<0.05). Fat accumulation was observed in both ethanol-treated groups, while fatty changes were more severe in group FE than those in group ME. The induction of hepatic microsomal cytochrome P450 2E1 (CYP2E1) was obviously seen in group ME and group FE, but was not detected in group MC and group FC. Jejunal lipase activity of group ME was significantly increased by 1.25-fold than that of group MC (P<0.05). In contrast to, sucrase, maltase, and lactase activities of group ME were significantly decreased by 63%, 62% and 67%, respectively, than those of group MC (P<0.05). Similarly, activities of these three enzymes of group FE were also significantly decreased by 43%, 46% and 52%, respectively, than those of group FC (P<0.05). There were no significant epithelial changes of the duodenal mucosa in any group. CONCLUSION: Long-term ethanol consumption significantly can increase jejunal lipase and decrease jejunal disaccharidase activities in both male and female rats.

Effects of ethanol on antioxidant capacity in isolated rat hepatocytes.

AIM: To investigate dose-response and time-course of the effects of ethanol on the cell viability and antioxidant capacity in isolated rat hepatocytes. METHODS: Hepatocytes were isolated from male adult Wistar rats and seeded into 100-mm dishes. Hepatocytes were treated with ethanol at concentrations between 0 (C), 10 (E10), 50 (E50), and 100 (E100) mmol/L (dose response) for 12, 24, and 36 h (time course). Then, lactate dehydrogenase (LDH) leakage, malondialdehyde (MDA) concentration, glutathione (GSH) level, and activities of glutathione peroxidase (GPX), glutathione reductase (GRD), superoxide dismutase (SOD), and catalase (CAT) were measured. RESULTS: Our data revealed that LDH leakage was significantly increased by about 30% in group E100 over those in groups C and E10 at 24 and 36 h, The MDA concentration in groups C, E10 and E50 were significantly lower than that in group E100 at 36 h. Furthermore, the concentration of MDA in group E100 at 36 h was significantly higher by 4.5- and 1.7-fold, respectively, than that at 12 and 24 h. On the other hand, the GSH level in group E100 at 24 and 36 h was significantly decreased, by 32% and 28%, respectively, compared to that at 12 h. The activities of GRD and CAT in group E100 at 36 h were significantly less than those in groups C and E10. However, The GPX and SOD activities showed no significant change in each group. CONCLUSION: These results suggest that long-time incubation with higher concentration of ethanol (100 mmol/L) decreased the cell viability by means of reducing GRD and CAT activities and increasing lipid peroxidation.

Pharmacokinetic model of daily selenium intake from contaminated seafood in Taiwan.

Contaminated seafood has been reported as an important source of human exposure to metals in Taiwan. Seafood represents a non-negligible source of selenium in the human diet. This study was designed to determine the concentration of selenium in different types of seafood and predict the concentration of selenium in the blood of Taiwanese using a one-compartment steady-state pharmacokinetic (PK) model. Samples involved three subgroups, including fish, crustaceans and bivalve molluscs. Quantitative analysis for selenium was performed using an ICP-AES (Perkin Elmer) instrument. Selenium concentrations in seafood ranged from 0.63 to 2.01 microg/g wet wt. The highest selenium concentration found in fish was 2.01+/-0.36 microg/g wet wt in Salmo salar Linnaeus. In general, selenium concentration increased in the order of bivalve molluscs

Effects of beta-carotene, vitamin C and E on antioxidant status in hyperlipidemic smokers.

Smoking can accelerate the consumption of the stored antioxidant vitamins and increase the oxidative stress in the hyperlipidemic patients. The study investigated the effects of combined beta-carotene, vitamin C, and vitamin E on plasma antioxidant levels, erythrocyte antioxidative enzyme activities, and LDL lipid peroxides. Male hyperlipidemic smokers (35-78 years old) were randomly divided into two antioxidant supplemented groups: intervention 1 (I1, n = 22) (15 mg beta-carotene/day, 500 mg vitamin C/day, and 400 mg alpha-tocopherol equivalent/day) and intervention 2 (I2, n = 20) (30 mg beta-carotene/day, 1000 mg vitamin C/day, and 800 mg alpha-tocopherol equivalent/day). After 6-week supplementation, plasma beta-carotene, vitamin C, vitamin E, and erythrocyte glutathione levels increased significantly by 200%, 98%, 129%, and 39%, respectively, in the I1 group, and by 209%, 216%, 197%, and 32%, respectively, in the I2 group. Plasma Fe(+2) concentrations and Fe(+2)/Fe(+3) decreased significantly in both groups. Except erythrocyte glutathione peroxidase activity in the I1 group, erythrocyte catalase, glutathione peroxidase, and superoxide dismutase activities increased significantly in both groups. Lipid peroxides in LDL decreased significantly by 56% and 72% in the I1 and I2 groups, respectively. However, the levels of plasma iron, erythrocyte glutathione, and LDL lipid peroxides, and the activities of erythrocyte antioxidative enzymes did not differ between two groups. In conclusion, combined antioxidant supplements increased plasma antioxidant levels and antioxidative enzyme activities, and lowered LDL lipid peroxides in male hyperlipidemic smokers. Higher dosage of the supplements did not have an additive effect.

Daily intake of TBT, Cu, Zn, Cd and As for fishermen in Taiwan.

The consumption of contaminated seafood has been reported as an important route of human exposure to metals in Taiwan. We consider the concentrations of TBT, Cu, Zn, Cd, As, and the consumption of oysters of Taiwanese to be the important information related to public health in Taiwan. Therefore, the aim of this study was to evaluate the public health risks associated with TBT, Cu, Zn, Cd and As from shellfish for the general population and fishermen of Taiwan. In general, TBT concentrations in various oysters ranging from 0.32 to 1.51 microg/g dry wt. varied with sampling locations. The highest TBT, Cu, and Zn geometric mean (GM) concentrations in oysters of 1.51, 1180 and 1567 microg/g dry wt. were obtained from the Hsiangshan coastal area. The values of oyster consumption for fishermen were 94.1 and 250 g/day for typically and maximally exposed individuals, respectively. In particular, the highest intake (250 g/day) from fishermen was almost two times greater than that of the general population (139 g/day). The THQ (target hazard quotient) values of Hsiangshan's fishermen are 3.87 and 20.50 for TBT and Cu for maximally exposed individuals are higher than other oyster culture areas. It is interesting that those consuming oysters from Hsiangshan, Lukang, Taishi caused abnormally high THQs of TBT and other metals (100% over 1.0), and TBT was attributed to only 3-21% of the total THQs in different fishermen of Taiwan. Our results suggest that current environmental levels of TBT and other metals are associated with a significant potential threat to human health for fishermen resident in coastal areas of Taiwan.