The effects of dietary linoleic acid on reducing serum cholesterol and atherosclerosis development are nullified by a high-cholesterol diet in male and female apoE-deficient mice.

Linoleic acid (LA) has a two-sided effect with regard to serum cholesterol-lowering and pro-inflammation, although whether this fatty acid reduces serum cholesterol and the development of atherosclerosis under high-cholesterol conditions has yet to be ascertained. In this study, we examine the effects of dietary LA on reducing serum cholesterol and atherosclerosis development under high-cholesterol conditions. Male and female apoE-deficient (ApoE-/-) mice were fed AIN-76-based diets containing 10% SFA and 0·04 % cholesterol, 10% LA and 0·04% low cholesterol (LALC), or 10% LA and 0·1% high cholesterol (LAHC) for 9 weeks. The results revealed significant reduction in serum cholesterol levels and aortic lesions with increasing levels of pro-inflammatory biomarkers (urinary isoprostane and aortic MCP-1 mRNA) in male and female LALC groups compared with those in the SFA groups (P < 0·05). Furthermore, whereas there were significant increases in the serum cholesterol levels and aortic lesions (P < 0·05), there was no difference in aortic MCP-1 mRNA levels in male and female LAHC groups compared with those in the LALC groups. A high-dietary intake of cholesterol eliminated the serum cholesterol-lowering activity of LA but had no significant effect on aortic inflammation in either male or female ApoE-/- mice. The inhibitory effect of LA on arteriosclerosis is cancelled by a high-cholesterol diet due to a direct increase in serum cholesterol levels. Accordingly, serum cholesterol levels might represent a more prominent pathogenic factor than aortic inflammation in promoting the development of atherosclerosis.

Metallothionein Gene Deficiency Facilitates the Differentiation of C2C12 Myoblasts into Slow-Twitch Myotubes.

Metallothionein (MT) 1 and 2 are ubiquitously expressed cysteine-rich, low molecular weight proteins. MT expression is upregulated in skeletal muscle during aging. MTs also play role in multiple types of skeletal muscle atrophy. Meanwhile, it has been reported that MT1 and MT2 gene deficiency increases myogenesis in MT knockout (MTKO) mice. However, little is known about the effect of MTs on muscle formation and atrophy. In this study, we investigated the effect of MT1 and MT2 gene knock-out using the clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (CRISPR-Cas9) system in an in vitro skeletal muscle differentiation model (C2C12 cell line). MT deficiency promoted myogenic differentiation and myotube formation in C2C12 cells. Muscle-specific transcription factors MyoD and myogenin were found to be upregulated at the late stage of myotube differentiation in MTKO cells. Furthermore, the fast-twitch myosin heavy chain (MyHC) protein expression was similar in MTKO and mock-transfected myotubes, but slow-MyHC expression was higher in MTKO cells than in mock cells. The MT gene deletion did not affect the number of fast MyHC-positive myotubes but increased the number of slow MyHC-positive myotubes. Treatment with the antioxidant N-acetylcysteine (NAC) inhibited the increase in the number of slow MyHC-positive myotubes as well as slow-MyHC expression in MTKO cells. In contrast, NAC treatment did not alter the number of fast MyHC-positive myotubes or the expression of fast-MyHC in MTKO cells. These results suggest that the antioxidant effects of MTs may be involved in slow-twitch myofiber formation in skeletal muscle.

A diet supplemented with cholic acid elevates blood pressure accompanied by albuminuria in rats.

A diet supplemented with cholic acid (CA), the primary 12α-hydroxylated bile acid, can induce hepatic lipid accumulation in rats without obesity. This study examined the effects of a CA-supplemented diet on blood pressure (BP). After acclimation, WKAH/HkmSlc rats (3 weeks old) were divided into two groups and fed with a control AIN-93-based diet or a CA-supplemented diet (0.5 g CA/kg) for 13 weeks. The CA diet increased systolic and diastolic BP as well as hepatic lipid concentrations in the rats. No changes were found in the blood sodium concentration. Urinary albumin concentration increased in CA-fed rats. An increase was observed in the hepatic expression of ATP-binding cassette subfamily B member 1B that correlated BPs and urinary albumin concentration accompanied by an increase in portal taurocholic acid concentration. These results suggest that 12α-hydroxylated bile acids are involved in increased BP and albuminuria via alteration of hepatic function.

The levels of plasma plasmalogen in retired female rats decrease by ovariectomy and intake of cholesterol-diet.

Plasmalogens are functional glycerophospholipids that play important biological roles in the human body and are associated with various diseases. In our previous study, plasma choline plasmalogen level was reported to be strongly associated with factors of atherosclerosis and decreases with age. In this study, we created an animal model of low plasma plasmalogen and clarified the effect of aging on plasma plasmalogen metabolism and other plasma lipids in ovariectomized rats. Consequently, in the ovariectomized model using retired rats (Retire + OVX rats), we found a reduction in the ratio of plasmalogen in total phospholipids and an increase in cholesterol in plasma. Furthermore, this was more pronounced with the intake of a high-cholesterol diet in the Retire + OVX rats and is similar to the changes in plasmalogen and cholesterol levels in human atherosclerosis. In summary, this suggests that the ovariectomy model using retired rats is a useful model for low plasma plasmalogen levels.

α-globulin-rich rice cultivar, low glutelin content-1 (LGC-1), decreases serum cholesterol concentration in exogenously hypercholesterolemic rats.

BACKGROUND: Rice α-globulin has been reported to have serum cholesterol-lowering activity in rats. However, it is still unclear whether α-globulin exerts this effect when taken as one of the dietary components. In the present study, we investigated the effect of two cultivars of rice, low glutelin content (LGC)-1 and LGC-Jun, on reducing serum cholesterol in exogenously hypercholesterolemic (ExHC) rats. LGC-1 is enriched in α-globulin (10.6 mg g-1 rice flour, which is an approximately 1.5 times higher α-globulin content than in Koshihikari a predominant rice cultivar in Japan), whereas LGC-Jun is a globulin-negative cultivar. METHODS: ExHC rats, the model strain of diet-induced hypercholesterolemia, were fed 50% LGC-1 or LGC-Jun and 0.5% cholesterol-containing diets for 2 weeks, followed by measurement of cholesterol metabolism parameters in serum and tissues. RESULTS: Serum cholesterol and non-high-density lipoprotein cholesterol levels were significantly lower in the LGC-1 group compared to the LGC-Jun group. Cholesterol intestinal absorption markers, hepatic and serum levels of campesterol and ß-sitosterol, and lymphatic cholesterol transport were not different between the two groups. Levels of 7α-hydroxycholesterol, an intermediate of bile acid synthesis, showed a downward trend in the livers of rats that were fed LGC-1 (P = 0.098). There was a significant decrease in the hepatic mRNA expression of Cyp7a1 (a synthetic enzyme for 7α-hydroxycholesterol) in the LGC-1 group compared to the LGC-Jun group. CONCLUSION: Dietary LGC-1 significantly decreased serum cholesterol levels in ExHC rats. The possible mechanism for the cholesterol-lowering activity of LGC-1 is partial inhibition of bile acid and cholesterol synthesis in the liver. © 2021 Society of Chemical Industry.

Inhibition of Niemann-Pick C1-Like 1 by Ezetimibe Reduces Dietary 5ß,6ß-Epoxycholesterol Absorption in Rats.

PURPOSE: Oxycholesterols (OCs) are produced from cholesterol by oxidation of the steroidal backbone and side-chain. OCs are present in blood and evidence suggests their involvement in disease development and progression. However, limited information is available regarding the absorption mechanisms and relative absorption rates of dietary OCs. Although ezetimibe is known to inhibit intestinal cholesterol absorption via Niemann-Pick C1-Like 1 (NPC1L1), whether it also inhibits dietary OC absorption is unclear. METHODS: We investigated the effects of ezetimibe on OC absorption in rats fed an OC-rich diet containing 10 different OCs. We collected lymphatic fluid using permanent cannulation of the thoracic duct and quantified OC levels. RESULTS: Ezetimibe treatment significantly reduced the apparent absorption of 5ß,6ß-epoxycholesterol (5,6ß-epoxy) and its levels in the proximal intestinal mucosa in OC-fed rats. Using in silico analyses, the binding energy of NPC1L1 N-terminal domain (NPC1L1-NTD) and 5,6ß-epoxy was found to be similar to that of NPC1L1-NTD and cholesterol, suggesting that polar uncharged amino acids located in the steroidal part of 5,6ß-epoxy were involved. CONCLUSION: Our results indicate that ezetimibe-mediated inhibition of dietary OC absorption varies depending on the specific OC, and only the absorption of 5,6ß-epoxy is significantly reduced.

Starch synthase IIIa and starch branching enzyme IIb-deficient mutant rice line ameliorates pancreatic insulin secretion in rats: screening and evaluating mutant rice lines with antidiabetic functionalities.

Diabetes mellitus is a metabolic disease spreading worldwide that has been reported to worsen the development and progression of other diseases (cancer, vascular diseases and dementia). To establish functional rice lines with anti-postprandial hyperglycaemic effects, we developed mutant rice lines, which lack one or two gene(s) related to starch synthesis, and evaluated their effects. Powder of mutant rice lines or other grains was loaded to rats fasted overnight (oral grain powder loading test). Incremental area under time-concentration curves (iAUC) were calculated with monitored blood glucose levels. Rice lines with anti-postprandial hyperglycaemic effects were separated by cluster analysis with calculated iAUC. A double mutant rice #4019 (starch synthase IIIa (ss3a)/branching enzyme IIb (be2b)), one of the screened mutant rice lines, was fed to Goto-Kakizaki (GK) rats, an animal model for type 2 diabetes, for 5 weeks. Plasma levels of C-peptide, a marker of pancreatic insulin secretion, were measured with ELISA. For in vitro study, a rat pancreatic cell line was cultured with a medium containing rat serum which was sampled from rats fed #4019 diet for 2 d. After 24-h of incubation, an insulin secretion test was performed. Through the oral rice powder loading test, seven rice lines were identified as antidiabetic rice lines. The intake of #4019 diet increased plasma C-peptide levels of GK rats. This result was also observed in vitro. In rat serum added to cell medium, ornithine was significantly increased by the intake of #4019. In conclusion, the mutant rice #4019 promoted pancreatic insulin secretion via elevation of serum ornithine levels.

High Serum Phospholipid Dihomo-γ-Linoleic Acid Concentration and Low Δ5-Desaturase Activity Are Associated with Increased Risk of Type 2 Diabetes among Japanese Adults in the Hitachi Health Study.

Background: The association between the circulating fatty acid (FA) composition and type 2 diabetes (T2D) has been reported in Western populations, but evidence is scarce among Asian populations, including Japanese, who consume large amounts of fish.Objective: The objective of the present study was to prospectively examine the association between circulating concentrations of individual FAs and T2D incidence among Japanese adults.Methods: We conducted a nested case-control study in a cohort of 4754 employees, aged 34-69 y, who attended a comprehensive health checkup in 2008-2009 and donated blood samples for the Hitachi Health Study. During 5 y of follow-up, diabetes was identified on the basis of plasma glucose, glycated hemoglobin, and self-report. Two controls matched to each case by sex, age, and date of checkup were randomly chosen by using density sampling, resulting in 336 cases and 678 controls with FA measurements. GC was used to measure the FA composition in serum phospholipids. Cox proportional hazards regression was used to estimate the HRs and 95% CIs after adjusting for potential confounders. We examined the association of T2D risk with 25 different individual and combinations of FAs.Results: T2D risk was positively associated with serum dihomo-γ-linoleic acid concentration (highest compared with the lowest quartile-HR: 1.49; 95% CI: 1.04, 2.11; P-trend = 0.02) and inversely associated with Δ5-desaturase activity (highest compared with the lowest quartile-HR: 0.72; 95% CI: 0.52, 0.99; P-trend = 0.02), independent of body mass index (BMI). There were also inverse associations between T2D risk with serum total n-6 (ω-6) polyunsaturated fatty acids (PUFAs), linoleic acid, and cis-vaccenic acid, but these were attenuated and became nonsignificant after adjustment for BMI. Serum n-3 (ω-3) PUFAs and saturated fatty acids (SFAs) were not associated with T2D risk.Conclusions: T2D risk was associated with circulating concentrations of the n-6 PUFA dihomo-γ-linoleic acid and Δ5-desaturase activity but not with n-3 PUFA or SFA concentrations in Japanese adults.

Dietary egg-white protein increases body protein mass and reduces body fat mass through an acceleration of hepatic ß-oxidation in rats.

Egg-white protein (EWP) is known to reduce lymphatic TAG transport in rats. In this study, we investigated the effects of dietary EWP on body fat mass. Male rats, 4 weeks old, were fed diets containing either 20 % EWP or casein for 28 d. Carcass protein levels and gastrocnemius leg muscle weights in the EWP group were significantly higher than those in the casein group. In addition, carcass TAG levels and abdominal fat weights in the EWP group were significantly lower than those in the casein group; adipocyte size in abdominal fat in the EWP group was smaller than that in the casein group. To identify the involvement of dietary fat levels in the rats, one of two fat levels (5 or 10 %) was added to their diet along with the different protein sources (EWP and casein). Abdominal fat weight and serum and hepatic TAG levels were significantly lower in the EWP group than in the casein group. Moreover, significantly higher values of enzymatic activity related to ß-oxidation in the liver were observed in the EWP group compared with the casein group. Finally, abdominal fat weight reduction in the EWP group with the 10 % fat diet was lower than that in the EWP group with the 5 % fat diet. In conclusion, our results indicate that, in addition to the inhibition of dietary TAG absorption reported previously, dietary EWP reduces body fat mass in rats through an increase of body protein mass and the acceleration of ß-oxidation in the liver.

Circulating ferritin concentrations are differentially associated with serum adipokine concentrations in Japanese men and premenopausal women.

PURPOSE: Increased iron storage, as measured by circulating ferritin, has been linked to an increased risk of various diseases including diabetes. We examined the association of circulating ferritin with serum adiponectin, leptin, resistin, plasminogen activator inhibitor-1 (PAI-1), and visfatin levels. METHODS: We conducted a cross-sectional study among 429 Japanese employees (284 men and 145 premenopausal women, mean age: 42.5 ± 10.5 years). Serum adipokines were measured using Luminex suspension bead-based multiplexed array, and serum ferritin was determined using a chemiluminescence immunoassay. Multivariable regression analysis was performed to calculate mean concentrations of adipokine according to the tertile of ferritin concentrations with adjustment for potential confounders. RESULTS: Leptin and visfatin concentrations increased with increasing ferritin concentrations in men after multivariable adjustment of physical activity, smoking, alcohol use, and body mass index (P for trend = 0.02 and 0.01 for leptin and visfatin, respectively). Serum ferritin concentrations were inversely and significantly associated with adiponectin in women (P for trend = 0.01). Resistin and PAI-1 were not appreciably associated with ferritin concentration. CONCLUSIONS: Increased iron storage may be associated with higher circulating concentrations of leptin and visfatin in men and with lower concentrations of adiponectin in women.

Probiotic Lactobacillus gasseri SBT2055 improves glucose tolerance and reduces body weight gain in rats by stimulating energy expenditure.

Probiotic Lactobacillus gasseri SBT2055 (LG2055) reduces postprandial TAG absorption and exerts anti-obesity effects in rats and humans; however, the underlying mechanisms are not fully understood. In the present study, we addressed the mechanistic insights of the anti-obesity activity of LG2055 by feeding Sprague-Dawley rats diets containing skimmed milk fermented or not by LG2055 for 4 weeks and by analysing energy expenditure, glucose tolerance, the levels of SCFA in the caecum and serum inflammatory markers. Rats fed the LG2055-containing diet demonstrated significantly higher carbohydrate oxidation in the dark cycle (active phase for rats) compared with the control group, which resulted in a significant increase in energy expenditure. LG2055 significantly reduced cumulative blood glucose levels (AUC) compared with the control diet after 3 weeks and increased the molar ratio of butyrate:total SCFA in the caecum after 4 weeks. Furthermore, the LG2055-supplemented diet significantly reduced the levels of serum amyloid P component - an indicator of the inflammatory process. In conclusion, our results demonstrate that, in addition to the inhibition of dietary TAG absorption reported previously, the intake of probiotic LG2055 enhanced energy expenditure via carbohydrate oxidation, improved glucose tolerance and attenuated inflammation, suggesting multiple additive and/or synergistic actions underlying the anti-obesity effects exerted by LG2055.

Taurine ameliorates cholesterol metabolism by stimulating bile acid production in high-cholesterol-fed rats.

This study was designed to investigate the effects of dietary taurine on cholesterol metabolism in high-cholesterol-fed rats. Male Sprague-Dawley rats were randomly divided into two dietary groups (n = 6 in each group): a high-cholesterol diet containing 0.5% cholesterol and 0.15% sodium cholate, and a high-cholesterol diet with 5% (w/w) taurine. The experimental diets were given for 2 weeks. Taurine supplementation reduced the serum and hepatic cholesterol levels by 37% and 32%, respectively. Faecal excretion of bile acids was significantly increased in taurine-treated rats, compared with untreated rats. Biliary bile acid concentrations were also increased by taurine. Taurine supplementation increased taurine-conjugated bile acids by 61% and decreased glycine-conjugated bile acids by 53%, resulting in a significant decrease in the glycine/taurine (G/T) ratio. Among the taurine-conjugated bile acids, cholic acid and deoxycholic acid were significantly increased. In the liver, taurine supplementation increased the mRNA expression and enzymatic activity of hepatic cholesterol 7α-hydroxylase (CYP7A1), the rate-limiting enzyme for bile acid synthesis, by three- and two-fold, respectively. Taurine also decreased the enzymatic activity of acyl-CoA:cholesterol acyltransferase (ACAT) and microsomal triglyceride transfer protein (MTP). These observations suggest that taurine supplementation increases the synthesis and excretion of taurine-conjugated bile acids and stimulates the catabolism of cholesterol to bile acid by elevating the expression and activity of CYP7A1. This may reduce cholesterol esterification and lipoprotein assembly for very low density lipoprotein (VLDL) secretion, leading to reductions in the serum and hepatic cholesterol levels.

Development and evaluation of rice giant embryo mutants for high oil content originated from a high-yielding cultivar 'Mizuhochikara'.

Rice bran oil is a byproduct of the milling of rice (Oryza sativa L.). It offers various health benefits and has a beneficial fatty acid composition. To increase the amount of rice bran as a sink for triacylglycerol (TAG), we developed and characterized new breeding materials with giant embryos. To induce mutants, we treated fertilized egg cells of the high-yielding cultivar 'Mizuhochikara' with N-methyl-N-nitrosourea (MNU). By screening M2 seeds, we isolated four giant embryo mutant lines. Genetic analysis revealed that the causative loci in lines MGE12 and MGE13 were allelic to giant embryo (ge) on chromosome 7, and had base changes in the causal gene Os07g0603700. On the other hand, the causative loci in lines MGE8 and MGE14 were not allelic to ge, and both were newly mapped on chromosome 3. The TAG contents of all four mutant lines increased relative to their wild type, 'Mizuhochikara'. MGE13 was agronomically similar to 'Mizuhochikara' and would be useful for breeding for improved oil content.

Habitual consumption of coffee and green tea in relation to serum adipokines: a cross-sectional study.

PURPOSE: Coffee and green tea consumption may be associated with circulating adipokines, but data are inconsistent, scarce or lacking. We examined the association of coffee and green tea consumption with serum adiponectin, leptin, visfatin, resistin and plasminogen activator inhibitor-1 (PAI-1) among a Japanese working population. METHODS: The authors analyzed data (n = 509) from a cross-sectional survey among Japanese workers aged 20-68 years. Serum adipokines were measured using a Luminex suspension bead-based multiplexed array. Coffee and green tea consumption was assessed using a validated diet history questionnaire, and caffeine consumption from these beverages was estimated. Multiple regression analysis was performed with adjustment for potential confounding variables. RESULTS: Coffee consumption was significantly, inversely associated with leptin and PAI-1 (P for trend = 0.007 and 0.02, respectively); compared with subjects consuming <1 cup per day, those consuming ≥4 cups per day had 13 and 10 % lower means of leptin and PAI-1, respectively. Similar associations were observed for caffeine consumption (P for trend = 0.02 for both leptin and PAI-1). Additionally, we noted a significant positive association between coffee consumption and adiponectin in men (P for trend = 0.046), but not in women (P for trend = 0.43, P for interaction = 0.11). Moreover, there was a positive association between coffee consumption and resistin in current male smokers (P for trend = 0.01), but not in male non-smokers (P for trend = 0.35, P for interaction = 0.11). Green tea consumption was not associated with any adipokine. CONCLUSIONS: Higher consumption of coffee and caffeine but not green tea was associated with lower serum levels of leptin and PAI-1 in Japanese adults.

Association of dietary patterns with serum adipokines among Japanese: a cross-sectional study.

BACKGROUND: Diet may influence disease risk by modulating adipokines. Although some foods and nutrients have been linked to circulating adipokine levels, little is known about the role of dietary patterns on adipokines. We investigated the association between major dietary patterns and circulating levels of adiponectin, leptin, resistin, visfatin, and plasminogen activator inhibitor-1 (PAI-1) in a working population. METHODS: The subjects were 509 employees (296 men and 213 women), aged 20 to 65 years, of two municipal offices. Serum adipokines were measured using a Luminex suspension bead-based multiplexed array. Dietary patterns were derived by using principal component analysis of the consumption of 52 food and beverage items, which were ascertained by a validated diet history questionnaire. Multiple regression analysis was performed to assess the association between dietary pattern scores and adipokine concentrations, with adjustment for potential confounders. RESULTS: Three major dietary patterns were extracted: a Japanese, a Westernized breakfast, and a meat food patterns. Of these, we found significant, inverse associations of the Westernized breakfast pattern, which was characterized by higher intake of confectioneries, bread, and milk and yogurt but lower intake of alcoholic beverages and rice, with serum leptin and PAI-1 concentrations in a fully adjusted model (P for trend = 0.04 for both leptin and PAI-1). The other adipokines were not significantly associated with any dietary pattern. CONCLUSION: The Westernized breakfast dietary pattern may be associated with lower circulating levels of leptin and PAI-1.

Prolonged endoplasmic reticulum stress alters placental morphology and causes low birth weight.

The role of endoplasmic reticulum (ER) stress in pregnancy remains largely unknown. Pregnant mice were subcutaneously administered tunicamycin (Tun), an ER stressor, as a single dose [0, 50, and 100 µg Tun/kg/body weight (BW)] on gestation days (GDs) 8.5, 12.5, and 15.5. A high incidence (75%) of preterm delivery was observed only in the group treated with Tun 100 µg/kg BW at GD 15.5, indicating that pregnant mice during late gestation are more susceptible to ER stress on preterm delivery. We further examined whether prolonged in utero exposure to ER stress affects fetal development. Pregnant mice were subcutaneously administered a dose of 0, 20, 40, and 60 µg Tun/kg from GD 12.5 to 16.5. Tun treatment decreased the placental and fetal weights in a dose-dependent manner. Histological evaluation showed the formation of a cluster of spongiotrophoblast cells in the labyrinth zone of the placenta of Tun-treated mice. The glycogen content of the fetal liver and placenta from Tun-treated mice was lower than that from control mice. Tun treatment decreased mRNA expression of Slc2a1/glucose transporter 1 (GLUT1), which is a major transporter for glucose, but increased placental mRNA levels of Slc2a3/GLUT3. Moreover, maternal exposure to Tun resulted in a decrease in vascular endothelial growth factor receptor-1 (VEGFR-1), VEGFR-2, and placental growth factor. These results suggest that excessive and exogenous ER stress may induce functional abnormalities in the placenta, at least in part, with altered GLUT and vascular-related gene expression, resulting in low infant birth weight.

Coffee intake is associated with lower levels of oxidative DNA damage and decreasing body iron storage in healthy women.

Habitual coffee drinking has been linked to a lower risk for some forms of cancer, but the mechanism remains elusive. Coffee may decrease oxidative DNA damage, an important pathway to carcinogenesis. We examined the association between coffee consumption and urinary 8-hydroxydeoxyguanosine (8-OHdG) concentrations, a biomarker of systemic oxidative DNA damage and repair, in 507 healthy subjects (298 men and 209 women aged 21-67 yr) while adjusting for age, sex, smoking status, body mass index, job type, and fasting blood glucose in multivariable regression models. The association with green tea consumption was also assessed. Urinary 8-OHdG concentrations tended to decrease with coffee consumption in women (trend P = 0.046), with women drinking 2-3 cups of coffee per day showing the lowest mean of urinary 8-OHdG concentrations. This association was largely attenuated after further adjustment for serum ferritin concentrations, a marker of body iron storage (trend P = 0.96). Green tea consumption was not associated with urinary 8-OHdG concentrations. Coffee drinking may be associated with decreased systemic oxidative DNA damage through decreasing body iron storage in women.

Association of serum leptin and ghrelin with depressive symptoms in a Japanese working population: a cross-sectional study.

BACKGROUND: Leptin and ghrelin have been implicated in the pathogenesis of major depression. However, evidence is lacking among apparently healthy people. This study examined the relationship of these appetite hormones to depressive symptoms in a Japanese working population. METHODS: A cross-sectional study was conducted in 2009 among 497 Japanese employees (287 men and 210 women) aged 20-68 years. Fasting serum leptin and ghrelin levels were measured using a Luminex suspension bead-based multiplexed array. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale. Logistic regression analysis was performed to estimate odds ratio (OR) and 95% confidence interval (CI) for depressive symptoms with adjustment for potential confounders. RESULTS: The prevalence of depressive symptoms (CES-D ≥16) was 26.5% and 33.3% among men and women, respectively. Women in the middle and highest tertiles of leptin levels showed lower odds for depressive symptoms compared with those in the lowest level, although the trend association was not statistically significant (Ptrend = 0.14). Higher ghrelin levels were associated with increased odds for depressive symptoms in women (Ptrend = 0.02). The multivariable adjusted OR (95% CI) of having depressive symptoms for the lowest through highest tertiles of ghrelin levels were 1.00 (reference), 1.71 (0.76 - 3.86), and 2.69 (1.16 - 6.28), respectively. Neither leptin nor ghrelin was associated with depressive symptoms in men. CONCLUSIONS: Results suggest that lower leptin and higher ghrelin levels may be related to higher prevalence of depressive status among Japanese women.

Green tea and coffee consumption is inversely associated with depressive symptoms in a Japanese working population.

OBJECTIVE: To examine the association between the consumption of green tea, coffee and caffeine and depressive symptoms. DESIGN: Cross-sectional study. Consumption of green tea and coffee was ascertained with a validated dietary questionnaire and the amount of caffeine intake was estimated from these beverages. Depressive symptoms were measured using the Center for Epidemiologic Studies Depression Scale. Multiple logistic regression analysis was performed to compute odds ratios and 95% confidence intervals for depressive symptoms with adjustments for potential confounders. SETTING: Two workplaces in north-eastern Kyushu, Japan, in 2009. SUBJECTS: A total of 537 men and women aged 20-68 years. RESULTS: Higher green tea consumption was associated with a lower prevalence of depressive symptoms. Compared with participants consuming ≤1 cup/d, those consuming ≥4 cups green tea/d had a 51% significantly lower prevalence odds of having depressive symptoms after adjustment for potential confounders, with significant trend association (P for trend = 0·01). Further adjustment for serum folate slightly attenuated the association. Coffee consumption was also inversely associated with depressive symptoms (≥2 cups/d v. <1 cup/d: OR = 0·61; 95% CI 0·38, 0·98). Multiple-adjusted odds for depressive symptoms comparing the highest with the lowest quartile of caffeine consumption was OR = 0·57 (95% CI 0·30, 1·05; P for trend = 0·02). CONCLUSIONS: Results suggest that higher consumption of green tea, coffee and caffeine may confer protection against depression.

Lactobacillus gasseri SBT2055 reduces postprandial and fasting serum non-esterified fatty acid levels in Japanese hypertriacylglycerolemic subjects.

BACKGROUND: Lactobacillus gasseri SBT2055 (LG2055) inhibits dietary fat absorption in rats and exerts preventive effects on abdominal adiposity in rats and humans. The present study aimed to evaluate the effects of LG2055 on postprandial serum lipid responses in Japanese subjects with hypertriacylglycerolemia after the intake of oral fat-loading test (OFLT) meals. METHODS: We conducted a single-blind, placebo-controlled, within-subject, repeated-measure intervention trial. Twenty subjects initially ingested the fermented milk (FM) without LG2055 for 4 weeks (control FM period), followed by a 4-week washout period, and then consumed FM containing LG2055 for 4 weeks (active FM period). The subjects were asked to consume FM at 200 g/day. At the end of each 4-week period, an 8-h OFLT was conducted. Blood samples were collected at fasting and every hour for 8 h after OFLT meal intake. Thereafter, postprandial serum non-esterified fatty acid (NEFA) and triacylglycerol (TAG) levels and fasting blood parameters were measured. RESULTS: The OFLT showed that the postprandial serum NEFA levels from 120 to 480 min and the postprandial serum TAG level at 120 min in the active FM period were significantly (P < 0.05) lower than those in the control FM period. The fasting serum NEFA level in the active FM period significantly (P < 0.001) decreased at week 4 from the initial period compared with the control FM period. CONCLUSIONS: The consumption of probiotic LG2055 reduced postprandial and fasting serum NEFA levels, suggesting its possible contribution to the reduction of the risk for obesity and type 2 diabetes mellitus. TRIAL REGISTRATION: UMIN000011605.