The 6-month effect of whole soy and purified isoflavones daidzein on thyroid function-A double-blind, randomized, placebo controlled trial among Chinese equol-producing postmenopausal women

The aim of this study was to examine the effect of whole soy and purified daidzein on markers of thyroid function in Chinese postmenopausal women who were equol-producers. Total 270 eligible women were randomized to either one of the three isocaloric supplements: 40 g soy flour (whole soy group), 40 g low-fat milk powder +63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo) daily for 6 months. Serum thyroid markers were tested at baseline and 6 months for thyroid stimulating hormone, free triiodothyronine, reverse triiodothyronine and free thyroxine (FT4). There was no significant difference in the 6-month changes of thyroid markers among the three groups. Subgroup analysis among women with lowered thyroid function suggested a modest decrease of FT4. This randomized controlled trial among Chinese equol-producing postmenopausal women indicates the consumption of whole soy and purified daidzein at the provided dosages are safe and have no detrimental effect on thyroid function.

Effect of whole soy and purified daidzein on androgenic hormones in chinese equol-producing post-menopausal women: a six-month randomised, double-blinded and Placebo-Controlled trial

A randomised, double-blind and placebo-controlled trial was performed to examine the effects of whole soy and isoflavone daidzein on serum androgenic hormones in Chinese equol-producing post-menopausal women. A total of 270 eligible women aged 45-70 years were randomised to either one of the three iso-caloric supplements: 40 g soy flour (whole soy group), 40 g low-fat milk powder +63 mg daidzein (daidzein group) or 40 g low-fat milk powder (placebo group) daily for 6 months. Fasting venous samples were tested for serum androstenedione (AD), testosterone (T), prolactin, sex hormone binding globulin and dehydroepiandrosterone sulphate. Intention-to-treat analysis indicated that serum T (p = .022) and AD (p = .05) levels modestly but significantly decreased after 6-month daidzein treatment in comparison with placebo, with a mean difference of -0.057 nmol/L (95%CI: -0.185 to 0.070, p = .018) and -0.118 ng/mL (95%CI: -0.240-0.004, p = .045), respectively. This 6-month trial suggested that purified daidzein may exhibit less androgenic effect.Trial registration: The trial was registered in ClinicalTrials.gov with identifier of NCT01270737. (URL: http://clinicaltrials.gov/ct2/show/NCT01270737.).

Serum copper and zinc levels at diagnosis and hepatocellular carcinoma survival in the Guangdong Liver Cancer Cohort

Copper and zinc are essential micronutrients, whose imbalance may be involved in the development and progression of cancer. However, the role of copper and/or zinc imbalance in the prognosis of hepatocellular carcinoma (HCC) is currently unclear. Our objective was to investigate the association between serum levels of copper, zinc and their ratio (copper/zinc) at diagnosis with HCC survival. We included 989 patients with incident HCC in this prospective cohort study, who were enrolled in the Guangdong Liver Cancer Cohort (GLCC) study within 30 days of diagnosis between September 2013 and February 2017. Serum copper and zinc were measured using inductively coupled plasma mass spectrometry. Primary outcomes were liver cancer-specific survival (LCSS) and overall survival (OS). Cox proportional hazards models were used to calculate the multivariable hazard ratios (HRs) and 95% confidence interval (CI). Higher serum copper levels were strongly associated with worse LCSS (Q4 vs. Q1: HR = 1.87, 95% CI: 1.22-2.86; p < 0.01 for trend) and OS (Q4 vs. Q1: HR = 2.06, 95% CI: 1.36-3.11; p < 0.01 for trend). The calculated copper/zinc ratio was positively associated with LCSS (Q4 vs. Q1: HR = 1.31, 95% CI: 0.89-1.92; P = 0.04 for trend) and OS (Q4 vs. Q1: HR = 1.43, 95% CI: 0.99-2.08; P = 0.01 for trend). No overall associations were observed between serum zinc levels and LCSS or OS in the entire cohort. The results suggest that higher serum copper and copper in relation to zinc levels (i.e., higher copper/zinc ratio) may be associated with worse HCC survival, but serum zinc levels may be not associated with HCC survival.

Effects of Anthocyanins on Cardiometabolic Health: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Numerous clinical trials have examined the role of anthocyanins on cardiometabolic health, but their effects have not been quantitatively synthesized and systematically evaluated. The aim of our study was to conduct a systematic review and meta-analysis of randomized controlled trials (RCTs) assessing the effects of anthocyanins on glycemic regulation and lipid profiles in both healthy populations and those with cardiometabolic diseases. The MEDLINE, EMBASE, Cochrane database, OVID EBM Reviews, and clinicaltrials.gov databases were searched until February 2017. RCTs with a duration of ≥2 wk that evaluated the effects of anthocyanins on glycemic control, insulin sensitivity, and lipids as either primary or secondary outcomes were included. The Cochrane Risk of Bias tool was used to assess the study quality. Standardized mean differences (SMDs) were determined by random-effects models. Meta-regression, sensitivity, and subgroup analyses were performed to explore the influence of covariates on the overall effects. Thirty-two RCTs (1491 participants) were eligible for meta-analysis. Anthocyanins significantly reduced fasting glucose (SMD: -0.31; 95% CI: -0.59, -0.04; I² = 80.7%), 2-h postprandial glucose (SMD: -0.82; 95% CI: -1.49, -0.15; I² = 77.7), glycated hemoglobin (SMD: -0.65; 95% CI: -1.00, -0.29; I² = 72.7%), total cholesterol (SMD: -0.33; 95% CI: -0.62, -0.03; I² = 86.9%), and LDL (SMD: -0.35; 95% CI: -0.66, -0.05; I² = 85.2%). Sensitivity analyses showed that the overall effects remained similar by excluding the trials with a high or unclear risk of bias. The significant improvements in glycemic control and lipids support the benefits of anthocyanins in the prevention and management of cardiometabolic disease. Further well-designed RCTs are needed to evaluate the long-term effects of anthocyanins on metabolic profiles and to explore the optimal formula and dosage. The protocol for this review was registered at https://www.crd.york.ac.uk/PROSPERO/#index.php as CRD42016033210.

Downregulation of mitochondrial cyclooxygenase-2 inhibits the stemness of nasopharyngeal carcinoma by decreasing the activity of dynamin-related protein 1

Cancer stem cells (CSCs) are a small subset of malignant cells, possessing stemness, with strong tumorigenic capability, conferring resistance to therapy and leading to the relapse of nasopharyngeal carcinoma (NPC). Our previous study suggested that cyclooxygenase-2 (COX-2) would be a novel target for the CSCs-like side population (SP) cells in NPC. In the present study, we further found that COX-2 maintained the stemness of NPC by enhancing the activity of mitochondrial dynamin-related protein 1 (Drp1), a mitochondrial fission mediator, by studying both sorted SP cells from NPC cell lines and gene expression analyses in NPC tissues. Using both overexpression and knockdown of COX-2, we demonstrated that the localization of COX-2 at mitochondria promotes the stemness of NPC by recruiting the mitochondrial translocation of p53, increasing the activity of Drp1 and inducing mitochondrial fisson. Inhibition of the expression or the activity of Drp1 by siRNA or Mdivi-1 downregulates the stemness of NPC. The present study also found that inhibition of mitochondrial COX-2 with resveratrol (RSV), a natural phytochemical, increased the sensitivity of NPC to 5-fluorouracil (5-FU), a classical chemotherapy drug for NPC. The underlying mechanism is that RSV suppresses mitochondrial COX-2, thereby reducing NPC stemness by inhibiting Drp1 activity as demonstrated in both the in vitro and the in vivo studies. Taken together, the results of this study suggest that mitochondrial COX-2 is a potential theranostic target for the CSCs in NPC. Inhibition of mitochondrial COX-2 could be an attractive therapeutic option for the effective clinical treatment of therapy-resistant NPC.

[The Role of FGF21 in Regulating Lipid and Glucose Metabolism]

Fibroblast growth factor 21 (FGF21), a member of fibroblast growth factor superfamily has received extensive attention for its positive effect on metabolism. Many tissues are target of FGF21 action. The effect of FGF21 on improving lipid and glucose metabolism has been proved. It also suggests that FGF21 plays a conspicuous role in a state of prolonged fasting and starvation. This article will review the role of FGF21 in regulating lipid and glucose metabolism and discuss the involved cellular and molecular mechanisms.

A CONSORT-compliant, randomized, double-blind, placebo-controlled pilot trial of purified anthocyanin in patients with nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a common liver disease that can progress to cirrhosis and liver failure. Anthocyanin, a member of the flavonoid family, has been shown to ameliorate NAFLD-associated pathologies in rodents.The aim of this CONSORT-compliant pilot study is to evaluate the effects of anthocyanin supplementation on insulin resistance and liver injury biomarkers in patients with NAFLD.A total of 74 subjects with NAFLD were divided into 2 groups in this double-blind, randomized study. Patients received either purified anthocyanin (320 mg/d) derived from bilberry and black currant or placebo for 12 weeks. Diet, physical activity, anthropometric parameters, glucose tolerance, and a set of biomarkers related to NAFLD were evaluated before and after intervention.No significant differences were observed in nutrient intake, physical activity, anthropometric parameters, or plasma lipid profile between patients receiving anthocyanin or placebo. Compared to controls, the anthocyanin group exhibited significant decreases (P < 0.05, all comparisons) in plasma alanine aminotransferase (-19.1% vs 3.1%), cytokeratin-18 M30 fragment (-8.8% vs 5.6%) and myeloperoxidase (-75.0% vs -44.8%). Significant decreases from baseline in fasting blood glucose and homeostasis model assessment for insulin resistance were observed in the anthocyanin group; however, these differences were not significant relative to placebo controls. In addition, the oral glucose tolerance test indicated that anthocyanin supplementation significantly decreased the 2-hour loading glucose level compared to control (-18.7% vs -3.8%, P = 0.02).A 12-week supplement of purified anthocyanin improved insulin resistance, indicators of liver injury, and clinical evolution in NAFLD patients. Further studies are warranted to determine the clinical applications of anthocyanin in NAFLD.This trial was registered at clinicaltrials.gov as NCT01940263.

Parthenolide inhibits cancer stem-like side population of nasopharyngeal carcinoma cells via suppression of the NF-κB/COX-2 pathway

Cancer stem cells play a central role in the pathogenesis of nasopharyngeal carcinoma and contribute to both disease initiation and relapse. In this study, cyclooxygenase-2 (COX-2) was found to regulate cancer stem-like side population cells of nasopharyngeal carcinoma cells and enhance cancer stem-like cells' characteristics such as higher colony formation efficiency and overexpression of stemness-associated genes. The regulatory effect of COX-2 on cancer stem-like characteristics may be mediated by ABCG2. COX-2 overexpression by a gain-of-function experiment increased the proportion of side population cells and their cancer stemness properties. The present study also demonstrated that in contrast to the classical chemotherapy drug 5-fluorouracil, which increased the proportion of side population cells and upregulated the expression of COX-2, parthenolide, a naturally occurring small molecule, preferentially targeted the side population cells of nasopharyngeal carcinoma cells and downregulated COX-2. Moreover, we found that the cancer stem-like cells' phenotype was suppressed by using COX-2 inhibitors NS-398 and CAY10404 or knocking down COX-2 with siRNA and shRNA. These findings suggest that COX-2 inhibition is the mechanism by which parthenolide induces cell death in the cancer stem-like cells of nasopharyngeal carcinoma. In addition, parthenolide exhibited an inhibitory effect on nuclear factor-kappa B (NF-κB) nucler translocation by suppressing both the phosphorylation of IκB kinase complex and IκBα degradation. Taken together, these results suggest that parthenolide may exert its cancer stem cell-targeted chemotherapy through the NF-κB/COX-2 pathway.

Soy food consumption, cardiometabolic alterations and carotid intima-media thickness in Chinese adults

BACKGROUND AND AIM

The associations between soy food consumption, cardiometabolic disturbances and subclinical atherosclerosis remain controversial due to limited evidence. We examined the associations of habitual soy food consumption with cardiometabolic disturbances and carotid intima-media thickness (CIMT).

METHODS AND RESULTS

We included 2939 subjects (2135 women and 804 men) aged 50-75 years in this community-based cross-sectional study. Dietary data and other covariates were collected using interviewer-administered questionnaires. We determined CIMT in relation to each subject's common carotid artery, internal carotid artery, carotid bifurcation, blood lipids, glucose and urine acid, blood pressure and waist circumference. A logistic regression model was applied to estimate the odd ratios (ORs) and 95% confidence intervals (CIs), and linear regression was used to estimate the regression coefficient and 95% CIs. After adjusting for potential confounders, we found that greater consumption of soy protein (6.1 vs. 0.5 g/d) was inverse associated with the presence of elevated total cholesterol (TC), dyslipidemia, abdominal obesity and hyperuricemia in women, and with abdominal obesity in men, although no significant sex-soy interactions were observed (P: 0.145-0.985). The consumption of soy protein and isoflavones was inversely associated with the number of cardiometabolic disturbances among women, but not men. There were no significant associations of soy protein and isoflavones with CIMT thickening and other cardiometabolic disturbances.

CONCLUSION

Greater soy consumption was associated with a lower presence of elevated TC, dyslipidemia, hyperuricemia and less number of cardiometabolic disturbances components in women.

Effects of blood triglycerides on cardiovascular and all-cause mortality: a systematic review and meta-analysis of 61 prospective studies

The relationship of triglycerides (TG) to the risk of death remains uncertain. The aim of this study was to determine the associations between blood triglyceride levels and cardiovascular diseases (CVDs) mortality and all-cause mortality. Four databases were searched without language restriction for relevant studies: PubMed, ScienceDirect, EMBASE, and Google Scholar. All prospective cohort studies reporting an association between TG and CVDs or all-cause mortality published before July 2013 were included. Risk ratios (RRs) with 95% confidence intervals (CIs) were extracted and pooled according to TG categories, unit TG, and logarithm of TG using a random-effects model with inverse-variance weighting. We identified 61 eligible studies, containing 17,018 CVDs deaths in 726,030 participants and 58,419 all-cause deaths in 330,566 participants. Twelve and fourteen studies, respectively, reported the effects estimates of CVDs and total mortality by TG categories. Compared to the referent (90–149 mg/dL), the pooled RRs (95% CI) of CVDs mortality for the lowest (< 90 mg/dL), borderline-high (150–199 mg/dL), and high TG (≥ 200 mg/dL) groups were 0.83 (0.75 to 0.93), 1.15 (1.03 to 1.29), and 1.25 (1.05 to 1.50); for total mortality they were 0.94 (0.85 to 1.03), 1.09 (1.02 to 1.17), and 1.20 (1.04 to 1.38), respectively. The risks of CVDs and all-cause deaths were increased by 13% and 12% (p < 0.001) per 1-mmol/L TG increment in twenty-two and twenty-two studies reported RRs per unit TG, respectively. In conclusion, elevated blood TG levels were dose-dependently associated with higher risks of CVDs and all-cause mortality.

Antioxidant capacities, phenolic compounds and polysaccharide contents of 49 edible macro-fungi

Edible macro-fungi are widely consumed as food sources for their flavors and culinary features. In order to explore the potential of macro-fungi as a natural resource of bioactive compounds, the antioxidant properties and polysaccharide contents of 49 edible macro-fungi from China were evaluated systematically. A positive correlation between antioxidant capacity and total phenolic content indicated that phenolic compounds could be main contributors of antioxidant capacities of these macro-fungi. Furthermore, many bioactive compounds such as gallic, homogentisic, protocatechuic, and p-hydroxybenzoic acid were identified and quantified. The macro-fungi species Thelephora ganbajun Zang, Boletus edulis Bull., Volvariella volvacea Sing, Boletus regius Krombh, and Suillus bovinus Kuntze displayed the highest antioxidant capacities and total phenolic contents, indicating their potential as important dietary sources of natural antioxidants.

Insulin receptor substrate 1 (IRS1) variants confer risk of diabetes in the Boston Puerto Rican Health Study

OBJECTIVE

Published data concerning associations between IRS1 variants and type 2 diabetes and related traits have been inconsistent. We examined the relationship between common variants in IRS1, type 2 diabetes, and related traits including insulin resistance, hyperglycemia and DNA damage in the Boston Puerto Rican Health Study.

METHODS

We genotyped six common IRS1 variants in an adult Puerto Rican population (n=1132) and tested for association with risk of type 2 diabetes and related traits.

RESULTS

SNPs rs934167 and rs1801123 showed significant association with fasting glucose concentrations (p = 0.005 and p = 0.016, respectively) and rs934167 showed significant association with plasma insulin levels (p = 0.005). Carriers of the rs934167 minor allele had significantly higher HOMA-IR and lower QUICKI (p = 0.001 and p = 0.001, respectively), and a 40% and 58% greater likelihood of being hyperglycaemic or hyperinsulinemic (OR = 1.40 and 1.58; p = 0.013 and 0.002, respectively). However, they exhibited only a marginally significant trend towards having type 2 diabetes (OR=1.27, p = 0.077). Furthermore, carriers of the haplotype C-T of the rs934167 and rs1801123 minor alleles showed consistent patterns of associations after correction for multiple testing. In addition, the G972R (rs1801278) minor allele was significantly associated with higher urinary 8-OHdG concentrations (p = 0.020) and plasma CRP levels (p = 0.035).

CONCLUSIONS

Our results support IRS1 variants associated with type 2 diabetes risk in adult Puerto Ricans. Moreover, we report the novel finding that IRS1 variant G972R (rs1801278) may contribute to oxidative DNA damage and inflammation.

Antiproliferative activities of tea and herbal infusions

The consumption of tea and herbal infusions has increased rapidly in recent years. More and more people consume these infusions as daily beverages as well as for health purposes. The aim of this study was to supply new information on the antiproliferative function of these infusions for nutritionists and the general public. The in vitro antiproliferative activities of 60 different tea and herbal infusions on four cancer cell lines were evaluated by MTT assay. The results showed that some infusions strongly inhibited the proliferation of A549 (human lung cancer cells), MCF-7 (human breast cancer cells), HepG2 (human hepatoma cells) and HT-29 (human colon cancer cells), and decreased the viability of these cancer cell lines in a dose-dependent manner. In addition, some bioactive components in the infusions were also separated and determined by HPLC. The results suggested that some tea and herbal infusions may be potential dietary supplements for the prevention and treatment of cancer.

Lycopene suppresses proinflammatory response in lipopolysaccharide-stimulated macrophages by inhibiting ROS-induced trafficking of TLR4 to lipid raft-like domains

We recently showed that lycopene inhibited lipopolysaccharide (LPS)-induced productions of nitric oxide (NO) and interleukin-6 (IL-6) in murine RAW264.7 macrophages by mechanisms related to inhibition of ERK and nuclear factor-κB. Since the assembly of Toll-like receptor 4 (TLR4) in lipid rafts is a key element in LPS induced signaling, we investigated whether this process would be influenced by lycopene. We found that pretreatment of RAW264.7 cells with lycopene inhibited LPS-induced recruitment of TLR4 into fractions - enriched with lipid raft marker. By the methods of immunoprecipitation and immunoblotting, we also found that lycopene inhibited the subsequent formation of the complex of TLR4 with its adaptors including myeloid differentiation primary-response protein 88 and TIR domain-containing adaptor-inducing IFN-β. We also found that the lycopene induced inhibition was associated with reduced formation of reactive oxygen species (ROS), which was an upstream mechanism for the effects of lycopene, because treating the cells with the antioxidant N-acetyl-l-cysteine and NADPH oxidase inhibitor diphenyleneiodonium chloride significantly inhibited LPS-induced recruitment of TLR4 into lipid raft-like domains as well as the production of proinflammatory molecule NO and IL-6. Thus, our findings suggest that lycopene may prevent LPS-induced TLR4 assembly into lipid rafts through reducing intracellular ROS level.

1,25-dihydroxyvitamin D3 inhibits fibrosis in mice with NAFLD induced by a methionine-choline-deficient diet

AIM: To investigate whether 1,25-dihydroxyvitamin D₃ (1,25(OH)₂D₃), the active form of vitamin D, inhibits fibrosis induced by a methionine-choline-deficient (MCD) diet in C57BL/6J mice and to explore the possible mechanisms involved.

METHODS: Male C57BL/6J mice (n = 30) were divided randomly into control group, MCD group, and MCD + 1,25(OH)₂D₃ group. The MCD and MCD + 1,25(OH)₂D₃ groups were fed a MCD diet. All the mice were intraperitoneally injected with 1,25(OH)₂D₃ (5 μg/kg) or equal volume of saline twice weekly. After 8 wk, the mice were sacrificed to take serum samples for biochemical measurements and liver samples for HE staining and RT-PCR.

RESULTS: Serum levels of alanine aminotransferase, aspartate aminotransferase, and mRNA expression of transforming growth factor beta1 (TGF-β1), α-smooth muscle actin (α-SMA) and collagenⅠa1 of MCD group significantly increased in the MCD group compared to the control group (P = 0.000, 0.000, 0.044, 0.003, 0.027). In the MCD + 1,25(OH)₂D₃ group, all the above parameters significantly decreased (P = 0.000, 0.005, 0.020, 0.027) except the mRNA expression of TGF-β1, which showed no significant change, compared to the MCD group. Steatosis was significantly improved, as revealed by the presence of fewer lipid drops in the cytoplasm and less inflammatory cell infiltration around the vessels, in the MCD + 1,25(OH)₂D₃ group compared to the MCD group.

CONCLUSION: 1,25(OH)₂D₃ can improve liver function and inhibit fibrosis possibly by down-regulating the mRNA expression of α-SMA and collagenⅠa1 in mice with NAFLD induced by a MCD diet.

Evaluation of acrylamide in food from China by a LC/MS/MS method

Acrylamide is potential carcinogenic compound that possesses neurotoxicity activity. In this study, the levels of acrylamide in 123 selected food samples from China was evaluated using a LC/MS/MS method. One hundred and fifteen (115) out of 123 samples showed positive levels of acrylamide in the range of 0.41 to 4,126.26 µg/kg. Generally, the highest acrylamide levels were found in fried products, such as potato, prawn strips and rice crust, with average values of 604.27, 341.40, and 201.51 µg/kg, respectively. Heated protein-rich food also showed some acrylamide content (ranging from 2.31 to 78.57 µg/kg). The results revealed that a potential acrylamide public health risk occurred in processed snacks, as well as the food consumed daily. This study supplied new information on acrylamide content of a variety of heat-treated foods from China.

Curcumin attenuates Nrf2 signaling defect, oxidative stress in muscle and glucose intolerance in high fat diet-fed mice

AIM: To investigate the signaling mechanism of anti-oxidative action by curcumin and its impact on glucose disposal.

METHODS: Male C57BL/6J mice were fed with either a normal diet (n = 10) or a high fat diet (HFD) (n = 20) to induce obesity and insulin resistance. After 16 wk, 10 HFD-fed mice were further treated with daily curcumin oral gavage at the dose of 50 mg/kg body weight (BW) (HFD + curcumin group). After 15 d of the curcumin supplementation, an intraperitoneal glucose tolerance test was performed. Fasting blood samples were also collected for insulin and glucose measurements. Insulin-sensitive tissues, including muscle, adipose tissue and the liver, were isolated for the assessments of malondialdehyde (MDA), reactive oxygen species (ROS) and nuclear factor erythroid-2-related factor-2 (Nrf2) signaling.

RESULTS: We show here that in a HFD mouse model, short-term curcumin gavage attenuated glucose intolerance without affecting HFD-induced BW gain. Curcumin also attenuated HFD-induced elevations of MDA and ROS in the skeletal muscle, particularly in its mitochondrial fraction, but it had no such an effect in either adipose tissue or the liver of HFD-fed mice. Correspondingly, in skeletal muscle, the levels of total or nuclear content of Nrf2, as well as its downstream target, heme oxygenase-1, were reduced by HFD-feeding. Curcumin intervention dramatically reversed these defects in Nrf2 signaling. Further analysis of the relationship of oxidative stress with glucose level by a regression analysis showed a positive and significant correlation between the area under the curve of a glucose tolerance test with MDA levels either in muscle or muscular mitochondria.

CONCLUSION: These findings suggest that the short-term treatment of curcumin in HFD-fed mice effectively ameliorates muscular oxidative stress by activating Nrf2 function that is a novel mechanism for its effect in improving glucose intolerance.

Role of nuclear factor (erythroid-derived 2)-like 2 in metabolic homeostasis and insulin action: A novel opportunity for diabetes treatment?

Redox balance is fundamentally important for physiological homeostasis. Pathological factors that disturb this dedicated balance may result in oxidative stress, leading to the development or aggravation of a variety of diseases, including diabetes mellitus, cardiovascular diseases, metabolic syndrome as well as inflammation, aging and cancer. Thus, the capacity of endogenous free radical clearance can be of patho-physiological importance; in this regard, the major reactive oxygen species defense machinery, the nuclear factor (erythroid-derived 2)-like 2 (Nrf2) system needs to be precisely modulated in response to pathological alterations. While oxidative stress is among the early events that lead to the development of insulin resistance, the activation of Nrf2 scavenging capacity leads to insulin sensitization. Furthermore, Nrf2 is evidently involved in regulating lipid metabolism. Here we summarize recent findings that link the Nrf2 system to metabolic homeostasis and insulin action and present our view that Nrf2 may serve as a novel drug target for diabetes and its complications.

Interaction between heavy smoking and CYP2A6 genotypes on type 2 diabetes and its possible pathways

OBJECTIVE

To explore the interactions between smoking and CYP2A6 genotypes on type 2 diabetes (T2DM) as well as potential pathways for smoking in causing T2DM.

DESIGN

Cross-sectional study.

METHODS

A total of 1344 smokers with complete data from a community-based T2DM survey in Guangzhou and Zhuhai of China from July 2006 to June 2007 were interviewed with a structured questionnaire about socio-demographic status and daily cigarette consumption. Serum glucose, insulin, and cotinine were measured after an overnight fast. Subjects were genotyped for CYP2A6 and classified, according to genotype, into normal, intermediate, slow, or poor nicotine metabolizers based on prior knowledge of CYP2A6 allele associations with nicotine C-oxidation rate. Abdominal obesity was defined as a waist-to-hip ratio ≥0.90 for males or ≥0.85 for females. Type 2 diabetic patients (n=154) were diagnosed according to WHO 1999 criteria. Chi-square tests, multivariate logistic regression models, and a structural equation model were used in this study.

RESULTS

Multivariate analysis indicated that, compared with light smoking, heavy smoking significantly increased the risk of T2DM (odds ratio (OR)=1.75, 95% CI=1.01-3.05). There were significant interactions between heavy smoking and slow CYP2A6 (OR=5.12, 95% CI=1.08-24.23) and poor CYP2A6 metabolizer genotypes (OR=8.54, 95% CI=1.28-57.02) on T2DM. Structural equation modeling indicated that CYP2A6 moderation of smoking quantity risk on T2DM was mediated by the effects on serum cotinine, abdominal obesity, insulin resistance, and insulin secretion.

CONCLUSIONS

Heavy smoking was significantly associated with T2DM, and this association was moderated by CYP2A6 genotype and mediated by serum cotinine, abdominal obesity, insulin resistance, and insulin secretion.

Differences of smoking knowledge, attitudes, and behaviors between medical and non-medical students

BACKGROUND

Previous studies in the world reported inconsistent results about the relationship of medical professional education with medical students' smoking behaviors, and no similar research had been published in China.

PURPOSE

This paper aims to explore whether the differences of smoking-related knowledge, attitudes, and behaviors existed between medical and non-medical undergraduate students.

METHODS

Eight thousand one hundred thirty-eight undergraduate students sampled from a university in Guangzhou were investigated with a self-administered structured questionnaire about their smoking-related knowledge, attitude and behaviors, and other relevant factors. General linear model and multinomial logistic regression were conducted to test the differences in smoking-related knowledge, attitude, and behaviors between medical and non-medical students while controlling for potential confounding variables.

RESULTS

There was no difference in smoking-related knowledge scores between medical and non-medical freshmen, but medical sophomores and juniors had higher scores of smoking-related knowledge than their non-medical counterparts. The medical sophomores had higher mean score of attitudes towards smoking than non-medical ones. Before entering university, the difference in the prevalence of experimental and regular smoking between medical and non-medical college students was not significant. After entering university, in contrast, the overall prevalence of regular smoking was significantly higher among male non-medical college students than among male medical students. Stratified by current academic year, this difference was significant only among male sophomores.

CONCLUSIONS

Medical students have higher smoking-related knowledge, stronger anti-smoking attitude, and lower prevalence of regular smoking than non-medical college students of similar age, which may be associated with medical professional education.

Anthocyanin supplementation improves serum LDL- and HDL-cholesterol concentrations associated with the inhibition of cholesteryl ester transfer protein in dyslipidemic subjects

BACKGROUND

Anthocyanins have been shown to exert benefits on the lipid profile in many animal models. Whether these molecules have similar beneficial effects in humans is currently unknown.

OBJECTIVE

The objective was to investigate the effects of berry-derived anthocyanin supplements on the serum lipid profile in dyslipidemic patients.

DESIGN

A total of 120 dyslipidemic subjects (age 40-65 y) were given 160 mg anthocyanins twice daily or placebo for 12 wk in a double-blind, randomized, placebo-controlled trial.

RESULTS

Anthocyanin consumption increased HDL-cholesterol concentrations (13.7% and 2.8% in the anthocyanin and placebo groups, respectively; P < 0.001) and decreased LDL-cholesterol concentrations (13.6% and -0.6% in the anthocyanin and placebo groups, respectively; P < 0.001). Cellular cholesterol efflux to serum increased more in the anthocyanin group than in the placebo group (20.0% and 0.2%, respectively; P < 0.001). Anthocyanin supplementation decreased the mass and activity of plasma cholesteryl ester transfer protein (CETP) (10.4% and 6.3%, respectively, in the anthocyanin group and -3.5% and 1.1%, respectively, in the placebo group; P < 0.001). In the anthocyanin group, the change in HDL cholesterol was negatively correlated with the change in CETP activity (r(s) = -0.330). The change in LDL cholesterol was positively correlated with the change in CETP mass (r(s) = 0.354). The change in cellular cholesterol efflux to serum was positively correlated with the change in HDL cholesterol (r(s) = 0.485). In vitro, cyanidin 3-O-beta-glucosides dose-dependently lowered CETP activity in human HepG2 cells.

CONCLUSIONS

Anthocyanin supplementation in humans improves LDL- and HDL-cholesterol concentrations and enhances cellular cholesterol efflux to serum. These benefits may be due to the inhibition of CETP.

Beneficial effects of designed dietary fatty acid compositions on lipids in triacylglycerol-rich lipoproteins among Chinese patients with type 2 diabetes mellitus

Elevated levels of postprandial triacylglycerol-rich lipoproteins (ppTRLs) are atherogenic. Patients with type 2 diabetes mellitus (T2DM) have exaggerated postprandial lipemia associated with elevation or prolonged residence of ppTRL remnants. We examined whether dietary fatty acid compositions (DFACs) decrease atherogenic lipid profiles in ppTRL subfractions in T2DM Chinese patients. A single-blind randomized controlled trial was conducted among 28 T2DM patients. Patients consumed 1 of 3 standardized DFAC-specific fat meals: equidominant (1:1:1), polyunsaturated fatty acid (PUFA)-dominant (PUFA-D, 1:1.7:2.3), or monounsaturated fatty acid (MUFA)-dominant (MUFA-D, 1:1.7:1.2) meals. Numbers in parenthesis, respectively, represent the ratio of saturated fatty acids, MUFA, and PUFA to saturated fatty acids. The MUFA-D meal was the control. Triacylglycerol and cholesterol levels were measured in Svedberg flotation rate (S(f)) greater than 400, S(f) 60 to 400, S(f) 20 to 60, and S(f) 12 to 20 ppTRL subfractions at fasting (0 hour) and 2, 4, and 6 hours after the consumption of the fat meals. Effects of DFACs on mean concentrations of triacylglycerols and cholesterol averaged over 0, 2, 4, and 6 hours in ppTRL subfractions were assessed using linear mixed models. Stability and robustness were validated with 1000 bootstrap replicates. Contrasted to the control, equidominant meal reduced 6-hour average triacylglycerol levels in S(f) greater than 400 (P = .002, bootstrap P < .05) and S(f) 20 to 60 (P = .02, bootstrap P < .05) subfractions, and decreased average S(f) 20 to 60 cholesterol (P = .04, bootstrap P < .05); PUFA-D decreased S(f) greater than 400 average triacylglycerol levels (P = .09, bootstrap P < .05). Bootstrap samples suggested that PUFA-D decreased average S(f) 20 to 60 cholesterol levels (bootstrap P < .05). Therefore, modifying DFACs attenuates the atherogenic lipid profile of ppTRLs in T2DM patients; but increasing PUFA ratio may be more feasible.

Which preventive measures might protect health care workers from SARS?

Background

Despite the use of a series of preventive measures, a high incidence of severe acute respiratory syndrome (SARS) was observed among health care workers (HCWs) during the SARS epidemic. This study aimed to determine which preventive measures may have been effective in protecting HCWs from infection, and which were not effective.

Methods

A retrospective study was performed among 758 'frontline' health care workers who cared for SARS patients at the Second Affiliated Hospital and the Third Affiliated Hospital of Sun Yat-sen University. The HCWs with IgG against SARS and those without IgG against SARS were respectively defined as the "case group" and the "control group", and logistic regression was conducted to explore the risk factors for SARS infection in HCWs.

Results

After adjusting for age, gender, marital status, educational level, professional title, and the department in which an individual worked, the results of a multivariate logistic regression analysis indicated that incidence of SARS among HCWs was significantly and positively associated with: performing tracheal intubations for SARS patients, methods used for air ventilation in wards, avoiding face-to-face interaction with SARS patients, the number of pairs of gloves worn by HCWs, and caring for serious SARS cases.

Conclusion

Some measures, particularly good air ventilation in SARS wards, may be effective in minimizing or preventing SARS transmission among HCWs in hospitals.

[A meta-analysis on the association between maternal passive smoking during pregnancy and small-for-gestational-age infants]

OBJECTIVE

To study the association between maternal passive smoking during pregnancy and the small-for-gestational-age (SGA) infants and to analyze independent factors on duration, in different areas.

METHODS

Totally, 8 retrospective studies published in PubMed (no year limited), OVID-MEDLINE (no year limited), CNKI (from 1911 to 2008), VIP (from 1989 to 2008), and CBM (no year limited), on maternal passive smoking during pregnancy and SGA were analyzed synthetically by Meta-analysis.

RESULTS

The unadjusted pooled OR value on the association between maternal passive smoking during pregnancy and SGA was 1.45 (95% CI: 1.05-2.01). Data showed that the adjusted pooled OR value was 1.76 (95% CI: 1.15-2.69). Maternal passive smoking in early pregnancy was a risk factor for SGA (OR = 1.85, 95% CI: 1.25-2.72), and so was the exposure in mid or late pregnancy(OR = 2.12, 95% CI: 1.43-3.13). No statistically significant relationship between SGA and passive smoking at home or at workplace was found.

CONCLUSION

Avoiding passive smoking in pregnancy for mothers could reduce the possibility of delivering SGA infants. Other than at home or at workplace, problem of passive smoking in other places should also be brought up.

[Effects of flavonoids with different structures on proliferation of leukemia cell line HL-60]

BACKGROUND & OBJECTIVE

Flavonoids, with some beneficial biological activities, exist extensively in foods and herbal products. This study was to evaluate the effects of 23 flavonoids on the proliferation of leukemia cell line HL-60, and elucidate the structure-activity relationship (SAR).

METHODS

HL-60 cells were treated with 23 flavonoids with high purity and definite structure. Cell proliferation was detected by MTT assay. The 50% inhibition concentrations (IC50) of the 23 flavonoids were calculated. The effects of particular structures on IC50 were evaluated.

RESULTS

Most of the 23 flavonoids inhibited the proliferation of HL-60 cells distinctly, and the effects were enhanced along with increasing concentrations. However, the intensity of their effects were different, which were arranged from strong to weak as follows:3,6-dihydroxyflavone > luteolin > geraldol > 2'-hydroxyflavanone > apigenin > 3,7-dihydroxyflavone > myricetin > fisetin > baicalein > quercetin > flavanone > chrysin > galangin > 4'-hydroxyflavanone > 6-hydroxyflavone > genistein > flavone >7-hydroxyflavone > daidzein > hesperetin > naringenin. The 2,3-double bond in ring C, appropriate hydroxyls, ring B attached at position 2, hydroxyls in position 3, ortho-substituting hydroxyls in ring B were related to enhanced inhibitory effects of flavonoids on the proliferation of HL-60 cells, while the lack of 2,3-double bond, deficiency or redundancy of hydroxyl groups, hydroxyl group in position 5, 7 or meta-substituting hydroxyls in ring B, isoflavone structure were related to reduced inhibitory effects of flavonoids.

CONCLUSION

The 2,3-double bond in ring C, appropriate hydroxyls, ring B attached at position 2, hydroxyls in position 3, ortho-substituting hydroxyls in ring B may be key structural requirements of flavonoids for potent cytotoxicity to HL-60 cells.

[Study of the association between paraoxonase1 55 Met/Leu, paraoxonase2 148 Ala/Gly and manganese superoxide dismutase (MnSOD) 9 Ala/Val genetic polymorphisms and coronary heart disease]

OBJECTIVE

To study the associations between paraoxonase, 55 Met/Leu (PON1 55 Met/ Leu), paraoxonase2 148 Ala/Gly (PON2 148 Ala/Gly) and manganese superoxide dismutase 9 Ala/Val (MnSOD 9 Ala/Val) genetic polymorphisms and coronary heart disease (CHD), plasma activities of paraoxonase (PON), total superoxide dismutase (T-SOD), MnSOD, as well as plasma concentration of maleic dialdehyde (MDA).

METHODS

Using PCR-RFLP method to identify genotype of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val genetic polymorphisms, and using colorimetry to detect plasma activities of PON, T-SOD, MnSOD and plasma concentration of MDA in 262 CHD patients and 100 controls.

RESULTS

Compared with controls, the plasma activities of PON [(349.27 +/- 138.36 vs. 454.75 +/- 166.00) nmol x min(-1) x ml(-1), P < 0.001], T-SOD [(23.61 +/- 16.51 vs. 44.01 +/- 22.68) U/ml, P < 0.001] and MnSOD [(21.56 +/- 13.11 vs. 28.79 +/- 8.65) U/ml, P < 0.001] reduced obviously,while plasma MDA concentration increased markedly [(2.47 +/- 0.73 vs. 2.15 +/- 0.55)nmol/ml, P < 0.01] in CHD patients. There were more LM genotype and Met allele of PON, 55 Met/Leu (24.8% vs. 1.4%, P < 0.001 and 12.4% vs. 0.5%, P = 0.001, respectively), GG and AG genotype and G allele of PON2 148 Ala/Gly (11.8% vs. 5.0%, P < 0.001, 48.1% vs. 24.0%, P < 0.001 and 36.0% vs. 17.0%, P < 0.001, respectively) and AA genotype, A allele of MnSOD 9 Ala/Val genetic polymorphisms (64.2% vs. 43.0%, P = 0.001 and 80.0% vs. 67.0%, P = 0.014, respectively) in CHD patients than in controls. The activities of plasma PON and T-SOD were lower in individuals with PON1 55 LM genotype than those with LL genotype. The activity of plasma PON was also lower in individuals with PON2 148 GG/AG genotype than those with AA genotype. The activities of plasma PON and MnSOD depressed in individuals with MnSOD AA genotype compared with those with VV genotype. Logistic regression analysis demonstrated that PON1 55 LM genotype, PON2 148 GG/AG genotype and G allele were independent risk factors for CHD.

CONCLUSION

The antioxidative ability decreased, while lipid superoxide increased in CHD patients. Gene polymorphisms of PON1 55 Met/Leu, PON2 148 Ala/Gly and MnSOD 9 Ala/Val seemed to involve in the morbidity of CHD by influencing the plasma activities of PON and MnSOD.

[Study on the related factors of smoking behavior transition at different stages among undergraduate students]

OBJECTIVE

To explore the influencing factors of smoking behavior transition at different stage of smoking among undergraduate students.

METHODS

8138 undergraduate students from grade 1 to 3 were selected using cluster sampling method from an university in Guangzhou with their smoking behaviors and relevant factors studied through a self-administered questionnaire. Beginners, un-regular smokers and regular smokers were defined as "case group", while non-smokers, beginners and un-regular smokers were defined as "control group" accordingly. Three multivariable logistic regressions were separately conducted to explore the influencing factors of behavioral transition at different stage of smoking.

RESULTS

Of the 8138 students investigated, the prevalence rates of beginners, un-regular smokers and regular smokers were 19.6%, 2.0% and 1.1%, respectively; while all of the above said three rates increased with grades of the students. Some students might still try to smoke or become regular smoker in the university. In male undergraduate students, determinants for the transition from non-smokers to s mokers were: source of students, father' s educational level, smoking-related knowledge and belief, and smoking habit of the roommates. Risks that influencing the transition from beginners to un-regular smokers were: being non-medical students,smoking-related belief, roommates and classmates who were smokers and transition from un-regular smokers to regular smokers would include father' s educational level and average income of family. In female undergraduate students,influencing factors from non-smokers to beginners were mother's educational level, smoking-related belief, and roommates smokers, while father's educational level, roommates and classmates' smoking habits were significant associated with beginners' change to un-regular smokers.

CONCLUSION

The influencing factors related to the transition of different stage on smoking would be different in undergraduate students,and some specific measures should be taken based on the different stage of smoking.

Sequence analysis and structural prediction of the severe acute respiratory syndrome coronavirus nsp5

Abstract The non‐structural proteins (nsp or replicase proteins) of coronaviruses are relatively conserved and can be effective targets for drugs. Few studies have been conducted into the function of the severe acute respiratory syndrome coronavirus (SARS‐CoV) nsp5. In this study, bioinformatics methods were employed to predict the secondary structure and construct 3‐D models of the SARS‐CoV GD strain nsp5. Sequencing and sequential comparison was performed to analyze the mutation trend of the polymerase nsp5 gene during the epidemic process using a nucleotide‐nucleotide basic local alignment search tool (BLASTN) and a protein‐protein basic local alignment search tool (BLASTP). The results indicated that the nsp5 gene was steady during the epidemic process and the protein was homologous with other coronavirus nsp5 proteins. The protein encoded by the nsp5 gene was expressed in COS‐7 cells and analyzed by sodium dodecylsulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). This study provided the foundation for further exploration of the protein's biological function, and contributed to the search for anti‐SARS‐CoV drugs.

Edited by Bing SUN

Anti-SARS-CoV immunoglobulin G in healthcare workers, Guangzhou, China

To determine the prevalence of inapparent infection with severe acute respiratory syndrome (SARS) among healthcare workers, we performed a serosurvey to test for immunoglobulin (Ig) G antibodies to the SARS coronavirus (SARS-CoV) among 1,147 healthcare workers in 3 hospitals that admitted SARS patients in mid-May 2003. Among them were 90 healthcare workers with SARS. As a reference group, 709 healthcare workers who worked in 2 hospitals that never admitted any SARS patients were similarly tested. The seroprevalence rate was 88.9% (80/90) for healthcare workers with SARS and 1.4% (15/1,057) for healthcare workers who were apparently healthy. The seroprevalence in the reference group was 0.4% (3/709). These findings suggest that inapparent infection is uncommon. Low level of immunity among unaffected healthcare workers reinforces the need for adequate personal protection and other infection control measures in hospitals to prevent future epidemics.

Humoral immune responses in rabbits induced by an experimental inactivated severe acute respiratory syndrome coronavirus vaccine prepared from F69 strain

BACKGROUND

The etiologic agent of severe acute respiratory syndrome (SARS) has been confirmed to be a novel coronavirus (CoV), namely SARS-CoV. Developing safe and effective SARS-CoV vaccines is essential for us to prevent the possible reemergence of its epidemic. Previous experiences indicate that inactivated vaccine is conventional and more hopeful to be successfully developed. Immunogenicity evaluation of an experimental inactivated SARS-CoV vaccine in rabbits was conducted and reported in this paper.

METHODS

The large-scale cultured SARS-CoV F69 strain was inactivated with 0.4% formaldehyde and purified, then used as the immunogen combined with Freund's adjuvant. Eight adult New Zealand rabbits were immunized four times with this experimental inactivated vaccine. Twelve sets of rabbit serum were sampled from the third day to the seventy-fourth day after the first vaccination. The titers of specific anti-SARS-CoV IgG antibody were determined by indirect enzyme-linked immunosorbent assay, and the neutralizing antibody titers were detected with micro-cytopathic effect neutralization test.

RESULTS

Rapid and potent humoral immune responses were induced by the inactivated SARS-CoV vaccine in all the eight test rabbits. Titers of both specific IgG antibody and neutralizing antibody peaked at about six weeks after first vaccination, with the maximum value of 1:81 920 and 1:20 480, respectively. After that, serum antibody levels remained at a plateau or had a slight decrease, though two boosters were given in the succedent 4 to 5 weeks. Cross neutralization response existed between SARS-CoV F69 strain and Z2-Y3 strain.

CONCLUSIONS

The inactivated SARS-CoV vaccine made from F69 strain owns strong immunogenicity, and the cross neutralization response between the two different SARS-CoV strains gives a hint of the similar neutralizing epitopes, which provide stable bases for the development of inactivated SARS-CoV vaccines.

Red and black rice decrease atherosclerotic plaque formation and increase antioxidant status in rabbits

The influence of white, red and black rice consumption on atherosclerotic plaque formation induced by hypercholesterolemia was investigated in rabbits. Male rabbits (n = 36) were divided into five groups. They were fed a normal laboratory purified diet (normal group, n = 6), a high cholesterol (0.5 g/100 g) diet (HC group, n = 6), a high cholesterol diet with 30 g/100 g white rice (WR group, n = 8), 30 g/100 g red rice (RR group, n = 8), or 30 g/100 g black rice (BR group, n = 8) for 10 wk. Blood samples were collected for lipid measurements and aorta were removed for assessment of atherosclerotic plaques at the end of the protocol. The oxidant and antioxidant status of blood, erythrocytes, liver and aorta was evaluated. The area of atherosclerotic plaque was 50% lower in rabbits fed the red or black rice diets than in those fed the white rice diet. Compared with the HC and WR groups, serum HDL cholesterol and apolipoprotein (apo) A-I concentration were greater (P < 0.05) in the RR and BR groups. Liver reactive oxygen species (ROS) and aortic malondialdehyde (MDA) were significantly lower, and the liver total antioxidative capacity (TAC) and erythrocyte superoxide dismutase (SOD) activity were significantly higher in the RR and BR groups compared with the HC and WR groups. Red or black rice consumption reduced or retarded the progression of atherosclerotic plaque development induced by dietary cholesterol. The enhanced serum HDL cholesterol and apo A-I concentrations, and the increased antioxidant and decreased oxidative status may be mechanisms of the antiatherogenic effect of red or black rice.

[p53 gene expression of human hepatoma cell lines and their sensitivities to parvovirus H-1]

DNA structure and expression of p53 gene in human hepatoma cell lines SMMC-7721, YY-8103 and a spontaneously transformed liver cell line L-02 were analysed using the following method: analysis of allelic losses on chromosome 17p, PCR/SSCP, Northern blot and immunoprecipitation. There was no point mutation found in the exons 4-9 of the p53 gene, and a low level of expression of p53 gene was detected in the three cell lines. These observations were in agreement to the reported results of the relevant experiment using the human hepatoma cell line QGY-7703. Sensitivities of these cell lines and other eight human hepatoma cell lines (QGY-7703, PLC/PRF/5, Tong/HCC, Huh-7, FOCUS, Hep3B, SK-Hep-1, HepG2) with known p53 backgrounds to parvovirus H-1 was assayed using MTT method. Abnormality in the structure and/or function was observed in all of the cell lines examined except HepG2. The cell line HepG2 with normal structure and function of the p53 gene was found to be the least sensitive to H-1 in comparison to all the cell lines which have defeated structure and/or function of the p53 gene. The present study serves as a preliminary evidence that enhancement of the sensitivity of human hepatoma cell lines to H-1 is correlated to the abnormality of the structure and/or function of the p53 gene.

Enhanced efficacy of sitostanol-containing versus sitostanol-free phytosterol mixtures in altering lipoprotein cholesterol levels and synthesis in rats

To investigate the action and mechanism of a dietary phytosterol mixture naturally containing sitostanol, derived from tall-oil, on circulating cholesterol and lipoprotein levels, five groups of rats were fed a control elemental diet (group 1), a control elemental diet with 1% cholesterol alone (group 2) or with sitostanol mixtures or a sitostanol-free mixture supplemented at 0.2% (group 3), 0.5% (group 4) or 1% (group 5) of dietary levels. One per cent supplementation of sitostanol (21%) compared with sitostanol-free mixtures decreased (P < 0.02) total serum cholesterol. Dietary sitostanol (16% or 21%) mixture at 1% dietary levels decreased (P < 0.05) low density lipoprotein (LDL) cholesterol and increased (P < 0.05) high density lipoprotein (HDL) cholesterol levels. The decrease of LDL and increase of HDL cholesterol were correlated (P < 0.01) with the level of sitostanol mixture in the diet. Consumption of the sitostanol-containing mixture (1% dietary levels) caused a compensatory increase in cholesterol synthesis as indicated by elevated (P < 0.05) lathosterol/ cholesterol ratios in plasma and hepatic cholesterol fractional synthesis rate (FSR) (P < 0.02). Both sitostanol and sitostanol-free mixtures at 0.5% or 1% dietary intake levels increased plasma campesterol and beta-sitosterol levels, while plasma sitostanol levels were negligible. The absence of sitostanol in plasma and the increase in cholesterol synthesis induced by dietary sitostanol mixtures in addition to elevation of plasma campesterol and beta-sitosterol by sitostanol or sitostanol-free mixtures suggest that sitostanol mixtures effectively modify circulating lipoprotein cholesterol concentrations at the level of the intestine, rather than internally at the level of cholesterogenesis.

Dietary phytosterols: a review of metabolism, benefits and side effects

Most animal and human studies show that phytosterols reduce serum/or plasma total cholesterol and low density lipoprotein (LDL) cholesterol levels. Phytosterols are structurally very similar to cholesterol except that they always contain some substitutions at the C24 position on the sterol side chain. Plasma phytosterol levels in mammalian tissue are normally very low due primarily to poor absorption from the intestine and faster excretion from liver compared to cholesterol. Phytosterols are able to be metabolized in the liver into C21 bile acids via liver other than normal C24 bile acids in mammals. It is generally assumed that cholesterol reduction results directly from inhibition of cholesterol absorption through displacement of cholesterol from micelles. Structure-specific effects of individual phytosterol constituents have recently been shown where saturated phytosterols are more efficient compared to unsaturated compounds in reducing cholesterol levels. In addition, phytosterols produce a wide spectrum of therapeutic effects in animals including anti-tumour properties. Phytosterols have been shown experimentally to inhibit colon cancer development. With regard to toxicity, no obvious side effects of phytosterol have been observed in studies to date, except in individual with phytosterolemia, an inherited lipid disorder. Further characterization of the influence of various phytosterol subcomponents on lipoprotein profiles in humans is required to maximize the usefulness of this non-pharmacological approach to reduction of atherosclerosis in the population.

Oral bacteriotherapy for viral gastroenteritis

The effect of orally administered lactobacilli on acute rotavirus diarrhea was tested in 42 well-nourished children ages 5-28 months. After oral rehydration, the patients were randomized to a study group, receiving human Lactobacillus casei strain GG 10(10) colony-forming units twice daily for five days, or a control group not given lactobacilli. Lactobacillus GG was found in the feces in 83% of the study group. The diarrheal phase was shortened in that group. Dietary supplementation with lactobacilli significantly influenced the bacterial enzyme profile: urease activity during diarrhea transiently increased in the control group but not in the study group; F = 8.6, P = 0.01. No intergroup differences were found in beta-glucuronidase, beta-glucosidase, and glycocholic acid hydrolase levels. We suggest that rotavirus infection gives rise to biphasic diarrhea, the first phase being an osmotic diarrhea and the second associated with overgrowth of specifically urease-producing bacteria. Oral bacteriotherapy appears a promising means to counteract the disturbed microbial balance.

Lactobacillus strain GG supplementation decreases colonic hydrolytic and reductive enzyme activities in healthy female adults

The effects of yogurt containing viable Lactobacillus strain GG (L. GG) and/or fiber supplements on fecal enzyme activities (beta-glucuronidase, nitroreductase, beta-glucosidase, glycocholic acid hydrolase, urease) and on bacterial metabolites in urine (phenol, p-cresol) were studied in 64 females, 20-41 y old. The subjects were randomly divided into three groups: the first group received L. GG yogurt (2 x 150 mL/d, containing 10(11) colony-forming units (cfu)/L of L. GG), the second group received L. GG yogurt and a rye fiber product (30 g/d, equivalent to 9 g fiber/d), and the third group received placebo yogurt (pasteurized) and fiber. The supplementation period lasted 4 wk, with a preceding 2-wk baseline period and a 2-wk follow-up period. The mean fecal count of L. GG was approximately 10(6) cfu/g feces during the supplementation, and L. GG persisted in the fecal samples of 28% of the subjects for 2 wk after supplementation. L. GG yogurt alone or with fiber significantly decreased fecal beta-glucuronidase, nitroreductase and glycocholic acid hydrolase activities. These enzyme activities returned to baseline levels during the follow-up period. beta-Glucosidase and urease activities were not altered significantly during the study. The addition of fiber to L. GG and placebo yogurt had no effect on the enzymic activities. Urinary excretion of p-cresol decreased significantly in groups receiving L. GG. These data demonstrate that L. GG can modify the colonic environment with possible health effects.

Effects of eating an uncooked vegetable diet for 1 week

Biochemical and metabolic indicators were monitored in a group of volunteers suffering from a variety of chronic illnesses participating in a week's course on a special uncooked vegetable diet, known as "living food". Unmatched healthy controls ate the same diet cooked for 2 min in a microwave oven. After 1 week on the regimen, serum protein and urea contents decreased and alanine aminotransferase (ALAT) activity increased in both groups, although all within the normal range. Blood glucose increased in both groups to slightly above normal limits but total serum cholesterol dropped about 1 mmol/l from normal starting levels. Serum tocopherol and retinol increased only in the group eating the uncooked diet. In both groups urinary sodium dropped drastically without a significant change in potassium. Serum and urinary phenol and p-cresol diminished also significantly. It is concluded that this vegetable diet may be of some benefit in the short term but any longer-term use requires evaluation.

An uncooked vegan diet shifts the profile of human fecal microflora: computerized analysis of direct stool sample gas-liquid chromatography profiles of bacterial cellular fatty acids

The effect of an uncooked extreme vegan diet on fecal microflora was studied by direct stool sample gas-liquid chromatography (GLC) of bacterial cellular fatty acids and by quantitative bacterial culture by using classical microbiological techniques of isolation, identification, and enumeration of different bacterial species. Eighteen volunteers were divided randomly into two groups. The test group received an uncooked vegan diet for 1 month and a conventional diet of mixed Western type for the other month of the study. The control group consumed a conventional diet throughout the study period. Stool samples were collected. Bacterial cellular fatty acids were extracted directly from the stool samples and measured by GLC. Computerized analysis of the resulting fatty acid profiles was performed. Such a profile represents all bacterial cellular fatty acids in a sample and thus reflects its microflora and can be used to detect changes, differences, or similarities of bacterial flora between individual samples or sample groups. GLC profiles changed significantly in the test group after the induction and discontinuation of the vegan diet but not in the control group at any time, whereas quantitative bacterial culture did not detect any significant change in fecal bacteriology in either of the groups. The results suggest that an uncooked extreme vegan diet alters the fecal bacterial flora significantly when it is measured by direct stool sample GLC of bacterial fatty acids.

Shifting from a conventional diet to an uncooked vegan diet reversibly alters fecal hydrolytic activities in humans

We studied the effect on fecal hydrolytic activities of adopting an uncooked extreme vegan diet and readopting a conventional diet. Eighteen subjects were randomly divided into test and control groups. In the test group subjects adopted the uncooked extreme vegan diet for 1 mo and then resumed a conventional diet for a second month. Controls consumed a conventional diet throughout the study. Phenol and p-cresol concentrations in serum and daily output in urine and fecal enzyme activities were measured. The activity of fecal urease significantly decreased (by 66%) as did cholylglycine hydrolase (55%), beta-glucuronidase (33%) and beta-glucosidase (40%) within 1 wk of beginning the vegan diet. The new level remained throughout the period of consuming this diet. Phenol and p-cresol concentrations in serum and daily outputs in urine significantly declined. The fecal enzyme activities returned to normal values within 2 wk of resuming the conventional diet. Concentrations of phenol and p-cresol in serum and daily output in urine had returned to normal after 1 mo of consuming the conventional diet. No changes were observed in the control group during the study. Results suggest that this uncooked extreme vegan diet causes a decrease in bacterial enzymes and certain toxic products that have been implicated in colon cancer risk.

Colonization and fecal enzyme activities after oral Lactobacillus GG administration in elderly nursing home residents

This study was undertaken to investigate the effect of 2-week oral administration of a Lactobacillus-GG-fermented whey drink on fecal enzymes in elderly nursing home residents complaining of difficulties in defecation. The study was divided into three 2-week periods: baseline (2 dl placebo drink/day); Lactobacillus GG treatment (2 dl of a Lactobacillus-GG-fermented whey drink containing 10(8) cfu lactobacilli/ml); follow-up (2 dl placebo drink). Administration of the fermented whey drink resulted in colonization of feces by Lactobacillus GG in all the subjects. Glycocholic acid hydrolase activity and tryptic activity were significantly decreased at the end of the treatment period. The effect of Lactobacillus GG treatment on bowel function was less evident. Although the consistency of the stools appeared to normalize, no significant changes in the fecal frequency, weight and pH were observed. The results indicated that a Lactobacillus-GG-fermented whey drink can change the bacterial metabolism, and has no significant effect on bowel function.