ABSTRACT
Animal studies have shown the beneficial effects of piceatannol on metabolic health; however, there is a lack of human studies designed to examine these effects. The objective of this study was to investigate the effects of piceatannol on metabolic health in humans. This randomized, placebo-controlled study was conducted on 39 subjects, including 10 overweight men and 9 overweight women (BMI ≥ 25), as well as 10 non-overweight men and 10 non-overweight women (BMI < 25). Subjects received piceatannol (20 mg/day) or placebo capsules for eight weeks in a random order. The primary outcome was the effect of piceatannol on glucose-metabolism, including insulin sensitivity. The secondary outcomes were the effects on other parameters, including blood pressure (BP), heart rate (HR), endothelial function, lipids, inflammation, oxidative stress, mood status, and Sirt1 and phospho-AMP-activated kinase (p-AMPK) expression in isolated peripheral blood mononuclear cells (PBMNCs). Supplementation with piceatannol in overweight men reduced serum insulin levels, HOMA-IR, BP and HR. Other groups, including non-overweight men, as well as overweight and non-overweight women, showed no beneficial effects on insulin sensitivity, BP and HR. Furthermore, piceatannol is not associated with other data, including body weight (BW), body composition, endothelial function, lipids, inflammation, oxidative stress, mood status, and Sirt1/p-AMPK expression in PBMNCs. In conclusion, supplementation with piceatannol can improve metabolic health, including insulin sensitivity, BP and HR, in overweight men.
Subject(s)
Energy Metabolism/drug effects , Overweight/drug therapy , Passiflora , Seeds , Stilbenes/administration & dosage , Administration, Oral , Adult , Aged , Biomarkers/blood , Blood Pressure/drug effects , Capsules , Double-Blind Method , Female , Health Status , Heart Rate/drug effects , Humans , Insulin Resistance , Japan , Male , Middle Aged , Overweight/blood , Overweight/diagnosis , Overweight/physiopathology , Passiflora/chemistry , Phytotherapy , Plants, Medicinal , Seeds/chemistry , Stilbenes/adverse effects , Stilbenes/isolation & purification , Time Factors , Treatment Outcome , Young AdultABSTRACT
Lactic acid bacteria that produce Lactococcus-specific bacteriocins were isolated and identified as Lactococcus lactis from fresh corn or lettuce. Among them, four isolates were identified as lactococcin Q producers. Seven isolates showed antimicrobial activity against a lactococcin Q producer, L. lactis QU 4, as well as against nisin Z and lacticin Q producers belonging to L. lactis. Strain QU 7 was selected as a standard strain and showed no cross-immunity to lactococcin Q or other lactococcal bacteriocins. The bacteriocin produced by strain QU 7 was purified in three chromatographic steps, and its molecular mass was determined to be 5041.35 Da. The amino acid sequence analysis revealed that it is a novel class IId bacteriocin, referred to as lactococcin Z. It consisted of 45 amino acid residues. The lczA gene encoding the prepeptide of lactococcin Z showed homology to lactococcins A, B, and M. Thus, this report demonstrates a new example of Lactococcus-specific bacteriocins.
Subject(s)
Bacteriocins/isolation & purification , Lactococcus lactis/metabolism , Amino Acid Sequence , Bacteriocins/chemistry , Base Sequence , DNA, Bacterial/genetics , Genes, Bacterial , Lactococcus lactis/genetics , Molecular Sequence Data , Molecular Weight , Nisin/analogs & derivatives , Nisin/chemistry , Nisin/isolation & purification , RNA, Ribosomal, 16S/genetics , Sequence Analysis, DNA , Zea mays/microbiologyABSTRACT
The aim of this study was to verify the possible association of visceral fat accumulation with carotid atherosclerosis in order to identify the practical and feasible determinants for each parameter of atherosclerosis in type 2 diabetic subjects. The subjects were 151 diabetic (DM) and age-matched 83 nondiabetic subjects (C), without atherosclerotic disease. Visceral fat area (VFA) on a CT scan at the umbilicus level was measured. Ambulatory 24-h blood pressure (BP) was recorded. Stiffness index beta, intima-media thickness (IMT) and plaque formation of carotid arteries were measured by ultrasonography. Insulin sensitivity was estimated by homeostasis model assessment (HOMA). Serum levels of adiponectin and tumor necrosis factor (TNF)-alpha were determined. Male gender, HOMA, serum non-HDL-Cholesterol (Chol) and TNF-alpha/adiponectin ratio were higher, and VFA was larger in DM than in C. The IMT, stiffness index beta and plaque formation in DM were more pronounced than in C, even after adjusting for age, sex and 24-h systolic BP (sBP). VFA was positively correlated with TNF-alpha/adiponectin ratio and serum non-HDL-Chol in DM. Furthermore, multiple regression analysis revealed that, in DM, serum non-HDL-Chol was associated with IMT, VFA probably via an increase in TNF-alpha/adiponectin ratio was associated with stiffness index beta, and 24-h sBP, HOMA and VFA were associated with plaque formation independently of age and sex, respectively, although any association was not observed in C. Thus, we conclude that visceral fat-associated alterations in adipokines may be mediating the development and progression of atherosclerosis in type 2 diabetic subjects, compared with nondiabetic subjects.
