Effect of Non-Surgical Periodontal Treatment on Oxidative Stress Markers in Leukocytes and Their Interaction with the Endothelium in Obese Subjects with Periodontitis: A Pilot Study.

AIM: The primary objective of this pilot study was to evaluate the effect of non-surgical periodontal treatment. The secondary aim was to evaluate the effect of dietary therapy on both parameters of oxidative stress in leukocytes and leukocyte-endothelial cell interactions in an obese population. METHODS: This was a pilot study with a before-and-after design. Forty-nine obese subjects with periodontitis were randomized by means of the minimization method and assigned to one of two groups, one of which underwent dietary therapy while the other did not. All the subjects underwent non-surgical periodontal treatment. We determined periodontal, inflammatory and oxidative stress parameters-total reactive oxygen species (ROS), superoxide production, intracellular Ca2+, mitochondrial membrane potential and superoxide dismutase (SOD) activity. We also evaluated interactions between leukocytes and endothelium cells-velocity, rolling flux and adhesion-at baseline and 12 weeks after intervention. RESULTS: Periodontal treatment improved the periodontal health of all the patients, with a reduction in serum retinol-binding protein 4 (RBP4), total superoxide production and cytosolic Ca2+ in leukocytes. In the patients undergoing dietary therapy, there were less leukocyte adhesion to the endothelium, an effect that was accompanied by a decrease in TNFα, P-selectin and total ROS and an increase in SOD activity. CONCLUSIONS: Whereas non-surgical periodontal treatment induces an improvement in leukocyte homeostasis, dietary therapy as an adjuvant reduces systemic inflammation and increases antioxidant status which, in turn, modulates leukocyte-endothelium dynamics.

Effects of a Carob-Pod-Derived Sweetener on Glucose Metabolism.

BACKGROUND: Patients with type 2 diabetes mellitus (T2DM) have a higher incidence of cardiovascular (CV) events. The ingestion of high-glycemic index (GI) diets, specially sweetened beverage consumption, has been associated with the development of T2DM and CV disease. OBJECTIVE: We investigated the effects of the intake of a sweetened beverage, obtained from natural carbohydrates containing pinitol (PEB) compared to a sucrose-enriched beverage (SEB) in the context of impaired glucose tolerance (IGT) and diabetes. METHODS: The study was divided in three different phases: (1) a discovery phase where the plasma proteomic profile was investigated by 2-DE (two-dimensional electrophoresis) followed by mass spectrometry (matrix-assisted laser desorption/ionization time-of-flight-MALDI-TOF/TOF) in healthy and IGT volunteers; (2) a verification phase where the potential mechanisms behind the observed protein changes were investigated in the discovery cohort and in an additional group of T2DM volunteers; and (3) the results were validated in a proof-of-concept interventional study in an animal model of diabetic rats with complementary methodologies. RESULTS: Six weeks of pinitol-enriched beverage (PEB) intake induced a significant increase in two proteins involved in the insulin secretion pathway, insulin-like growth factor acid labile subunit (IGF1BP-ALS; 1.3-fold increase; P = 0.200) and complement C4A (1.83-fold increase; P = 0.007) in IGT subjects but not in healthy volunteers. Changes in C4A were also found in the serum samples of Zucker diabetic fatty (ZDF) rats after four weeks of PEB intake compared to basal levels (P = 0.042). In addition, an increased expression of the glucose transporter-2 (GLUT2) gene was observed in the jejunum (P = 0.003) of inositol-supplemented rats when compared to sucrose supplementation. This change was correlated with the observed change in C4A (P = 0.002). CONCLUSIONS: Our results suggest that the substitution of a common sugar source, such as sucrose, by a naturally-based, pinitol-enriched beverage induces changes in the insulin secretion pathway that could help to reduce blood glucose levels by protecting ß-cells and by stimulating the insulin secretion pathway. This mechanism of action could have a relevant role in the prevention of insulin resistance and diabetes progression.

Chronic consumption of an inositol-enriched carob extract improves postprandial glycaemia and insulin sensitivity in healthy subjects: A randomized controlled trial.

BACKGROUND & AIMS: Inositols are thought to be mediators of the insulin signalling pathway. We assessed the effects of inositols on glycaemic control in fasting and postprandial states and evaluated lipoprotein profile and LDL particle size in healthy population. METHODS: A 12-week double-blind clinical trial was performed with forty healthy subjects administered either an inositol-enriched beverage (IEB) -containing 2.23 g of inositols in 250 ml- or a sucrose-sweetened beverage (SB) twice a day. Anthropometric measurements, fasting glucose levels, insulin and HOMA-IR index, lipoprotein profile and postprandial glucose concentrations (measured using the continuous glucose monitoring system (CGMS)) were recorded throughout the intervention period. RESULTS: Following the 12-week trial subjects receiving the IEB exhibited a significant decrease in insulin, HOMA-IR and Apo B and an increase in LDL particle size, whereas the SB group showed increases in BMI and fasting glucose concentration. Analysis of postprandial glucose levels at breakfast, lunch and dinner revealed a mean reduction of glucose of ≈14% and a significant reduction in the area under the curve at 24 h after consumption of the IEB. CONCLUSIONS: Our results show that chronic IEB supplementation induces a significant improvement in carbohydrated metabolism parameters in healthy subjects.

A single acute dose of pinitol from a naturally-occurring food ingredient decreases hyperglycaemia and circulating insulin levels in healthy subjects.

A limited amount of research suggests that oral ingestion of pinitol (3-O-methyl-d-chiro-inositol) positively influences glucose tolerance in humans. This study assessed the effects of different doses of pinitol supplementation on glucose tolerance, insulin sensitivity and plasma pinitol concentrations. Thirty healthy subjects underwent two one-day trials in which they consumed a nutritive beverage (Fruit Up®) containing 2.5, 4.0 or 6.0g of pinitol and a corresponding placebo equivalent in both energy and carbohydrates. Blood samples were collected frequently over the 240-min test period. The pinitol-enriched beverage reduced serum glucose and insulin at 45 and 60min, but only at a dose of 6.0g. Plasma pinitol concentrations, maximum concentration and AUC increased according to the dose administered. The results show that a single dose of pinitol from a naturally-occurring food ingredient at the highest dose administered acutely influences indices of whole-body glucose tolerance and insulin sensitivity in healthy subjects.

A review on the role of phytosterols: new insights into cardiovascular risk.

Phytosterols, which are structurally related to cholesterol, are found in all plant foods with highest concentration occurring in vegetable oils and nuts. Phytosterols are known to reduce serum low-density lipoprotein cholesterol level without changing high-density lipoprotein cholesterol or triglyceride levels. Daily consumption of phytosterols-enriched foods is widely used as a therapeutic option to lower plasma cholesterol and atherosclerotic disease risk. The cholesterol-lowering action of phytosterols is thought to occur, at least in part, through competitive replacement of dietary and biliary cholesterol in mixed micelles, which undermines the absorption of cholesterol. The aim of this review is to provide a general overview of available evidence regarding the effects of phytosterols on cholesterol metabolism and addressing issues related to efficacy as dose, length, frequency of consumption, type of phytosterol (sterols versus stanols) or food matrix. Furthermore, we will explore the factors that influence the response of individuals to phytosterol therapy and evaluate their safety and the possibility that elevated plasma phytosterol concentrations contribute to the development of premature coronary artery disease.

[(11)C]-DASB microPET imaging in the aged rat: frontal and meso-thalamic increases in serotonin transporter binding.

Whereas molecular imaging studies in the aging human brain have predominantly demonstrated reductions in serotonin transporter (5-HTT) availability, the majority of the rodent studies, using autoradiographic methods, report increases in neural 5-HTT levels with age. To our knowledge, however, no previous rodent studies have assessed this topic in vivo, and therefore it remains unclear whether this discrepancy arises from methodological or inter-species differences. We performed an [(11)C]-DASB microPET study to evaluate the effects of aging on 5-HTT availability in the rat brain. To generate binding potential estimates, quantitative tracer kinetic modeling was applied using the simplified reference tissue model. A global increase in whole-brain [(11)C]-DASB binding potential was observed in the aged rats in comparison to the control group. More specifically, regional analyses revealed a highly significant increase in 5-HTT binding in the medial frontal cortex, and more modest increments in the midbrain/thalamus. Our results suggest that the frontal cortex represents a site of robust age-related alterations in the rat serotonergic system, and stress the need for further research assessing this topic in the human frontal cortex. Moreover, these findings suggest that the reported discrepancies between rodent and human data may reflect a divergence in the aging processes affecting human and rat serotonergic terminals.

Low intestinal cholesterol absorption is associated with a reduced efficacy of phytosterol esters as hypolipemic agents in patients with metabolic syndrome.

BACKGROUND & AIMS: Phytosterols (PS) lower LDLc, but their effect on metabolic syndrome (MetS) remains unknown. We evaluated whether low-fat milk enriched with PS improves cardiovascular risk factors in these patients. METHODS: A randomised parallel trial employing 24 moderate-hypercholesterolaemic MetS patients and consisting of two 3-month intervention phases. After a 3-month healthy diet, patients were divided into two intervention groups: diet (n = 10) and diet + PS (n = 14) (2 g/day). A control group of 24 moderate-hypercholesterolaemic patients without MetS (matched in age and BMI) underwent the same procedure. RESULTS: Neither dietary intervention nor enrichment of PS induced any improvement in the serum lipoprotein profile of MetS patients. By contrast, in the non-MetS population, a healthy diet effectively reduced TC, LDLc, non-HDLc and Apo B-100, with further decreases in TC (6.9%), LDLc (10.5%), non-HDLc (10.3%), Apo B-100 (6.2%) and Apo B-100/ApoA-I ratio (11.6%) being observed when PS were administered. No differences in LDL diameter, hsCRP or homocysteine were detected in any of the groups after consuming PS. This supplementation produced a significant increase in PS levels only in the non-MetS population. CONCLUSIONS: PS therapy appears to be of little value to MetS patients, likely due to its reduced intestinal cholesterol absorption. The efficacy of PS as hypocholesterolaemic agents is thus limited.

Effects of phytosterol ester-enriched low-fat milk on serum lipoprotein profile in mildly hypercholesterolaemic patients are not related to dietary cholesterol or saturated fat intake.

Phytosterols (PS) are recommended to reduce LDL-cholesterol. However, the influence of cholesterol and fat intake on the lipid-lowering effect of PS in mildly hypercholesterolaemia is unclear. Thus, the aim of the present study was to evaluate whether the efficacy of PS is related to the composition of saturated fat and dietary cholesterol intake. Additionally, serum carotenoid content was analysed to evaluate to what extent it was undermined by PS. This was a 3-month randomised, parallel trial with a three-arm design. Patients were divided into three groups: healthy diet (n 24), healthy diet+PS (n 31) and free diet+PS (n 29), receiving 2 g/d of PS. Healthy and free diets were characterised by a daily ingestion of 6.8 % of saturated fat and 194.4 mg of cholesterol and 12.7 % of saturated fat and 268.1 mg of cholesterol, respectively. After PS therapy, patients receiving the healthy diet+PS or a free diet+PS exhibited a similar reduction in total cholesterol (6.7 and 5.5 %), LDL-cholesterol (9.6 and 7.0 %), non-HDL-cholesterol (12.2 and 8.9 %) and apo B-100/apo A-I ratio (11.5 and 11.6 %), respectively. In patients following the healthy diet, (ß-carotene concentration rose by 26.9 %, whereas the ß-carotene and lycopene levels dropped by 21.0 and 22.8 % in the group receiving the free diet+PS, respectively. No change was observed in carotenoid levels in healthy diet+PS group. In conclusion, the efficacy of PS in relation to lipoprotein profile is not influenced by saturated fat or dietary cholesterol intake, which confirms the positive effect of healthy diet therapy in improving the negative effects that PS exert on carotenoid levels.

Evaluation of cardiovascular risk and oxidative stress parameters in hypercholesterolemic subjects on a standard healthy diet including low-fat milk enriched with plant sterols.

A healthy diet and plant sterols (PS) are recommended for reducing low-density lipoprotein (LDL) cholesterol and, subsequently, the risk of premature cardiovascular disease. PS mediate a decrease in fat-soluble vitamin concentration, which can lead to a general impairment of antioxidative defenses and an increase in oxidative stress. Thus, we evaluated the effects of a healthy diet, including PS-enriched low-fat milk, on cardiovascular risk and oxidative stress parameters in hypercholesterolemic subjects. This was a randomized parallel trial employing 40 subjects and consisting of two 3-month intervention phases. After 3 months on a standard healthy diet, subjects were divided into two intervention groups: a diet group and a diet+PS group (2 g/day). Lipid profile, apolipoproteins, high-sensitivity C-reactive protein and oxidative stress parameters were analyzed. Diet significantly reduced total and LDL cholesterol (4.0% and 4.7%, respectively), produced an increase in the level of beta-carotene (23%) and improved the antioxidant capacity of LDL cholesterol particles (4.6%). PS induced a significant decrease in total cholesterol (6.4%), LDL (9.9%) and the apolipoprotein B100/apolipoprotein A1 ratio (4.9%), but led to a decrease in cryptoxanthin level (29%) without any change being observed in the antioxidant capacity of LDL cholesterol particles, total antioxidant status or lipid peroxidation. After 3 months, we observed the positive effect of including a PS supplement in dietary measures, as the lipoprotein-mediated risk of cardiovascular disease was reduced. Despite a decrease in the concentration of cryptoxanthin, no evidence of a global impairment of antioxidative defenses or an enhancement of oxidative stress parameters was found.

Physiologic estradiol levels enhance hypothalamic expression of the long form of the leptin receptor in intact rats.

Estradiol is a potent hypophagic agent that reduces food intake and body weight without a concomitant fall in plasma leptin levels. We investigated whether the hypophagic effect of estradiol is mediated by stimulating POMC and/or inhibiting NPY neuronal pathways in the hypothalamus, which respectively inhibit and stimulate feeding. We examined hypothalamic gene expression of Ob-Rb, NPY, POMC, MC4-R, and AgRP in intact Wistar rats treated with estradiol for 48 hours. Food intake and body weight were reduced in estradiol-treated rats but fat mass was unchanged; plasma leptin and insulin levels were not significantly different from untreated, freely fed controls. In untreated rats that were pair-fed to match the estradiol-treated group, body weight was also reduced without changes in fat mass, although leptin and insulin levels decreased significantly. Ob-Rb expression was increased in both hypophagic groups despite serum leptin were only decreased in pair-fed animals, suggesting an estradiol-stimulating effect on Ob-Rb expression. No significant differences were found in POMC, AgRP, or MC4-R expression among any of the experimental groups. A significant but small decrease in NPY expression was also found in both hypophagic groups; this was explained by the combined effect of both surgery and reduced food intake. These results indicate that estradiol mediated hypophagia in intact rats could be brought about by an enhanced hypothalamic leptin sensitivity but is unlikely to be driven by changes in NPY or melanocortin system.

Pregnancy-induced hyperphagia is associated with increased gene expression of hypothalamic agouti-related peptide in rats.

Pregnancy is characterized by an increase in food intake that, in turn, produce a positive energy balance in order to face the considerable metabolic demands associated with the challenge of reproduction. Since hypothalamus is a key brain region involved in many peripheral signals and neuronal pathways that control energy homeostasis and food intake, we investigated if during pregnancy the increase in food intake is mediated by stimulating orexigenic and/or inhibiting anorexigenic neural pathways. We examined hypothalamic gene expressions of Ob-Rb, NPY, AgRP, POMC, MC4-R, and preproorexins in pregnant Wistar rats at day 19 of gestation. Food intake and body weight were increased progressively during the pregnancy. Visceral fat mass depots and serum leptin levels were also increased when compared with virgin animals. No differences were found in mRNA expression of Ob-Rb, POMC, MC4-R, NPY or preproorexin between virgin and pregnant animals. However, pregnancy produced a selective increase in AgRP mRNA levels. These results indicate that the positive energy balance that occurred during pregnancy can hardly be explained by changes in Ob-Rb despite hyperleptinemia associated with pregnancy. The enhanced expression of AgRP suggests the involvement of this neuropeptide in mediating pregnancy-associated hyperphagia.