Effects of Wheat Biscuits Enriched with Plant Proteins Incorporated into an Energy-Restricted Dietary Plan on Postprandial Metabolic Responses of Women with Overweight/Obesity

This study investigates the effect of daily consumption of wheat biscuits enriched with plant proteins in postprandial metabolic responses of women with overweight/obesity who follow an energy-restricted diet. Thirty apparently healthy women participated in a 12-week randomized controlled trial and were assigned either to a control (CB) or an intervention (PB) group. Participants consumed daily either a conventional (CB) or an isocaloric wheat biscuit enriched with plant proteins (PB) containing high amounts of amino acids with appetite-regulating properties, i.e., BCAAs and L-arg. At baseline and the end of the intervention, a mixed meal tolerance test was performed. The responses of glucose, insulin, ghrelin, GLP-1, and glicentin were evaluated over 180 min. After 12 weeks, both groups experienced significant decreases in body weight, fat mass, and waist circumference. In the PB group, a trend towards higher weight loss was observed, accompanied by lower carbohydrate, fat, and energy intakes (p < 0.05 compared to baseline and CB group), while decreases in fasting insulin and the HOMA-IR index were also observed (p < 0.05 compared to baseline). In both groups, similar postprandial glucose, ghrelin, and GLP-1 responses were detected, while iAUC for insulin was lower (p < 0.05). Interestingly, the iAUC of glicentin was greater in the PB group (p < 0.05 compared to baseline). Subjective appetite ratings were beneficially affected in both groups (p < 0.05). Consumption of wheat biscuits enriched in plant proteins contributed to greater weight loss, lower energy intake, and insulin resistance and had a positive impact on postprandial glicentin response, a peptide that can potentially predict long-term weight loss and decreased food intake.

Legumes: A Vehicle for Transition to Sustainability

Legumes are an excellent source of protein and have been used in the human diet for centuries. Consumption of legumes has been linked to several health benefits, including a lower risk of cardiovascular diseases, type 2 diabetes mellitus, and certain types of cancer, while legumes' high fiber content promotes digestive health. Aside from the positive health benefits, one of the most significant advantages of legumes is the low environmental footprint of their cultivation. They can be grown in a variety of climates and soil types, and they require less water and fertilizer than other crops, making them a sustainable option for farmers. Thanks to their nutritional and physicochemical properties, they are widely used by the food industry since the growing popularity of plant-based diets and the increasing demand for alternatives to meat offers the opportunity to develop legume-based meat substitutes. As the use of legumes as a source of protein becomes widespread, new market opportunities could be created for farmers and food industries, while the reduction in healthcare costs could have a potential economic impact. Achieving widespread adoption of legumes as a sustainable source of protein requires coordinated efforts by individuals, governments, and the private sector. The objective of this narrative review is to present the benefits coming from legume consumption in terms of health and environmental sustainability, and underline the importance of promoting their inclusion in the daily dietary pattern as well as their use as functional ingredients and plant-based alternatives to animal products.

Polar Phenol Detection in Plasma and Serum: Insights on Sample Pre-Treatment for LC/MS Analysis and Application on the Serum of Corinthian Currant-Fed Rats

Analysis of plasma and serum provides valuable information on the amounts of polar phenols' circulating after ingestion. In the present study, protein precipitation (PPT), liquid-liquid extraction (LLE), solid phase extraction (SPE), enzymatic hydrolysis and their combinations were meticulously evaluated for the extraction of a variety of polar phenolic moieties from plasma and serum. The recovery values of the above methods were compared; satisfactory recoveries (>60%) were attained for most analytes. Polar phenol aglycones undergo degradation with enzymatic hydrolysis; however, their extended phase II metabolism makes enzymatic hydrolysis a mandated process for their analysis in such biofluids. Hence, enzymatic hydrolysis followed by LLE was used for the identification of polar phenols in rats' serum, after the long-term oral consumption of Corinthian Currant. Corinthian Currant is a Greek dried vine product rich in bioactive polar phenolics. Flavonoids and phenolic acids, detected as aglycones, ranged from 0.57 ± 0.08 to 181.66 ± 48.95 and 3.45 ± 1.20 to 897.81 ± 173.96 ng/mL, respectively. The majority of polar phenolics were present as phase II metabolites, representing their fasting state in the blood stream. This is the first study evaluating the presence of polar phenolics in the serum of rats following a long-term diet supplemented with Corinthian Currant as a whole food.

Postprandial Glucose and Gastrointestinal Hormone Responses of Healthy Subjects to Wheat Biscuits Enriched with L-Arginine or Branched-Chain Amino Acids of Plant Origin

The study investigates the effects of wheat biscuits supplemented with plant flours originating from legumes/seeds enriched either in L-arginine (L-arg) or branched-chain amino acids (BCAAs) on postprandial glucose response of healthy subjects. Gastrointestinal hormone and amino acid responses as well as subjective appetite sensations are also evaluated. Subjects consumed wheat-based biscuits, enriched either in L-arg (ArgB) or BCAAs (BCAAsB) or a conventional wheat biscuit (CB) or a glucose solution (GS) in an acute randomized crossover design. Responses of glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1), peptide YY (PYY) and glicentin, as well as those of L-arginine, L-leucine, L-isoleucine and L-valine, were evaluated over 180 min. Consumption of ArgB and BCAAsB elicited lower glucose iAUC compared to GS (p < 0.05). A lower iAUC for insulin was observed after consumption of BCAAsB (p < 0.05 compared to CB and ArgB), while ArgB elicited higher iAUC for GLP-1 accompanied by higher glicentin response (p < 0.05 compared to CB). BCAAsB and ArgB increased postprandial amino acid concentrations and caused stronger satiety effects compared to CB. Increasing protein content of wheat biscuits with supplementation of plant flours originating from legumes/seeds decreases postprandial glycemia and provides with healthier snack alternatives which can easily be incorporated into diet.

Wheat Biscuits Enriched with Plant-Based Protein Contribute to Weight Loss and Beneficial Metabolic Effects in Subjects with Overweight/Obesity

The present study aimed to assess the impact of daily consumption of a snack fortified with plant proteins with high content in amino acids with appetite regulating properties (BCAAs and L-arginine), as part of a dietary intervention, on weight loss. Seventy adults without diabetes (26 male, 44 female) and with overweight/obesity participated in a 12-week restricted dietary intervention and were randomized to either a control or an intervention group, consuming daily 70 g of conventional wheat biscuits (CB) or an isocaloric amount of wheat biscuits enriched with plant proteins (PB) originating from legumes and seeds, respectively. Anthropometric characteristics were measured and venous blood samples were collected at baseline and at the end of the intervention. Decreases in body weight, body fat mass and waist circumference were observed in both groups. Participants in the intervention group experienced greater weight loss (7.6 ± 2.7 vs. 6.2 ± 2.7%, p = 0.025) and marginally significant larger decrease in body fat mass (4.9 ± 2.2 vs. 3.9 ± 2.4 kg, p = 0.059). A moderate reduction in IL-1β levels (p = 0.081), a significantly higher decrease in TNF-α levels (p < 0.001) and a marginally significant greater leptin decrease (p = 0.066) in subjects of the PB group were noticed. Greater reductions in caloric and carbohydrate intake and a trend towards a higher decrease in fat intake were also observed in participants of this group. Incorporation of plant-based proteins with high content in amino acids with appetite-regulating properties in wheat biscuits may contribute to greater weight loss and improvement of metabolic parameters in subjects who are overweight or obese. Protein enrichment of snacks offers a beneficial qualitative manipulation that could be successfully incorporated in a diet plan.

Effects of 12-week, non-energy-restricted dietary intervention with conventional yogurt οn appetite hormone responses of type 2 diabetic patients

Hunger-reducing effects and beneficial changes in gastrointestinal hormones have been reported, in overweight/obese individuals consuming dairy while yogurt takes pride of place due to its unique structure and composition. Although the contribution of yogurt to metabolic regulation has received growing attention, the research studies which examine its role on appetite are limited, especially regarding type 2 diabetes mellitus (T2DM) patients. The aim of the present study was to investigate the effects of non-fat, conventional yogurt consumption on appetite hormone responses of T2DM patients following a non-energy-restricted diet. Overweight subjects participated in a 12-week dietary intervention including 2 meals/day (2 × 200 g) of yogurt. At the beginning and the end of the intervention, a mixed meal tolerance test assessing the postprandial response of glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1), and peptide-YY (PYY) was performed. Subjective appetite ratings were also evaluated. Area under the curve for glucose, insulin, ghrelin, GLP-1, and PYY responses did not differ after the 12-week intervention with yogurt (p > .05) as well as for subjective appetite ratings (p > .05). No significant differences were indicated at specific time points in any of the examined parameters. Regular consumption of non-fat, conventional yogurt for 12-week duration does not affect appetite hormone responses in overweight patients with T2DM following a non-energy-restricted diet.

Physical properties, sensory acceptance, postprandial glycemic response, and satiety of cereal based foods enriched with legume flours: a review

Legumes are rich in proteins and widely consumed around the world. Their consumption has been associated with improved glycemic and lipidemic profile and positive alterations of gut microbiota. These beneficial effects have created a growing scientific interest in the role of legume-enriched foods on the promotion of human health. The aim of this review was to critically record the studies examining the nutritional value and textural properties of these products, as well as their efficacy on lowering postprandial glucose response and satiety. Reviewed data have shown that cereal products with high nutritional value are formulated when fortified with legume flours. The postprandial glucose response appears to be ameliorated and the enriched foods have a medium or a low glycemic index, however not enough data are presented referring to the appetite hormones responses. Textural properties are affected by the addition of legumes and occasionally, when substitution level is high, the final product has not acceptable odor and appearance. To overcome this barrier, particular food processes such as fermentation, extrusion and addition of hydrocolloids, are used and have shown great results on the textural and sensory properties of the final products. The development of healthy legume-enriched cereal-based products is of great importance for the increase of legume consumption and the promotion of public health.

The role of yoghurt consumption in the management of type II diabetes

Enrichment of yoghurt with specific ingrdients beneficially affects the management of Type II Diabetes Mellitus (DMII). As far as the role of yoghurt in the management of DMII is concerned, the limited number of randomized clinical trials (RCTs) which have been conducted suggest that daily intake of yoghurt enriched with vitamin D and/or calcium as well as probiotics positively influences glycemic regulation and may contribute to more effective control of the disease. It is argued that the various ingredients which are already contained in the complex matrix of food, such as bioactive peptides, calcium, B-complex vitamins and beneficial microbes, as well as the fact that it can be used as a vehicle for the inclusion of other effective ingredients can have an impact on the metabolic control of diabetic patients. The aim of this review is to present the RCTs which have been conducted in the last decade in patients with DMII in an attempt to highlight the positive effects of yoghurt in the management of the disease.

Functional modulation of gut microbiota in diabetic rats following dietary intervention with pistachio nuts (Pistacia vera L.)

BACKGROUND

Gut microbiota holds a key-role in numerous biological functions and has emerged as a driving force for the development of diabetes. Diet contributes to gut microbiota diversity and functionality providing a tool for the prevention and management of the disease. The study aimed to investigate the effect of a dietary intervention with pistachio nuts, a rich source of monounsaturated fatty acids, dietary fibers and phytochemicals on gut microbiota composition in the rat model of Type 1 Diabetes.

METHODS

Male Wistar rats were randomly assigned into four groups: healthy animals which received control diet (CD) or pistachio diet (PD), and diabetic animals which received control diet (DCD) or pistachio diet (DPD) for 4 weeks. Plasma biochemical parameters were determined and histological examination of liver and pancreas was performed at the end of the dietary intervention. Adherent intestinal microbiota populations in jejunum, ileum, caecum and colon were analyzed. Fecal microbiota populations at the beginning and the end of the study were determined by microbiological analysis and 16S rRNA sequencing.

RESULTS

Diabetic animals of both groups exhibited high plasma glucose and low insulin concentrations, as well as characteristic pancreatic lesions. Pistachio supplementation significantly increased lactobacilli and bifidobacteria populations in jejunum, ileum and caecum (p < 0.05) and normalized microbial flora in all examined intestinal regions of diabetic animals. After 4 weeks of supplementation, populations of bifidobacteria and lactobacilli were increased in feces of both healthy and diabetic animals, while enterococci levels were decreased (p < 0.05). Next Generation Sequencing of fecal samples revealed increased and decreased counts of Firmicutes and Bacteroidetes, respectively, in healthy animals that received the pistachio diet. Actinobacteria OTUs were higher in diabetic animals and increased over time in the pistachio treated groups, along with increased abundance of Bifidobacterium. Lactobacillus, Turicibacter and Romboutsia populations were elevated in healthy animals administered the pistachio nuts. Of note, relative abundance of Bacteroides was higher in healthy than in diabetic rats (p < 0.05).

CONCLUSION

Dietary pistachio restored normal flora and enhanced the presence of beneficial microbes in the rat model of streptozotocin-induced diabetes.

Enrichment of bread with beta-glucans or resistant starch induces similar glucose, insulin and appetite hormone responses in healthy adults

PURPOSE

β-Glucans (βG) and resistant starch (RS) are known for their effects on the improvement of glucose tolerance and enhancement of insulin sensitivity. Enrichment of bread with βG or RS was performed to examine potential postprandial benefits regarding gastrointestinal hormone responses.

METHODS

Ten healthy normoglycaemic adults participated in the study and were provided with either a glucose solution (reference food, GS) or bread enriched with β-glucans (βGB) (3.6 g/30 g available CHO) or bread enriched with resistant starch (RSB) (15% of total starch), with 1-week intervals in amounts that yielded 50 g of available carbohydrates. Venous blood samples were collected before consumption and at 15, 30, 45, 60, 90, 120 and 180 min postprandially. Glucose, insulin, ghrelin, glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) responses as well as glycaemic index (GI) and subjective appetite ratings were evaluated.

RESULTS

Ingestion of βGB and RSB elicited lower incremental area under the curve (iAUC) for glycaemic response compared to GS (P < 0.05). Both breads demonstrated a low GI (βGB: 48, RSB: 40). There were no significant differences in insulin response, ghrelin, GLP-1 or PYY between the two breads. A significantly lower desire to eat and higher fullness were detected 15 min after βGB and RSB consumption and until 180 min (P < 0.05 compared to GS).

CONCLUSION

Enrichment of bread with either βG or RS produced a low GI product but the two breads were not significantly different in relation to insulin, ghrelin, GLP-1 and PYY responses. The development of bread products which cause improved metabolic effects is of great importance for the promotion of public health.

Daily consumption of fruit-flavored yoghurt enriched with vitamins B contributes to lower energy intake and body weight reduction, in type 2 diabetic patients: a randomized clinical trial

Fruit-yoghurt enriched with vitamins B promotes body weight reduction and improves vitamin B status and homocysteine levels in T2DM patients.

Controlling type-2 diabetes by inclusion of Cr-enriched yeast bread in the daily dietary pattern: a randomized clinical trial

PURPOSE

Chromium (Cr)-enriched yeast supplementation to whole wheat bread (WWCrB) has been shown to ameliorate postprandial glycemic response in healthy subjects. The present study investigates the long-term benefit of WWCrB consumption for patients with type-2 diabetes mellitus (T2DM).

METHODS

Thirty patients with T2DM were randomly assigned to a group receiving WWCrB or the plain whole wheat bread (WWB) group. Plasma glucose, insulin, glycosylated hemoglobin (HbA_1c) and insulin resistance were determined, and oral glucose tolerance test (OGTT) was performed at the beginning and the end of the dietary intervention, which lasted for 12 weeks. Biochemical parameters related to the disease, markers of inflammation as well as body weight and energy balance were examined.

RESULTS

At the end of the study, subjects of WWCrB group exerted lower levels of glucose, insulin and HbA_1c and improved insulin resistance (P < 0.05 against before treatment). Area under the glucose curve attained during OGTT decreased after the intervention (28,117.5 ± 1266.4 vs. 31,588.5 ± 1187.5 mg min/dL before treatment, P < 0.05) with significantly lower values of glucose concentration at 0 and 60 min. A significant reduction in body weight and systolic blood pressure (SBP) was observed (P < 0.05 against before treatment). Markers of inflammation and lipid profiles were not affected by WWCrB consumption.

CONCLUSIONS

Inclusion of WWCrB in the daily dietary pattern of diabetic patients resulted in improvement of glucose tolerance and insulin resistance, significant reduction in HbA_1c, weight loss and lower SBP. Patients with inadequate glycemic control may benefit from the consumption of WWCrB.

The laboratory rabbit: an animal model of atherosclerosis research

The aim of the present mini review is to describe the laboratory rabbit, an animal that has been widely used for the study of atherosclerosis, the leading cause of mortality in Western society. Due to the fact that the rabbit exhibits hypercholesterolaemia within a few days of an administration of a high cholesterol diet, it is very sensitive to the inducement of atheromatic lesions. The administration of different types of diets can cause different types of lesions. Although these lesions do not develop as tissue plaques, a great number of researchers use this animal model to test the effectiveness of drugs because of their similarity to human fatty streaks. The generation over recent years of transgenic rabbits with alterations in specific genes is expected to help with the elucidation of the mechanisms underlying the initial and developmental stages of the disease. The laboratory rabbit is significantly broadening our understanding on the pathogenesis of atherosclerosis.

Effects of dietary Corinthian currants (Vitis vinifera L., var. Apyrena) on atherosclerosis and plasma phenolic compounds during prolonged hypercholesterolemia in New Zealand White rabbits

Corinthian currants are a rich source of phenolic compounds, which are known to exert beneficial effects on cardiovascular disease. The hypothesis tested is whether dietary supplementation with currants attenuates atherosclerosis and affects plasma phenolics during prolonged hypercholesterolemia in rabbits. Thirty New Zealand White rabbits were fed one of four diets (normal and supplemented with 10% currants, with 0.5% cholesterol, and with 0.5% cholesterol plus 10% currants) for eight weeks. Plasma lipids, glucose and hepatic enzymes were determined. Individual phenolic compounds were identified and quantified in plasma during the dietary intervention. At the end of the study, histological examinations of aorta and liver were performed. The high-cholesterol diet resulted in hypercholesterolemia and oxidative stress, increased aspartate aminotransferase (AST) activity and induced aortic and hepatic lesion formation. Corinthian currant supplementation attenuated atherosclerotic lesions, maintained AST within the normal range and reduced oxidative stress without affecting glucose concentrations. The p-OH-benzoic and p-OH-phenylacetic acids predominated at high concentrations in plasma and remained almost constant during the study in the group that received the normal rabbit chow and the groups given food with added cholesterol either alone or supplemented with currants. Currant supplementation to the normal diet resulted in the reduced absorption of phenolic compounds, as revealed by the measurement of their plasma metabolites, suggesting a regulatory mechanism at the gut level under normal conditions.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Ultrasound and Biochemical Diagnostic Tools for the Characterization of Vulnerable Carotid Atherosclerotic Plaque

Stroke is a leading cause of morbidity and mortality worldwide, and characterization of vulnerable carotid plaque remains the spearhead of scientific research. Plaque destabilization, the key factor that induces the series of events leading to the clinical symptoms of carotid artery disease, is a consequence of complex mechanical, structural and biochemical processes. Novel imaging and molecular markers have been studied as predictors of disease outcome with promising results. The aim of this review is to present the current state of research on the association between ultrasound-derived echogenicity indices and blood parameters indicative of carotid plaque stability and activity. Bibliographic research revealed that there are limited available data. Among the biomarkers studied, those related to oxidative stress, lipoproteins and diabetes/insulin resistance are associated with echolucent plaques, whereas adipokines are associated with echogenic plaques. Biomarkers of inflammation and coagulation have not exhibited any conclusive relationship with plaque echogenicity, and it is not possible to come to any conclusion regarding calcification-, apoptosis- and neo-angiogenesis-related parameters because of the extremely limited bibliographic data.

Non-cereal ingredients for the attenuation of glycaemic response to bread: a review of the clinical evidence

Enrichment of bread with non-cereal ingredients could favourably influence postprandial glucose response to bread.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Evaluation of a high nutritional quality snack based on oat flakes and inulin: effects on postprandial glucose, insulin and ghrelin responses of healthy subjects

A low GI snack with satiety promoting effects.

Clusterin/Apolipoprotein J immunolocalization on carotid artery is affected by TNF-alpha, cigarette smoking and anti-platelet treatment

Background

Clusterin (CLU) /Apolipoprotein J is a protein biosensor of oxidative stress and inflammation, which is upregulated in many pathological processes including atherosclerosis. Previous studies have shown that in aortic tissue, CLU expression increases with atherosclerotic lesion progression and it has been coupled with vascular damage and coronary artery disease. A few studies enter into CLU and carotid atherosclerosis while the apolipoprotein’s expression on human carotid tissue and its association with parameters related to the disease development has not been examined. The present study was designed to reveal the relationships between the degree of CLU immunolocalization on carotid artery and demographic characteristics, blood parameters and pharmacological treatment of patients underwent internal carotid artery endarterectomy.

Methods

CLU expression was detected by immunohistochemistry in 42 carotid endarterectomy specimens. Patients’ serum levels of tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), high sensitive C-reactive protein (hsCRP) and classical parameters related to atherosclerosis such as lipid profile, as well as thrombosis related parameters such as fibrinogen, antithrombin III, protein C and protein S were determined. Demographic characteristics, smoking habits and the use of medications were recorded. Comparisons between groups were performed by students’t-test and analysis of variance. Independent associations with CLU expression on carotid tissue were denoted by linear regression analysis.

Results

CLU imuunolocalization was denser in smokers than in non-smokers (p = 0.041) while it was rarefied in specimens of patients on cropidogrel treatment (p = 0.045) compared to the rest not taking this medication. Clopidogrel intake was independent predictor of lower CLU expression on carotid artery (p =0.045). CLU was positively correlated with serum TNF-a concentration (r = 0.33, p = 0.040) that was independent predictor of higher expression of the apolipoprotein (p = 0.001). IL-6, hsCRP and classical parameters related to atherosclerosis and thrombosis were not associated with CLU immunolocalization.

Conclusion

Our study suggests that CLU expression on carotid artery is affected by TNF-alpha, cigarette smoking confirming its association with oxidative and cellular stress and anti-platelet medication reflecting the protective effects of such pharmacological treatment on vascular wall.

Bioactive microconstituents and antioxidant properties of wild edible mushrooms from the island of Lesvos, Greece

Crude composition, fatty acids, sterols, total phenolic content (TPC), individual polyphenols and terpenic acids were determined in five wild edible mushrooms species (Lactarius deliciosus, Lactarius sanguifluus, Lactarius semisanguifluus, Russula delica, Suillus bellinii) from Lesvos Island, Greece. In addition, the DPPH scavenging capacity, the ferric ion reducing power (FRAP) and the ferrous ion chelating activity of mushroom methanolic extracts were assessed. Among sterols, ergosterol predominated at concentrations 9.2-18.0mg/100g fw. Total phenolic content of mushroom extracts ranged from 6.0 to 20.8mg GAE/100g fw. Up to 19 simple polyphenols were determined in mushrooms extracts, the more abundant being p-OH-benzoic acid, p-OH-phenylacetic acid, o-coumaric acid, ferulic acid and chrysin. In addition, the triterpenic acids oleanolic and ursolic were detected for the first time in mushrooms. All species exerted antioxidant activity and ferrous ion chelating capacity. Principal component analysis revealed good correlations between TPC, DPPH and FRAP but not with metal chelating activity. It seems that mushrooms polyphenols exert antiradical and reducing activities, but they are not strong metal chelators, the observed chelating ability being probably due to other classes of compounds. To our knowledge, this is the first report on the bioactive microconstituents and antioxidant activity of wild Greek edible mushrooms.

Effects of oral administration of (L)-arginine, (L)-NAME and allopurinol on intestinal ischemia/reperfusion injury in rats

AIMS

Intestinal ischemia/reperfusion (I/R) injury is implicated in many clinical conditions, and it performs a fundamental role in their pathophysiologies. Oral administration of antioxidants and nitric oxide (NO) donors ameliorate intestinal injury. Here, the effects of l-arginine, allopurinol and N(G)-nitro-l-arginine methyl ester (l-NAME) were investigated.

MAIN METHODS

One hundred twenty-eight male Wistar rats were separated into 4 groups and subjected to occlusion of the superior mesenteric artery for 60 min. The Control group did not receive any substance before the surgical operation. However, the 3 other groups received the following: l-arginine (800 mg/kg body weight; l-Arg group), l-NAME (50mg/kg; l-NAME group) or allopurinol (100mg/kg; Allo group). Each substance was given by mouth in 3 equal doses 24, 12 and 1h before the surgical operation. Each group was then divided into 4 subgroups, which underwent different durations of reperfusion (0, 1, 8 or 24h). At the end of each time point, blood and tissue samples were collected, and histological examinations were performed. Serum nitrite and catalase, intestinal tissue myeloperoxidase (MPO), inducible nitric oxide synthase (iNOS) and nitrotyrosine (NT) levels were determined.

KEY FINDINGS

At each reperfusion time point, the Allo group exhibited the mildest histological lesions in contrast to the l-NAME group, which showed the most severe lesions. MPO was decreased significantly in the Allo and l-Arg groups during reperfusion, and allopurinol administration caused earlier and stronger effect. iNOS and NT levels were higher in the l-Arg group and lower in the Allo group. Serum nitrite and catalase were increased in the l-NAME group after 24h.

SIGNIFICANCE

Oral administration of allopurinol exerted a strong and protective effect on the intestinal tissue that was subjected to I/R earlier than l-arginine. This finding was also supported with the MPO, iNOS and NT data.

Acute exercise-induced changes in basal VLDL-triglyceride kinetics leading to hypotriglyceridemia manifest more readily after resistance than endurance exercise

Resistance training is considered less effective than endurance training in lowering plasma triglyceride (TG) concentrations. Acutely, however, a single bout of strenuous exercise, whether endurance or resistance, increases the efficiency of very low-density lipoprotein (VLDL)-TG removal from the circulation and leads to hypotriglyceridemia. The comparative effects of these two types of exercise on VLDL-TG metabolism are not known. We therefore examined basal VLDL-TG kinetics by using stable isotope-labeled tracers in seven healthy, nonobese, untrained young men in the postabsorptive state, the morning after a single 90-min bout of either low-intensity endurance exercise (approximately 30% of peak oxygen consumption) or high-intensity resistance exercise (3 sets of 10 repetitions for 12 exercises at 80% of peak torque production), matched for total energy expenditure (approximately 400 kcal), or an equivalent period of rest on the preceding afternoon. Compared with rest, resistance exercise lowered fasting plasma VLDL-TG concentration by -28 +/- 10% (P = 0.034), increased VLDL-TG plasma clearance rate by 30 +/- 8% (P = 0.003), and shortened the mean residence time (MRT) of VLDL-TG in the circulation by -36 +/- 11 min (P = 0.016), whereas endurance exercise had no effect (all P > 0.05). Basal VLDL-TG plasma clearance rate was greater (P = 0.003) and VLDL-TG MRT was shorter (P = 0.012) the morning after resistance than endurance exercise. We conclude that, for the same total energy expenditure, resistance exercise is more potent than endurance exercise in eliciting changes in VLDL-TG metabolism that have been linked with hypotriglyceridemia, and it should thus be considered as an alternative to or in addition to endurance exercise for the control of plasma TG concentrations.

Time-dependent alterations in serum NO concentration after oral administration of L-arginine, L-NAME, and allopurinol in intestinal ischemia/reperfusion

Objective

To study the effect of oral administration of a nitric oxide (NO) donor l-arginine (l-Arg), a NO synthase inhibitor N^G-nitro-l-arginine methyl ester (l-NAME) and an inhibitor of xanthine oxidase, allopurinol (Allo), on serum NO concentration and catalase activity after intestinal ischemia/reperfusion (I/R) in rats.

Methods

Male Wistar rats received per osl-Arg (800 mg/kg) or l-NAME (50 mg/kg) or Allo (100 mg/kg) 24 hrs, 12 hrs and 1 hr before underwent 1 hr occlusion of superior mesenteric artery followed by 1 hr of reperfusion (l-Arg(IR1), l-NAME(IR1) and Allo(IR1) respectively) or 1 hr occlusion followed by 8 hrs of reperfusion (l-Arg(IR8), l-NAME(IR8) and Allo(IR8) respectively). There was one group underwent 1 hr occlusion (I), a group underwent 1 hr occlusion followed by 1 hr reperfusion (IR1), a group subjected to 1 hr occlusion followed by 8 hrs of reperfusion (IR8) and a last group that served as control (C). Serum NO concentration and catalase activity were measured.

Results

After 1 hr of reperfusion serum NO concentration was elevated in IR1 and l-Arg(IR1) groups compared with group C but not in l-NAME(IR1) and Allo(IR1) group. Catalase activity was enhanced in l-NAME(IR1) group. Interestingly, serum NO concentration was increased after 8 hrs of reperfusion in all groups (IR8, l-Arg(IR8), l-NAME(IR8) and Allo(IR8)) compared with control while catalase activity did not show significant difference in any group.

Conclusions

The results of the present study show that NO concentration is elevated in serum after intestinal I/R and the elevation sustained after administration of l-Arg but not after administration of l-NAME or Allo after 1 hr reperfusion. However, after 8 hrs of reperfusion NO concentration was increased in all groups studied, focusing attention on its possible important role in a complicated situation such as intestinal I/R that involves intestine and other organs. Serum catalase activity does not seem to be affected by per os supplementation of l-Arg or Allo in intestinal I/R.

A single bout of brisk walking increases basal very low-density lipoprotein triacylglycerol clearance in young men

Very low-density lipoprotein triacylglycerol (VLDL-TG) turnover rate was evaluated in the morning, 12 hours after a single bout of brisk walking (90 minutes at approximately 60% of VO2max; EXE), compared to a resting control period (CON) in 10 recreationally active men. VLDL-TG fractional catabolic rate was calculated from the decay in isotopic enrichment after a bolus injection of [2H5]glycerol. Plasma VLDL-TG concentration was 24% lower in the morning after the EXE trial compared to control (0.47+/-0.04 and 0.36+/-0.04 mmol L(-1), for CON and EXE, respectively; P<.01). Serum insulin (7.4+/-0.7 and 5.6+/-0.4 mIU L(-1), CON and EXE, respectively; P<.05) and plasma glucose (5.6+/-0.1 and 5.4+/-0.1 mmol/L, CON and EXE, respectively; P<.05) concentrations were also significantly lower in the EXE trial. Insulin sensitivity (homeostasis model assessment [HOMA] index) was improved by 27% in EXE compared with the CON trial (P<.05).VLDL-apolipoprotein B-100 and plasma fatty acid concentrations were similar in the two trials. Hepatic VLDL-TG secretion rates were not significantly affected by exercise (13.1+/-1.2 and 13.2+/-1.6 micromol.min(-1) for the CON and EXE trials, respectively), whereas VLDL-TG clearance rate increased by 36% (28.1+/-1.3 and 38.1+/-3.5 mL.min(-1) for the CON and EXE trials, respectively; P<.05). It is concluded that the decrease in fasting plasma VLDL-TG concentration observed 12 hours after brisk walking is related mainly to increased VLDL-TG clearance from plasma.

Effect of green tea on angiogenesis and severity of atherosclerosis in cholesterol-fed rabbit

BACKGROUND AND AIMS

Since the development of the atherosclerotic plaque requires the growth of new microvessels in the plaque itself (vasa vasorum), we postulated that green tea may exert an anti-atherogenic effect.

METHODS AND RESULTS

Thirteen male New Zealand white rabbits were studied for 17 weeks. All rabbits were fed an hypecholesterolemic diet. After 2 weeks of adaptation rabbits were randomly assigned into two groups. Animals in Group A were fed the hypercholesterolemic diet and received plain tap water ad libitum. Animals in Group B were fed with the same diet and furthermore received 2.5% (g/g) green tea for 17 weeks.

CONCLUSION

According to our results the atherosclerotic lesions were more severe in Group B than in Group A specimens. Also, the number of VEGF positively stained foam cells and smooth muscle cells of Group B were significantly greater than in Group A. About 30% less plaque was found in Group A than in the control group (Group B). So, our study showed that the consumption of green tea leads to a reduction of atherosclerosis as well as a significant decrease of VEGF expression in the atherosclerotic plaque of rabbit aorta. The hypothesis that probably green tea may produce its anti-atherogenetic effect through an anti-angiogenetic mechanism needs more investigation.

Effect of antiatherogenic L-aspartate and L-glutamate on serum lipoproteins cholesterol and apolipoproteins A-1 and B in rabbits fed with high cholesterol diet

BACKGROUND AND AIM

It has been shown that aspartate and glutamate inhibit mononuclear cell adhesion to the endothelium and formation of foam cells in the intima of thoracic aorta in cholesterol-fed rabbits. The purpose of the present study was to investigate whether a high cholesterol diet supplemented with aspartate and glutamate may alter lipoproteins cholesterol and apolipoproteins A-1 and B levels in rabbits.

METHODS AND RESULTS

Serum total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), apolipoprotein A-1 (apoA-1), apolipoprotein B (apoB), atherogenic index (AI) and apoA-1/apoB ratio were determined in 17 male New Zealand white rabbits fed a cholesterol plus corn oil diet (control group) or the same diet supplemented with aspartate and glutamate (Asp+Glu group) for 4 weeks. Both diets were found to increase TC, LDL-C, apoB and AI, while apoA-1/apoB ratio was decreased compared to baseline values. TG did not seem to be affected in the 4 weeks time in both groups. There was a significant increase of HDL-C in Asp+Glu group and a marked decrease of apoA-1 in control group during the study.

CONCLUSIONS

Oral administration of aspartate and glutamate has been shown to inhibit fatty streak initiation in cholesterol-fed rabbits. The two amino acids did not have any effect on serum TC, LDL-C, TG and apoB concentrations. However, they increased HDL-C and maintained apoA-1 levels. Their antiatherogenic effect probably may be explained by different mechanisms than these related to the atherogenic lipids lowering, and it is possible to involve HDL-C and apoA-1.

Dietary L-aspartate and L-glutamate inhibit fatty streak initiation in cholesterol-fed rabbit

BACKGROUND AND AIM

Low-density lipoprotein (LDL) oxidation is a potential atherogenic agent, and protecting LDL from oxidation prevents atherogenesis. It has been shown that L-aspartate and L-glutamate decrease lipid peroxidation after reoxygenation by means of the initiation of the cardiopulmonary bypass circuit (CPB), when supplemented to the CPB prime, and so they may protect against atherogenesis. The aim of this study was to evaluate the effect of the dietary administration of L-aspartate and L-glutamate on fatty streak onset in cholesterol-fed rabbit.

METHODS AND RESULTS

Male New Zealand white rabbits were fed for four weeks with either a high-cholesterol plus corn oil diet (control group) or the same diet supplemented with 12.5 mM L-aspartate and 12.5 mM L-glutamate in drinking water (Asp + Glu group). The mononuclear cells adhering to the endothelium and the intimal foam cells of the thoracic aorta were used to quantify the extent of atherosclerosis. Total serum cholesterol and lipid peroxidation activity, measured as thiobarbituric acid reactive substances (TBARS), were determined 0, 1 and 4 weeks after a 2-week adaptation period. There were no between-group differences in body weight or food intake during the intervention. Serum TBARS were significantly increased in both groups during the experimental period but without any statistical difference between groups. At the end of the dietary intervention, there was a ten-fold increase in total serum cholesterol concentration in both groups vs baseline. The numbers of adherent mononuclear cells and intimal foam cells were both significantly lower in the Asp + Glu group.

CONCLUSIONS

Our results suggest that dietary supplementation with L-aspartate and L-glutamate seems to protect the arterial wall from atherogenesis in an experimental animal.