Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 21
Filter
1.
Nutrients ; 16(3)2024 Jan 31.
Article in English | MEDLINE | ID: mdl-38337697

ABSTRACT

The main purpose of this study was to investigate the effect of a novel alginate-encapsulated carbohydrate-protein (CHO-PRO ratio 2:1) supplement (ALG) on cycling performance. The ALG, designed to control the release of nutrients, was compared to an isocaloric carbohydrate-only control (CON). Alginate encapsulation of CHOs has the potential to reduce the risk of carious lesions. METHODS: In a randomised cross-over clinical trial, 14 men completed a preliminary test over 2 experimental days separated by ~6 days. An experimental day consisted of an exercise bout (EX1) of cycling until exhaustion at W~73%, followed by 5 h of recovery and a subsequent time-to-exhaustion (TTE) performance test at W~65%. Subjects ingested either ALG (0.8 g CHO/kg/hr + 0.4 g PRO/kg/hr) or CON (1.2 g CHO/kg/hr) during the first 2 h of recovery. RESULTS: Participants cycled on average 75.2 ± 5.9 min during EX1. Levels of plasma branched-chain amino acids decreased significantly after EX1, and increased significantly with the intake of ALG during the recovery period. During recovery, a significantly higher plasma insulin and glucose response was observed after intake of CON compared to ALG. Intake of ALG increased plasma glucagon, free fatty acids, and glycerol significantly. No differences were found in the TTE between the supplements (p = 0.13) nor in the pH of the subjects' saliva. CONCLUSIONS: During the ALG supplement, plasma amino acids remained elevated during the recovery. Despite the 1/3 less CHO intake with ALG compared to CON, the TTE performance was similar after intake of either supplement.


Subject(s)
Alginates , Athletic Performance , Male , Humans , Alginates/pharmacology , Athletic Performance/physiology , Physical Endurance , Dietary Carbohydrates/pharmacology , Athletes , Dietary Supplements
2.
Nutrients ; 13(12)2021 Dec 03.
Article in English | MEDLINE | ID: mdl-34959910

ABSTRACT

The study was conducted to comprehensively assess the association of the concentration of vitamin D in the blood and insulin resistance in non-diabetic subjects. The objective was to pool the results from all observational studies from the beginning of 1980 to August 2021. PubMed, Medline and Embase were systematically searched for the observational studies. Filters were used for more focused results. A total of 2248 articles were found after raw search which were narrowed down to 32 articles by the systematic selection of related articles. Homeostatic Model Assessment of Insulin Resistance (HOMAIR) was used as the measure of insulin resistance and correlation coefficient was used as a measure of the relationship between vitamin D levels and the insulin resistance. Risk of bias tables and summary plots were built using Revman software version 5.3 while Comprehensive meta-analysis version 3 was used for the construction of forest plot. The results showed an inverse association between the status of vitamin D and insulin resistance (r = -0.217; 95% CI = -0.161 to -0.272; p = 0.000). A supplement of vitamin D can help reduce the risk of insulin resistance; however further studies, like randomized controlled trials are needed to confirm the results.


Subject(s)
Insulin Resistance , Vitamin D Deficiency/metabolism , Vitamin D/blood , Adolescent , Adult , Aged , Aged, 80 and over , Dietary Supplements , Female , Homeostasis , Humans , Male , Middle Aged , Models, Biological , Observational Studies as Topic , Risk , Vitamin D/administration & dosage , Vitamin D Deficiency/blood , Vitamin D Deficiency/drug therapy , Young Adult
3.
Mol Nutr Food Res ; 64(18): e2000473, 2020 09.
Article in English | MEDLINE | ID: mdl-32761736

ABSTRACT

A growing number of people worldwide are changing their lifestyle leading to an increasing number of overweight and obese individuals with metabolic syndrome (MetS). With obesity and MetS come an elevated inflammatory state resulting in increased risk of Type 2 diabetes, cardiovascular disease, among other lifestyle diseases. Fruits and vegetables (FV) contain phytochemicals with health beneficial effects including anti-oxidative and anti-inflammatory properties. This systematic review and meta-analysis aims to investigate the effects of diets high in FV, and plant-based products on C-reactive protein (CRP). A systematic search in PUBMED and EMBASE gave rise to 883 articles, 16 of which are included in the meta-analysis. The effects of plant-based products and diets are investigated in subgroups including overweight, obese, and diabetes; as wells as the effect of plant-oils and anthocyanin on CRP. The analysis shows an overall significant reduction in CRP for all articles (p = 0.0006). A significant decrease in diabetic (p = 0.01), overweight (p = 0.005), and obese patients (p = 0.05) is observed, including significant effects of anthocyanins (p = 0.001) and plant-oils (p < 0.00001) on CRP. These findings strongly support the recommendation for diets high in FV and plant-oils to help attenuate elevated CRP.


Subject(s)
C-Reactive Protein , Fruit , Inflammation/diet therapy , Vegetables , Anthocyanins/pharmacology , Biological Products/pharmacology , C-Reactive Protein/analysis , Diabetes Mellitus/blood , Diabetes Mellitus/diet therapy , Diet , Fatty Acids/pharmacology , Humans , Inflammation/prevention & control , Insulin Resistance , Obesity/complications , Obesity/diet therapy , Overweight/diet therapy , Plant Oils
4.
Ugeskr Laeger ; 182(21)2020 05 18.
Article in Danish | MEDLINE | ID: mdl-32515321

ABSTRACT

In this review, we discuss isoflavones, which are bioactive selective estrogen receptor modulators shown to have therapeutic efficacy in reducing bone resorption and improving menopause symptoms in women with estrogen deficiency. The European Food Safety Authority reached consensus that there "is no evidence of harm" of isoflavone supplements for peri- and post-menopausal women. Bioavailable isoflavone aglycones being rich in fermented sources are shown to have enhanced effects compared to glycosides, and isoflavones represent an effective and safe new treatment for oestrogen deficient bone loss and climacteric symptoms.


Subject(s)
Bone Diseases, Metabolic , Isoflavones , Dietary Supplements , Estrogens/therapeutic use , Female , Humans
5.
Nutrients ; 12(5)2020 May 20.
Article in English | MEDLINE | ID: mdl-32443678

ABSTRACT

Endurance athletes participating in sporting events may be required to complete multiple training sessions a day or on successive days with a limited recovery time. Nutritional interventions that enhance the restoration of endogenous fuel stores (e.g., liver and muscle glycogen) and improve muscle damage repair have received a lot of attention. The purpose of this review is to investigate the effect of ingesting carbohydrate (CHO) and protein (PRO) on athletic performance. Studies were identified by searching the electronic databases PubMed and EMBASE. Random-effects meta-analyses were conducted to examine the intervention efficacy. A total of 30 randomized controlled trials (RCT), comprising 43 trials and 326 participants in total, were included in this review. The meta-analysis showed an overall significant effect in Time-To-Exhaustion (TTE) and Time-Trial (TT) performance, when ingesting carbohydrates and proteins (CHO-PRO) compared to CHO-only (p = 0.03 and p = 0.0007, respectively). A subgroup analysis demonstrated a significant effect in TTE by ingesting CHO-PRO compared to CHO, when supplements were provided during and/or following an exercise bout. CHO-PRO significantly improved TTE compared to CHO-only, when a long-term recovery (i.e., ≥8 h) was implemented (p = 0.001). However, no effect was found when the recovery time was short-term (i.e., ≤8 h). No significant effect was observed when CHO-PRO and CHO-only supplements were isocaloric. However, a significant improved TTE was evident with CHO-PRO compared to CHO-only, when the supplements were matched for carbohydrate content (p < 0.00001). In conclusion, co-ingesting carbohydrates and proteins appears to enhance TTE and TT performance compared to CHO-only and presents a compelling alternate feeding strategy for athletes.


Subject(s)
Athletes , Athletic Performance/physiology , Dietary Carbohydrates/metabolism , Dietary Proteins/metabolism , Sports Nutritional Physiological Phenomena/physiology , Databases, Factual , Dietary Supplements , Eating , Glycogen/metabolism , Humans , Randomized Controlled Trials as Topic , Time Factors
6.
Endocrinol Diabetes Metab ; 2(4): e00093, 2019 Oct.
Article in English | MEDLINE | ID: mdl-31592450

ABSTRACT

AIMS: Steviol glycosides are the sweet components extracted from medicinal plant Stevia rebaudiana Bertoni, which have antihyperglycaemic effects. Steviol glucuronide (SVG) is the metabolite excreted in human urine after oral administration of steviol glycosides. We aimed to clarify whether SVG exerts direct insulin stimulation from pancreatic islets and to explore its mode of action. MATERIALS AND METHODS: Insulin secretion was measured after 60 minutes static incubation of isolated mouse islets with (a) 10-9-10-5 mol/L SVG at 16.7 mmol/L glucose and (b) 10-7 mol/L SVG at 3.3-16.7 mmol/L glucose. Islets were perifused with 3.3 or 16.7 mmol/L glucose in the presence or absence of 10-7 mol/L SVG. Gene transcription was measured after 72 hours incubation in the presence or absence of 10-7 mol/L SVG. RESULTS: SVG dose-dependently increased insulin secretion from mouse islets with 10-7 mol/L exerting the maximum effect in the presence of 16.7 mmol/L glucose (P < .001). The insulinotropic effect of SVG was critically dependent on the prevailing glucose concentration, and SVG (10-7 mol/L) enhanced insulin secretion at or above 11.1 mmol/L glucose (P < .001) and showed no effect at lower glucose concentrations. During perifusion of islets, SVG (10-7 mol/L) had a long-acting and apparently reversible insulinotropic effect in the presence of 16.7 mmol/L glucose (P < .05). Gene-transcript levels of B2m and Gcgr were markedly altered. CONCLUSION: This is the first report to demonstrate that SVG stimulates insulin secretion in a dose- and glucose-dependent manner from isolated mouse islets of Langerhans. SVG may be the main active metabolite after oral intake of steviol glycosides.

7.
Nutrients ; 10(10)2018 Oct 19.
Article in English | MEDLINE | ID: mdl-30347674

ABSTRACT

The literature is inconsistent as to how coffee affects metabolic syndrome (MetS), and which bioactive compounds are responsible for its metabolic effects. This study aimed to evaluate the effects of unfiltered coffee on diet-induced MetS and investigate whether or not phenolic acids and trigonelline are the main bioactive compounds in coffee. Twenty-four male Sprague‒Dawley rats were fed a high-fat (35% W/W) diet plus 20% W/W fructose in drinking water for 14 weeks, and were randomized into three groups: control, coffee, or nutraceuticals (5-O-caffeoylquinic acid, caffeic acid, and trigonelline). Coffee or nutraceuticals were provided in drinking water at a dosage equal to 4 cups/day in a human. Compared to the controls, total food intake (p = 0.023) and mean body weight at endpoint (p = 0.016) and estimated average plasma glucose (p = 0.041) were lower only in the coffee group. Surrogate measures of insulin resistance including the overall fasting insulin (p = 0.010), endpoint HOMA-IR (p = 0.022), and oral glucose tolerance (p = 0.029) were improved in the coffee group. Circulating triglyceride levels were lower (p = 0.010), and histopathological and quantitative (p = 0.010) measurements indicated lower grades of liver steatosis compared to controls after long-term coffee consumption. In conclusion, a combination of phenolic acids and trigonelline was not as effective as coffee per se in improving the components of the MetS. This points to the role of other coffee chemicals and a potential synergism between compounds.


Subject(s)
Coffee , Diet, High-Fat/adverse effects , Dietary Carbohydrates/administration & dosage , Fructose/administration & dosage , Metabolic Syndrome/chemically induced , Alkaloids/pharmacology , Animals , Blood Glucose/drug effects , Body Weight , Caffeic Acids/pharmacology , Coffee/chemistry , Dietary Supplements , Eating , Insulin Resistance , Male , Quinic Acid/analogs & derivatives , Quinic Acid/pharmacology , Random Allocation , Rats , Rats, Sprague-Dawley
8.
Curr Opin Clin Nutr Metab Care ; 21(6): 475-480, 2018 11.
Article in English | MEDLINE | ID: mdl-30239339

ABSTRACT

PURPOSE OF REVIEW: Isoflavones exert estrogenic activity distinct from estrogen, they have the potential to treat diseases and symptoms related to estrogen deficiency with minimal side effects and risks. Isoflavone supplementation, in general, is shown to exert beneficial effects against estrogen-deficient bone loss in women, however, some clinical trials still produce conflicting findings. The purpose of this review is to highlight and summarize the most recent and up-to-date research in the field and to bring attention to factors that play a major role in the outcomes of clinical trials that investigate phytoestrogens. Here, we also discuss the latest and most relevant data regarding the clinical safety of these substances. RECENT FINDINGS: Isoflavones are naturally occurring secondary metabolites found in the Fabacaea plant family. Clinical data from isoflavone interventions support that aglycones (abundant in fermented products) exert enhanced beneficial effects against estrogen-deficient bone loss in women compared with isoflavone glycosides. Studies that employ methods to determine isoflavone content and form of treatments are more likely detect beneficial effects on bone. EFSA have confirmed the safety of isoflavones for women in the most comprehensive report to date. SUMMARY: Isoflavone aglycones exert greater effects against bone loss than glycosides. Isoflavones show promise as a first-line prophylactic/treatment for bone loss in women.


Subject(s)
Dietary Supplements , Isoflavones/pharmacology , Perimenopause/metabolism , Phytoestrogens/pharmacology , Postmenopause/metabolism , Adult , Bone and Bones/drug effects , Female , Humans , Middle Aged
9.
Nutrients ; 10(9)2018 Aug 28.
Article in English | MEDLINE | ID: mdl-30154381

ABSTRACT

The deficiency of vitamin D is prevalent all over the world. Studies have shown that vitamin D may play an important role in the development of obesity. The current study was conducted to quantitatively evaluate the association between serum 25-(OH) vitamin D levels and the risk of obesity in both diabetic and non-diabetic subjects. A systematic review and meta-analysis of observational studies was carried out for that purpose. We searched the Medline, PubMed, and Embase databases throughout all of March 2018. A total of fifty five observational studies for both diabetic and non-diabetic subjects were finally included in the meta-analysis. The data were analyzed by comprehensive meta-analysis software version 3 and the random effects model was used to analyze the data. The meta-analysis showed an overall inverse relationship between serum vitamin D status and body mass index (BMI) in studies of both diabetic (r = -0.173, 95% = -0.241 to -0.103, p = 0.000) and non-diabetic (r = -0.152, 95% = -0.187 to -0.116, p = 0.000) subjects. The evidence of publication bias was not found in this meta-analysis. In conclusion, the deficiency of vitamin D is associated with an increased level of BMI in the studies of both diabetic and non-diabetic subjects. Reliable evidence from well-designed future randomized controlled trials is required to confirm the findings from observational studies and to find out the potential regulatory effects of vitamin D supplementation to lower BMI.


Subject(s)
Body Mass Index , Diabetes Mellitus, Type 2/epidemiology , Obesity/epidemiology , Vitamin D Deficiency/epidemiology , Vitamin D/blood , Biomarkers/blood , Blood Glucose/metabolism , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Humans , Obesity/blood , Obesity/diagnosis , Prognosis , Risk Factors , Vitamin D Deficiency/blood , Vitamin D Deficiency/diagnosis
10.
J Nutr ; 148(7): 1186S-1205S, 2018 07 01.
Article in English | MEDLINE | ID: mdl-29982648

ABSTRACT

Steviol glycoside sweeteners are extracted and purified from the Stevia rebaudiana Bertoni plant, a member of the Asteraceae (Compositae) family that is native to South America, where it has been used for its sweet properties for hundreds of years. With continued increasing rates of obesity, diabetes, and other related comorbidities, in conjunction with global public policies calling for reductions in sugar intake as a means to help curb these issues, low- and no-calorie sweeteners (LNCSs, also known as high-potency sweeteners) such as stevia are gaining interest among consumers and food manufacturers. This appeal is related to stevia being plant-based, zero calorie and with a sweet taste that is 50-350 times sweeter than sugar, making it an excellent choice for use in sugar- and calorie-reduced food and beverage products. Despite the fact that the safety of stevia has been affirmed by several food regulatory and safety authorities around the world, insufficient education about stevia's safety and benefits, including continuing concern with regard to the safety of LNCSs in general, deters health professionals and consumers from recommending or using stevia. Therefore, the aim of this review and the stevia symposium that preceded this review at the ASN's annual conference in 2017 was to examine, in a comprehensive manner, the state of the science for stevia, its safety and potential health benefits, and future research and application. Topics covered included metabolism, safety and acceptable intake, dietary exposure, impact on blood glucose and insulin concentrations, energy intake and weight management, blood pressure, dental caries, naturality and processing, taste and sensory properties, regulatory status, consumer insights, and market trends. Data for stevia are limited in the case of energy intake and weight management as well as for the gut microbiome; therefore, the broader literature on LNCSs was reviewed at the symposium and therefore is also included in this review.


Subject(s)
Diterpenes, Kaurane/pharmacology , Glucosides/pharmacology , Plant Extracts/chemistry , Plant Leaves/chemistry , Stevia/chemistry , Sweetening Agents , Diterpenes, Kaurane/chemistry , Glucosides/chemistry , Humans
11.
Nutrients ; 10(1)2018 Jan 10.
Article in English | MEDLINE | ID: mdl-29320437

ABSTRACT

There is evidence that vitamin D status is associated with type 2 diabetes. Many observational studies have been performed investigating the relationship of vitamin D status and circulating biomarkers of glycemic regulation. To find out whether this association holds, we conducted a systematic review and meta-analysis of cross sectional and longitudinal studies. We searched Pubmed, Medline and Embase, all through June 2017. The studies were selected to determine the effect of vitamin D on the parameters of glucose metabolism in diabetic and non-diabetic subjects. Correlation coefficients from all studies were pooled in a random effects meta-analysis. The risk of bias was assessed using Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. We found significant inverse relationship of vitamin D status with glycemic level in both diabetic (r = -0.223, 95% CI = -0.184 to -0.261, p = 0.000) and non-diabetic (r = -0.073, 95% CI = -0.052 to -0.093, p = 0.000) subjects. This meta-analysis concludes that hypovitaminosis D is associated with increased risk of hyperglycemia both in diabetic and non-diabetic subjects. A future strategy for the prevention of impaired glycemic regulation could be individualized supplementation of vitamin D.


Subject(s)
Blood Glucose/metabolism , Diabetes Mellitus, Type 2/epidemiology , Fasting/blood , Vitamin D Deficiency/epidemiology , Vitamin D/analogs & derivatives , Biomarkers/blood , Diabetes Mellitus, Type 2/blood , Diabetes Mellitus, Type 2/diagnosis , Humans , Incidence , Observational Studies as Topic , Risk Factors , Up-Regulation , Vitamin D/blood , Vitamin D Deficiency/blood , Vitamin D Deficiency/diagnosis
12.
J Nat Prod ; 80(12): 3267-3275, 2017 12 22.
Article in English | MEDLINE | ID: mdl-29192771

ABSTRACT

Ocimum gratissimum and Ocimum basilicum are plants ethnopharmacologically used to treat diabetes mellitus, a life-threatening disease that affects millions of people worldwide. In order to further understand their antidiabetic potential, which has been previously demonstrated in animal models, we aimed to investigate the acute and chronic effects of major phenolic substances from both plants on insulin secretion and gene expression in pancreatic islets isolated from NMRI mice. Insulin secretion was measured after acute (1 h) and long-term (72 h) incubation of islets with one of four cinnamic acid derivatives (caftaric, caffeic, chicoric, and rosmarinic acids) or a C-glucosylated flavonoid (vicenin-2). All substances acutely enhanced glucose-stimulated insulin secretion (GSIS) from islets at concentrations from 10-10 to 10-6 M. They also increased GSIS after chronic incubation (10-8 M). None of them increased insulin secretion in the presence of low glucose concentration. Furthermore, these substances markedly changed the gene expression profile of key insulin regulatory genes INS1, INS2, PDX1, INSR, IRS1, and proliferative genes as well as glucose transporter 2 (GLUT2), in treated islets. Thus, they may play an important role in diabetes treatment. This is the first report on the insulin-secretory activity of caftaric acid, rosmarinic acid, and vicenin-2.


Subject(s)
Glucose/metabolism , Insulin Secretion/drug effects , Insulin/metabolism , Islets of Langerhans/drug effects , Ocimum basilicum/chemistry , Plant Extracts/chemistry , Plant Extracts/pharmacology , Animals , Biological Transport/drug effects , Cinnamates/chemistry , Cinnamates/pharmacology , Diabetes Mellitus/metabolism , Female , Flavonoids/chemistry , Flavonoids/pharmacology , Gene Expression/drug effects , Islets of Langerhans/metabolism , Mice
13.
Nutrients ; 10(1)2017 Dec 22.
Article in English | MEDLINE | ID: mdl-29271886

ABSTRACT

Since coffee may help to prevent the development of metabolic syndrome (MetS), we aimed to evaluate the short- and long-term effects of a coffee-based supplement on different features of diet-induced MetS. In this study, 24 Sprague Dawley rats were divided into control or nutraceuticals groups to receive a high-fat/high-fructose diet with or without a mixture of caffeic acid (30 mg/day), trigonelline (20 mg/day), and cafestol (1 mg/day) for 12 weeks. An additional 11 rats were assigned to an acute crossover study. In the chronic experiment, nutraceuticals did not alter body weight or glycemic control, but improved fed hyperinsulinemia (mean difference = 30.80 mU/L, p = 0.044) and homeostatic model assessment-insulin resistance (HOMA-IR) (mean difference = 15.29, p = 0.033), and plasma adiponectin levels (mean difference = -0.99 µg/mL, p = 0.048). The impact of nutraceuticals on post-prandial glycemia tended to be more pronounced after acute administration than at the end of the chronic study. Circulating (mean difference = 4.75 U/L, p = 0.014) and intrahepatocellular alanine transaminase activity was assessed by hyperpolarized-13C nuclear magnetic resonance NMR spectroscopy and found to be reduced by coffee nutraceuticals at endpoint. There was also a tendency towards lower liver triglyceride content and histological steatosis score in the intervention group. In conclusion, a mixture of coffee nutraceuticals improved insulin sensitivity and exhibited hepatoprotective effects in a rat model of MetS. Higher dosages with or without caffeine deserve to be studied in the future.


Subject(s)
Alkaloids/pharmacology , Caffeic Acids/pharmacology , Coffea , Diet, High-Fat , Dietary Sucrose , Dietary Supplements , Diterpenes/pharmacology , Insulin Resistance , Liver/drug effects , Metabolic Syndrome/prevention & control , Non-alcoholic Fatty Liver Disease/prevention & control , Alkaloids/blood , Alkaloids/isolation & purification , Animals , Blood Glucose/drug effects , Blood Glucose/metabolism , Caffeic Acids/blood , Caffeic Acids/isolation & purification , Carbon-13 Magnetic Resonance Spectroscopy , Coffea/chemistry , Cytokines/blood , Disease Models, Animal , Diterpenes/blood , Diterpenes/isolation & purification , Insulin/blood , Lipids/blood , Liver/metabolism , Liver/pathology , Metabolic Syndrome/blood , Metabolic Syndrome/etiology , Metabolic Syndrome/pathology , Non-alcoholic Fatty Liver Disease/blood , Non-alcoholic Fatty Liver Disease/etiology , Non-alcoholic Fatty Liver Disease/pathology , Rats, Sprague-Dawley , Seeds , Time Factors
14.
J Nat Prod ; 80(8): 2353-2359, 2017 08 25.
Article in English | MEDLINE | ID: mdl-28763212

ABSTRACT

Daily coffee consumption is inversely associated with risk of type-2 diabetes (T2D). Cafestol, a bioactive substance in coffee, increases glucose-stimulated insulin secretion in vitro and increases glucose uptake in human skeletal muscle cells. We hypothesized that cafestol can postpone development of T2D in KKAy mice. Forty-seven male KKAy mice were randomized to consume chow supplemented daily with either 1.1 (high), 0.4 (low), or 0 (control) mg of cafestol for 10 weeks. We collected blood samples for fasting glucose, glucagon, and insulin as well as liver, muscle, and fat tissues for gene expression analysis. We isolated islets of Langerhans and measured insulin secretory capacity. After 10 weeks of intervention, fasting plasma glucose was 28-30% lower in cafestol groups compared with the control group (p < 0.01). Fasting glucagon was 20% lower and insulin sensitivity improved by 42% in the high-cafestol group (p < 0.05). Cafestol increased insulin secretion from isolated islets by 75-87% compared to the control group (p < 0.001). Our results show that cafestol possesses antidiabetic properties in KKAy mice. Consequently, cafestol may contribute to the reduced risk of developing T2D in coffee consumers and has a potential role as an antidiabetic drug.


Subject(s)
Coffee/chemistry , Diterpenes/isolation & purification , Diterpenes/pharmacology , Glucose/metabolism , Hypoglycemic Agents/isolation & purification , Liver/metabolism , Animals , Diabetes Mellitus, Type 2/drug therapy , Diabetes Mellitus, Type 2/prevention & control , Diterpenes/chemistry , Humans , Hypoglycemic Agents/chemistry , Hypoglycemic Agents/pharmacology , Insulin Resistance , Mice , Molecular Structure
15.
Am J Clin Nutr ; 106(3): 801-811, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28768649

ABSTRACT

Background: Age-related estrogen deficiency leads to accelerated bone resorption. There is evidence that, through selective estrogen receptor modulation, isoflavones may exert beneficial effects against estrogen-deficient bone loss. Isoflavone aglycones show higher bioavailability than their glycosidic counterparts and thus may have greater potency.Objective: To summarize evidence, we executed a systematic review and meta-analysis examining isoflavone therapies and bone mineral density (BMD) loss in peri- and postmenopausal women.Design: We systematically searched EMBASE and PubMed for randomized controlled trials (RCTs) evaluating isoflavone therapies for treating BMD loss at the lumbar spine and femoral neck in estrogen-deficient women. Separate meta-analyses were carried out with the use of random-effects models for the lumbar spine and femoral neck for all studies providing isoflavones as aglycones.Results: Twenty-six RCTs (n = 2652) were included in the meta-analysis. At the lumbar spine, isoflavone treatment was associated with a significantly (P < 0.00001) higher weighted mean difference (WMD) of BMD change of 0.01 (95% CI: 0.01, 0.02) than the control. For the femoral neck (18 RCTs, n = 1604), isoflavone treatment showed a significantly (P < 0.01) higher WMD of BMD change of 0.01 (95% CI: 0.00, 0.02) compared with the control. When isolating studies that provide isoflavone aglycones in their treatment arm, the average effect was further significantly increased at the spine (5 RCTs, n = 682) to 0.04 (P < 0.00001; 95% CI: 0.02, 0.05) and femoral neck (4 RCTs, n = 524) to 0.03 (P < 0.05; 95% CI: 0.00, 0.06) compared with the control. This protective effect against bone loss disappeared when only studies with formulations comprising predominantly isoflavone glycosides were included.Conclusions: Isoflavone treatments exert a moderately beneficial effect against estrogen-deficient bone loss in women. The effect appears dependent on whether isoflavone treatments are in aglycone form; we conclude that beneficial effects against bone loss may be enhanced for isoflavone aglycones.


Subject(s)
Bone Density Conservation Agents/therapeutic use , Bone Density/drug effects , Bone Resorption/prevention & control , Bone and Bones/metabolism , Glycosides/therapeutic use , Isoflavones/therapeutic use , Osteoporosis/prevention & control , Biological Availability , Bone Density Conservation Agents/pharmacology , Bone Resorption/etiology , Bone Resorption/metabolism , Bone and Bones/drug effects , Estrogens/deficiency , Female , Glycosides/pharmacology , Humans , Isoflavones/pharmacology , Menopause , Middle Aged , Osteoporosis/etiology , Osteoporosis/metabolism , Osteoporosis/pathology , Phytotherapy , Plant Extracts/pharmacology , Plant Extracts/therapeutic use
16.
Am J Clin Nutr ; 106(3): 909-920, 2017 Sep.
Article in English | MEDLINE | ID: mdl-28768651

ABSTRACT

Background: Female age-related estrogen deficiency increases the risk of osteoporosis, which can be effectively treated with the use of hormone replacement therapy. However, hormone replacement therapy is demonstrated to increase cancer risk. Bioavailable isoflavones with selective estrogen receptor affinity show potential to prevent and treat osteoporosis while minimizing or eliminating carcinogenic side effects.Objective: In this study, we sought to determine the beneficial effects of a bioavailable isoflavone and probiotic treatment against postmenopausal osteopenia.Design: We used a novel red clover extract (RCE) rich in isoflavone aglycones and probiotics to concomitantly promote uptake and a favorable intestinal bacterial profile to enhance isoflavone bioavailability. This was a 12-mo, double-blind, parallel design, placebo-controlled, randomized controlled trial of 78 postmenopausal osteopenic women supplemented with calcium (1200 mg/d), magnesium (550 mg/d), and calcitriol (25 µg/d) given either RCE (60 mg isoflavone aglycones/d and probiotics) or a masked placebo [control (CON)].Results: RCE significantly attenuated bone mineral density (BMD) loss at the L2-L4 lumbar spine vertebra (P < 0.05), femoral neck (P < 0.01), and trochanter (P < 0.01) compared with CON (-0.99% and -2.2%; -1.04% and -3.05%; and -0.67% and -2.79, respectively). Plasma concentrations of collagen type 1 cross-linked C-telopeptide was significantly decreased in the RCE group (P < 0.05) compared with CON (-9.40% and -6.76%, respectively). RCE significantly elevated the plasma isoflavone concentration (P < 0.05), the urinary 2-hydroxyestrone (2-OH) to 16α-hydroxyestrone (16α-OH) ratio (P < 0.05), and equol-producer status (P < 0.05) compared with CON. RCE had no significant effect on other bone turnover biomarkers. Self-reported diet and physical activity were consistent and differences were nonsignificant between groups throughout the study. RCE was well tolerated with no adverse events.Conclusions: Twice daily RCE intake over 1 y potently attenuated BMD loss caused by estrogen deficiency, improved bone turnover, promoted a favorable estrogen metabolite profile (2-OH:16α-OH), and stimulated equol production in postmenopausal women with osteopenia. RCE intake combined with supplementation (calcium, magnesium, and calcitriol) was more effective than supplementation alone. This trial was registered at clinicaltrials.gov as NCT02174666.


Subject(s)
Bone Density/drug effects , Bone Diseases, Metabolic/drug therapy , Bone Remodeling/drug effects , Bone and Bones/drug effects , Estrogens/metabolism , Isoflavones/therapeutic use , Probiotics/therapeutic use , Biological Availability , Bone Density Conservation Agents/pharmacology , Bone Density Conservation Agents/therapeutic use , Bone Diseases, Metabolic/metabolism , Bone and Bones/metabolism , Collagen Type I/blood , Double-Blind Method , Drug Combinations , Estrogens/deficiency , Female , Gastrointestinal Microbiome , Humans , Intestinal Mucosa/metabolism , Intestines/drug effects , Intestines/microbiology , Isoflavones/blood , Isoflavones/pharmacokinetics , Isoflavones/pharmacology , Middle Aged , Osteoporosis, Postmenopausal/metabolism , Osteoporosis, Postmenopausal/prevention & control , Peptides/blood , Phytotherapy , Plant Extracts/pharmacology , Plant Extracts/therapeutic use , Selective Estrogen Receptor Modulators/pharmacology , Selective Estrogen Receptor Modulators/therapeutic use , Trifolium/chemistry
17.
J Nat Prod ; 78(10): 2447-51, 2015 Oct 23.
Article in English | MEDLINE | ID: mdl-26465380

ABSTRACT

Diet and exercise intervention can delay or prevent development of type-2-diabetes (T2D), and high habitual coffee consumption is associated with reduced risk of developing T2D. This study aimed to test whether selected bioactive substances in coffee acutely and/or chronically increase insulin secretion from ß-cells and improve insulin sensitivity in skeletal muscle cells. Insulin secretion from INS-1E rat insulinoma cells was measured after acute (1-h) and long-term (72-h) incubation with bioactive substances from coffee. Additionally, we measured uptake of radioactive glucose in human skeletal muscle cells (SkMC) after incubation with cafestol. Cafestol at 10(-8) and 10(-6) M acutely increased insulin secretion by 12% (p < 0.05) and 16% (p < 0.001), respectively. Long-term exposure to 10(-10) and 10(-8) M cafestol increased insulin secretion by 34% (p < 0.001) and 68% (p < 0.001), respectively. Caffeic acid also increased insulin secretion acutely and chronically. Chlorogenic acid, trigonelline, oxokahweol, and secoisolariciresinol did not significantly alter insulin secretion acutely. Glucose uptake in SkMC was significantly enhanced by 8% (p < 0.001) in the presence of 10(-8) M cafestol. This newly demonstrated dual action of cafestol suggests that cafestol may contribute to the preventive effects on T2D in coffee drinkers and be of therapeutic interest.


Subject(s)
Coffee/chemistry , Diabetes Mellitus, Type 2/prevention & control , Diterpenes/pharmacology , Glucose/pharmacokinetics , Insulin/metabolism , Muscle, Skeletal/metabolism , Alkaloids/pharmacology , Animals , Butylene Glycols/pharmacology , Caffeic Acids/pharmacology , Chlorogenic Acid/pharmacology , Diabetes Mellitus, Type 2/drug therapy , Diterpenes/chemistry , Glucose/immunology , Glucose/metabolism , Guinea Pigs , Humans , Insulin Secretion , Insulin-Secreting Cells/metabolism , Lignans/pharmacology
18.
Article in English | MEDLINE | ID: mdl-26265926

ABSTRACT

Objective. To investigate the effect by which daily consumption of a novel red clover (RC) extract influences bone health, inflammatory status, and cardiovascular health in healthy menopausal women. Design. A 12-week randomized, double-blinded, placebo-controlled trial involving 60 menopausal women receiving a daily dose of 150 mL RC extract containing 37.1 mg isoflavones (33.8 mg as aglycones) or placebo. Methods. Bone parameters were changes in bone mineral density (BMD), bone mineral content (BMC), and T-score at the lumbar spine and femoral neck. Bone turnover (CTx) and inflammatory markers were measured in plasma and finally blood pressure (BP) was evaluated. Results. RC extract had positive effect on bone health, and only the women receiving the placebo experienced a decline in BMD (p < 0.01) at the lumbar spine. T-score at the lumbar spine only decreased in the placebo group (p < 0.01). CTx decreased in the RC group with -9.94 (±4.93)%, although not significant. Conclusion. Daily consumption of RC extract over a 12-week period was found to have a beneficial effect on bone health in menopausal women based on BMD and T-score at the lumbar spine and plasma CTx levels. No changes in BP or inflammation markers were found and no side effects were observed.

20.
J Endocrinol ; 215(1): 79-88, 2012 Oct.
Article in English | MEDLINE | ID: mdl-22798014

ABSTRACT

Chronic hyperglycemia and hyperlipidemia cause deleterious effects on ß-cell function. Interestingly, increased circulating amino acid (AA) levels are also a characteristic of the prediabetic and diabetic state. The chronic effects of AAs on ß-cell function remain to be determined. Isolated mouse islets and INS-1E cells were incubated with or without excess leucine. After 72 h, leucine increased basal insulin secretion and impaired glucose-stimulated insulin secretion in both mouse islets and INS-1E cells, corroborating the existence of aminoacidotoxicity-induced ß-cell dysfunction. This took place concomitantly with alterations in proteins and genes involved in insulin granule transport, trafficking (e.g. collapsin response mediator protein 2 and GTP-binding nuclear protein Ran), insulin signal transduction (proteasome subunit α type 6), and the oxidative phosphorylation pathway (cytochrome c oxidase). Leucine downregulated insulin 1 gene expression but upregulated pancreas duodenum homeobox 1 and insulin 2 mRNA expressions. Importantly, cholesterol (CH) accumulated in INS-1E cells concomitantly with upregulation of enzymes involved in CH biosynthesis (e.g. 3-hydroxy-3-methylglutaryl-CoA reductase, mevalonate (diphospho) decarboxylase, and squalene epoxidase) and LDL receptor, whereas triglyceride content was decreased. Our findings indicate that chronic exposure to elevated levels of leucine may have detrimental effects on both ß-cell function and insulin sensitivity. Aminoacidotoxicity may play a pathogenic role in the development of type 2 diabetes.


Subject(s)
Insulin-Secreting Cells/drug effects , Islets of Langerhans/drug effects , Leucine/pharmacology , Pancreatic Diseases/chemically induced , Animals , Apoptosis/drug effects , Apoptosis/physiology , Cells, Cultured , Dose-Response Relationship, Drug , Drug Evaluation, Preclinical , Female , Gene Expression Regulation/drug effects , Glucose/pharmacology , Insulin/metabolism , Insulin Secretion , Insulin-Secreting Cells/metabolism , Insulin-Secreting Cells/pathology , Insulin-Secreting Cells/physiology , Islets of Langerhans/metabolism , Islets of Langerhans/pathology , Islets of Langerhans/physiology , Mice , Pancreatic Diseases/pathology , Proteomics , Time Factors
SELECTION OF CITATIONS
SEARCH DETAIL