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Effet du glycérol sur le cancer du foie

24/03/2018 | Etudes Compléments alimentaires et Etudes Anti-âge

 

Attenuation of liver cancer development by oral glycerol supplementation in the rat
Alejo M. Capiglioni   European Journal of Nutrition April 2018, Volume 57, Issue 3, pp 1215–1224 | Cite as

Purpose
Glycerol usage is increasing in food industry for human and animal nutrition. This study analyzed the impact of glycerol metabolism when orally supplemented during the early stage of rat liver carcinogenesis.

Methods
Wistar rats were subjected to a 2-phase model of hepatocarcinogenesis (initiated-promoted, IP group). IP animals also received glycerol by gavage (200 mg/kg body weight, IPGly group).

Results
Glycerol treatment reduced the volume of preneoplastic lesions by decreasing the proliferative status of liver foci, increasing the expression of p53 and p21 proteins and reducing the expression of cyclin D1 and cyclin-dependent kinase 1. Besides, apoptosis was enhanced in IPGly animals, given by an increment of Bax/Bcl-2 ratio, Bad and PUMA mitochondrial expression, a concomitant increase in cytochrome c release and caspase-3 activation. Furthermore, hepatic levels of glycerol phosphate and markers of oxidative stress were increased in IPGly rats. Oxidative stress intermediates act as intracellular messengers, inducing p53 activation and changes in JNK and Erk signaling pathways, with JNK activation and Erk inhibition.

Conclusion
The present work provides novel data concerning the preventive actions of glycerol during the development of liver cancer and represents an economically feasible intervention to treat high-risk individuals.

Irisine: le lien entre la muscu et le renforcement osseux?

14/03/2018 | Etudes sur les hormones et Etudes Perte de poids et Etudes Anti-âge

 

Myokine—Irisin—and Its Effects Linking Bone and Muscle Function
Graziana Colaianni           Clinical Reviews in Bone and Mineral Metabolism March 2018, Volume 16, Issue 1, pp 16–21

Irisin is a myokine secreted by the skeletal muscle during physical activity both in mice and humans. Its first identified role was to activate the browning response in white adipocytes, subsequently triggering non-shivering thermogenesis; therefore, Irisin has raised great expectations as a potential target in the treatment of obesity. In 2015, we demonstrated that Irisin plays a central role in the control of bone mass, driving positive effects on cortical mineral density and bone mechanical properties. This effect on the bone was triggered using an Irisin dosage 70 times lower than the one needed to induce the browning response, suggesting that the skeleton is the primary target organ of this myokine. Moreover, our studies also highlighted the autocrine effect of Irisin on the skeletal muscle, overall suggesting that Irisin plays a fundamental role in the physiology of the musculoskeletal system. More recently, we demonstrated the efficacy of Irisin in preventing and restoring bone and muscle losses in a mouse model affected by disuse-induced osteoporosis and muscular atrophy. Hopefully, if future investigations will be confirmed in humans, it may lead to develop an Irisin-based therapy for physically disable or bedridden patients and it might also represent a countermeasure for astronauts subjected to microgravity.

Du propionate de sodium pour perdre du gras?

13/03/2018 | Etudes Compléments alimentaires et Etudes Perte de poids

 

Acute oral sodium propionate supplementation raises resting energy expenditure and lipid oxidation in fasted humans
Edward S. Chambers   Diabetes, Obesity and Metabolism Content Alert: 20, 4 (April 2018)

Short-chain fatty acids (SCFAs), produced from fermentation of dietary fibre by the gut microbiota, have been suggested to modulate energy metabolism.

Previous work using rodent models has demonstrated that oral supplementation of the SCFA propionate raises resting energy expenditure (REE) by promoting lipid oxidation. The objective of the present study was to investigate the effects of oral sodium propionate on REE and substrate metabolism in humans. Eighteen healthy volunteers (9 women and 9 men; age 25 ± 1 years; body mass index 24.1 ± 1.2 kg/m2) completed 2 study visits following an overnight fast.

Tablets containing a total of 6845 mg sodium propionate or 4164 mg sodium chloride were provided over the 180-minute study period in random order. REE and substrate oxidation were assessed by indirect calorimetry. Oral sodium propionate administration increased REE (0.045 ± 0.020 kcal/min; P = .036); this was accompanied by elevated rates of whole-body lipid oxidation (0.012 ± 0.006 g/min; P = .048) and was independent of changes in glucose and insulin concentrations. Future studies are warranted to determine whether the acute effects of oral sodium propionate on REE translate into positive improvements in long-term energy balance in humans.

L’acide carnosique du romarin comme protecteur articulaire?

13/03/2018 | Echauffement et blessures et Etudes Compléments alimentaires et Etudes Anti-âge

 

Carnosic acid inhibits inflammation response and joint destruction on osteoclasts, fibroblast-like synoviocytes, and collagen-induced arthritis rats
Mei Liu       J. Cell. Physiol.      9 March 2018

The discovery of new therapeutic drugs with the ability of preventing inflammation and joint destruction with less adverse effects is urgently needed for rheumatoid arthritis (RA). Carnosic acid (CA), a major phenolic compound isolated from the leaves of Rosemary (Rosmarinus officinalis L.), has been reported to have antioxidative and antimicrobial properties. However, its effects on RA have not been elucidated. Here, we investigated the effects of CA on osteoclasts and fibroblast-like synoviocytes in vitro and on collagen-induced arthritis (CIA) in Wistar rats in vivo. Our in vitro and in vivo studies showed that CA suppressed the expression of pro-inflammatory cytokines including TNFɑ, IL-1β, IL-6, IL-8, IL-17 and MMP-3, and downregulated the production of RANKL. More importantly, we observed that CA inhibited osteoclastogenesis and bone resorption in vitro and exerted therapeutic protection against joint destruction in vivo. Further biochemical analysis demonstrated that CA suppressed RANKL-induced activations of NF-κB and MAPKs (JNK and p38) leading to the downregulation of NFATc1.

Taken together, our findings provide the convincing evidence that rosemary derived CA is a promising natural compound for the treatment of RA.

Altération des protéines de lait par la chaleur

07/03/2018 | Etudes Compléments alimentaires

 

Flavor and flavor chemistry differences among milks processed by high temperature, short time or ultra-pasteurization
Y. Jo     Journal of Dairy Science 2018

Typical high-temperature, short-time (HTST) pasteurization encompasses a lower heat treatment and shorter refrigerated shelf life compared with ultra-pasteurization (UP) achieved by direct steam injection (DSI-UP) or indirect heat (IND-UP). A greater understanding of the effect of different heat treatments on flavor and flavor chemistry of milk is required to characterize, understand, and identify the sources of flavors.

The objective of this study was to determine the differences in the flavor and volatile compound profiles of milk subjected to HTST, DSI-UP, or IND-UP using sensory and instrumental techniques. Raw skim and raw standardized 2% fat milks (50 L each) were processed in triplicate and pasteurized at 78°C for 15 s (HTST) or 140°C for 2.3 s by DSI-UP or IND-UP. Milks were cooled and stored at 4°C, then analyzed at d 0, 3, 7, and 14. Sensory attributes were determined using a trained panel, and aroma active compounds were evaluated by solid-phase micro-extraction or stir bar sorptive extraction followed by gas chromatography-mass spectrometry, gas chromatography-olfactometry, and gas chromatography-triple quad mass spectrometry.

The UP milks had distinct cooked and sulfur flavors compared with HTST milks. The HTST milks had less diversity in aroma active compounds compared with UP milks.

Flavor intensity of all milks decreased by d 14 of storage.
Aroma active compound profiles were affected by heat treatment and storage time in both skim and 2% milk. High-impact aroma active compounds were hydrogen sulfide, dimethyl trisulfide, and methional in DSI-UP and 2 and 3-methylbutanal, furfural, 2-heptanone, 2-acetyl-1-pyrroline, 2-aminoacetophenone, benzaldehyde, and dimethyl sulfide in IND-UP.

These results provide a foundation knowledge of the effect of heat treatments on flavor development and differences in sensory quality of UP milks.

Altération des protéines de lait par séchage

07/03/2018 | Etudes Compléments alimentaires

 

The effect of spray drying on the difference in flavor and functional properties of liquid and dried whey proteins, milk proteins, and micellar casein concentrates
Brandon Carter     Journal of Dairy Science 2018
 
Traditionally most protein ingredients are sold as a powder due to transport ease and longer shelf life. Many high-protein powder ingredients such as milk protein concentrate with 85% protein and micellar casein concentrate have poor rehydration properties (e.g., solubility) after storage, which might limit their use. An alternative to the production of dried protein ingredients is the option to use liquid protein ingredients, which saves the cost of spray drying, but may also improve flavor and offer different functional properties. The objective of this study was to determine the effect of spray drying on the flavor and functionality of high-protein ingredients. Liquid and dried protein ingredients (whey protein concentrate with 80% protein, whey protein isolate, milk protein concentrate with 85% protein, and micellar casein concentrate) were manufactured from the same lot of milk at the North Carolina State University pilot plant. Functional differences were evaluated by measurement of foam stability and heat stability. Heat stability was evaluated by heating at 90°C for 0, 10, 20, and 30 min followed by micro-bicinchoninic acid and turbidity loss measurements. Sensory properties were evaluated by descriptive analysis, and volatile compounds were evaluated by gas chromatography-mass spectrometry. No differences were detected in protein heat stability between liquids and powders when spray dried under these conditions. Whey protein concentrate with 80% protein (liquid or spray dried) did not produce a foam.

All powders had higher aroma intensity and cooked flavors compared with liquids.

Powder proteins also had low but distinct cardboard flavor concurrent with higher relative abundance of volatile aldehydes compared with liquids. An understanding of how spray drying affects both flavor and functionality may help food processors better use the ingredients they have available to them.

Effet d’une supplémentation en corps cétoniques sur la glycémie?

17/02/2018 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

Prior ingestion of exogenous ketone monoester attenuates the glycemic response to an oral glucose tolerance test in healthy young individuals
Etienne Myette-Côté              The Journal of Physiology               15 February 2018  

The main objectives of this study were threefold: (1) To determine whether acute ingestion of Kme; (R)-3-hydroxybutyl (R)-3-hydroxybutyrate impacts plasma glucose levels during a standardized oral glucose tolerance test (OGTT). (2) To compare changes in insulin concentrations and estimates of insulin sensitivity after acute Kme supplementation. Twenty healthy participants (n = 10 males/females) aged between 18–35 years took part in a randomized crossover study. After an overnight fast, participants consumed a Kme supplement (ΔG®; 0.45 ml kg−1 body weight) or placebo (water) 30 min before completing a 75-gram OGTT. Blood samples were collected every 15–30 min over a period of 2.5 h. Participants and study personnel performing laboratory analyses were blinded to condition. Kme acutely raised blood D-beta-hydroxybutyrate (β-OHB) to 3.2±0.6 mm within 30 min with levels remaining elevated throughout the entire OGTT. Compared to placebo, Kme significantly decreased glucose area under the curve (AUC; −16%, P = 0.001), non-esterified fatty acid (NEFA) AUC (-44%, P

< 0.001) and C-peptide incremental AUC (P = 0.005), while improving oral glucose insulin sensitivity index by ∼11% (P = 0.001).

In conclusion, a

Kme supplement that acutely increased β-OHB levels up to ∼3 mm attenuated the glycemic response to an OGTT in healthy humans. The reduction in glycemic response did not appear to be driven by an increase in insulin secretion, but was accompanied by improved markers of insulin sensitivity. These results suggest that ketone monoester supplements could have therapeutic potential in the management and prevention of metabolic disease.

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