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Effets du Cissus Quadrangularis sur la force et la prise de muscle?

21/09/2018 | Etudes Compléments alimentaires

 

The Effects of 6 weeks of Cissus Quadrangularis Supplementation and High Intensity Exercise Training
Eric E. Noreen,      MEDICINE & SCIENCE IN SPORTS & EXERCISE   2018 S598 Vol. 49 No. 5 Supplement

Previous studies have shown that supplementation with Cissus Quadrangularis
(CQ) can positively alter body composition in sedentary adults. However, it is
unknown if this same effect is observed in active adults.

PURPOSE: The purpose
of this study was to determine the effects of 6 wks of supplementation with CQ on
body composition and exercise performance in healthy adults enrolled in a crossfit
class.

METHODS: A total of 18 adults (9 males, 9 females, 40.2+8.3 y; mean+SD)
completed this study. All subjects had been enrolled in crossfit classes prior to the
study. Baseline body composition was assessed by whole body densitometry using air
displacement plethysmogrophy, and exercise performance was assessed using a time
to completion 1000 m rowing test and a 3 repetition max for the standing press and
back squat. Following baseline testing, subjects were randomly assigned in a doubleblind
manner into one of two groups: 3.2 g/d of CQ; or 3.2 g/d of a maltodextrin
placebo (PL). Subjects consumed half of the daily dose in the morning and half in the
evening on an empty stomach. All testing was repeated following 6 wks of treatment.
Pre to post differences were analyzed using a treatment by time repeated measures
ANOVA.

RESULTS: After 6 wks of treatment, there were no significant differences
observed between the CQ or PL group for change in body weight (CQ= -0.2+0.8 kg,
PL= -0.07+1.5 kg, p=0.77), fat mass (CQ= -1.1+0.7 kg, PL= -1.0+1.9 kg, p=0.96),
fat free mass (CQ= +0.8+0.7 kg, PL= +0.7+1.5 kg, p=0.89), body fat % (CQ=
-1.2+0.7 % body fat, PL= -1.1+1.9 % body fat, p=0.94), 3 rep max back squats (CQ=
+16.7+11.5 lbs, PL= +16.7+13.2 lbs, p=1.0), 3 rep standing press (CQ= +8.3+6.1 lbs,
PL= +3.30+5.6 lbs, p=0.08), or 1000 m rowing test (CQ= -3.0+6.0s, PL= -3.9+9.3s,
p=0.81).

CONCLUSION: Compared to the placebo, 6wk of supplementation with
CQ did not alter the body composition or exercise performance adaptations to crossfit
training in experienced crossfitters.

Existe-t’il une fatigue digestive?

23/08/2018 | Etudes Compléments alimentaires

 

Excess of nutrient-induced morpho-functional adaptation and inflammation degree in a Caco2/HT-29 in vitro intestinal co-culture
M. Bottani,        j.nut.2018.07.018

Highlights
•A nutrient excess increases in vitro mucus production and reduces tight junctions.
•A nutrient excess increases the specific activity of intestinal enzymes.
•A nutrient excess increases the intestinal permeability.
•A higher ROS, NO and PYY hormone production is associated to a nutrient excess.
•A low grade inflammation status is induced by a nutrient excess.

Abstract
The intestinal cell function can be modulated by the type and quantity of nutrients. The aim of this study was to evaluate the effects due to an excess of nutrients on intestinal morpho-functional features and a possible associated inflammation in a 70/30 Caco2/HT-29 intestinal in vitro co-culture. An excess of nutrients (EX) has been obtained by increasing progressively the medium change frequency respect to standard cell growth conditions (ST) from confluence (T0) to 15 days after confluence (T15). In comparison with ST group, the EX group revealed a maintenance of the number of microvilli, an increase of follicle like-structures and mucus production, a decrease in the number of tight junction. The specific activity of markers of intestinal differentiation, Alkaline Phosphatase and Aminopeptidase N, and of the enterocyte differentiation specific marker, Dipeptidyl Peptidase-IV, progressively raised. The Transepithelial Electrical Resistance, indicative of the co-culture barrier properties, decreased, while Lucifer Yellow Papp evaluation, an index of the paracellular permeability to large molecules, showed an increase. ROS and NO production, indicative of an oxidative status, together with IL-6, IL-8, indicative of a low inflammation grade, and PYY secretion were higher in EX than in ST condition. The differences between ST and EX were particularly evident at T15.

These data support the suitability of our in vitro gut model for obesity studies at the molecular level and the necessity to standardize the medium frequency change in intestinal culture.

Blancs d’oeufs VS blancs + jaunes sur l’anabolisme?

23/08/2018 | Etudes Compléments alimentaires

 

Il me semble y avoir un gros biais calorique

Whole egg, but not egg white ingestion, induces mTOR co-localization with the lysosome after resistance exercise in trained young men
Sidney Abou Sawan

We have recently demonstrated that whole egg ingestion induces a greater muscle protein synthetic (MPS) response when compared to isonitrogenous egg white ingestion after resistance exercise in young men. Our aim was to determine whether whole egg or egg white ingestion differentially influenced co-localization of key regulators of mechanistic target of rapamycin complex 1 (mTORC1) as means to explain our previously observed divergent post-exercise MPS response. In crossover trials, 10 healthy resistance-trained men (21±1 y; 88±3 kg; body fat: 16±1 %; means±SEM) completed lower body resistance exercise before ingesting whole eggs (18 g protein, 17 g fat) or egg whites (18 g protein, 0 g fat). Muscle biopsies were obtained before exercise and at 120 and 300 min after egg ingestion to assess, by immunofluorescence, protein co-localization of key anabolic signaling molecules. After resistance exercise, TSC2-Rheb co-localization decreased (P<0.01) at 120 and 300 min after whole egg and egg white ingestion with concomitant increases (P<0.01) in mTOR-Rheb co-localization. After resistance exercise, mTOR-LAMP2 co-localization significantly increased at 120 and 300 min only after whole egg ingestion (P<0.01), and mTOR-LAMP2 co-localization correlated with rates of MPS at rest and after exercise (r=0.40, P<0.05).

We demonstrated that the greater post-exercise MPS response with whole egg ingestion is related in part to an enhanced recruitment of mTORC1-Rheb complexes to the lysosome during recovery. These data suggest non-protein dietary factors influence the post-exercise regulation of mRNA translation in human skeletal muscle.

α‐Cedrene pour plus de muscle?

19/06/2018 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

α‐Cedrene, a Newly Identified Ligand of MOR23, Increases Skeletal Muscle Mass and Strength
Tao Tong Molecular Nutrition &  Food Research 14 June 2018

Scope
Skeletal muscle atrophy is a common and debilitating condition that lacks an effective therapy. In this study, we tested the effects of α‐cedrene, a natural ligand of mouse olfactory receptor 23 (MOR23) whose ectopic function regulating myogenesis was reported recently, on skeletal muscle growth.

Methods and results
α‐Cedrene, not only stimulated hypertrophy but also attenuated free fatty acid–induced atrophy of cultured skeletal myotubes, as evidenced by an increased myotube diameter, fusion index, and total cellular protein content. These hypertrophic and antiatrophic properties of α‐cedrene in cultured myotubes were confirmed in corresponding mouse models. The skeletal muscle mass, total muscle protein content, average cross‐sectional area of myofibers, and muscle strength were significantly greater in α‐cedrene–treated mice compared with untreated animals during either a regular chow diet or high‐fat diet. Receptor knockdown experiments using RNA interference in cultured skeletal myotubes revealed that the hypertrophic and antiatrophic properties of α‐cedrene may be mediated by MOR23. Furthermore, α‐cedrene induced the expression of MOR23 and enhanced its downstream cAMP–PKA–CREB signaling in the skeletal muscle of mice fed chow or high‐fat diet.

Conclusions
α‐Cedrene is a promising agent that may be applied to enhance the mass and strength of skeletal muscle.

Pourquoi le diabète augmente le niveau de BCAA sanguins?

10/06/2018 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

Fasting serum amino acids concentration is associated with insulin resistance and pro-inflammatory cytokines
Diabetes Research and Clinical Practice Volume 140, June 2018, Pages 107-117               Sang-GukLee
Highlights
• Serum branched chain amino acids (BCAAs) were increased in type 2 diabetes mellitus.
• Serum non-BCAAs were also elevated in patients with type 2 diabetes.
• HOMA-IR and pro-inflammatory cytokines were independent predictors of amino acid.
• Insulin resistance or inflammatory cytokines could induce skeletal muscle proteolysis.
• Elevated serum amino acids are an early manifestation of impaired insulin action.

Aims
We evaluated specific alterations in amino acids (AAs) profile in patients with type 2 diabetes mellitus (T2DM) and impaired fasting glucose (IFG) compared with healthy controls. In addition, we tried to find the mechanisms behind these AA alterations.

Methods
Twenty AAs, TNF-α, and IL-6 were analyzed in fasting serum samples from a total of 198 individuals (56 drug-naïve patients with T2DM, 69 patients IFG, and 73 healthy controls). The C2C12 mouse myoblast cell lines were used to examine the changes of MAFbx and MuRF1 expressions, which are muscle specific E3 ligases acting as major mediators of skeletal muscle proteolysis, after development of insulin resistance induced by palmitate treatment.

Results
In addition to branched chain amino acids BCAAs, fasting serum AAs such as glutamic acid, lysine, phenylalanine, arginine, alanine, tyrosine, aspartic acid, were higher in patients with T2DM and intermediately elevated in patients with IFG compared with normoglycemic controls. These serum AA concentrations positively correlated with fasting glucose, homeostasis model assessment of insulin resistance (HOMA-IR), and pro-inflammatory cytokines. In addition, HOMA-IR and pro-inflammatory cytokines were two important independent predictors of serum AA levels. In vitro experiments showed that palmitate treatment in C2C12 myotubes induced insulin resistance, increased pro-inflammatory cytokine gene expression, and increased MAFbx gene and protein expression.

Conclusions
The increase in fasting serum AAs can be an early manifestation of insulin resistance. Increased muscle proteolysis induced by insulin resistance and inflammatory cytokines can be a possible mechanism for the rise in serum AA levels.

Comment une alimentation acide agresse les reins?

25/05/2018 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

Kidney Response to the Spectrum of Diet-Induced Acid Stress
Nimrit Goraya                     Nutrients 2018, 10(5), 596;


Chronic ingestion of the acid (H+)-producing diets that are typical of developed societies appears to pose a long-term threat to kidney health. Mechanisms employed by kidneys to excrete this high dietary H+ load appear to cause long-term kidney injury when deployed over many years. In addition, cumulative urine H+ excretion is less than the cumulative increment in dietary H+, consistent with H+ retention. This H+ retention associated with the described high dietary H+ worsens as the glomerular filtration rate (GFR) declines which further exacerbates kidney injury. Modest H+ retention does not measurably change plasma acid–base parameters but, nevertheless, causes kidney injury and might contribute to progressive nephropathy. Current clinical methods do not detect H+ retention in its early stages but the condition manifests as metabolic acidosis as it worsens, with progressive decline of the glomerular filtration rate.

We discuss this spectrum of H+ injury, which we characterize as “H+ stress”, and the emerging evidence that high dietary H+ constitutes a threat to long-term kidney health.

Influence de la sérine sur la sécrétion de GH et cortisol?

28/03/2018 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

Effects of L-serine supplementation on the daily rhythms of growth hormone and corticosterone concentrations in mice
Li Wu,      Biological Rhythm Research       22 Mar 2018    

The impact of L-serine on the daily rhythms of growth hormone (GH) and corticosterone remains unknown. We explored whether the daily rhythms of these hormones were affected by L-serine supplementation as well as the supplementation time.

The results showed that plasma GH concentration at Zeitgeber time (ZT) 4 and 8 were significantly increased by L-serine supplementation at ZT22, while the diurnal rhythms peaks of plasma corticosterone at ZT12 were suppressed by L-serine supplementation at ZT10. After the supplementation was stopped, the effects of L-serine on the diurnal rhythms of plasma GH and corticosterone lasted for 2 days then they were fading on day 4. L-serine concentrations in plasma and hypothalamus after supplementation at ZT22 was lower than those after supplementation at ZT10.

In conclusion, L-serine modulates the daily rhythms of GH and corticosterone depending on its supplementation time. The modulation effect might be association with the daily rhythms of L-serine metabolism.

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