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Ils sont très forts les mecs

30/01/2015 | Etudes Compléments alimentaires et Etudes Perte de poids

 

T’interdis une “plante”, ils en ont déjà pour remplacer dans les cartons

Clinical safety assessment of oral higenamine supplementation in healthy, young men.
Hum Exp Toxicol. 2015 Jan 14.  Bloomer R

OBJECTIVE:
Higenamine, an herbal agent also known as norcoclaurine, is thought to stimulate β-androgenic receptors and possess lipolytic activity. It is currently making its way into the dietary supplement market. To our knowledge, no studies have been conducted to determine the safety profile of oral higenamine when used alone and in conjunction with other commonly used lipolytic agents.
METHODS:
Forty-eight men were assigned to ingest either a placebo, higenamine, caffeine, or higenamine + caffeine + yohimbe bark extract daily for a period of 8 weeks. Before and after 4 and 8 weeks of supplementation, the following variables were measured: resting respiratory rate, heart rate, blood pressure, urinalysis, complete blood count, metabolic panel, liver enzyme activity, and lipid panel.
RESULTS:
No interaction effects were noted for any variable (p > 0.05), with no changes of statistical significance occurring across time for any of the four conditions (p > 0.05).
CONCLUSION:
This is the first study to determine the safety profile of oral higenamine intake in human subjects. Our data indicate that 8 weeks of daily higenamine supplementation, either alone or in conjunction with caffeine and yohimbe bark extract, does not result in a statistically significant change in any of the measured outcome variables. Additional studies, inclusive of a larger sample size, are needed to extend these initial findings.


Beta2-adrenoceptor-mediated tracheal relaxation induced by higenamine from Nandina domestica Thunberg.

Tsukiyama M           Planta Med. 2009 Oct;75(13):1393-9.

The fruit of Nandina domestica Thunberg (ND, Berberidaceae) has been used to improve cough and breathing difficulties in Japan for many years, but very little is known about the constituent of ND responsible for this effect. We have recently reported that the crude extract from ND (NDE) inhibits histamine- and serotonin-induced contraction of isolated guinea pig trachea, and the inhibitory activity was not explained by nantenine, a well-known alkaloid isolated from ND. To explore other constituent(s) of NDE with tracheal smooth muscle relaxant activity, we fractionated NDE and assessed the pharmacological effects of the fractions using isolated guinea pig tracheal ring preparations. NDE was introduced into a polyaromatic absorbent resin column and stepwise eluted to yield five fractions, among which only the 40 % methanol fraction was active in relaxing tracheal smooth muscle precontracted with histamine. Further separation of the 40 % methanol fraction with high-performance liquid chromatography yielded multiple subfractions, one of which was remarkably active in relaxing histamine-precontracted trachea. Chemical analysis with a time-of-flight mass spectrometer and nuclear magnetic resonance spectrometer identified the constituent of the most active subfraction as higenamine, a benzyltetrahydroisoquinoline alkaloid. The potency and efficacy of the active constituent from NDE in relaxing trachea were almost equivalent to synthetic higenamine. In addition, the effect of the active constituent from NDE was competitively inhibited by the selective beta (2)-adrenoceptor antagonist ICI 118,551. These results indicate that the major constituent responsible for the effect of NDE is higenamine, which probably causes the tracheal relaxation through stimulation of beta (2) adrenoceptors.

La glucosamine n’est pas bénéfique pour les tendons

30/01/2015 | Echauffement et blessures et Etudes Perte de poids et Etudes Anti-âge

 

Pour les tendons, il faut prendre du peptan, pas de la gluco. Tout le monde le sait mais merci de le confirmer!

Glucosamine Supplementation after Anterior Cruciate Ligament Reconstruction in Athletes: A Randomized Placebo-controlled Trial

Research in Sports Medicine: An International Journal Volume 23, Issue 1, 2015 pages 14-26   Ali Eraslan

Although glucosamine is commonly consumed by athletes, its effectiveness in sports injuries is still under debate. We aimed to investigate the effects of glucosamine to the rehabilitation outcomes of anterior cruciate ligament (ACL) reconstructed athletes. Glucosamine-sulfate (1000 mg daily, for 8 weeks) was administered to half of the cohort of 30 male athletes, the other half used a placebo. Both groups received the same rehabilitation protocol. Knee pain and functions were evaluated by a visual analogue scale (VAS), International Knee Documentation Committee (IKDC) and Lysholm scores before and after oral administration. Additionally, an isokinetic test was performed after the administration period. The scores revealed significant improvements in both groups after 8 weeks, but no significant difference was detected between groups in any of the parameters.

Glucosamine supplementation did not improve the rehabilitation outcomes of athletes after ACL reconstruction. This is the first study investigating this topic. Further studies will help to obtain clear evidence about glucosamine efficacy on ACL injured or ACL reconstructed athletes.

Les mecs sont arrivés à dé-cuire un œuf

29/01/2015 | Etudes Compléments alimentaires

 

Je ne vois pas trop les applications mais visiblement, on risque de se retrouver avec des prot de lait dé-cuites

Shear-Stress-Mediated Refolding of Proteins from Aggregates and Inclusion Bodies
Dr. Tom Z. Yuan             ChemBioChem Early View (Online Version of Record published before inclusion in an issue) 23 JAN 2015

Recombinant protein overexpression of large proteins in bacteria often results in insoluble and misfolded proteins directed to inclusion bodies. We report the application of shear stress in micrometer-wide, thin fluid films to refold boiled hen egg white lysozyme, recombinant hen egg white lysozyme, and recombinant caveolin-1. Furthermore, the approach allowed refolding of a much larger protein, cAMP-dependent protein kinase A (PKA). The reported methods require only minutes, which is more than 100 times faster than conventional overnight dialysis. This rapid refolding technique could significantly shorten times, lower costs, and reduce waste streams associated with protein expression for a wide range of industrial and research applications.

La protéine de pois: aussi efficace ou inefficace que la whey?

26/01/2015 | Etudes Compléments alimentaires

 

J’aime ce genre d’étude: vu qu’aucune des 2 protéines n’a eu d’effet, on peut en conclure que les pois sont aussi efficaces ou inefficaces que la whey: au choix!

Pea proteins oral supplementation promotes muscle thickness gains during resistance training:
a double-blind, randomized, Placebo-controlled clinical trial vs. Whey protein  
Nicolas Babault         Journal of the International Society of Sports Nutrition (2015) 12:3

The effects of protein supplementation on muscle thickness and strength seem largely dependent on
its composition. The current study aimed at comparing the impact of an oral supplementation with vegetable Pea
protein (NUTRALYS®) vs. Whey protein and Placebo on biceps brachii muscle thickness and strength after a 12-week
resistance training program.

Methods:
One hundred and sixty one males, aged 18 to 35 years were enrolled in the study and underwent
12 weeks of resistance training on upper limb muscles. According to randomization, they were included in the Pea
protein (n = 53), Whey protein (n = 54) or Placebo (n = 54) group. All had to take 25 g of the proteins or placebo
twice a day during the 12-week training period. Tests were performed on biceps muscles at inclusion (D0), mid
(D42) and post training (D84). Muscle thickness was evaluated using ultrasonography, and strength was measured
on an isokinetic dynamometer.

Results:
Results showed a significant time effect for biceps brachii muscle thickness (P< 0.0001). Thickness
increased from 24.9 ± 3.8 mm to 26.9 ± 4.1 mm and 27.3 ± 4.4 mm at D0, D42 and D84, respectively, with only a
trend toward significant differences between groups (P= 0.09). Performing a sensitivity study on the weakest
participants (with regards to strength at inclusion), thickness increases were significantly different between groups
(+20.2 ± 12.3%, +15.6 ± 13.5% and +8.6 ± 7.3% for Pea, Whey and Placebo, respectively;
P< 0.05). Increases in thickness were significantly greater in the Pea group as compared to Placebo whereas there was no difference
between Whey and the two other conditions. Muscle strength also increased with time with no statistical
difference between groups.

Conclusions:
In addition to an appropriate training, the supplementation with pea protein promoted a greater
increase of muscle thickness as compared to Placebo and especially for people starting or returning to a muscular
strengthening. Since no difference was obtained between the two protein groups, vegetable pea proteins could be
used as an alternative to Whey-based dietary products.

Rôle clé de la testostérone dans la différentiation des cellules satellites

25/01/2015 | Etudes sur les hormones et Etudes Musculation

 

The activity of satellite cells and myonuclei following 8 weeks of strength training in young men with suppressed testosterone levels
T. Kvorning         Acta Physiologica Volume 213, Issue 3, pages 676–687, March 2015      

To investigate how suppression of endogenous testosterone during an 8-week strength training period influences the activity of satellite cells and myonuclei.

Methods
Twenty-two moderately trained young men participated in this randomized, placebo-controlled, and double-blinded intervention study. The participants were randomized to treatment with a GnRH analogue, goserelin (n = 12), which suppresses testosterone or placebo (n = 10) for 12 weeks. The strength training period of 8 weeks started after 4 weeks of treatment and included exercises for all major muscles. Biopsies were obtained from the mid-portion of the vastus lateralis muscle.

Results
Testosterone resting level in goserelin was 10–20 times lower compared with placebo, and the training-induced increase in the level of testosterone was abolished in goserelin. Training increased satellite cells number in type II fibres by 20% in placebo and by 52% in goserelin (P < 0.01), whereas the myonuclear number significantly increased by 12% in type II fibres in placebo and remained unchanged in goserelin (P < 0.05). No changes in satellite cells and myonuclei were seen in type I fibres in either group. Data from the microarray analysis indicated that low testosterone affects the bone morphogenetic proteins signalling, which might regulate proliferation vs. differentiation of satellite cells.

Conclusion
Eight weeks of strength training enhances the myonuclear number in type II fibres, and this is largely blocked by the suppression of testosterone. The data indicate that low testosterone levels could reduce the differentiation of satellite cells to myonuclei via the bone morphogenetic proteins signalling pathway, resulting in reduced increases in lean leg mass.

L’entraînement au poids de corps, inefficace pour gagner du muscle chez les seniors

24/01/2015 | Etudes Musculation

 

L’entraînement au poids de corps est inefficace pour gagner du muscle chez les seniors

Effect of resistance training using bodyweight in the elderly: Comparison of resistance exercise movement between slow and normal speed movement.
Watanabe Y       Geriatr Gerontol Int. 2015 Jan 17.

The present study investigated whether a slow movement protocol can be applied to resistance training using bodyweight. In addition, the intervention program combined plyometric exercise with resistance exercise to improve physical function overall.

METHODS:
A total of 39 active elderly adults participated in a 16-week intervention. The program consisted of five resistance exercises and four plyometric exercises using their own bodyweight with a single set for each exercise. Participants were assigned to one of two experimental groups. One group carried out resistance exercise with slow movement and tonic force generation (3-s concentric, 3-s eccentric and 1-s isometric actions with no rest between each repetition). The other group as a movement comparison followed the same regimen, but at normal speed (1-s eccentric and 1-s concentric actions with 1-s rest between each repetition). Muscle size, strength and physical function were measured before and after the intervention period.

RESULTS:
After the intervention, strengths of upper and lower limbs, and maximum leg extensor power were significantly improved in both groups. Muscle size did not change in either group. There were no significant differences in any of the parameters between groups.

CONCLUSIONS:
The intervention program using only own bodyweight that comprised resistance exercise with slow movement and plyometric exercise can improve physical function in the elderly, even with single sets for each exercise. However, there was no enhanced muscle hypertrophic effect. Further attempts, such as increasing performing multiple sets, would be required to induce muscle hypertrophy.

La cuisson détruit la carnitine

19/01/2015 | Etudes Compléments alimentaires et Etudes Perte de poids et Etudes Anti-âge

 

C’est comme la créatine, en théorie, il y en a plein, une fois la viande cuite, il reste pas grand chose

Impacts of different cooking and storage methods on the retention and in vitro bioaccessibility of l-carnitine in veal muscle (M. longissimus dorsi)
European Food Research and Technology February 2015, Volume 240, Issue 2, pp 311-318     Ozge Kurt Gokhisar

In this study, effects of different cooking and storage methods on free carnitine (l-carnitine) content, in vitro l-carnitine bioaccessibility, and antioxidant capacity of veal longissimus muscle were examined. Four different cooking methods (boiling, frying, baking, and grilling) and six different storage methods (modified atmosphere, spraying antioxidants, ascorbic acid, l-carnitine solutions, freezing, and storage of samples at +4 °C (by covering with stretch film and in resealable commercial refrigerator bags) were applied to veal longissimus muscle.

The l-carnitine content of muscle was decreased in all cooking and storage methods significantly (p

< 0.05).

In vitro bioaccessibility of l-carnitine in cooked samples was in the range of 34.82 ± 17.98–43.39 ± 11.15 %.

The best performance in protection of antioxidant capacities of samples was achieved by spraying ascorbic acid onto the surface of the veal muscle (p < 0.05).

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