scholarly journals Parsing the life-shortening effects of dietary protein: effects of individual amino acids

2017 ◽  
Vol 284 (1846) ◽  
pp. 20162052 ◽  
Author(s):  
Sara Arganda ◽  
Sofia Bouchebti ◽  
Sepideh Bazazi ◽  
Sophie Le Hesran ◽  
Camille Puga ◽  
...  

High-protein diets shorten lifespan in many organisms. Is it because protein digestion is energetically costly or because the final products (the amino acids) are harmful? To answer this question while circumventing the life-history trade-off between reproduction and longevity, we fed sterile ant workers on diets based on whole proteins or free amino acids. We found that (i) free amino acids shortened lifespan even more than proteins; (ii) the higher the amino acid-to-carbohydrate ratio, the shorter ants lived and the lower their lipid reserves; (iii) for the same amino acid-to-carbohydrate ratio, ants eating free amino acids had more lipid reserves than those eating whole proteins; and (iv) on whole protein diets, ants seem to regulate food intake by prioritizing sugar, while on free amino acid diets, they seem to prioritize amino acids. To test the effect of the amino acid profile, we tested diets containing proportions of each amino acid that matched the ant's exome; surprisingly, longevity was unaffected by this change. We further tested diets with all amino acids under-represented except one, finding that methionine, serine, threonine and phenylalanine are especially harmful. All together, our results show certain amino acids are key elements behind the high-protein diet reduction in lifespan.

1993 ◽  
Vol 264 (6) ◽  
pp. G1057-G1065 ◽  
Author(s):  
C. Moundras ◽  
C. Remesy ◽  
C. Demigne

The aim of the present study was to evaluate the effect of changes in dietary protein level on overall availability of amino acids for tissues. For this purpose, rats were adapted to diets containing various concentrations of casein (7.5, 15, 30, and 60%) and were sampled either during the postprandial or postabsorptive period. In rats fed the protein-deficient diet, glucogenic amino acids (except threonine) tended to accumulate in plasma, liver, and muscles. In rats fed high-protein diets, the hepatic balance of glucogenic amino acids was markedly enhanced and their liver concentrations were consistently depressed. This response was the result of a marked induction of amino acid catabolism (a 45-fold increase of liver threonine-serine dehydratase activity was observed with the 60% casein diet). The muscle concentrations of threonine, serine, and glycine underwent changes parallel to plasma and liver concentrations, and a significant reduction of glutamine was observed. During the postabsorptive period, adaptation to high-protein diets resulted in a sustained catabolism of most glucogenic amino acids, which accentuated the drop in their concentrations (especially threonine) in all the compartments studied. The time course of metabolic adaptation from a 60 to a 15% casein diet has also been investigated. Adaptation of alanine and glutamine metabolism was rapid, whereas that of threonine, serine, and glycine was delayed and required 7-11 days. This was paralleled by a relatively slow decay of liver threonine-serine dehydratase (T-SDH) activity in contrast to the rapid adaptation of pyruvate kinase activity after refeeding a high-carbohydrate diet.(ABSTRACT TRUNCATED AT 250 WORDS)


Agronomy ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1637
Author(s):  
Quintino Reis de Araujo ◽  
Guilherme Amorim Homem de Abreu Loureiro ◽  
Cid Edson Mendonça Póvoas ◽  
Douglas Steinmacher ◽  
Stephane Sacramento de Almeida ◽  
...  

Free amino acids in cacao beans are important precursors to the aroma and flavor of chocolate. In this research, we used inferential and explanatory statistical techniques to verify the effect of different edaphic crop conditions on the free amino acid profile of PH-16 dry cacao beans. The decreasing order of free amino acids in PH-16 dry cacao beans is leucine, phenylalanine, glutamic acid, alanine, asparagine, tyrosine, gamma-aminobutyric acid, valine, isoleucine, glutamine, lysine, aspartic acid, serine, tryptophan, threonine, glycine. With the exception of lysine, no other free amino acid showed a significant difference between means of different edaphic conditions under the ANOVA F-test. The hydrophobic free amino acids provided the largest contribution to the explained variance with 58.01% of the first dimension of the principal component analysis. Glutamic acid stands out in the second dimension with 13.09%. Due to the stability of the biochemical profile of free amino acids in this clonal variety, it is recommended that cacao producers consider the genotype as the primary source of variation in the quality of cacao beans and ultimately the chocolate to be produced.


2021 ◽  
Vol 33 (12) ◽  
pp. 2989-2992
Author(s):  
Borche Makarijoski ◽  
Gordana Dimitrovska ◽  
Vesna K. Hristova ◽  
Elena Joshevska ◽  
Mahmoud A. Abdelaziz Mahmoud ◽  
...  

The present work is focussed to determine the Macedonian white brined cheese’s free amino acid profile. Four variants of the Macedonian white brined cheese to analyze and determine free amino acid concentration; cheese samples define the Macedonian white brined cheese as a typical cheese. All free amino acids were specified, except the amino acid tyrosine. The detected amino acids in the tested cheese variants were present in different but approximate parameter values. The estimated essential free amino acids, the concentration of lysine was found highest in all examined samples with values from 26.40 ± 0.02 mg% to 28.20 ± 0.04 mg% and the concentration of threonine was the lowest from 3.19 ± 0.02 mg% to 3.32 ± 0.02 mg%). In the detected unessential free amino acids, the concentration of aspartic amino acid was highest in all the samples with values from 11.02 ± 0.05 mg% to 11.32 ± 0.03 mg% and the concentration of proline was at the lowest level from 4.16 ± 0.06 mg% to 4.22 ± 0.04 mg%.


1982 ◽  
Vol 206 (1) ◽  
pp. 13-18 ◽  
Author(s):  
P Fafournoux ◽  
C Rémésy ◽  
C Demigné

After adaptation of rats to a 90%-casein diet, hepatic uptake of alanine is strikingly increased in vivo, with concomitant appearance of a concentration of favourable for uptake. With a high-protein diet, uptake of 2-aminoisobutyrate by isolated hepatocytes in the presence of various concentrations of substrates suggested induction of the A system (high-affinity system), whose emergence has been reported during starvation or after glucagon treatment. The other system (ASC, L) were characterized: induction processes only affected the A system. Dibutyryl cyclic AMP addition resulted in an increase in 2-aminoisobutyrate transport at low substrate concentration, the response being greater after adaptation to a high-protein diet. Evidence is presented suggesting that the increased uptake of amino acids by the liver of rats fed on high-protein diets is obtained by developing favourable gradients and enhancing transport capacities. These adaptations allow sufficient amounts of amino acids to enter the liver, where accelerated metabolism plays a decisive role.


Author(s):  
L. V. Vronska ◽  
A. Ye. Demyd

The aim of the research was to study the amino acid profile of the phaseolus vulgaris pods and extract prepared of them. Materials and methods. Five samples of raw material of phaseolus vulgaris pods (erect herbaceous bushes varieties with white seeds) were collected in the Ternopil and Volyn regions, dry extract of phaseolus vulgaris pods was obtained according to previously developed technology. The study of amino acid composition of the raw materials of phaseolus vulgaris pods and extract prepared of them was carried out using a thin-layer chromatography (TLC) and a high-performance liquid chromatography (HPLC). Results and discussion. The better separation of amino acids in TLC-research of the raw material of phaseolus vulgaris pods was observed in the system of solvents isopropanol - formic acid - water (40: 2: 10). As a result of the study, aspartic and glutamic acids, glycine, valine, tyrosine and leucine were identified. The amino acid profile of the studied samples of raw material is quite homogeneous in composition: 7 essential amino acids (histidine, threonine, valine, methionine, phenylalanine, isoleucine and leucine) and 8 non-essential amino acids (aspartic and glutamic acids, arginine, serine, glycine, alanine, tyrosine and proline); lysine was found among the bound amino acids in the 4th sample of raw material. Proline predominates in all samples of raw materials among free amino acids. Among the bound amino acids the content of glutamic acid, which is the product of the glutamine hydrolysis, is the highest. The content of glycine, serine and alanine is also high. Among the essential amino acids, leucine, phenylalanine, histidine, threonine, isoleucine, valine were determined in content descending order. The quantitative determination of amino acids in the extract of phaseolus vulgaris pods proved that the content of proline was the highest (12.47 mg / g); the content of some compounds was also high: aspartic (5.41 mg / g) and glutamic (3.41 mg / g) acids, arginine (5.10 mg / g; both in free and bound forms), glycine (1.02 mg / g) and serine (1.04 mg / g). Among the essential amino acids in the extract, the amount of valine (0.80 mg / g), phenylalanine (0.67 mg / g), threonine (0.66 mg / g), leucine (0.63 mg / g) and isoleucine (0.58 mg / g) was a little different. The total content of amino acids in the extract was 3.2%. Conclusions. 1. The amino acid profile of five samples of phaseolus vulgaris pods was studied by the HPLC method. It has been established that the composition is quite homogeneous, and the total content varies within 0.7-1.1%. 2. In the dry extract of phaseolus vulgaris pods the content of 5 essential and 7 non-essential amino acids has been determined. The content of free amino acids in the extract is 0.52%; the total content of free and bound amino acids is 3.2%. 3. When studying the stability and establishing the shelf life of the dry extract of phaseolus vulgaris pods, it is necessary to take into account the presence of free amino acids and protein substances.  


Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 500
Author(s):  
Juliana A. Barreto Peixoto ◽  
Gerardo Álvarez-Rivera ◽  
Rita C. Alves ◽  
Anabela S. G. Costa ◽  
Susana Machado ◽  
...  

The phenolics profile, free amino acids composition, and antioxidant potential of rosemary infusions were studied. Forty-four compounds belonging to nine different groups (hydroxybenzoic acids, hydroxycinnamic acids, flavan-3-ols, flavanones, flavones, phenolic diterpenes, hydroxybenzaldehydes, coumarins, and pyranochromanones) were identified by UHPLC-ESI-Q-TOF-MS. Of these, seven were firstly described in rosemary infusions: a rosmanol derivative, two dihydroxycoumarin hexosides, a hydroxybenzaldehyde, a dihydroxybenzoic acid hexoside, coumaric acid hexoside, and isocalolongic acid. The free amino acid profile of the beverages was also reported by the first time with seven amino acids found (asparagine, threonine, alanine, tyrosine, phenylalanine, isoleucine, and proline). Furthermore, DPPH• scavenging ability, Ferric Reducing Antioxidant Power and Oxygen Radical Absorbance Capacity, as well as total phenolics and flavonoids contents, were assessed. Overall, rosemary infusions showed to be a very good source of antioxidants. A 200 mL cup of this infusion contributes to the ingestion of ~30 mg of phenolic compounds and about 0.5–1.1 μg of free amino acids. This type of beverages may present a positive impact on the maintenance of the body antioxidant status and contribute to the prevention of oxidative stress related diseases.


2001 ◽  
Vol 281 (1) ◽  
pp. G267-G274 ◽  
Author(s):  
Julio J. Boza ◽  
Martial Dangin ◽  
Denis Moënnoz ◽  
Franck Montigon ◽  
Jacques Vuichoud ◽  
...  

The objectives of the present study were to determine the splanchnic extraction of glutamine after ingestion of glutamine-rich protein (15N-labeled oat proteins) and to compare it with that of free glutamine and to determine de novo glutamine synthesis before and after glutamine consumption. Eight healthy adults were infused intravenously in the postabsorptive state with l-[1-13C]glutamine (3 μmol · kg−1 · h−1) andl-[1-13C]lysine (1.5 μmol · kg−1 · h−1) for 8 h. Four hours after the beginning of the infusion, subjects consumed (every 20 min) a liquid formula providing either 2.5 g of protein from 15N-labeled oat proteins or a mixture of free amino acids that mimicked the oat-amino acid profile and contained l-[2,5-15N2]glutamine andl-[2-15N]lysine. Splanchnic extraction of glutamine reached 62.5 ± 5.0% and 66.7 ± 3.9% after administration of 15N-labeled oat proteins and the mixture of free amino acids, respectively. Lysine splanchnic extraction was also not different (40.9 ± 11.9% and 34.9 ± 10.6% for15N-labeled oat proteins and free amino acids, respectively). The main conclusion of the present study is that glutamine is equally bioavailable when given enterally as a free amino acid and when protein bound. Therefore, and taking into consideration the drawbacks of free glutamine supplementation of ready-to-use formulas for enteral nutrition, protein sources naturally rich in this amino acid are the best option for providing stable glutamine.


1998 ◽  
Vol 67 (1) ◽  
pp. 139-145 ◽  
Author(s):  
H. Y. Al-Matubsi ◽  
G. Bervanakis ◽  
S. M. Tritton ◽  
R. G. Campbell ◽  
R. J. Fairclough

AbstractForty first cross hybrid gilts were used to study the effect of dietary protein during lactation on free amino acid, protein and total oestrogen concentrations in colostrum and milk. The diets were formulated to contain similar levels of digestible energy (DE) but with either 236 or 186 g protein per kg and 13·3 and 8·1 g lysine per kg air-dried diet respectively. Both diets were offered at 2·5 kg/day for 1 week prior to farrowing and ad libitum throughout a 24-day lactation (no. = 20 gilts per treatment). Colostrum and milk were collected manually at 3h (colostrum), 3, 7, 14 and 22 days (milk) post partum. Free amino acid concentrations in colostrum and milk were determined by high-performance liquid chromatography following derivatization of the amino acids by 9-fluorenylmethyl chloroformate. The lysine and glutamic acid concentrations in colostrum were the most abundant free amino acids followed by tryptophan and taurine in order of decreasing abundance. Milk free taurine concentrations increased to the greatest extent among all free amino acids over the 21 days of lactation. Gilts' mature milk was rich in free taurine, glutamic acid, glycine and lysine. During the first 3 h post partum, the protein content of colostrum was unaffected by dietary protein. However, milk protein content over 7 to 21 days of lactation was significantly higher in gilts offered the higher protein diet (P < 0·001). Total solids in colostrum and milk was not significantly affected by dietary protein. At 3h and 3 days post partum the concentrations of total oestrogen in colostrum and milk, determined by radioimmunoassay, were significantly higher in gilts offered the high protein diet (P < 0·05). These finding indicate that a high protein diet in late gestation and during lactation can influence protein content, amino acid and oestrogen concentrations of milk in gilts.


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