Conjugated linoleic acids (CLAs) are positional and geometrical isomers of linoleic acid and some researchers have shown biological activities including modulation of lipid metabolism, atherogenesis, ...diabetes, and immune functions. In this study, the animals were supplemented with 2% of the average feed consumption with CLA (G1 = positive control) and safflower oil (G2 = negative control) and the test groups were supplemented with CLA at the concentration of 2 and 4% of the average feed consumption. To assess the CLA potential protective effect, two groups were used; G3 = CLA 2% + cyclophosphamide (CP) and G5 = CLA 4% + CP. To assess the mutagenic effects of CLA, two groups were used; G4 = CLA 2% + NaCI 0.9% and G6 = CLA 4% + NaCI 0.9%. In order to investigate the mutagenic/antimutagenic effects of CLA, micronucleus test was used. The results showed variation of feed consumption in the groups that received 4% of CLA, when compared to the control group (G1 and G2) and CLA groups (G3 and G4) (p < 0.05), during the period studied. It was observed that CLA did not show mutagenic effect at the concentrations tested (2 and 4%). Also, CLA showed antimutagenic effect at the same concentrations. However, the animals that received 4% of CLA, presented clinical signs of malnutrition.
The aim of the study was to investigate the effect of leucine supplementation combined with exercise and whey protein in cardiac mTOR anabolic pathway. Ninety-six weanling male Wistar rats were ...divided into eight groups and fed diets containing either casein or WP plus increasing levels (0, 3, 4.5 and 6% of diet) of l-leucine for 30days. A parallel set of eight groups was exercised for comparison. Serum aspartate amino transferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase and branched chain amino acids were determined by standard methods, and mammalian target of rapamycin (mTOR) and p70S6K by the Western blot analysis. Chronic l-leucine supplementation was capable of increasing both mTOR and p70S6K phosphorylation in the heart in a dose-dependent fashion, independent of the type of dietary protein in both groups, sedentary and exercised, but the exercise potentialized the activation of the anabolic pathway. The content of protein in heart increase with l-leucine supplementation and the heart mass relativized by body mass did not change. In conclusion, the combination of l-leucine and milk proteins (casein or whey protein) has the potential to increase the mTOR pathway in the cardiac muscle without increasing the heart mass. The novelty of this study is to show the effectiveness of a blend of leucine and whey protein as a viable alternative to maximize the activation of the anabolic pathway of cardiac muscle and that the exercise can improve this process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
The aim of the study was to investigate the effect of leucine supplementation combined with exercise and whey protein in cardiac mTOR anabolic pathway. Ninety-six weanling male Wistar rats were ...divided into eight groups and fed diets containing either casein or WP plus increasing levels (0, 3, 4.5 and 6% of diet) of l-leucine for 30 days. A parallel set of eight groups was exercised for comparison. Serum aspartate amino transferase, alanine aminotransferase, creatine kinase, lactate dehydrogenase and branched chain amino acids were determined by standard methods, and mammalian target of rapamycin (mTOR) and p70S6K by the Western blot analysis. Chronic l-leucine supplementation was capable of increasing both mTOR and p70S6K phosphorylation in the heart in a dose-dependent fashion, independent of the type of dietary protein in both groups, sedentary and exercised, but the exercise potentialized the activation of the anabolic pathway. The content of protein in heart increase with l-leucine supplementation and the heart mass relativized by body mass did not change. In conclusion, the combination of l-leucine and milk proteins (casein or whey protein) has the potential to increase the mTOR pathway in the cardiac muscle without increasing the heart mass. The novelty of this study is to show the effectiveness of a blend of leucine and whey protein as a viable alternative to maximize the activation of the anabolic pathway of cardiac muscle and that the exercise can improve this process.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
An association has been identified between the extent of roasting and the amount of extractable protein from the cocoa bean, its nutritive value, and the sensorial quality of the liquor. Cocoa nibs ...from fermented seeds (Theobroma cacao L.) were precision-roasted at 150 degrees C for 0, 30, 34, 38, 42, and 46 min and the protein fraction extracted. From the beginning of roasting, until minute 38, about 87% of the proteins were extractable, but the extractability substantially decreased to 72.7% at 42 min and to 65.3% at 46 min. Both total soluble protein determination and albumin concentration of the roasted nibs diminished slightly until minute 38, when acceptable sensory characteristics were obtained for the liquor. Both total nitrogen and capillary-electrophoretic separation and quantification of the albumin showed that the amounts of extractable protein in this fraction consistently followed a cyclic pattern until minute 42, irreversibly decreasing thereafter. Biological evaluation of the protein from the cocoa nibs roasted for the various times showed that at the point that the sensory rating approached that of a commercial liquor, the albumin content and nutritive value were still high. The findings suggest that with moderate, uniform roasting it may not be necessary to sacrifice the protein's biological value for the sensorial attributes of chocolate in a standard commercial roast.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Previous studies have shown that hydrolyzed proteins exhibit antioxidant properties and may confer physical and physiological advantages when consumed by the exercising rat. The purpose of this study ...was to compare the effects of feeding either intact (I) and partly hydrolyzed (H) milk whey proteins on gastrocnemial DNA contents and protein metabolism in exercising Wistar rats. Protein synthesis and degradation, protein and DNA contents, and concentration of the serum insulin-like growth factor-1 (IGF1) were determined in six experimental groups according to the type of protein consumed casein (C), whey protein isolate (I), hydrolyzed whey protein (H) and level of physical activity (sedentary (S) and trained (T). H produced significantly lower rates of protein synthesis and degradation and DNA contents in the gastrocnemius, while no differences were observed in the total muscle protein content and serum levels of IGF1. These results indicate that consumption of prehydrolyzed whey protein alters muscle metabolism resulting in less DNA, but maintains the muscle protein levels constant and sustain or improves physical performance, compared to the unhydrolyzed protein.
Exhaustion time, serum lactate, serum glucose, albumin and total proteins were determined in exercising young rats as means to assess the physiological effect of consuming a diet based on partly ...hydrolysed milk whey protein in comparison to the intact protein, fed at a sub-optimal protein level. A medium degree-of-hydrolysis (DH) whey protein hydrolysate (H), fed at 12% protein, have been examined. The rats were grouped according to the level of activity for sedentary (S), trained (T) and exercised to exhaustion (E) and to the type of protein in the diet: whey-protein isolate (I) or its partial hydrolysate (H). After feeding the diets under sedentary conditions for 2 weeks, the animals underwent physical training on the treadmill for 8 days, followed by an exhaustion test. Time to exhaustion and blood lactate were recorded immediately after exhaustion. Serum glucose, albumin and total proteins, and gastrocnemius protein were determined at 48
h post-exhaustion. The animals consuming the hydrolysed protein endured longer times of activity, in comparison to those consuming the isolate (156±18 vs. 60±13
min). Blood lactate was significantly (
P
<
0.0001
) lower in all of the hydrolysate-fed groups as compared to the rats fed the whole protein. Analogously, serum albumin levels were higher in all H groups, as compared to the I groups (
P
<
0.001
), while the levels of total serum protein were significantly higher for the trained and exhausted groups (
P
<
0.0025
). No differences in muscle protein content and glycemic levels for any of the groups were observed. It can be concluded that a dietary protein, fed at a sub-optimal level for growth in the form of a hydrolysate with medium DH may result in augmented physical performance of the exercising rat, while no adverse effects are observable. Alternatively, these observations suggest that consumption of a protein in the hydrolysed form may increase its efficiency in terms of physical performance.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
Aflatoxin B1 (AFB1) exerts a chronic carcinogenic and an acute toxic effect on animals. Whereas the mechanism for carcinogenicity is known, no mechanism has been proposed for the toxic action. Among ...the most prominent signs of aflatoxicosis in several species, including birds and mammals, are hypolipidaemia, hypocholesterolaemia, and hypocarotenaemia, associated with severe hepatic steatosis and weight loss. We suggest that these signs of acute imbalance of lipid metabolism can be the result of the chemical modification (blocking) of key lysyl residues on the LDL protein B-100 by the activated AFB1 molecule. Modified LDLs are not recognised by their specific receptors and thus are rejected by peripheral cells. Upon return to the liver, the modified particles bind to the sinusoidal lining cells. Lipid starvation of peripheral tissues takes place while fat accumulates in the liver. This abnormal state is maintained and reinforced by further modification of nascent apoproteins, which in turn become unable to receive a lipid load for as long as aflatoxin continues to be available in the liver.
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DOBA, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SIK, UILJ, UKNU, UL, UM, UPCLJ, UPUK, VSZLJ
Aflatoxin B1 (AFB1) exerts a chronic carcinogenic and an acute toxic effect on animals. Whereas the mechanism for carcinogenicity is known, no mechanism has been proposed for the toxic action. Among ...the most prominent signs of aflatoxicosis in several species, including birds and mammals, are hypolipidaemia, hypocholesterolaemia, and hypocarotenaemia, associated with severe hepatic steatosis and weight loss. We suggest that these signs of acute imbalance of lipid metabolism can be the result of the chemical modification (blocking) of key lysyl residues on the LDL protein B-100 by the activated AFB1 molecule. Modified LDLs are not recognised by their specific receptors and thus are rejected by peripheral cells. Upon return to the liver, the modified particles bind to the sinusoidal lining cells. Lipid starvation of peripheral tissues takes place while fat accumulates in the liver. This abnormal state is maintained and reinforced by further modification of nascent apoproteins, which in turn become unable to receive a lipid load for as long as aflatoxin continues to be available in the liver.
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DOBA, GEOZS, IJS, IMTLJ, IZUM, KILJ, KISLJ, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SIK, UILJ, UKNU, UL, UM, UPCLJ, UPUK, VSZLJ
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