Effect of Nopal (Opuntia ficus indica) Consumption at Different Maturity Stages as an Only Calcium Source on Bone Mineral Metabolism in Growing Rats.

This work determines the effect nopal consumption at different maturity stages (60, 200, 400, and 600 g) as the only calcium source in bone metabolism. The apparent mineral absorption, the biomarkers of bone metabolism, the bone mineral density at different femoral regions, and crystal properties of the bone were evaluated during the growth stage. The Ca absorption was increased with the rat age in most of the experimental groups, while Mg supplementation decreased intestinal absorption probably due to a saturation process. Intestinal Ca and Mg absorption showed an opposite trend; this result suggests that both ions can compete for vitamin D absorption sites. The percentage of absorption of K was lower in the groups fed with Nopal; nevertheless, due to supplementation, the net absorption was higher than the control group. In all groups, osteocalcin levels decreased with the rat age. Nopal consumption increased osteocalcin levels during the adolescence stage in comparison to the control group. Amino N-terminal propeptide of type I procollagen levels increased in puberty and adolescence in all groups compared to the control group. Bone mineral density in different femoral regions was lower in the groups fed with nopal at early maturity stages (N-60 and N-200) than the groups fed with nopal at late maturity stages (N-400 and N-600). The crystal size of hydroxyapatite exhibited changes for all the groups, indicating the inclusion of mono and divalent ions in calcium replacement. On this basis, the nopal at late maturity stage contributed to bone formation.

Antihyperglycemic and hypoglycemic activity of naturally occurring peptides and protein hydrolysates from easy-to-cook and hard-to-cook beans (Phaseolus vulgaris L.).

The present study was undertaken to examine the antidiabetic potential of naturally occurring peptides and hydrolysate fractions from easy-to-cook (ETC) and hard-to-cook (HTC) beans. All fractions were tested regarding their in vitro inhibitory activities against α-amylase and α-glucosidase as well as in vivo anti-hyperglycemic and hypoglycemic effects. Results evidenced that the peptide fractions with the lowest molecular weight (<3 kDa) have the highest inhibitory activities, and a 16.9%-89.1% inhibition of α-amylase and 34.4%-89.2% inhibition of α-glucosidase were observed. Regarding the antihyperglycemic activity, the fraction ETCNO3-10 showed a better performance than the positive control (acarbose). In addition, results from hypoglycemic activity evidenced that the tested peptide fractions were able to decrease the glucose levels at the same extension of glibenclamide, maintaining a constant basal glucose level without a postprandial hyperglycemia peak. Finally, it is possible to suggest that the naturally occurring peptides and hydrolysate fractions obtained from ETC and HTC common beans could be used in functional food production or pharmaceutical formulations to prevent diabetes.

High relative consumption of vegetable protein is associated with faster walking speed in well-functioning older adults.

BACKGROUND: Adequate nutrition and, especially, optimal protein intake are necessary to preserve physical function during aging. Increased consumption of animal-derived protein is often advocated as a strategy to support physical performance in old age. However, there is a lack of empirical evidence to support this claim. AIMS: To assess the relationship of protein consumption and specific protein sources with physical function in older adults. METHODS: Participants were community dwellers aged 60 years and older recruited in São Paulo, Brazil. Enrollees had their medical books reviewed and were evaluated for anthropometry, physical performance, and diet. Physical performance was evaluated by isometric handgrip strength and walking speed (WS) tests. Diet was assessed using a 24-h recall diary. RESULTS: Ninety older adults were recruited (mean age: 68.0 ± 6.7 years; 87.0% women). Body weight-adjusted protein consumption was significantly associated with upper-limb muscle strength (r = 0.21; p < 0.05), but not with usual (r = 0.09; p > 0.05) or fast WS (r = 0.08; p > 0.05). Conversely, relative protein consumption was correlated with usual WS (r = 0.13; p < 0.05), while fast WS was negatively associated with relative animal protein intake (r = - 0.18; p < 0.05) and positively associated with relative plant-based protein ingestion (r = 0.15; p < 0.05). DISCUSSION: Findings of the present study indicate that different measures of protein intake are associated with distinct components of physical function. In addition, high relative ingestion of vegetable protein is associated with faster WS. CONCLUSIONS: A comprehensive dietary evaluation is necessary to appreciate the impact of specific nutrients on physical performance in older people. Future interventional studies are needed to establish the optimal blend of protein sources to support physical performance in old age.

Satietogenic Protein from Tamarind Seeds Decreases Food Intake, Leptin Plasma and CCK-1r Gene Expression in Obese Wistar Rats.

OBJECTIVE: This study evaluated the effect of a protein, the isolated Trypsin Inhibitor (TTI) from Tamarindus indica L. seed, as a CCK secretagogue and its action upon food intake and leptin in obese Wistar rats. METHODS: Three groups of obese rats were fed 10 days one of the following diets: Standard diet (Labina®) + water; High Glycemic Index and Load (HGLI) diet + water or HGLI diet + TTI. Lean animals were fed the standard diet for the 10 days. Food intake, zoometric measurements, plasma CCK, plasma leptin, relative mRNA expression of intestinal CCK-related genes, and expression of the ob gene in subcutaneous adipose tissue were assessed. RESULTS: TTI decreased food intake but did not increase plasma CCK in obese animals. On the other hand, TTI treatment decreased CCK-1R gene expression in obese animals compared with the obese group with no treatment (p = 0.027). Obese animals treated with TTI presented lower plasma leptin than the non-treated obese animals. CONCLUSION: We suggest that TTI by decreasing plasma leptin may improve CCK action, regardless of its increase in plasma from obese rats, since food intake was lowest.

Effect of free or protein-associated soy isoflavones on the antioxidant status in rats.

BACKGROUND: The objective of this study was to investigate the effect of chronic ingestion of free and protein-associated soy isoflavones on the antioxidant status in male Wistar rats. Free isoflavone (iso), protein-associated soy isoflavone (iso + prot) and soy protein (prot) extracts were administered for 30 days by gavage to the rats at a dosage of 1 mg aglycone isoflavones per 200 g body weight, adjusted daily, and the prot group was given the same concentration of soy protein received by the iso + prot group. Antioxidant capacity of plasma, thiobarbituric acid-reactive substance (TBARS) and glutathione (GSH) levels and catalase (CAT), glutathione peroxidase (GPx) and superoxide dismutase (SOD) activities in plasma, erythrocytes and tissues and gene expression levels in liver and kidney were evaluated. RESULTS: Chronic ingestion of free but not of protein-associated soy isoflavones nor of solely soy protein increased plasma antioxidant capacity and GPx activity in erythrocytes. Soy protein increased CAT activity and gene expression in liver. SOD activity in erythrocytes was increased by all treatments. CONCLUSION: The overall results confirm that dietary soy isoflavones have a positive effect on antioxidant status, enhancing antioxidant capacity of plasma and antioxidant enzymes in various tissues, but the effects are dependent on the form of administration and on a complex mechanism of antioxidant status balance on the organism.

Effect of methionine supplementation to a low-soybean protein diet on liver lipid metabolism.

Female Wistar rats were fed a low-soybean protein (8%) diet supplemented with different concentrations of DL-methionine (0-1.2%) during the lactation period. Diet supplementation with methionine caused a significant increase in rat body weight. The addition of 0.3% DL-methionine to the diet did not cause an increase in liver triacylglycerol concentration in 21-day-old rats, but an increase did occur after the addition of 0.6% DL-methionine to the diet. Supplementation of the diet with DL-methionine did not change liver phospholipid or protein concentrations, nor plasma triacylglycerol levels. Liver lipid synthesis from [1-14C]acetate in 21-day-old rats whose dams had been fed an 8% soybean protein diet supplemented with 1.2% DL-methionine was significantly higher than in the group receiving no DL-methionine supplementation. Hepatic production of CO2 and of water-soluble acid products from [1-14C]palmitate did not differ between groups. Inositol addition to a low-soybean protein diet supplemented with DL-methionine did not change triacylglycerol nor phospholipid levels in the liver.

[Biochemical and nutritional value of seeds of the lima bean (Phaseolus lunatus) in comparison with those of the common bean (Phaseolus vulgaris)]. / El valor bioquímico y nutricional de las semillas del haba de lima (Phaseolus lunatus) en comparación con las del frijol común (Phaseolus vulgaris).

Composition in nutrients and antinutritional factors, digestibility and growth in rats fed diets prepared with raw and cooked beans of Ph. vulgaris, cultivar "Tacarigua", and Ph. lunatus cultivar "Tapiramo", are compared. Grains from both cultivars are similar in appearance, taste, nutritional value, and acceptability. Protein and phosphorus contents were greater in Ph. vulgaris than in Ph. lunatus seeds. The chemical score and availability of lysine were better in Ph. lunatus. Diets prepared with raw beans from Ph. lunatus resulted non toxic for the rats during a 12-day period of feeding. All rats fed with raw beans from Ph. Vulgaris died in the same period of time. Protein efficiency was better with cooked beans of Ph. lunatus. The cultivar "Tapiramo" (Ph. lunatus) is recommended for autoconsumption by small farmers.

El valor bioquímico y nutricional de las semilla del haba de lima (Phaseolus lunatus) en comparación con las del frijol común (Phaseolus vulgaris) / Biochemical and nutritional value of seeds of lima bean (Phaseolus lunatus) in comparison with those of common bean (Phaseolus vulgaris>

Se compara la composición de nutrientes y factores antinutricionales, así como la digestibilidad y crecimiento, en ratas alimentadas con dietas preparadas a base de las semillas de un cultivar negro de Ph. vulgaris, "Tacarigua", y un cultivar negro de Ph. lunatus, "Tapiramo". Los granos cocidos de ambos cultivares se distinguen muy poco en su aspecto, sabor, valor nutricional y aceptabilidad. Las semillas de Ph. vulgaris continen más proteínas y fósforo que las de Ph. lunatus. El puntaje "score" químico para lisina y la disponibilidad de este aminoácido fue mejor en el caso del Ph. lunatus. Las dietas elaboradas con semillas crudas de Ph. lunatus no demostraron ser tóxicas para las ratas luego de 12 días de administrárseles, contrariamente a lo observado con el Ph. vulgaris. Se observa una mejor eficiencia proteínica con las semillas cocidas de Ph. lunatus. Se recomienda la producción del cultivar "Tapiramo" (Ph. lunatus) para autoconsumo de los pequeños agricultores

Developmental changes on protein turnover in growing rats fed on diets containing field beans (Vicia faba L.) as source of protein.

The effects of nutrition with Vicia Faba L. administered at two different levels (12 and 18% protein) on the developmental changes of protein turnover were investigated in the rat. The myofibrillar gain and synthesis values were lower in the animals fed on legume protein as compared with casein-fed controls, while no differences were found in myofibrillar degradation during the three periods of time evaluated (0-14, 14-28 and 28-45 days). The fractional myofibrillar gain, breakdown and synthesis calculated as the sum of both, decreased with age in all the dietary groups. The antinutritional effects of the inclusion of Vicia faba L. in diets were more evident in the first 28 days, and attributed to a decreased muscle protein synthesis.

[Effect of animal protein supplementation and energy on the protein quality of diets based on rice and beans in adult males]. / Efecto de la suplementación de proteína animal y energia en la calidad proteínica de dietas a base de arroz y frijol en hombres adultos.

Four short nitrogen balance index studies were carried out in adult subjects to evaluate the biological quality of a mixture based on rice and beans, and also to measure the effect of animal protein and/or energy supplementation on the nutritive value of the mixture. In the first study, rice supplied 60% and beans, 40% of the protein's diet, which was administered at an energy level of 45.5 kcal/kg/day of metabolizable energy. A regression coefficient of 0.76 +/- 0.11 was found between ingested nitrogen and nitrogen balance, and a value for nitrogen maintenance of 96.2 +/- 13.7 mg/kg/day. When this same diet was administered in the second study at a 51.2 kcal/kg/day of metabolizable energy, the regression coefficient was 0.80 +/- 0.13, and that of nitrogen for maintenance, 90.1 +/- 8.7 mg/kg/day, without differences being significant (P less than 0.05) for any of the two measures. In the third study, 10% of the mixture's protein was substituted by milk protein, and given at a level of 45.2 kcal/kg/day of metabolizable energy. In this case, the regression coefficient found was 0.96 +/- 0.08, and that of nitrogen for maintenance, 78.6 +/- 10.2 mg/kg/day. These values do differ significantly (P less than 0.05) from those found in the two previous studies. When the diet of the third study was administered to the same subjects at a level of 48.9 kcal/kg/day of metabolizable energy, the regression coefficient of the equation was 0.86 +/- 0.17, and that for maintenance nitrogen, 82.4 +/- 10.2 mg/kg/day. These values are statistically equal to those found in the third study and do differ significantly from those of the first two studies. Information indicates that the supplementary effect of protein and milk occurs mainly at the digestive level. It is therefore concluded that when rice and beans are consumed jointly, in the adequate proportions, they constitute an excellent-quality food for adult humans.