Potential antiproliferative activity of polyphenol metabolites against human breast cancer cells and their urine excretion pattern in healthy subjects following acute intake of a polyphenol-rich juice of grumixama (Eugenia brasiliensis Lam.).

The bioavailability and metabolism of anthocyanins and ellagitannins following acute intake of grumixama fruit, native Brazilian cherry, by humans, and its in vitro antiproliferative activity against breast cancer cells (MDA-MB-231) were investigated. A single dose of grumixama juice was administered to healthy women (n = 10) and polyphenol metabolites were analyzed in urine and plasma samples collected over 24 h. The majority of the metabolites circulating and excreted in urine were phenolic acids and urolithin conjugates, the gut microbiota catabolites of both classes of polyphenols, respectively. According to pharmacokinetic parameters, the subjects were divided into two distinct groups, high and low urinary metabolite excretors. The pool of polyphenol metabolites found in urine samples showed a significant inhibition of cell proliferation and G2/M cell cycle arrest in MDA-MB-231 cells. Our findings demonstrate the large interindividual variability concerning the polyphenol metabolism, which possibly could reflect in health promotion.

Parameters involved in binding of porcine pancreatic alpha-amylase with black bean inhibitor: role of sulfhydryl groups, chloride, calcium, solvent composition and temperature.

The amylase inhibitor of black (kidney) beans (Phaseolus vulgaris; MW 53,000) forms a 1:1 stoichiometric complex with porcine pancreatic alpha-amylase (MW 52,000) at pH 5.40. The single sulfhydryl group of the inhibitor and the two sulfhydryl groups of alpha-amylase are not involved in recognition and binding. Chloride ions, required for activity of alpha-amylase at both pH 5.40 and 6.90, are important for inhibitor--enzyme binding at pH 6.90 but not at pH 5.40. Calcium-free alpha-amylase binds with the inhibitor. An increase in the ionic strength of the solvent increases the rate of binding of the inhibitor with alpha-amylase; a decrease in the dielectric constant decreases the rate of binding; and decreasing the temperature increases the dissociation constant, Kd, of the complex. These data support the hypothesis that hydrophobic interaction is of primary importance in complex formation. The activation energy, Ea, for complex formation was found to be 12.4 kcal/mol at pH 5.40 and 24.2 kcal/mol at pH 6.90. In the presence of the poor substrate, p-nitrophenyl-alpha-D-maltoside, the Ea for complex formation was 4.1 kcal/mol at pH 6.90.

[Effect of phytohemagglutinins on cell proliferation of the small intestine epithelium of rats]. / Efeito da fitohemaglutinina na proliferação celular do epitélio do intestino delgado de ratos.

Twenty male rats, were divided into two groups of ten animals each: E group, which received solid diet containing 4% of phytohemagglutinin and P group iso-caloric par-fed control, which received the same diet but the phytohemagglutinin was inactivated by heat. Water was offered ad libitum to all groups. The animals were weighed every day and the consumption of diet and water was registered. In the fourteenth day of experiment, the animals were sacrificed and the fragments of jejunum and ileum were removed to morphokinetic study. The results showed that the hydric ingestion was the same in both groups, the body weight of the E group was significant smaller than P group, the villus cell population from the jejunum of the E group was statistically smaller than P group and the contrary happened with ileum samples, wherein the E group was statistically larger than P. The jejunum villus height from E group was similar with P group, but in the ileum of the E group was larger than P. The depth, the cell population and cell production rate of crypt of E group were larger than P, in the jejunum and in the ileum. In conclusion, these results in the present study supply evidence that the intake of the phytohemagglutinin provokes injury of jejunal mucosa, reducing the villus cell population and stimulating the crypt hyperplasia, developing local adaptation. This adaptative model is similar to the one that occurs in celic disease. This proximal lesion stimulate crypt-villus unit hyperplasia of the ileal epithelium, developing distal adaptation. These adaptations occurred in animals that ingested phytohemagglutinin, even though with multicarencial malnutrition.

[Effect of the ingestion of soybean fractions, raw or autoclaved, on the rat thyroid]. / Efeito da ingestão de frações de soja crua ou autoclavada sobre a tireóide de ratos.

Feeding rats for 16 days a water soluble fraction from raw soy flour caused a 40% enlargement of thyroid weight, a similar decrease of 131I uptake and an increase of tri-iodo-thyronine-binding capacity of rat serum. This effect was heat labile. The same fraction autoclaved was able to reduce radioactive iodine uptake and to decrease T3-binding capacity. In longer assays (29 days) this same fraction produced a 30% increase of 131I uptake and altered thyroid hormones increasing T3 and T4 synthesis. An increase of MIT/DIT and a decrease of T3/T4 ratios was also observed by the authors.

[Trypsin inhibitory activity of beans (Phaseolus vulgaris L.): critical evaluation of methods for determination]. / Atividade inibitória de tripsina do feijão (Phaseolus vulgaris L.): avaliação crítica dos métodos de determinação.

High values of residual trypsin inhibitory activity found for heat-treated beans indicated the occurrence of artifices due to the methodology. A critical evaluation of the methods in use and of possible interferents was performed trying to determine the most adequate way of measuring residual trypsin inhibitory activity. Results showed that extraction conditions, pH of reaction and sample preparation are responsible for significant alterations of the values found, requiring careful standardization. This is the first report about the influence of lyophilization upon residual trypsin inhibitory activity of cooked beans.

[Evolution of phenolic compounds and condensed tannins (Proanthocyanidins) during the development of bean seeds (Phaseolus vulgaris L.)]. / Evolução dos fenólicos totais e taninos condensados (Proantocianidinas) durante o desenvolvimento das sementes do feijão (Phaseolus vulgaris L.).

The evolution of phenolic compounds and tannins (proanthocyanidins) of bean seeds, Phaseolus vulgaris L., (cultivar aroana 80), from anthesis to maturity (10 to 45 days after anthesis), was investigated. During seed development, phenolic compounds and tannins contents increased by seed unit, until the 31st and 21st day after anthesis respectively, decreasing afterwards. The gradual decrease in catechin and the increase of its polymers (intermediate compounds), as well as the gradual increase in alpha-amylase inhibition capacity were indications that tannins polymerize during seed development.

[Antinutritional effect of phytohemagglutinins of Phaseolus vulgaris L]. / Ação anti-nutricional das fito-hemaglutininas de Phaseolus vulgaris,L.

The antinutritional effect caused by the ingestion of lectins from two Brazilian varieties of beans: Rico 23 and Jalo, was studied in rats. The two varieties were selected in a previous screening of toxicity in rats: one of them (Jalo) was lethal, and the other (Rico 23) was not, when injected intra-peritoneally. Different amounts of each one of the lectins were added to casein experimental diets and fed to rats. The amount of protein (casein) also varied from 5% to 20%. The addition to the diet of 1% lectins from the Jalo variety caused a growth depression, as well as a decrease in food efficiency ratio and serum glucose; also, it reduced the maltase and invertase activity of the intestinal mucosa. All these effects appeared when the protein contents in the rations were 5% or 10%. At the 20% level only a depression of the maltase activity was observed. Similar effects were shown by the lectins of the Rico 23 variety, but only when added in a higher (5%) percentage to the diet. The phosphatase and protease activity were not changed by any of the lectins. The inhibitor activity that occurred in vivo was not detected in vitro.

[Carbohydrates and fiber]. / Considerações sobre carboidratos e fibra.

Dietary carbohydrates comprise two fractions that may be classified as digestible, and which are useful as energy sources (simple and complex carbohydrates) and fiber, which is presumed to be of no use to the human body. There are insufficient epidemiologic data on the metabolic effects of simple carbohydrates and it is not advisable to make quantitative recommendations of intake. It is questionable to recommend in developing countries that a fixed proportion of dietary energy be derived from simple sugars, due to the high prevalence of deficient energy intake, cultural habits, and regional differences in food intake and physical activity. In relation to recommendations of complex carbohydrates, it should be considered that their absorption is influenced by many factors inherent to the individual and to the foods. Fiber is defined as a series of different substances derived from tissue structures, cellular residues and undigested chemical substances that may be partially utilized after intestinal bacteria have acted on them. There is not a clear definition of the chemical composition of fiber, but it consists mainly of polysaccharides (such as cellulose, hemicellulose and pectins), lignin and end products of the interactions of various food components. The effects of fiber, such as control of food intake, regulation of gastrointestinal transit, post-prandial blood concentrations of cholesterol, glucose and insulin, flatulence and alterations in nutrient bioavailability are due to various physical properties inherent to its chemical components. Impairment of nutrient absorption may be harmful, mainly among populations whose food intake is lower than their energy needs, and with a high fiber content. This may be particularly important in pregnant women, growing children and the elderly, and should be considered when making nutrient recommendations. A precise knowledge of fiber is also important to calculate the real energy value of foods, mainly for two reasons: 1) the proportion of "crude fiber" (as measured by acid and alkaline digestion) leads to an over-estimation of the proportion of digestible carbohydrates calculated by difference; 2) fiber may alter the polysaccharide utilization of some foods, as shown by the "glycemic index". It is difficult to make recommendations on dietary fiber due to insufficient data on intake, fiber composition, its physiological effects, and epidemiological studies. However, a preliminary evaluation of the diets from most Latin American countries shows large intakes of vegetable foods and, consequently, an adequate fiber intake may be expected.

[Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. II. Analysis of minerals]. / Estudo bromatológico de concentrados proteicos obtidos a partir da Sardinella aurita eda Tilapia melanopleura II. Ensaio dos minerais

The calcium and phosphorus of fish protein concentrates (FPC) prepared from whole sardines or tilapias have high biological availability, but the mineral fraction as a whole did not support the normal growth of young rats. Fluoride absorption and utilization is low; the amount retained in the carcass of rats depends on the amount given in the diet according to the equation: Y=0,0672X + 0,202 Y=mg of fluorine retained X=ppm of fluorine in the diet In case of sub-optimal levels of mineral ingestion, fluoride fixation increased proportionally to the deficiency. Our results demonstrate that does not seem necessary to reduce the amount of fluoride in FPC intended for human consumption, at least for people without mineral deficiency in the diet. Results concerning the Ca, P and F balance in rats are presented.

[Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. III. Effects of potassium suplementation on the biological value]. / Estudo bromatolotico de concentrados proteicos obtidos a partir da Sardinella aurita eda Tilapia melanopleura III. Effeito da suplementacao com potassio sobre ovalor biologico

Bromatological study of protein concentrates from Sardinella aurita and Tilapia melanopleura. III. Effect of potassium additions on the biological utilizations. The authors studied in rats, the effect of suplementation of fish protein concentrates with Ca, P, K, or Na. Only the addition of K, but not of Ca, P, or Na resulted a better utilization of protein, showing to be the major deficiency of the mineral fraction of the concentrates.

Water extracts of cabbage and kale inhibit ex vivo H(2)O(2)-induced DNA damage but not rat hepatocarcinogenesis.

The chemopreventive potential of water extracts of the Brassica vegetables cabbage and kale was evaluated by administering their aqueous extracts in drinking water ad libitum to Wistar rats submitted to Ito's hepatocarcinogenesis model (CB group and K group, respectively - 14 rats per group). Animals submitted to this same model and treated with water were used as controls (W group - 15 rats). Treatment with the vegetable extracts did not inhibit (P > 0.05) placental glutathione S-transferase-positive preneoplastic lesions (PNL). The number of apoptotic bodies did not differ (P > 0.05) among the experimental groups. Ex vivo hydrogen peroxide treatment of rat livers resulted in lower (P < 0.05) DNA strand breakage in cabbage- (107.6 +/- 7.8 microm) and kale- (110.8 +/- 10.0 microm) treated animals compared with control (120.9 +/- 12.7 microm), as evaluated by the single cell gel (comet) assay. Treatment with cabbage (2 +/- 0.3 microg/g) or kale (4 +/- 0.2 microg/g) resulted in increased (P < 0.05) hepatic lutein concentration compared with control (0.5 +/- 0.07 microg/g). Despite the absence of inhibitory effects of cabbage and kale aqueous extracts on PNL, these Brassica vegetables presented protection against DNA damage, an effect possibly related to increased hepatic lutein concentrations. However, it must be pointed out that the cause-effect relationship between lutein levels and protection is hypothetical and remains to be demonstrated.

Water extracts of cabbage and kale inhibit ex vivo H2O2-induced DNA damage but not rat hepatocarcinogenesis

The chemopreventive potential of water extracts of the Brassica vegetables cabbage and kale was evaluated by administering their aqueous extracts in drinking water ad libitum to Wistar rats submitted to Ito’s hepatocarcinogenesis model (CB group and K group, respectively - 14 rats per group). Animals submitted to this same model and treated with water were used as controls (W group - 15 rats). Treatment with the vegetable extracts did not inhibit (P > 0.05) placental glutathione S-transferase-positive preneoplastic lesions (PNL). The number of apoptotic bodies did not differ (P > 0.05) among the experimental groups. Ex vivo hydrogen peroxide treatment of rat livers resulted in lower (P < 0.05) DNA strand breakage in cabbage- (107.6 ± 7.8 µm) and kale- (110.8 ± 10.0 µm) treated animals compared with control (120.9 ± 12.7 µm), as evaluated by the single cell gel (comet) assay. Treatment with cabbage (2 ± 0.3 µg/g) or kale (4 ± 0.2 µg/g) resulted in increased (P < 0.05) hepatic lutein concentration compared with control (0.5 ± 0.07 µg/g). Despite the absence of inhibitory effects of cabbage and kale aqueous extracts on PNL, these Brassica vegetables presented protection against DNA damage, an effect possibly related to increased hepatic lutein concentrations. However, it must be pointed out that the cause-effect relationship between lutein levels and protection is hypothetical and remains to be demonstrated.

[Evolution of the total volatile basis and trimethylamine in fish and their use as an indicator of its quality]. / Evolução das bases voláteis totals e da trimetilamina em pescados e o seu uso como indicador de qualidade.

The authors followed trimetylamine (TMA) and Total Volatile Basis (TVB) evolution in some Brazilian fishes during ice storage at 4 degrees C for 15 days. The fishes studied were: Micropogon furniere, Umbrina canosai, Centropomus undecimalis, Cysnoscion acoupa; samples were taken and analyzed each 48 h. Each species was stored eviscerated (E) or not-eviscerated (NE) in order to estabilish a possible advantage of on board evisceration. The results showed a log. relation between TVB or TMA percentage in the fish tissues and the days of storage; Mathematical models were established for predicting "storage life" for each fish out the basis of its amine content. Evisceration, immediatly after capture retarded deterioration and seem to be a useful practice.

Jejunal ultrastructural changes induced by kidney bean (Phaseolus vulgaris) lectins in rats.

Rats maintained for a period of 5 days on a diet containing purified lectins extracted from a Brazilian variety (called 'Jalo') of white kidney beans (Phaseolus vulgaris) developed marked ultrastructural changes in the epithelium of the proximal jejunum, while both pair-fed and ad-libitum-fed controls did not. The jejunal absorptive cells of rats fed a diet containing lectins exhibited conspicuous abnormalities of the microvilli. They were shorter, slightly thicker, irregular and more sparse; some were bi- or tri-furcated, sharing a common base of implantation. A slightly disorganized terminal web was present below the brush border. The supranuclear cytoplasm of a great number of cells exhibited large cytolysosomes. Comparison with the results of pair-feeding suggests that purified bean lectins have a direct causative role in the pathogenesis of absorptive cell changes in the jejunal villi of rats. The possible pathogenic mechanism of these lesions is discussed.

Purification and Characterization of Two Major Lectins from Araucaria brasiliensis syn. Araucaria angustifolia Seeds (Pinhão).

Two major lectins (lectin I and lectin II) were purified to homogeneity from the seeds of Araucaria brasiliensis (Gymnospermae). The purity of the lectins was confirmed by polyacrylamide gel electrophoresis, isoelectric focusing, and high performance liquid chromatography. They are glycoproteins in nature containing 6.3 and 2.9%, respectively, of neutral sugar and have absorption coefficients of 3.8 and 4.7, respectively, at 280 nanometers. The molecular weights of both lectins obtained by gel filtration on Sephacryl S-400 were equal: 200,000. After dissociation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, molecular weights were 20,000 and 34,000, respectively, for lectin I and lectin II, suggesting they are decameric and hexameric in nature. The amino acid composition of both lectins showed little difference, but both had high amounts of acidic amino acids and lacked methionine in their molecule. The carbohydrate binding specificity of lectins was directed towards mannose, glucose, and their oligomers. High inhibitory activity was also found with thyroglobulin. The erythroagglutinating activity of the lectins was enhanced in the presence of high-molecular-weight substances both at 37 and 4 degrees C. Divalent cations do not appear to be essential for activity. They maintained their agglutinating activity over a broad but different range of pH: 5.5 to 7.5 and 6.5 to 7.5, respectively. Both lectins agglutinated erythrocytes of human ABO blood types equally well.

[Effect of irradiation and heat on the agglutination and mitogenic capacity of phytohemagglutinins]. / Efeito Da irradiação e do calor sobre a capacidade Aglutinante E Mitogênica De Fito-Hemaglutininas

The authors studied the effect of ionizing radiation on hemaglutinating and mitogenic activity of phytohemaglutinis (PHA) in solution. 10 Krad (electron beam) are needed for the destruction of 50% of the aglutinating capacity. The mitogenic effect is more resistent to irradiation (70 Krad for 50% inactivation) maybe because both effects are due to different molecules. Changes were also followed by electrophoresis in polyacrylamida. The resistence to irradiation showed to be exponential function of the concentration of PHA in solution.