Urinary excretion of kaempferol from common beans (Phaseolus vulgaris L.) in humans

The aim of this study was to assess kaempferol bioavailability in healthy humans, after bean (Phaseolus vulgaris L.) consumption through the monitoring of the excretion in relation to intake. In seven healthy subjects receiving kaempferol from cooked bean, maximum excretion of hydrolysed flavonol was obtained after 2-8 h. Intersexual variations in urinary excretion were found to be 6.10+/-5.50% and 5.40+/-5.40% of the kaempferol dose for male and female subjects, respectively. Although a 6.72-fold inter-individual variation between the highest and lowest excretion concentrations was found, all individuals exhibited similar excretion profiles. Moreover, a direct correlation between the percentage of kaempferol excreted and the body mass index of volunteers was observed with a correlation index equal to 0.80. All except two individuals exhibited a first peak of kaempferol excretion 2 h after ingestion. The study reveals information about inter-individual excretion capacity after kaempferol intake and that kaempferol can be used as a biomarker for flavonol consumption.     

Urinary excretion of kaempferol from common beans (Phaseolus vulgaris L.) in humans

Locust bean gum acts as a milk thickener in infant formula because of its high apparent viscosity. The effects of such thickening agents on metabolic and physiologic responses during infancy have not been clarified sufficiently. Due to the increased volume of the digest and the bulking and trapping effects, digestion and absorption of nutrients may be influenced in presence of locust bean gum. The central question addressed in this paper is whether the thickening properties of locust bean gum affect the availability of calcium, iron, and zinc. Increasing amounts of powdered locust bean gum were homogenised with infant formula and samples were diluted to 0.14, 0.27, 0.42 and 0.71 g/100 ml. Viscosity of the samples was measured by a Carrie-Med CSL100 rheometer. Available amounts of calcium, iron, and zinc were evaluated using a continuous-flow dialysis model with preliminary digestion. Elemental contents of samples and dialysates were analysed with atomic absorption spectrometry. The first set of experiments showed that addition of locust bean gum to infant formulas increased the viscosity of the luminal contents. Correlations between the locust bean gum concentration and the viscosity of the samples before and after gastric or intestinal digestion were highly significant (0.97). In the second set of experiments, the correlations between the locust bean gum concentration and the amounts of calcium trapped by the locust bean gum fraction also showed high significance (0.93). In the third experimental design, again strong correlations were found between the viscosity of the intestinal digest and the amounts of calcium trapped by the fibre fraction (0.90). For iron and zinc, no such relationships were found. From this experimental set-up it appears that locust bean gum influences calcium availability in infant formulas by means of its physical properties to act as thickening agent, rather than its chemical ability to form complexes as demonstrated earlier with respect to iron and zinc.     

Comparison of growth, nitrogen metabolism and organ weights in piglets and rats fed on diets containing Phaseolus vulgaris beans

The effects of lectins in the diet have been mainly studied in rats. An important question is whether results obtained in rats can be extrapolated to larger animals like the pig. Phaseolus vulgaris beans are rich in toxic lectins. Therefore a study was carried out to compare the effects of diets containing 200 g Phaseolus vulgaris beans (raw or toasted)/kg in rats and piglets. Live-weight gain, nitrogen digestibility and N balance were much lower in piglets than in rats fed on diets containing raw beans. Live-weight gain and N balance were slightly negative in the piglets. When toasted beans were given, live-weight gain and N balance values were reduced in piglets but hardly at all in rats. Giving raw beans caused hypertrophy of the pancreas in the rats but in piglets the weight of the pancreas was reduced. Spleen weight was depressed in the piglets but not in the rats. Weight of liver was not affected in either animal species. When toasted beans were given no effects on the weights of pancreas, spleen or liver were found in piglets or rats. It was concluded that the piglet is much more sensitive to antinutritional factors in the Phaseolus vulgaris bean than the rat.     

The influence of cooked kidney beans (Phaseolus vulgaris) on intestinal cell turnover and faecal nitrogen excretion in the rat

Male Wistar rats were fed on semi-synthetic diets containing cooked white kidney beans (Phaseolus vulgaris) or equivalent levels of protein and carbohydrate. No change was observed in over-all nitrogen balance in animals fed on the bean diet, but there was a two- to three-fold increase in their faecal excretion, compared with control rats. This was compensated by a decrease in urinary-N excretion. Homogenized small intestinal mucosa, prepared from bean-fed animals, showed a 28% increase in protein content compared with control material. Measurements of 3H-labelled thymidine turnover indicated that mucosal cell exfoliation was increased by approximately 35% in the small intestines of bean-fed rats compared with controls. It is concluded that though a diet rich in cooked P. vulgaris leads to some increase in mucosal cell turnover in the small intestine of rats, the consequent increase in mucosal protein loss could not account for the increased faecal-N excretion seen in these animals.     

Metabolomic analysis of the effects of edible dry beans (Phaseolus vulgaris L.) on tissue lipid metabolism and carcinogenesis in rats

Metabolite profiling using liquid chromatography-time-of-flight MS was undertaken to identify candidate metabolic processes that account for dry bean effects on disease risk with a specific focus on the development of breast cancer. Normal mammary gland and mammary carcinomas from previously reported experiments were evaluated. Principal component analysis (PCA) of mass spectral data revealed that tissue of both types from control-fed v. bean-fed rats could be distinguished by their metabolomic profiles. Candidate ion identification using MassTRIX analysis software revealed that alterations in eicosanoid, fatty acid, TAG and steroid metabolism partially accounted for the differences observed in both PCA. In addition, evidence was obtained consistent with the hypothesis that the varying inhibitory effects on mammary carcinogenesis of genetically distinct dry bean types were mirrored by differential patterns of lipid metabolites in mammary carcinoma. The use of MassTRIX provided links for metabolite profile enrichment with metabolic pathways in the Kyoto Encyclopedia of Genes and Genomes. Implicated pathways included a linkage between diacylglycerol and protein kinase C and eicosanoid metabolites and inducible cyclo-oxygenase-2 and/or eicosanoid degradation mediated via 15-PG dehydrogenase. These pathways have been reported to be misregulated during the development of cancer. The differences observed between control-fed and bean-fed rats in lipid metabolism require validation using targeted analytical methods and detailed analyses of how bean bioactive food components regulate genes that control lipid biosynthesis, interconversion and catabolism.     

Mechanisms associated with dose-dependent inhibition of rat mammary carcinogenesis by dry bean (Phaseolus vulgaris, L.)

The purpose of this study was to determine whether a dry bean (Phaseolus vulgaris, L.) containing diet exerts an inhibitory effect on mammary carcinogenesis in a well-characterized rodent model for breast cancer. Twenty-one-d-old female Sprague Dawley rats were given an intraperitoneal injection of 1-methyl-1-nitrosourea and 7 d after carcinogen injection were randomized to 1 of 5 groups fed a modification of the AIN-93G diet formulation containing 0, 7.5, 15, 30, or 60% (wt:wt) small red dry bean incorporated as cooked, freeze-dried, and milled powder. All experimental diets had the same macronutrient content based on proximate analysis. Compared with the control group, dry bean consumption resulted in dose-dependent reductions in mammary cancer incidence (P = 0.046), cancer multiplicity (P = 0.001), and tumor burden (P = 0.01). Dry bean consumption was associated with dose-dependent reductions in plasma concentrations of glucose, insulin, insulin-like growth factor-1, C-reactive protein, and interleukin-6 in food-deprived rats. Analysis of mammary adenocarcinomas indicated that a dominant mechanism accounting for reduced tumor burden was the induction of apoptosis. B cell lymphoma 2 and X-linked inhibitor of apoptosis protein levels decreased and BCL-2-associated X protein increased with increasing dry bean consumption, findings consistent with the induction of apoptosis via the mitochondrial pathway. These data demonstrate that a legume without noteworthy content of isoflavones inhibits the development of mammary carcinogenesis and are consistent with a recent report from the Nurses Health Study that bean or lentil intake is associated with a lower risk for breast cancer.     

Mineral excretion of rats fed on diets containing faba beans (Vicia faba L.) or faba bean fractions.

The effects on faecal mineral excretion of two commercial varieties (local cultivar and Troy cultivar) of raw faba beans (Vicia faba L., minor) meal (VFM) and its fractions have been studied in growing rats. Diets contained local-VFM (dark seed coat) and Troy-VFM (light seed coat) at 474-500 g/kg diet, hull (VFH) from both varieties at 65 g/kg diet, and the insoluble cotyledon residue (VFCR) obtained from the Troy variety at 237 g/kg diet. Rats were pair-fed on diets which had been supplemented with amino acids to target requirements and contained similar amounts of zinc, manganese, iron and copper. With VFM diets the apparent absorption of Zn and Mn was significantly reduced. On the other hand, with hulls the apparent absorption of Fe was reduced while that of Cu slightly increased. As the amounts of calcium, phosphorus and magnesium in VFM and VFH diets were higher than in the controls, the increased intake resulted in a significant increase in both the apparent absorption and the faecal excretion of these minerals. The inclusion of VFCR in the diet had no significant effect on the mineral content of faeces. The relatively low concentrations of phytate in the bean seeds of 7.8 and 6.7 g/kg for the local and Troy cultivars respectively, could not adequately account for the increased mineral excretion. The results suggest that other seed constituents, possibly the soluble non-starch polysaccharides, may be involved in the elevated loss of Zn and Mn in rats fed on diets containing faba bean for extended periods, while some insoluble structural hull components may interfere with the absorption of Fe from the gut.     

Effect of gamma irradiation on nutritional value of dry field beans (Phaseolus vulgaris) for chicks.

The effect of gamma irradiation (60Co) of different varieties and breeding lines of dry field beans (Phaseolus vulgaris) on chick growth was determined using a chick growth assay in which the diet contained approximately 50% beans. Total protein (N X 6.25) in beans was not changed appreciably by irradiation (21 Mrad) but protein solubility in water was decreased. Irradiation increased in vitro enzymatic digestibility of bean protein by pepsin and by a mixture of trypsin, chymotrypsin and peptidase. In the bioassay the diet was formulated to derive half of the total protein (22.6%) from beans. Autoclaved Pinto and Pink beans gave significantly better growth than Red Mexican and White Pea beans. The differences between Red Mexican and White Pea beans were not significant except for Red Mexican breeding line number RS-59. The nutritional value of all varieties of beans, based on chick growth, was significantly improved by gamma irradiation. The irradiation treatment of beans tended to increase nitrogen retention by chicks and decrease uric acid nitrogen excretion in relation to nitrogen intake.     

Effect of variable protein contents in diets containing Phaseolus vulgaris beans on performance, organ weights and blood variables in piglets, rats and chickens

A comparison was made of the effects of antinutritional factors present in Phaseolus vulgaris on piglets, rats and chickens. Also the hypothesis of whether the negative effect on weight gain due to the inclusion of raw Phaseolus vulgaris in the diet can be attributed to an insufficient supply of amino acids was tested. Test diets containing 200 g raw Phaseolus beans/kg were balanced for digestible protein and amino acids; in one diet extra casein was incorporated. The main response criteria were live-weight gain and the weight of various organs including the intestine. Live-weight gain in piglets was markedly reduced during feeding 200 g raw Phaseolus vulgaris/kg in the diet, but not in rats and chickens. Addition of casein did not improve the weight gain of the piglets, indicating that a toxic factor was responsible for the reduced weight gain and not an insufficient supply of amino acids. The weights of the spleen and thymus were markedly reduced in the piglets when the diets with raw Phaseolus beans were given, but not in the rats and chickens. Additional supply of casein did not change this effect. Indications were found that when the supply of dietary protein is adequate there is no reduction in pancreas weight with raw Phaseolus beans as was observed in previous experiments. The weight of the intestine was increased in all three species due to feeding raw Phaseolus vulgaris.     

Optimization of the extraction of chlorophylls in green beans (Phaseolus vulgaris L.) by N,N-dimethylformamide using response surface methodology

A method for extracting and determining chlorophyll pigments (chlorophyll a and b) in green beans (Phaseolus vulgaris L.) was developed. The procedure was based on the solvent extraction of pigments in vegetable samples using N,N-dimethylformamide as the extractant. Optimal conditions for extraction were determined by experimental design using response surface methodology. Central composite design “2ⁿ+star” was used in order to optimize the following solvent extraction parameters: extraction time, homogenization time and number of extractions. The results suggest that the number of extractions is statistically the most significant factor and that the optimum values for the variables are 90 min extraction time, 1 min homogenization time and number of extractions 5. This work confirms the advantages of experimental design compared to traditional optimization strategies because it allows a large number of factors to be screened simultaneously, provides less ambiguous data and helps to visualize relationships between responses and factor levels. Pigments were determined using UV–vis spectrophotometry at 647 and 664 nm. The chlorophyll content was analyzed in three green-bean cultivars: Donna, Negrital and Emerite.     

Clinical complications of kidney bean (Phaseolus vulgaris L.) consumption

Kidney beans (Phaseolus vulgaris L.), are common legumes, consumed worldwide. The delicacy of kidney beans is highly appreciable but, at the same time, their toxicity has raised an alarming concern. Kidney bean toxicity may be divided into two subcategories: toxicity caused by its lectins, saponins, phytates, and protease inhibitors or allergenicity induced by its allergenic proteins. The purpose of this review is to unravel the facts behind the different aspects of toxicity and allergenicity induced by kidney beans and try to fill the gaps that exist currently.     

Non-digestible fraction of beans (Phaseolus vulgaris L.) modulates signalling pathway genes at an early stage of colon cancer in Sprague-Dawley rats

Colorectal cancer is one of the most common causes of morbidity and mortality in Western countries, the second cause of cancer mortality in the USA and a major public health problem in Mexico. A diet rich in legumes is directly related to the prevention of colon cancer, showing an inverse relationship with the development of colorectal adenomas in human subjects. The present study shows the results of molecular changes involved in the Tp53 pathway at an early stage in the distal colon tissue of azoxymethane (AOM)-induced colon cancer in rats evaluated by PCR array after exposure to diets containing the non-digestible fraction (NDF) of cooked bean (cultivar Bayo Madero). Significant differences were detected in seventy-two genes of the Tp53-mediated signalling pathway involved in apoptosis, cell-cycle regulation and arrest, inhibition of proliferation and inflammation, and DNA repair. Tp53, Gadd45a, Cdkn1a and Bax were highly expressed (9·3-, 18·3-, 5·5- and 3·5-fold, respectively) in the NDF+AOM group, whereas Cdc25c, Ccne2, E2f1 and Bcl2 were significantly suppressed (?-?9·2-, -?2·6-, -?18·4- and -?3·5-fold, respectively), among other genes, compared with the AOM group, suggesting that chemoprevention of aberrant crypt foci results from a combination of cell-cycle arrest in G1/S and G2/M phases and cell death by apoptotic induction. We demonstrate that the NDF from common bean modulates gene expression profiles in the colon tissue of AOM-induced rats, contributing to the chemoprotective effect of common bean on early-stage colon cancer.     

Edible dry bean consumption (Phaseolus vulgaris L.) modulates cardiovascular risk factors and diet-induced obesity in rats and mice

Pulses are grain legumes that have sustained the civilisations of the world throughout their development; yet this staple food crop has fallen into disuse, particularly in Westernised societies, and decreased consumption parallels increased prevalence of CVD. The objective of the present study was to identify mechanisms that account for the cardioprotective activity of dry bean (Phaseolus vulgaris L.), one of the four primary pulse crops, which is widely produced and consumed globally. Laboratory assays that can be used for in vivo screening of dry beans and other pulses to identify those with the greatest potential to benefit human health are also reported. Sprague-Dawley rats and a diet-induced obesity model in C57Bl/6 mice were used to assess the effect of cooked dry bean incorporated into a purified diet formulation on plasma lipids and hepatic proteins involved in the regulation of lipid biosynthesis. In both animal species, short-term feeding of a bean-containing diet reduced plasma total cholesterol and LDL-cholesterol without affecting HDL-cholesterol or total TAG. Mechanisms associated with cholesterol catabolism and excretion are the likely targets of the bean effect. Unexpectedly, bean-fed obese mice experienced weight loss as well as an improved plasma lipid profile within a 12?d time frame. These findings support the use of short-term (7-14?d) assays to investigate mechanisms that account for the cardioprotective and weight regulatory effects of dry bean and to screen dry bean germplasm resources for types of bean with high protective activity. These same assays can be used to identify the bioactive components of bean that account for the observed effects.     

Biofortification of green bean (Phaseolus vulgaris L.) and lettuce (Lactuca sativa L.) with iodine in a plant-calcareous sandy soil system irrigated with water containing KI

Uptake and translocation of iodine by green bean (Phaseolus vulgaris L.) and lettuce (Lactuca sativa L.) were investigated in a calcareous sandy soil-plant system. These plants were cultivated in calcareous sandy soil in presence of irrigation water with the iodine concentrations of 0.10, 0.25 and 0.50 mg/L. The growth of these plants was stimulated at the two lower iodine concentrations of 0.10 and 0.25 mg/L, but hampered at 0.50 mg/L. In lettuce the highest iodine dosage resulted in smaller leaf surface and higher number of leaves, nearly with the same biomass production. In the edible parts of green bean and lettuce plants irrigated with 0.25 mg/L iodine containing water, the iodine concentration levels amounted to 0.6 and 5.2 mg/kg dry weight (DW), respectively. In lettuce, the uptake and translocation of selected essential elements (P, Mg, Mn, Fe, Cu, Zn, B) were also stimulated (20-260%) by iodine treatment; however, in fresh bean pods this phenomenon was negligible. Considering the iodine level and moisture content of the fresh lettuce leaves and fresh bean pods, the consumption of 100 g fresh vegetable covers about 66%, 3% of the recommended dietary allowance (150 μg).     

Consumption of black beans and navy beans (Phaseolus vulgaris) reduced azoxymethane-induced colon cancer in rats

Beans (Phaseolus vulgaris) are an important food staple in many traditional diets. There is limited evidence to suggest an inverse relationship between bean consumption and colon cancer. The objective of this study was to determine whether consumption of black beans and/or navy beans would reduce colon carcinogenesis in rats. Rats were fed a modified AIN-93G diet (control) or diets containing 75% black beans or 75% navy beans for 4 wk, and then colon cancer was initiated by administration of two injections of azoxymethane 1 wk apart. At 31 wk after the second injection, the incidence of colon adenocarcinomas was significantly lower (P < 0.05) in rats fed the black bean (9%) and navy bean (14%) diets than in rats fed the control diet (36%). Total tumor multiplicity was also significantly lower in rats fed the black bean (1.1) and navy bean (1.0) diets than in rats fed the control diet (2.2). The 44-75% reduction in colon carcinogenesis in rats fed beans was attributed to 1) more controlled appetites, leading to significantly less body fat, and 2) much greater concentrations of butyrate in the distal colon. It was concluded that eating black beans and navy beans significantly lowered colon cancer incidence and multiplicity.     

Assessment of Genotoxic Effects of Boron on Wheat (Triticum aestivum L.) and Bean (Phaseolus vulgaris L.) by Using RAPD Analysis

In boron-rich soils of Turkey, boron tolerant wheat (Triticum aestivum L.) and sensitive bean (Phaseolus vulgaris L.) are most widely cultivated crops. In this study they have been studied to elucidate the probable genotoxic effects of boron by using RAPD analysis. During the study, root and stem lengths have been measured and inhibitory rates (%) of root growth have been found to be significant, starting from 10 (13%) and 5 ppm (19%) for wheat and bean, respectively, which is in strong correlation with the root DNA alterations; RAPD variations starting from 100 ppm for wheat and 25 ppm for bean. The preliminary findings encourage the use of these tools in investigation of genotoxic effects of boron on wheat, bean and the other crops.     

Effect of soaking prior to cooking on the levels of phytate and tannin of the common bean (Phaseolus vulgaris,L.) and the protein value

The effect of soaking in domestic processing, on the nutritive value of the common bean (Phaseolus vulgaris, L.) cv IAC-Carioca, was studied. Five treatments were carried out with experimental diets, and offered to male, recently weaned Wistar rats. The protein sources were, respectively, control diet (casein) (CC), casein plus the soluble solids found in the soaking water (CSS), freeze dried bean cooked without soaking (BNS), freeze dried bean cooked with the non-absorbed soaking water (BSW), freeze dried bean cooked without the non-absorbed soaking water (BSNW). and an aproteic diet (AP) for corrective purposes. The anti-nutritional factors (phytates and tannins), were determined in the differently processed beans and in the soaking water. The following values for the reduction of phytates were obtained: BNS (20.9%), BSNW (60.8%) and BSW (53.0%), and the tannins were reduced by: BNS (86.6%), BSNW (88.7%) and BSW (89.0%). No significant differences were observed between the various treatments using the common bean as protein source, with respect to the net protein ratio (NPR). With respect to the digestibility corrected by non-protein diet, values varying between 94.1% and 94.6% for casein, and between 57.5% and 61.4% for the common bean, were observed, the treatment BNS being more digestible. It was concluded that soaking did not interfere with the NPR of the experimental diets containing the common bean as protein source, nor did it reduce the tannin content. However soaking was capable of reducing the phytate levels in the common bean. On the other hand, soaking was unable to increase the protein digestibility of the common bean, since the treatment BNS showed the highest value for digestibility.     

The influence of rat endogenous nitrogen excretion on the assessment of bean protein quality

The main objective of the present work was to study the interference of rat endogenous nitrogen excretion with the assessment of digestibility and biological value of dry bean (Phaseolus vulgaris, L.) protein. Dry bean plants were cultivated under (15NH4)2SO4 fertilization and at harvest dry beans had 1.080 atoms % of 15N-excess. Nitrogen balance studies indicated that bean protein digestibility and biological value were higher when N-balance was based on 15N-excess as compared to total nitrogen, both for undenaturated and heat-denaturated protein. The 15N-balance also showed that heat treatment significantly improved (p less than or equal to 0.05) the digestibility of bean protein in the integral flour and in protein isolate while the biological value decreased for both materials. The results permitted the conclusion that the conventional methods employed for calculation of bean protein digestibility and biological value, based on total nitrogen balance and protein-free diet, underestimate these indices of protein quality.