Dietary phytate and mineral bioavailability

Chitosan Phytate Nanoparticles: A Synergistic Strategy for Effective Dental Caries Prevention

Dental caries is a widespread oral disease that poses a significant medical challenge. Traditional caries prevention methods, primarily the application of fluoride, often fall short in effectively destroying biofilms and preventing enamel demineralization, thereby providing limited efficacy in halting the progression of caries over time. To address this issue, we have developed a green and cost-effective synergistic strategy for the prevention of dental caries. By combining natural sodium phytate and chitosan, we have created chitosan-sodium phytate nanoparticles that offer both the antimicrobial properties of chitosan and the enamel demineralization-inhibiting capabilities of sodium phytate. In an ex vivo biofilm model of human teeth, we found that these nanoparticles effectively prevent biofilm buildup and acid damage to the mineralized tissue. Additionally, topical treatment of dental caries in rodent models has shown that these nanoparticles effectively suppress disease progression without negatively impacting oral microbiota diversity or causing harm to the gingival-mucosal tissues, unlike traditional prevention methods.

Phytate Intake, Health and Disease: "Let Thy Food Be Thy Medicine and Medicine Be Thy Food"

Phytate (myo-inositol hexakisphosphate or InsP6) is the main phosphorus reservoir that is present in almost all wholegrains, legumes, and oilseeds. It is a major component of the Mediterranean and Dietary Approaches to Stop Hypertension (DASH) diets. Phytate is recognized as a nutraceutical and is classified by the Food and Drug Administration (FDA) as Generally Recognized As Safe (GRAS). Phytate has been shown to be effective in treating or preventing certain diseases. Phytate has been shown to inhibit calcium salt crystallization and, therefore, to reduce vascular calcifications, calcium renal calculi and soft tissue calcifications. Moreover, the adsorption of phytate to the crystal faces can inhibit hydroxyapatite dissolution and bone resorption, thereby playing a role in the treatment/prevention of bone mass loss. Phytate has a potent antioxidation and anti-inflammatory action. It is capable of inhibiting lipid peroxidation through iron chelation, reducing iron-related free radical generation. As this has the effect of mitigating neuronal damage and loss, phytate shows promise in the treatment/prevention of neurodegenerative disease. It is reported that phytate improves lipid and carbohydrate metabolism, increases adiponectin, decreases leptin and reduces protein glycation, which is linked with macrovascular and microvascular diabetes complications. In this review, we summarize the benefits of phytate intake as seen in in vitro, animal model, epidemiological and clinical trials, and we also identify questions to answer in the future.

Phytate Dephosphorylation Products Also Act as PotentInhibitors of Calcium Oxalate Crystallization

Phytate has been classified as an anti-nutrient, but there are no adverse effects from the consumption of a balanced diet with 1 to 2 g of daily phytate (inositol-hexaphosphate, InsP6) as a calcium magnesium salt, the form naturally present in grains. Furthermore, recent research has shown that phytate consumption may prevent pathological calcifications, such as kidney stones and cardiovascular calcifications. However, many endogenous and exogenous enzymes can hydrolyze phytate to lower inositol phosphates (InsPs) that also have biological activity. We performed a controlled hydrolysis of phytate and identified the products (InsPs) using tandem mass spectrometry (MS/MS). The total level of all InsPs was measured using a non-specific methodology. In addition, we evaluated the effects of the InsP6 hydrolysates on calcium oxalate crystallization using scanning electron microscopy and measuring the time needed for the induction of crystallization. Our results indicate that InsP6 and its hydrolysis products functioned as effective inhibitors of calcium oxalate crystallization. Thus, even though InsP6 is hydrolyzed after consumption, the enzymatic products also have the potential to reduce pathological calcifications. Finally, although it is useful to measure the overall level of InsPs in biological fluids, such as urine, there is a need to develop simple analytical methods to quantify the level of individual InsPs.

Effects of Phytic Acid-Degrading Bacteria on Mineral Element Content in Mice

Trace minerals are extremely important for balanced nutrition, growth, and development in animals and humans. Phytic acid chelation promotes the use of probiotics in nutrition. The phytic acid-degrading strain Lactococcus lactis psm16 was obtained from swine milk by enrichment culture and direct plate methods. In this study, we evaluated the effect of the strain psm16 on mineral element content in a mouse model. Mice were divided into four groups: basal diet, 1% phytic acid, 1% phytic acid + psm16, 1% phytic acid + 500 U/kg commercial phytase. Concentrations of acetic acid, propionic acid, butyric acid, and total short-chain fatty acids were significantly increased in the strain psm16 group compared to the phytic acid group. The concentrations of copper (p = 0.021) and zinc (p = 0.017) in liver, calcium (p = 0.000), manganese (p = 0.000), and zinc (p = 0.000) in plasma and manganese (p = 0.010) and zinc (p = 0.022) in kidney were significantly increased in psm16 group, while copper (p = 0.007) and magnesium (p = 0.001) were significantly reduced. In conclusion, the addition of phytic acid-degrading bacteria psm16 into a diet including phytic acid can affect the content of trace elements in the liver, kidney, and plasma of mice, counteracting the harmful effects of phytic acid.

Understanding the Protective Effect of Phytate in Bone Decalcification Related-Diseases

Myo-inositol hexaphosphate (phytate; IP6) is a natural compound that is abundant in cereals, legumes, and nuts, and it can bind to crystal surfaces and disturb crystal development, acting as crystallization inhibitor. The adsorption of such inhibitors to crystal faces can also inhibit crystal dissolution. The binding of phytate to metal cofactors suggests that it could be used for treatment of osteoporosis. Our in-vitro study showed that phytate inhibits dissolution of hydroxyapatite (HAP). The effect of phytate was similar to that of alendronate and greater than that of etidronate. This led us to perform a cross-sectional study to investigate the impact of consumption of IP6 on bone mineral density (BMD) in post-menopausal women. Our data indicate that BMD and t-score of lumbar spine increased with increasing phytate consumption, and a phytate consumption higher than 307 mg/day was associated with a normal BMD (t-score > −1). These data suggest that phytate may have a protective effect in bone decalcification by adsorbing on the surfaces of HAP, and a daily consumption of phytate-rich foods (at least one serving/day of legumes or nuts) may help to prevent or minimize bone-loss disorders, such as osteoporosis. However, further studies are needed to gain a better understanding about the mechanism of inhibition of phytate in bone-related diseases (see graphical abstract).

Salivary cystatin SN is a factor predicting iron bioavailability after phytic acid rich meals in female participants

Phytic acid is an inhibitor of iron bioavailability, but it has been suggested that individuals may adapt to phytic acid over time, and that the salivary protein, cystatin SN, may be involved. This study evaluated the relationship between human cystatin SN levels and iron bioavailability after a phytic acid rich meal. Three groups of ten women consumed meals with: (1) 500 mg phytate sprinkles, (2) 500 mg phytate capsules, or (3) no phytic acid. Iron bioavailability was measured by the mealtime percentage of maximum iron recovery; cystatin SN was measured pre-and post-meal by enzyme-linked immunosorbent assay. Pre-to-post meal cystatin SN was positively correlated with improved iron bioavailability in group 1. Pre-to-post meal cystatin SN was correlated with improved iron absorption in groups 1 and 2. Cystatin SN recovery after phytic acid rich meals may be a physiological factor predicting iron bioavailability.

Salivary Cystatin SN Binds to Phytic Acid In Vitro and Is a Predictor of Nonheme Iron Bioavailability with Phytic Acid Supplementation in a Proof of Concept Pilot Study

BACKGROUND

Acute phytic acid intake has been found to decrease iron bioavailability; however, repeated phytic acid consumption leads to iron absorption adaptation. Salivary proline-rich proteins (PRPs) have been shown to inhibit iron chelation to tannins and may mediate similar iron absorption adaptation with phytic acid intake.

OBJECTIVES

The objectives of this study were to determine whether salivary proteins bind to phytic acid in vitro, and to explore a proof of concept in a pilot study that examined the impact of 4-wk, daily phytic acid supplementation on individuals' iron status, bioavailability, and salivary PRP concentrations.

METHODS

High-performance liquid chromatography (HPLC) and matrix-assisted laser desorption/ionization-time of flight were used to characterize in vitro salivary protein-phytic acid interactions. Nonanemic women (n = 7) consumed 350 mg phytic acid supplements 3 times daily for 4 wk, and meal challenges were employed to determine iron bioavailability, iron status, and salivary protein concentrations before and after supplementation periods. Enzyme-linked immunosorbent assay (ELISA) analysis of purified protein fractions and participant saliva identified proteins bound to phytic acid.

RESULTS

In vitro salivary protein-phytic acid interaction identified cystatin SN, a non-proline rich salivary protein, as the specific bound protein to phytic acid. Iron bioavailability (P = 0.32), hemoglobin (P = 0.72), and serum ferritin (P = 0.08) concentrations were not reduced from week 0 to week 4 after phytic acid supplementation. Basic PRPs and cystatin SN concentrations were positively correlated with iron bioavailability at week 4.

CONCLUSIONS

Overall, results suggest that phytic acid binds to the non-PRP cystatin SN and that salivary protein production may improve iron bioavailability with phytic acid consumption.

Phytate Decreases Formation of Advanced Glycation End-Products in Patients with Type II Diabetes: Randomized Crossover Trial

Myo-inositol hexaphosphate (phytate; IP6) is a natural compound that is abundant in cereals, legumes, and nuts and it has the ability to chelate metal cations. The binding of IP6 to transition metals suggests that it could be used for the treatment of metal-catalyzed protein glycation, which appears to trigger diabetes-related diseases. Our in vitro studies showed that IP6 reduced the formation of Fe3+-catalyzed advanced glycation end-products (AGEs). This led us to perform a randomized cross-over trial to investigate the impact of the daily consumption IP6 on protein glycation in patients with type 2 diabetes mellitus (T2DM; n = 33). Thus, we measured AGEs, glycated hemoglobin (HbA1c), several vascular risk factors, and urinary IP6 at baseline and at the end of the intervention period. Patients who consumed IP6 supplements for 3 months had lower levels of circulating AGEs and HbA1c than those who did not consume IP6. This is the first report to show that consumption of IP6 inhibits protein glycation in patients with T2DM. Considering that AGEs contribute to microvascular and macrovascular complications in T2DM, our data indicates that dietary supplementation with IP6 should be considered as a therapy to prevent the formation of AGEs and therefore, the development of diabetes-related diseases in patients with T2DM.

Teff consumption and anemia in pregnant Ethiopian women: a case-control study

PURPOSE

Teff, an iron-rich staple grain in Ethiopia, is consumed mainly in the form of teff injera (TI). Studies on the association of TI consumption with anemia are limited. We aimed to determine the association of frequencies of TI consumption with anemia, in Addis Ababa, Ethiopia.

METHODS

We conducted a hospital-based case-control study involving 592 pregnant women: 187 anemic cases, and 405 non-anemic controls. TI consumption was assessed by a food frequency questionnaire (FFQ). Multiple logistic regression, adjusted for dietary and non-dietary covariates, was performed to determine the relation of TI consumption to anemia status.

RESULTS

We found that a decrease in frequency of TI consumption was significantly associated with an increase in the likelihood of anemia (p-trend = 0.009). Compared with everyday TI consumption, the adjusted odds ratios (AORs) of anemia associated with the other frequencies of teff consumption were 1.50 [95% confidence interval (CI) 0.71, 3.23; p = 0.285] for every other day, 2.13 (95% CI 1.03, 4.41; p = 0.04) for 1-2 times a week, and 3.17 (95% CI 1.62, 6.22; p < 0.001) for once in 2 weeks.

CONCLUSIONS

Teff consumption was associated with reduced odds of anemia in pregnant women. Further studies are warranted, including determining the feasibility and effectiveness of TI use for anemia prevention.

REGISTRATION

The study was registered as https://clinicaltrials.gov/ct2/show/NCT03251664 .

Plant phosphates, phytate and pathological calcifications in chronic kidney disease

Phytate, or myo-inositol 1,2,3,4,5,6-hexakis dihydrogen phosphate (InsP6), is a naturally occurring phosphorus compound that is present in many foods, mainly legumes, whole grains and nuts. Patients with chronic kidney disease (CKD) have cardiovascular disease mortality up to 30times higher than the general population. Vascular calcifications (VCs) directly contribute to overall morbidity and mortality, especially in CKD. In part, this high mortality is due to elevated levels of phosphorus in the blood. Therefore, control of dietary phosphorus is essential. Dietary phosphorus can be classified according to its structure in organic phosphorus (plant and animal) and inorganic (preservatives and additives). Plant-phosphorus (legumes and nuts), mainly associated with InsP6, is less absorbable by the human gastrointestinal tract as the bioavailability of phosphorous from plant-derived foods is very low. Recent data indicate that restriction of foods containing plant phosphates may compromise the adequate supply of nutrients that have a beneficial effect in preventing cardiovascular events, such as InsP6 or fibre found in legumes and nuts. Experimental studies in animals and observational studies in humans suggest that InsP6 can prevent lithiasis and VCs and protect from osteoporosis. In conclusion, we need prospective studies to elucidate the potential benefits and risks of phytate (InsP6) through the diet and as an intravenous drug in patients on haemodialysis.

Protective Effect of Myo-Inositol Hexaphosphate (Phytate) on Abdominal Aortic Calcification in Patients With Chronic Kidney Disease

OBJECTIVE

The aim of this study was to evaluate the relationship between physiological levels of myo-inositol hexaphosphate (phytate) and cardiovascular (CV) calcification in patients with chronic kidney disease (CKD).

DESIGN AND METHODS

This was a prospective cross-sectional study conducted from December 2012 to June 2013.

SUBJECTS

Sixty-nine consecutive patients with CKD who were not undergoing renal replacement therapy.

INTERVENTION

All subjects were given lateral lumbar X-rays to quantify abdominal aortic calcification (AAC). Clinical laboratory analyses and phytate food frequency questionnaires were also performed.

MAIN OUTCOME MEASURE

Phytate urinary excretion, estimated phytate consumption (based on food frequency questionnaire) and AAC score. Patients were divided into two groups based on median abdominal aortic calcification (AAC) score: no/mild AAC (AAC ≤ 6, n = 35) and moderate/severe AAC (AAC > 6, n = 34).

RESULTS

Patients with no/mild AAC were younger, had lower pulse pressure, greater dietary intake of phytate, greater urinary phytate and the prevalence of prior CV disease was significantly lower compared to patients with moderate/severe AAC. Among the top 10 phytate-rich foods, lentil consumption was significantly greater in patients with no/mild AAC than in those with moderate/severe AAC. Multivariate logistic regression analysis indicated that age, prior CV disease, urinary phytate (or lentil consumption) were independently associated to AAC.

CONCLUSION

Our results suggest that adequate consumption of phytate can prevent AAC in patients with CKD. Further prospective studies must be performed to elucidate the benefits of a phytate-rich diet and the associated risk of phosphorus bioavailability in these patients.

Protective effect of myo-inositol hexaphosphate (phytate) on bone mass loss in postmenopausal women

INTRODUCTION

The objective of this paper was to evaluate the relationship between urinary concentrations of InsP6, bone mass loss and risk fracture in postmenopausal women.

MATERIALS AND METHODS

A total of 157 postmenopausal women were included in the study: 70 had low (≤0.76 μM), 42 intermediate (0.76-1.42 μM) and 45 high (≥1.42 μM) urinary phytate concentrations. Densitometry values for neck were measured at enrollment and after 12 months (lumbar spine and femoral neck), and 10-year risk fracture was calculated using the tool FRAX(®).

RESULTS

Individuals with low InsP6 levels had significantly greater bone mass loss in the lumbar spine (3.08 ± 0.65 % vs. 0.43 ± 0.55 %) than did those with high phytate levels. Moreover, a significantly greater percentage of women with low than with high InsP6 levels showed more than 2 % of bone mass loss in the lumbar spine (55.6 vs. 20.7 %). The 10-year fracture probability was also significantly higher in the low-phytate group compared to the high-phytate group, both in hip (0.37 ± 0.06 % vs 0.18 ± 0.04 %) and major osteoporotic fracture (2.45 ± 0.24 % vs 1.83 ± 0.11 %).

DISCUSSION

It can be concluded that high urinary phytate concentrations are correlated with reduced bone mass loss in lumbar spine over 12 months and with reduced 10-year probability of hip and major osteoporotic fracture, indicating that increased phytate consumption can prevent development of osteoporosis.

Health benefits of algal polysaccharides in human nutrition

The interest in functional food, both freshwater and marine algal products with their possible promotional health effects, increases also in regions where algae are considered as rather exotic food. Increased attention about algae as an abundant source of many nutrients and dietary fiber from the nutrition point of view, as well as from the scientific approaches to explore new nutraceuticals and pharmaceuticals, is based on the presence of many bioactive compounds including polysaccharides extracted from algal matter. Diverse chemical composition of dietary fiber polysaccharides is responsible for their different physicochemical properties, such as their ability to be fermented by the human colonic microbiota resulted in health benefit effects. Fundamental seaweed polysaccharides are presented by alginates, agars, carrageenans, ulvanes, and fucoidans, which are widely used in the food and pharmaceutical industry and also in other branches of industry. Moreover, freshwater algae and seaweed polysaccharides have emerged as an important source of bioactive natural compounds which are responsible for their possible physiological effects. Especially, sulfate polysaccharides exhibit immunomodulatory, antitumor, antithrombotic, anticoagulant, anti-mutagenic, anti-inflammatory, antimicrobial, and antiviral activities including anti-HIV infection, herpes, and hepatitis viruses. Generally, biological activity of sulfate polysaccharides is related to their different composition and mainly to the extent of the sulfation of their molecules. Significant attention has been recently focused on the use of both freshwater algae and seaweed for developing functional food by reason of a great variety of nutrients that are essential for human health.

Effect of tetracalcium dimagnesium phytate on bone characteristics in ovariectomized rats

The aim was to evaluate the influence of dietary Ca-Mg-phytate consumption on the bone characteristics of ovariectomized rats, an animal model for postmenopausal osteoporosis. Twenty ovariectomized female Wistar rats were randomly assigned to two groups fed, respectively, with a non-phytate diet (AIN-76A) or the same diet enriched with 1% phytate (as the calcium magnesium salt, phytin). After 12 weeks of feeding the rats were sacrificed, and both femoral bones and L4 vertebra were removed from each rat. Bone mass, length, width, volume, and mineral density were measured, and the phosphorus, calcium, magnesium, and zinc contents of bones were determined. Deoxypyridinoline (a bone resorption marker) was measured in urine, and osteocalcin (a bone formation marker) was measured in serum. The calcium and phosphorus contents and bone mineral density were significantly higher in both femoral bones and L4 vertebra for phytate-treated rats in comparison to rats in the non-phytate group. Deoxypyridinoline was significantly increased in rats in the non-phytate treatment group. Ca-Mg-phytate consumption reduces bone mineral density loss due to estrogen deficiency. Thus, phytate exhibits effects similar to those of bisphosphonates on bone resorption and may be of use in the primary prevention of osteoporosis if larger studies in humans confirm these findings.

Towards a unifying, systems biology understanding of large-scale cellular death and destruction caused by poorly liganded iron: Parkinson's, Huntington's, Alzheimer's, prions, bactericides, chemical toxicology and others as examples

Exposure to a variety of toxins and/or infectious agents leads to disease, degeneration and death, often characterised by circumstances in which cells or tissues do not merely die and cease to function but may be more or less entirely obliterated. It is then legitimate to ask the question as to whether, despite the many kinds of agent involved, there may be at least some unifying mechanisms of such cell death and destruction. I summarise the evidence that in a great many cases, one underlying mechanism, providing major stresses of this type, entails continuing and autocatalytic production (based on positive feedback mechanisms) of hydroxyl radicals via Fenton chemistry involving poorly liganded iron, leading to cell death via apoptosis (probably including via pathways induced by changes in the NF-κB system). While every pathway is in some sense connected to every other one, I highlight the literature evidence suggesting that the degenerative effects of many diseases and toxicological insults converge on iron dysregulation. This highlights specifically the role of iron metabolism, and the detailed speciation of iron, in chemical and other toxicology, and has significant implications for the use of iron chelating substances (probably in partnership with appropriate anti-oxidants) as nutritional or therapeutic agents in inhibiting both the progression of these mainly degenerative diseases and the sequelae of both chronic and acute toxin exposure. The complexity of biochemical networks, especially those involving autocatalytic behaviour and positive feedbacks, means that multiple interventions (e.g. of iron chelators plus antioxidants) are likely to prove most effective. A variety of systems biology approaches, that I summarise, can predict both the mechanisms involved in these cell death pathways and the optimal sites of action for nutritional or pharmacological interventions.

Effects of Mediterranean diets with low and high proportions of phytate-rich foods on the urinary phytate excretion

BACKGROUND

Important health benefits have been reported recently to phytate intake. This includes the prevention of pathological calcifications such as renal calculi, dental calculi and cardiovascular calcification, due its action as crystallization inhibitor of calcium salts, and as preventive of cancer.

AIM OF STUDY

The aim of this study was to establish a relation between the intake of phytate, through consumption of typical components of the Mediterranean diet (including nuts), and its excretion in urine.

METHODS

This study recruited participants from subjects included in a larger trial (PREDIMED) of food habits, that were assigned to one of two diet groups: (1) the Mediterranean diet with low proportion of phytate-rich food group, where participants were asked to maintain their usual diet; and (2) the Mediterranean diet with high proportion of phytate-rich food group, where participants were asked to increase phytate-rich foods in their diet. Phytate intake was assessed on the basis of a food frequency questionnaire. Urinary phytate excretion was determined in 2-h urine samples.

RESULTS

The overall phytate consumption of the Mediterranean diet with high proportion of phytate-rich food group (672 +/- 50 mg) was significantly higher than the Mediterranean diet with low proportion of phytate-rich food group (422 +/- 34 mg), representing a 59% difference. Urinary phytate excretion was also significantly higher (54%) in the Mediterranean diet with high proportion of phytate-rich food group (1,016 +/- 70 microg/L) than the Mediterranean diet with low proportion of phytate-rich food group (659 +/- 45 microg/L).

CONCLUSIONS

Mediterranean diets high in whole cereals, legumes and nuts compared to Mediterranean diets low in these phytate-rich foods increase the urinary phytate excretion in humans.

Calcium availability from yogurt by itself or yogurt-cereal-containing products

Dairy products are the basic source of calcium (Ca) for many nations. The aim of this study was to determine the influence of addition of cereal products to yogurt on the ability of subsequent release of Ca present in yogurt. This was conducted in vitro by the process of enzymatic digestion simulating digestion in the human gastrointestinal tract (GIT). Calcium content was determined in commercial yogurts containing cereal and in yogurt meals with subsequent addition of cereal products or bread. Only 3 samples contained more Ca than 100 mg/100 g. Only about 45% (from 28.5 to 77.9%) of Ca was released from the samples with cereals. Innovations in yogurt production technologies actually result in less Ca being released to humans, which may be a problem for individuals with low daily Ca intake.

Phytate (myo-inositol hexaphosphate) and risk factors for osteoporosis

Several risk factors seem to play a role in the development of osteoporosis. Phytate is a naturally occurring compound that is ingested in significant amounts by those with diets rich in whole grains. The aim of this study was to evaluate phytate consumption as a risk factor in osteoporosis. In a first group of 1,473 volunteer subjects, bone mineral density was determined by means of dual radiological absorptiometry in the calcaneus. In a second group of 433 subjects (used for validation of results obtained for the first group), bone mineral density was determined in the lumbar column and the neck of the femur. Subjects were individually interviewed about selected osteoporosis risk factors. Dietary information related to phytate consumption was acquired by questionnaires conducted on two different occasions, the second between 2 and 3 months after performing the first one. One-way analysis of variance or Student's t test was used to determine statistical differences between groups. Bone mineral density increased with increasing phytate consumption. Multivariate linear regression analysis indicated that body weight and low phytate consumption were the risk factors with greatest influence on bone mineral density. Phytate consumption had a protective effect against osteoporosis, suggesting that low phytate consumption should be considered an osteoporosis risk factor.

Study of the Absorption of Myo-Inositol Hexakisphosphate (InsP6) through the Skin

Recently, some properties of myo-inositol hexakisphosphate (InsP(6)) are related to its dermatological use as discolouring agent, on preventing calcinosis cutis or due to its important role on premature aging. Some studies also seem to demonstrate a capacity of InsP(6) to inhibit skin cancer. In this paper, a first study of the absorption of InsP(6) through the skin is developed. Due to the correlation between InsP(6) absorption and its urinary excretion, these last values were used to evaluate this process. It was found that using a moisturizing cream as vehicle, the InsP(6) sodium salt was absorbed at significantly higher amounts than the InsP(6) calcium-magnesium salt. Maximum InsP(6) urinary concentrations were observed approximately at 14 d of 2% InsP(6) topical cream application, and gave 66.35+/-5.49 mg/l urinary InsP(6) when the sodium salt was used and 16.02+/-2.61 mg/l urinary InsP(6) when the calcium-magnesium salt was applied. When the InsP(6) topical cream administration ceased, the InsP(6) urinary excretion fell dramatically approximately during a period of 10 d. From these results, it can be deduced that by topical administration InsP(6) can achieve important concentrations in tissues and biological fluids, this demonstrating that it is possible to propose the topic use as a new InsP(6) administration route.

Dietary myo-inositol hexaphosphate prevents dystrophic calcifications in soft tissues: a pilot study in Wistar rats

Myo-inositol hexaphosphate (InsP6) is an abundant component of plant seeds. It is also found in significant levels in blood and mammalian tissues, but they are totally dependent on their dietary intake. In the present paper, we describe studies on the effect of InsP6 on a model of dystrophic calcification, which was chemically induced by subcutaneous injection of a 0.1% KMnO4 solution. Male Wistar rats were randomly divided into four groups for treatment over 31 days. A: animals consuming a purified diet in which InsP6 was absent but to which 1% of InsP6 (as sodium salt) was added. In this group, the InsP6 plasma levels (0.393 +/- 0.013 microM) were similar to those observed in rats consuming a standard diet. B: animals consuming only the purified diet in which InsP6 was absent. In this case the InsP6 plasma levels decreased (0.026 +/- 0.006 microM); C: animals consuming the same purified diet as group B but received daily subcutaneous injections of 50 microg kg(-1) etidronate during the last 14 days. In this case the InsP6 plasma levels were also very low (0.025 +/- 0.007 microM); D: animals consuming the same diet as group B but a 6% of carob germ (InsP6 rich product) was added. The InsP6 plasma levels (0.363 +/- 0.035 microM) were also similar to those observed in rats consuming a standard diet. After 21 days plaque formation was induced. Calcification plaques were allowed to proceed for 10 days, after which the plaque material present was excised, dried and weighed. It was found that the presence of myo-inositol hexaphosphate (phytate) in plasma at normal concentrations (0.3-0.4 microM) clearly inhibited the development of dystrophic calcifications in soft tissues. These results demonstrates that myo-inositol hexaphosphate acts as an inhibitor of calcium salt crystallization.

Effect of phytate on element bioavailability in the second generation of rats

In this paper the relation between long term consumption of a high dose of sodium phytate and the mineral status of the organism is evaluated in rats. For this purpose, element concentrations (Ca, Mg, Fe, Zn, Mn) were determined in liver, heart, testicle, bone and urine of a second generation of Wistar rats, treated with a phytate free diet (AIN-76A) and with the same diet plus 1% phytate as sodium salt. The most significant differences were observed between bone zinc contents of male and female rats. The zinc content of rats fed a 1% phytate as sodium salt diet resulted clearly lower than that found in no-phytate treated rats. Hence, it is concluded that when up to 1% of phytate as sodium salt is consumed together with an equilibrated purified diet (free of phytate), no decrease in mineral bioavailability is observed in second generation rats, except for an indication of lower zinc availability by lower zinc concentrations in some organs, mainly bone. However, using this purified diet, the zinc concentration in bone resulted around 10 times higher than found in rats fed with a common non purified rat chow.

Phytate as the sole phosphate source for growth of Tetrahymena

Phytate, the storage form of phosphate in seeds and grains, is a major form of environmental phosphate loading from fertilizer inputs and agricultural runoff. We have investigated the ability of Tetrahymena populations to grow on phytate as their sole phosphate source. Populations grew equally well in chemically defined medium with phosphate and medium in which the phosphate was replaced with phytate in comparable concentrations between 0.5 mM and 6 mM. Intracellular phytate concentrations of cells grown in phytate showed a 4-6-fold increase over those grown in phosphate when measured during the late stage of exponential growth. These results demonstrate that phytate can provide a source of adequate phosphate for sustained growth in phytate-rich environments.