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Journal of Zhejiang University.... Mar 2008Phytic acid (PA) is the primary storage compound of phosphorus in seeds accounting for up to 80% of the total seed phosphorus and contributing as much as 1.5% to the... (Review)
Review
Phytic acid (PA) is the primary storage compound of phosphorus in seeds accounting for up to 80% of the total seed phosphorus and contributing as much as 1.5% to the seed dry weight. The negatively charged phosphate in PA strongly binds to metallic cations of Ca, Fe, K, Mg, Mn and Zn making them insoluble and thus unavailable as nutritional factors. Phytate mainly accumulates in protein storage vacuoles as globoids, predominantly located in the aleurone layer (wheat, barley and rice) or in the embryo (maize). During germination, phytate is hydrolysed by endogenous phytase(s) and other phosphatases to release phosphate, inositol and micronutrients to support the emerging seedling. PA and its derivatives are also implicated in RNA export, DNA repair, signalling, endocytosis and cell vesicular trafficking. Our recent studies on purification of phytate globoids, their mineral composition and dephytinization by wheat phytase will be discussed. Biochemical data for purified and characterized phytases isolated from more than 23 plant species are presented, the dephosphorylation pathways of phytic acid by different classes of phytases are compared, and the application of phytase in food and feed is discussed.
Topics: 6-Phytase; Animals; Diet; Environment; Humans; Iron; Neoplasms; Phytic Acid
PubMed: 18357620
DOI: 10.1631/jzus.B0710640 -
Plant Science : An International... Mar 2014A pathway of phytic acid (PA) synthesis in plants has been revealed via investigations of low phytic acid mutants. However, the regulation of this pathway is not well...
A pathway of phytic acid (PA) synthesis in plants has been revealed via investigations of low phytic acid mutants. However, the regulation of this pathway is not well understood because it is difficult to control the environments of cells in the seeds, where PA is mainly synthesized. We modified a rice suspension culture system in order to study the regulation of PA synthesis. Rice cells cultured with abscisic acid (ABA) accumulate PA at higher levels than cells cultured without ABA, and PA accumulation levels increase with ABA concentration. On the other hand, higher concentrations of sucrose or inorganic phosphorus do not affect PA accumulation. Mutations in the genes RINO1, OsMIK, OsIPK1 and OsLPA1 have each been reported to confer low phytic acid phenotypes in seeds. Each of these genes is upregulated in cells cultured with ABA. OsITPK4 and OsITPK6 are upregulated in cells cultured with ABA and in developing seeds. These results suggest that the regulation of PA synthesis is similar between developing seeds and cells in this suspension culture system. This system will be a powerful tool for elucidating the regulation of PA synthesis.
Topics: Abscisic Acid; Cell Culture Techniques; Cells, Cultured; Oryza; Phosphates; Phytic Acid; Sucrose
PubMed: 24467907
DOI: 10.1016/j.plantsci.2013.12.015 -
Gut Apr 1996Phytic acid, a major constituent of cereals, pulses, and seeds has been advocated as an important antioxidant component of dietary fibre that affords possible protection...
AIMS
Phytic acid, a major constituent of cereals, pulses, and seeds has been advocated as an important antioxidant component of dietary fibre that affords possible protection against colorectal cancer. This is supported by experimental studies showing it has antineoplastic activity in animal models of both colon and breast cancer. To date the concentration of faecal phytic acid in human clinical groups has not been evaluated. Therefore the faecal phytic acid content of adenoma patients drawn from a placebo controlled calcium intervention trial was evaluated.
METHODS
Phytic acid was measured in faecal extracts by an improved ion-pair high performance liquid chromatography method.
RESULTS
Phytic acid was detected in the range 0.68-4.00 mumol/g wet faeces and 55-2038 mumol/day. Linear regression analyses showed no association between stool phytic acid and lipid content. Strong correlations were seen, however, between phytic acid and iron content, both on a concentration (r = 0.52; p = 0.00004) and daily excretion (r = 0.76; p = 5.5 x 10(-12) basis. Phytic acid was also strongly correlated with the daily excretion of calcium (r = 0.59; p = 1.36 x 10(-6) and magnesium (r = 0.42; p = 0.001). Cell proliferation in the sigmoid colon, an intermediate biomarker of colorectal cancer was not significantly associated with faecal phytic acid, minerals or lipid content in this compromised clinical group.
CONCLUSIONS
This improved method, developed for the determination of phytic acid in faeces should allow further studies on the role of phytic acid in the aetiology of colorectal cancer to be conducted on a population or case control basis.
Topics: Adenoma; Biomarkers, Tumor; Chromatography, High Pressure Liquid; Colorectal Neoplasms; Edible Grain; Feces; Female; Humans; Solanum lycopersicum; Male; Middle Aged; Phytic Acid; Seeds; Glycine max; Spices
PubMed: 8707094
DOI: 10.1136/gut.38.4.591 -
Viruses Nov 2018The mechanisms that drive formation of the HIV capsid, first as an immature particle and then as a mature protein shell, remain incompletely understood. Recent... (Review)
Review
The mechanisms that drive formation of the HIV capsid, first as an immature particle and then as a mature protein shell, remain incompletely understood. Recent discoveries of positively-charged rings in the immature and mature protein hexamer subunits that comprise them and their binding to the cellular metabolite inositol hexakisphosphate (IP6) have stimulated exciting new hypotheses. In this paper, we discuss how data from multiple structural and biochemical approaches are revealing potential roles for IP6 in the HIV-1 replication cycle from assembly to uncoating.
Topics: Capsid; HIV-1; Phytic Acid; Virus Assembly; Virus Uncoating
PubMed: 30445742
DOI: 10.3390/v10110640 -
PloS One 2023This study evaluated phytic acid (IP6) effect on the viability, alkaline phosphatase (ALP) activity and calcium release of human periodontal ligament (HPDL) cells in...
OBJECTIVES
This study evaluated phytic acid (IP6) effect on the viability, alkaline phosphatase (ALP) activity and calcium release of human periodontal ligament (HPDL) cells in optimal (OGL) and elevated glucose level (EGL) in cell culture media.
MATERIALS AND METHODS
Cells were seeded in OGL (1000mg/L) or EGL (4500 mg/L) media. IP6 was added at 0.005%, 0.01% or 0.02% concentrations for 24 or 48h, and XTT assay was performed. Cell differentiation and calcium release in presence of 0.02% IP6 in OGL or EGL in non-osteogenic or osteogenic media were analyzed using ALP assay and alizarin red staining, respectively.
RESULTS
In OGL, IP6 enhanced the viability of the cells at both exposure times (P<0.05). However, IP6 lowered the viability of the cells with the presence of EGL compared to the control at both exposure times, except for 0.02% IP6 which showed comparable viability to the control at 48 h. In OGL and EGL, ALP activity of the cells was not affected by the presence of IP6 in non-osteogenic media; however, in osteogenic media IP6 lowered the ALP activity. Meanwhile, calcium release was the highest with IP6 within osteogenic media of EGL.
CONCLUSIONS
IP6 effects on the HPDL cells were dependent on IP6 concentration, time of exposure, glucose levels and the osteogenic condition of the media.
CLINICAL RELEVANCE
This study gives insights on the potential therapeutic effect of IP6 as adjunctive periodontal therapy in patients with diabetes.
Topics: Humans; Phytic Acid; Periodontal Ligament; Calcium; Osteogenesis; Cells, Cultured; Cell Differentiation; Fibroblasts; Glucose; Cell Proliferation; Alkaline Phosphatase
PubMed: 38096253
DOI: 10.1371/journal.pone.0295612 -
Nature Communications Sep 2022Integrator is a multi-subunit protein complex associated with RNA polymerase II (Pol II), with critical roles in noncoding RNA 3'-end processing and transcription...
Integrator is a multi-subunit protein complex associated with RNA polymerase II (Pol II), with critical roles in noncoding RNA 3'-end processing and transcription attenuation of a broad collection of mRNAs. IntS11 is the endonuclease for RNA cleavage, as a part of the IntS4-IntS9-IntS11 Integrator cleavage module (ICM). Here we report a cryo-EM structure of the Drosophila ICM, at 2.74 Å resolution, revealing stable association of an inositol hexakisphosphate (IP) molecule. The IP binding site is located in a highly electropositive pocket at an interface among all three subunits of ICM, 55 Å away from the IntS11 active site and generally conserved in other ICMs. We also confirmed IP association with the same site in human ICM. IP binding is not detected in ICM samples harboring mutations in this binding site. Such mutations or disruption of IP biosynthesis significantly reduced Integrator function in snRNA 3'-end processing and mRNA transcription attenuation. Our structural and functional studies reveal that IP is required for Integrator function in Drosophila, humans, and likely other organisms.
Topics: Animals; Drosophila; Endonucleases; Humans; Phytic Acid; RNA Polymerase II; RNA, Messenger; RNA, Small Nuclear; RNA, Untranslated
PubMed: 36180473
DOI: 10.1038/s41467-022-33506-3 -
Nutrients Feb 2015Common beans are a staple food and the major source of iron for populations in Eastern Africa and Latin America. Bean iron concentration is high and can be further... (Review)
Review
Common beans are a staple food and the major source of iron for populations in Eastern Africa and Latin America. Bean iron concentration is high and can be further increased by biofortification. A major constraint to bean iron biofortification is low iron absorption, attributed to inhibitory compounds such as phytic acid (PA) and polyphenol(s) (PP). We have evaluated the usefulness of the common bean as a vehicle for iron biofortification. High iron concentrations and wide genetic variability have enabled plant breeders to develop high iron bean varieties (up to 10 mg/100 g). PA concentrations in beans are high and tend to increase with iron biofortification. Short-term human isotope studies indicate that iron absorption from beans is low, PA is the major inhibitor, and bean PP play a minor role. Multiple composite meal studies indicate that decreasing the PA level in the biofortified varieties substantially increases iron absorption. Fractional iron absorption from composite meals was 4%-7% in iron deficient women; thus the consumption of 100 g biofortified beans/day would provide about 30%-50% of their daily iron requirement. Beans are a good vehicle for iron biofortification, and regular high consumption would be expected to help combat iron deficiency (ID).
Topics: Adult; Biological Availability; Female; Food, Fortified; Humans; Intestinal Absorption; Iron Isotopes; Iron, Dietary; Male; Phytic Acid; Polyphenols; Seeds
PubMed: 25679229
DOI: 10.3390/nu7021144 -
The Journal of Nutrition Nov 2010Low iron absorption from common beans might contribute to iron deficiency in countries where beans are a staple food. High levels of phytic acid (PA) and polyphenols... (Clinical Trial)
Clinical Trial Randomized Controlled Trial
Low iron absorption from common beans might contribute to iron deficiency in countries where beans are a staple food. High levels of phytic acid (PA) and polyphenols (PP) inhibit iron absorption; however, the effect of bean PP on iron absorption in humans has not been demonstrated and, with respect to variety selection, the relative importance of PP and PA is unclear. To evaluate the influence of bean PP relative to PA on iron absorption in humans, 6 stable iron isotope absorption studies were conducted in women (16 or 17 per study). Bean PP (20, 50, and 200 mg) were added in studies 1-3 as red bean hulls to a bread meal. Studies 4- 6 investigated the influence on iron absorption of PP removal and dephytinization of whole red bean porridge and PP removal from dephytinized porridge. Iron absorption was lowered by 14% with 50 mg PP (P < 0.05) and by 45% with 200 mg PP (P < 0.001). The mean iron absorption from whole bean porridge was 2.5%. PP and PA removal increased absorption 2.6-fold (P < 0.001) and removal of PP from dephytinized porridge doubled absorption (P < 0.001). Between-study comparisons indicated that dephytinization did not increase iron absorption in the presence of PP, but in their absence, absorption increased 3.4-fold (P < 0.001). These data suggest that in countries where beans are a staple food, PP and PA concentrations should be considered when selecting bean varieties for human consumption. Lowering only one inhibitor will have a modest influence on iron absorption.
Topics: Adolescent; Adult; Bread; Cross-Over Studies; Diet; Fabaceae; Female; Flavonoids; Food Handling; Humans; Intestinal Absorption; Iron Isotopes; Iron, Dietary; Middle Aged; Phenols; Phytic Acid; Polyphenols; Seeds; Young Adult
PubMed: 20861210
DOI: 10.3945/jn.110.125369 -
Poultry Science Apr 2024Apparent ileal digestibility (AID) of P, apparent total tract retention (ATTR) of P, and phytic acid disappearance in canola meal were evaluated in the presence of...
Research Note: Evaluation of phytic acid disappearance, ileal P digestibility, and total tract P retention in canola meal supplemented with increasing levels of exogenous phytase using conventional and cecectomized precision-fed roosters and growing chicks.
Apparent ileal digestibility (AID) of P, apparent total tract retention (ATTR) of P, and phytic acid disappearance in canola meal were evaluated in the presence of increasing levels of exogenous phytase. In Experiment 1, a precision-fed rooster assay was used to determine phytic acid (myo-inositol 1,2,3,4,5,6-hexakis; InsP) and inositol phosphate (InsP; InsP-P) disappearance in conventional and cecectomized Leghorn roosters. Roosters were crop intubated with 25 g of canola meal mixed with 0, 500, 1,000, or 2,000 FTU/kg of exogenous phytase. In Experiment 2, InsP and InsP-P disappearance and AID and ATTR of P were determined using ad libitum-fed broiler chickens. Treatments consisted of semi-purified diets containing 45% canola meal as the sole source of P. Phytase was added to increase phytase activity by 0, 500, 1,000, or 2,000 FTU/kg. Experiments contained 6 replicates per treatment. Canola meal contained a high phytase activity (1,630 FTU/kg as-fed) due to contamination with a commercially available phytase at the feed mill from which the canola meal was sourced. In Experiment 1 with precision-fed roosters, there was no effect (P > 0.05) of phytase or bird type on InsP and InsP-P disappearance; however, phytase linearly reduced (P < 0.05) InsP concentrations in excreta. In Experiment 2 with ad libitum-fed chickens, phytase linearly increased (P < 0.05) ileal InsP and InsP-P disappearance, and phytase had a quadratic effect (P < 0.05) on excreta InsP and InsP-P disappearance. Increasing dietary phytase activity resulted in a linear increase (P < 0.05) in AID of P and phytase had a quadratic effect (P < 0.05) on ATTR of P. In conclusion, titration of high levels of phytase (1,600 to 3,600 FTU/kg as-fed) reduced InsP concentrations in precision-fed roosters but did not affect overall phytic acid hydrolysis, which was 78% or greater for all treatments; however, increasing the total phytase activity from 700 to 2,700 FTU in ad libitum-fed broiler chickens increased phytic acid disappearance and P digestibility.
Topics: Animals; Male; Chickens; Phytic Acid; 6-Phytase; Digestion; Animal Feed; Dietary Supplements; Diet; Brassica napus; Animal Nutritional Physiological Phenomena
PubMed: 38364607
DOI: 10.1016/j.psj.2024.103520 -
Molecules (Basel, Switzerland) Feb 2023Biopolymeric films were prepared with gelatin, plasticizer, and three different types of antioxidants (ascorbic acid, phytic acid, and BHA) corresponding to different...
Biopolymeric films were prepared with gelatin, plasticizer, and three different types of antioxidants (ascorbic acid, phytic acid, and BHA) corresponding to different mechanisms in activity. The antioxidant activity of films was monitored for 14 storage days upon color changes using a pH indicator (resazurin). The instant antioxidant activity of films was measured by a DPPH free radical test. The system using resazurin was composed of an agar, an emulsifier, and soybean oil to simulate a highly oxidative oil-based food system (AES-R). Gelatin-based films (GBF) containing phytic acid showed higher tensile strength and energy to break than all other samples due to the increased intermolecular interactions between phytic acid and gelatin molecules. The oxygen barrier properties of GBF films containing ascorbic acid and phytic acid increased due to the increased polarity, while GBF films containing BHA showed increased oxygen permeability compared to the control. According to "a-value" (redness) of the AES-R system tested with films, films incorporating BHA showed the most retardation of lipid oxidation in the system. This retardation corresponds to 59.8% antioxidation activity at 14 days, compared with the control. Phytic acid-based films did not show antioxidant activity, whereas ascorbic acid-based GBFs accelerated the oxidation process due to its prooxidant activity. The comparison between the DPPH free radical test and the control showed that the ascorbic acid and BHA-based GBFs showed highly effective free radical scavenging behavior (71.7% and 41.7%, respectively). This novel method using a pH indicator system can potentially determine the antioxidation activity of biopolymer films and film-based samples in a food system.
Topics: Antioxidants; Gelatin; Phytic Acid; Ascorbic Acid; Oxygen; Biofilms; Food Packaging
PubMed: 36903338
DOI: 10.3390/molecules28052092