Biotin Content Research Articles

Marginal biotin deficiency is teratogenic in mice and perhaps humans: a review of biotin deficiency during human pregnancy and effects of biotin deficiency on gene expression and enzyme activities in mouse dam and fetus

Recent studies of biotin status during pregnancy provide evidence that a marginal degree of biotin deficiency develops in a substantial proportion of women during normal pregnancy. Several lines of evidence suggest that although the degree of biotin deficiency is not severe enough to produce the classic cutaneous and behavioral manifestations of biotin deficiency, the deficiency is severe enough to produce metabolic derangements in women and may be teratogenic. In studies of mice, a similar degree of biotin deficiency induces characteristic fetal malformations at a high rate. Fetal hepatic biotin content and PCC activity decrease indicating that the fetuses also become biotin deficient. Fetal hepatic acetyl-CoA carboxylase, pyruvate carboxylase, propionyl-CoA carboxylase and β-methylcrotonyl-CoA carboxylase abundances determined by Western blotting decreased more than the dam holocarboxylase abundances (10% of sufficient vs. 50% of sufficient); however, hepatic mRNA for the carboxylases and for HCS did not change significantly in either dams or fetuses. These observations suggest that maternal biotin deficiency results in a lack of adequate biotin to biotinylate apocarboxylases in the fetus despite the normal expression of genes coding for the apocarboxylases and holocarboxylase synthetase.

Determination of biotin content in beet molasses by Lactobacillus plantarum

D-biotin content in beet molasses was determined by microbiological method using Lactobacillus plantarum, based on the comparison of the growth of this microorganism in molasses solutions with those in standard solutions of biotin. Incubation of the microorganism was performed on original Vitamin Biotin Testbouillon and laboratory prepared liquid culture medias. The amount of "real" biotin in molasses is low. The results depend upon the sample and volume of molasses solutions. Biotin contents obtained on both liquid media are close.

わが国の食品に含まれるビオチン量の分析

ビオチンは, 種々の食品に広く分布している。しかし, ビオチンは, 五訂日本食品標準成分表には収載されておらず, 食品中の含量をはじめとして, 食品中での存在状態, 調理や加工による変化, 生体内における利用率などについて, ほとんど明らかにされていない。そこで, 日常的に摂取している代表的な101食品について, 食品中のビオチン含量を分析し, 諸外国の食品ビオチン量と比較した。食品群ごとにビオチン含量をみると, 豆類, 種実類, 卵類, 調味料および香辛料類で平均10μg/100g以上の高値を示した。一方, 野菜類, 果実類, 乳類, 油脂類では, ビオチン含量は低値であった。調味料では, ビオチンは多く含まれているが諸外国と大きな相違がみられた。これは, 諸外国では酵母類に由来し, わが国では醤油や味噌が, 大豆を原料に作られていることに由来する。しかしながら, 全体として, デンマークやドイツの食品成分表では, 食品のビオチン含量について, わが国と大きな相違は認められず, これらの国の食品のビオチン含量値も利用が可能である。平成13年度の国民栄養調査結果から食品群別にビオチン摂取量を算出した。本研究の測定値から算出した結果では, 1日あたり男性で110μg, 女性で92.3μgであり, 食事摂取基準 (2005年版) の目安量と比較して, それぞれ244%および206%であった。ビオチンは, 食品によって含量だけでなく, 遊離ビオチン率にも大きな相違がみられた。鶏卵では, 卵黄中の遊離ビオチン率が高値を示し, 卵黄がビオチンの供給源として有用な食品であることが示唆された。

Determination of the biotin content of select foods using accurate and sensitive HPLC/avidin binding

Assessing dietary biotin content, biotin bioavailability, and resulting biotin status are crucial in determining whether biotin deficiency is teratogenic in humans. Accuracy in estimating dietary biotin is limited both by data gaps in food composition tables and by inaccuracies in published data. The present study applied sensitive and specific analytical techniques to determine values for biotin content in a select group of foods. Total biotin content of 87 foods was determined using acid hydrolysis and the HPLC/avidin-binding assay. These values are consistent with published values in that meat, fish, poultry, egg, dairy, and some vegetables are relatively rich sources of biotin. However, these biotin values disagreed substantially with published values for many foods. Assay values varied between 247 times greater than published values for a given food to as much as 36% less than the published biotin value. Among 51 foods assayed for which published values were available, only seven agreed within analytical variability (±20%). We conclude that published values for biotin content of foods are likely to be inaccurate.

Protein−Ligand Mediated Aggregation of Nanoparticles: A Study of Synthesis and Assembly Mechanism

Two difunctional, asymmetric PEG linkers were synthesized and utilized to prepare water-soluble, biotinylated CdS@SiO2 particles with various surface contents of the biotin groups. Aqueous dispersions of these particles were prepared, and upon addition of avidin, aggregation was observed using DLS, TEM, and SEM analysis. The resulting aggregates were dense but also had fractal shapes. It was shown that single-angle DLS measurements at 90° were sufficiently accurate for quickly measuring the size of the aggregates as it evolved with time. Initial aggregation rates were measured as a function of surface biotin content of the nanoparticles and initial avidin concentration. The initial rates displayed bell-shaped curve responses to variations in the avidin-to-particle ratio and biotin-to-avidin ratio, the shapes of which were attributed to the stoichiometric balance/imbalance of the avidin-to-biotin ratio in the system and to intraparticle and interparticle bridges that could sterically block avidin from reaching some biotin sites. The growth mechanism was postulated to be a step-growth process.

The Contents of Biotin, Pantothenic Acid and Niacin in Mature Milk of Japanese Women

The Contents of Biotin, Pantothenic Acid and Niacin in Mature Milk of Japanese Women

Electrophoretic Behaviour of Biotin and Biocytin in Capillary Electrophoresis. Determination of Biotin in Pharmaceutical Formulations

The migration behaviour of biotin and biocytin was investigated by capillary zone electrophoresis (CZE). The results indicate that with a 50 mM borate buffer at pH 9.0 the separation is excellent. The CZE method can be applied to the determination of biotin in multi-vitamin preparations. However, for samples with a low biotin content, a micellar electrokinetic chromatography (MEKC) approach was developed in order to avoid the overlapping of the small peak of biotin with the large peaks of other vitamins. As electrophoretic electrolyte the MEKC method uses a solution containing 20 mM phosphate buffer (pH 7.5), 75 mM sodium dodecylsulphate and 30% (v/v) methanol. The performance of the method was tested in the analysis of two pharmaceutical preparations.

Marginal Biotin Deficiency Is Teratogenic in ICR Mice

The incidence of marginal biotin deficiency in normal human gestation is approximately one in three. In ICR mice, maternal biotin deficiency results in cleft palate, micrognathia, microglossia and limb hypoplasia. However, the relationships among the severity of maternal biotin deficiency, fetal biotin status and malformations have not been reported. This study utilized validated indices of biotin status to investigate the relationships among maternal biotin status, fetal biotin status and the rate of fetal malformations in ICR mice. Biotin status was controlled by feeding diets with varying egg white concentration. In dams and fetuses, biotin status was assessed by hepatic biotin content and hepatic activity of the biotin-dependent enzyme propionyl-CoA carboxylase; in dams, status was also assessed by urinary excretion of biotin and 3-hydroxyisovaleric acid. Malformations were assessed morphologically. Biotin was measured by HPLC/avidin-binding assay. Propionyl-CoA carboxylase (PCC) activity was determined by H(14)CO(3) incorporation. 3-Hydroxyisovaleric acid concentration was determined by GC/MS. Although no overt signs of deficiency appeared, metabolic disturbances caused by biotin deficiency were detectable in dams and fetuses. These disturbances increased with increasing egg white. Fetal biotin status correlated significantly with maternal biotin status (fetal vs. dam hepatic biotin, r = 0.671; fetal vs. dam PCC activity, r = 0.70). The incidences of malformations were strikingly dependent on egg white concentration. We conclude that in ICR mice, marginal maternal biotin deficiency causes fetal biotin deficiency. We speculate that the fetal malformations are primarily the consequence of fetal biotin deficiency. Because murine malformations appeared at degrees of biotin deficiency that are similar to those in human gestation, we speculate that some human fetal malformations may be caused by biotin deficiency.

Biotin decreases retinal apoptosis and induces eye malformations in the early chick embryo

Proliferation, cell death and differentiation occur simultaneously in developing retina and are precisely orchestrated. We have studied the effects of biotin (vitamin H) on early retinal development. In vivo administration of biotin to early embryonic chick eyes at moderately elevated levels induced malformations, affecting retina and lens structures. The effects were strictly age dependent and were only found in embryos treated between Hamburger and Hamilton stage 14-17. Biocytin, a biotin analogue, mimicked biotin effects, while avidin could block the effects. At the cellular level, biotin did not affect proliferation but reduced apoptosis. These results suggest that an adequate content of biotin and a precise regulation of retinal cell death are required for the correct morphogenesis of the eye.

Dietary biotin requirement determined for Indian catfish, Heteropneustes fossilis (Bloch), fingerlings

Triplicate groups of Indian catfish, Heteropneustes fossilis (Bloch), fingerlings (average wet weight 3.55 ± 0.03 g) were fed semi-purified diets containing six levels of biotin (0, 0.086, 0.26, 0.86, 2.5 and 4.3 mg kg−1 diet) for 15 weeks. After 42 days of feeding, fish fed the control (no biotin) diet had developed severe deficiency signs characterized by convulsions, heavy mortality, listlessness, poor feed conversion and feed intake, dark skin colour, tetanus and weight loss. None of these signs was seen in fish fed biotin-supplemented diets. Among all the biotin-supplemented diets, percentage weight gain was significantly highest for fish fed the diet supplemented with 0.26 mg of biotin kg−1 and significantly lowest for fish fed the diet supplemented with 0.086 mg of biotin kg−1. Feed conversion ratio (FCR) and protein efficiency ratio (PER) patterns were similar to that of percentage weight gain. The carcass protein and lipid contents were influenced by the dietary biotin up to fish fed 0.26 mg of biotin kg−1. Significantly higher body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities were observed in fish fed biotin-supplemented diets than in fish fed the control diet. Broken-line analyses showed that the optimum dietary requirement for biotin for maximal weight gain, body biotin content, liver pyruvate carboxylase and acetyl CoA carboxylase activities was about 0.25 mg kg−1. Associated liver pyruvate carboxylase and acetyl CoA carboxylase activities for normal growth ranged from 105 to 120 units mg−1 protein and from 9 to 11 units mg−1 protein respectively.

Detection of biotin in individual sea urchin oocytes using a bioluminescence binding assay.

The ability to detect biomolecules in single cells is important in order to fully understand the processes by which many biochemical events occur. To that end, we have developed a bioluminescence binding assay capable of measuring the intracellular biotin content of individual cells. The assay depends on competition between an aequorin-biotin conjugate (AEQ-biotin) and free biotin within the oocytes for binding sites on the protein avidin. The assay is performed by microinjecting each component into the oocytes and following the resulting bioluminescence within the oocyte upon triggering of aequorin. Results obtained using sea urchin oocytes show that the assay performed within the cells behaves in a manner consistent with assay theory. Using the assay, the individual biotin content of the oocytes is an average of approximately 20 amol. To our knowledge, this is the first reported multicomponent binding assay to be performed inside an intact single cell.

Proliferation of peripheral blood mononuclear cells increases riboflavin influx.

Previously we demonstrated that proliferation of peripheral blood mononuclear cells (PBMC) causes a five-fold increase in cellular uptake of biotin; this increase is mediated by an increased number of biotin transporters on the PBMC surface. In the present study, we investigated the specificity of this phenomenon by determining whether the cellular uptake of riboflavin also increases in proliferating PBMC and whether the increase is also mediated by an increased number of transporters per cell. We characterized [3H]riboflavin uptake in both quiescent and proliferating PBMC. In quiescent PBMC, [3H]riboflavin uptake exhibited saturation kinetics and was reduced by addition of unlabeled riboflavin (P < 0.05) or lumichrome (P < 0.01). These observations are consistent with transporter-mediated uptake. [3H]Riboflavin uptake was reduced at 4 degrees C compared with 37 degrees C (P < 0.01) and by 2, 4-dinitrophenol (P < 0.05) but not by ouabain or incubation in sodium-free medium. These data provide evidence for an energy-dependent but sodium-independent transporter. Proliferating PBMC accumulated approximately four times more [3H]riboflavin than quiescent PBMC (P < 0.05). Because both transporter affinity and transporter number per cell (as judged by maximal transport rate) were similar in quiescent and proliferating PBMC, we hypothesize that the increased riboflavin uptake by proliferating PBMC reflects only increased cellular volume. To test this hypothesis, PBMC volume was reduced using hyperosmolar medium; [3H]riboflavin uptake decreased to about 50% of isotonic controls (P < 0.01). Thus we conclude that proliferating PBMC increase cellular content of riboflavin and biotin by two different mechanisms.

Water-soluble vitamins in natural plankton (copepods) during two consecutive spring blooms compared to vitamins in Artemia franciscana nauplii and metanauplii

Weight-specific contents of asorbic acid, thiamin, riboflavin, niacin, pantothenic acid, vitamin B6, biotin, folate and vitamin B12 were analysed in natural zooplankton collected from a sea water lagoon in a halibut fry production plant. The samples of natural zooplankton were collected from April/May to the end of June during two consecutive spring blooms. For comparison, the same vitamins were measured in nauplii of Artemia franciscana, just after hatching and after enrichment for 24 and 48 h with a commercial diet. The changes in vitamin content in zooplankton, which consisted mainly of Temora longicornis, during the two spring blooms were <2.5-fold for each specific vitamin. The large number of high quality halibut fry produced using the plankton as a dietary source suggests that the plankton contained sufficient amounts of all water-soluble vitamins. With the exception of thiamin and ascorbic acid, Artemia– both newly hatched and enriched for 24 and 48 h – contained higher levels of water-soluble vitamins than natural zooplankton. Enrichment feeding of Artemia for 48 h stabilised or increased the level of the water-soluble vitamins.

A permease exhibiting a dual role for lysine and biotin uptake in Saccharomyces cerevisiae

Among Saccharomyces cerevisiae strains each defective in one of 11 amino acid permeases, a lysine permease disruptant (DK) exhibited about 2-fold reductions in maximum cell density and fermentation ability compared to the parent in a synthetic medium. These unusual properties of DK were found to result from the requirement of biotin for growth, in contrast to the parent whose growth was not dependent on external biotin. The rate of 14C-labeled biotin uptake and the intracellular free biotin content of DK were 2–2.5 fold lower than in the parent. We suggest that lysine permease in S. cerevisiae has the ability to transport both lysine and biotin.

Determination of biotin in low-temperature fish-meal processed from different species by means of a microbiological method usingLactobacillus plantarum as test organism

Determination of biotin content in 10 fish-meals produced from different species was performed by a microbiological assay using Lactobacillus plantarum as test organism. The contents of biotin in the fish-meal samples ranged between 0.36 and 0.80 mg kg−1. Most of the fish-meals contained approximately 0.4 mg biotin kg−1. The highest value was found in meal processed from sand eel (Ammodytes marinus). The precision of the assay showed a 2.7% relative standard deviation. Recovery using addition of biotin to the fish-meal ranged between 93 and 95%. Testing of extraction procedure suggested that hydrolysis in 1.5 M H2SO4 at 121 °C for 3 h is sufficient for biotin to be liberated from proteins and amino acids. © 1999 Society of Chemical Industry

Determination of biotin in foods by high-performance liquid chromatography with post-column derivatization and fluorimetric detection

A method to determine the content of biotin in various foods by reverse phase liquid chromatography is proposed and includes extraction of the vitamers ( d-biotin and d-biocytin) by enzymatic hydrolysis (papain) and takadiastase if necessary, post-column derivatization by avidin-FITC (fluorescein 5-isothiocyanate) and fluorimetric detection of the complex obtained. Enzymatic hydrolysis is preferred to sulfuric acid hydrolysis because it does not induce any degradation of the vitamin and allows a good estimation of the bioavailable forms. The proposed method has a good recovery rate (90–106%), a satisfactory repeatability (coefficient of variation less than 7%) and a very low detection limit (0.005 μg g −1).

Low biotin content of infant formulas made in Japan

Since minor vitamins such as biotin are not yet registered as food additives in Japan, these cannot be used to supplement infant formulas or foods, despite their nutritional value. Therefore, the biotin contents of infant formulas made in Japan were determined and compared with those from the United States (US). The Japanese products were obtained from five companies, while the US products were limited to those from one company. The average content of total biotin in 11 Japanese products for nursing of normal infants (standard formulas) was 1.04 μg/100 kcal (0.69 μg/100 ml), which was significantly lower than that in two US products (2.56 μg/100kcal, 1.71 μg/100 ml). The total biotin content in 26 Japanese infant formulas specially prepared for medical treatment and prevention of disease (special formulas) was 0.45 μg/100 kcal (0.30 μg/100 ml) on average. This was less than a fifth of the level in the three US products (1.82 ug/ 100 kcal, 1.22 μg/100 ml). There was no difference in the proportion of free biotin (the percent of active biotin to total biotin) between the Japanese and US standard formulas (67.7% and 77.2%, respectively). However, in special formulas the mean proportion of the free biotin in the Japanese products (29.4%) was lower than that in the US products (71.2%). The nutrient intake of infants is limited to the maternal milk and/or infant formulas. These findings suggest that Japanese infant formulas should be appropriately improved to maintain growth and good health. Biotin should be registered as a food additive in Japan so that it can be used to fortify infant formulas.

Liquid chromatographic determination of biotin in multivitamin-multimineral tablets

A reproducible reverse phase high pressure liquid chromatography (RP-HPLC) method for the determination of biotin in multivitamin-multimineral tablets has been developed and validated. This method involves reverse phase separation of the component monitored by absorbance at 200 nm wavelength. The method has excellent precision and accuracy with S.D. 0.83 and 2.9%, respectively. The established linearity range was 0.5–2 μg ml −1 ( r 2>0.9999). The recovery of biotin from spiked placebo was >97% over the linear range. The extraction procedure is simple and the HPLC conditions separate biotin from its degradation products and excipients. The method has been successfully used in determining biotin content in 4 brands of commercially available multivitamin- multimineral tablets.

Strong decrease in biotin content may correlate with metabolic alterations in colorectal adenocarcinoma.

Short-chain fatty acids are an important source of energy for colonocytes. One of these is propionate, which is metabolized through carboxylation by propionyl-CoA carboxylase (PCC), an enzyme encoded by 2 genes, PCCA and PCCB. The co-factor of this reaction is biotin, a product of intestinal bacterial metabolism, as is propionate. Despite detailed knowledge about the metabolic effects and physiology of biotin, the relative amounts of this vitamin in normal colonic mucosae and in tumour tissue remains quite unknown. The biotin content in normal and cancerous cells from the distal digestive tract was examined on 10 pairs of tissue specimens of colorectal cancer and adjacent normal mucosae using reflectance in situ hybridization (RISH). Having observed a high biotin content in colon mucosae and a low content in colorectal-cancer cells, we then studied the transcription levels of PCCA and PCCB genes in 9 colorectal cancers and the corresponding mucosae. In all cases, the levels of mRNA were lower in colorectal cancers than in normal mucosae, the decrease being always more marked for PCCB than for PCCA. In normal mucosae and in adenocarcinoma cancer cells, PCCA and PCCB transcription levels were strongly related to the amount of biotin detected, but not to the number of chromosomes 13 (which carries PCCA) or 3 (which carries PCCB).

Concentrations of biotin metabolites in human milk

Because estimates of the biotin requirement for infants currently are based on the biotin concentration in human milk, we sought to determine whether inactive biotin metabolites are present. Samples were collected for 7 weeks post partum from 15 healthy women. Biotin and the inactive metabolites bisnorbiotin and biotin sulfoxide were measured by means of a high-performance liquid chromatography avidin-binding assay. At 8 days post partum the proportion of biotin was 44%, bisnorbiotin 48%, and biotin sulfoxide 8%. Although biotin content increased post partum (p < 0.003), the metabolites remained an important portion of the total providing evidence that accurate measurement of biotin in human milk requires an assay that is specific for biotin.