Micronutrient supplementation of lactating Guatemalan women acutely increases infants' intake of riboflavin, thiamin, pyridoxal, and cobalamin, but not niacin, in a randomized crossover trial.

BACKGROUND: Maternal supplementation during lactation could increase milk B-vitamin concentrations, but little is known about the kinetics of milk vitamin responses. OBJECTIVES: We compared acute effects of maternal lipid-based nutrient supplement (LNS) consumption (n = 22 nutrients, 175%-212% of the RDA intake for the nutrients examined), as a single dose or at spaced intervals during 8 h, on milk concentrations and infant intake from milk of B-vitamins. METHODS: This randomized crossover trial in Quetzaltenango, Guatemala included 26 mother-infant dyads 4-6 mo postpartum who were randomly assigned to receive 3 treatments in a random order: bolus 30-g dose of LNS (Bolus); 3 × 10-g doses of LNS (Divided); and no LNS (Control), with control meals. Mothers attended three 8-h visits during which infant milk consumption was measured and milk samples were collected at every feed. Infant intake was assessed as $\mathop \sum \nolimits_{i\ = \ 1}^n ( {{\rm{milk\ volum}}{{\rm{e}}_{{\rm{feed\ }}n}} \times \ {\rm{nutrient\ concentratio}}{{\rm{n}}_{{\rm{feed}}\ n}}} )$ over 8 h. RESULTS: Maternal supplementation with the Bolus or Divided dose increased least-squares mean (95% CI) milk and infant intakes of riboflavin [milk: Bolus: 154.4 (138.2, 172.5) µg · min-1 · mL-1; Control: 84.5 (75.8, 94.3) µg · min-1 · mL-1; infant: Bolus: 64.5 (56.1, 74.3) µg; Control: 34.5 (30.0, 39.6) µg], thiamin [milk: Bolus: 10.9 (10.1, 11.7) µg · min-1 · mL-1; Control: 7.7 (7.2, 8.3) µg · min-1 · mL-1; infant: Bolus: 5.1 (4.4, 6.0) µg; Control: 3.4 (2.9, 4.0) µg], and pyridoxal [milk: Bolus: 90.5 (82.8, 98.9) µg · min-1 · mL-1; Control: 60.8 (55.8, 66.3) µg · min-1 · mL-1; infant: Bolus: 39.4 (33.5, 46.4) µg; Control: 25.0 (21.4, 29.2) µg] (all P < 0.001). Only the Bolus dose increased cobalamin in milk [Bolus: 0.054 (0.047, 0.061) µg · min-1 · mL-1; Control: 0.041 (0.035, 0.048) µg · min-1 · mL-1, P = 0.039] and infant cobalamin intake [Bolus: 0.023 (0.020, 0.027) µg; Control: 0.015 (0.013, 0.018) µg, P = 0.001] compared with Control. Niacin was unaffected. CONCLUSIONS: Maternal supplementation with LNS as a Bolus or Divided dose was similarly effective at increasing milk riboflavin, thiamin, and pyridoxal and infant intakes, whereas only the Bolus dose increased cobalamin. Niacin was unaffected in 8 h. This trial was registered at clinicaltrials.gov as NCT02464111.

Efficacy and safety of pyridoxal in West syndrome: A retrospective study.

OBJECTIVE: To evaluate the efficacy and safety of pyridoxal for treating West syndrome. METHODS: We retrospectively investigated pyridoxal's efficacy and safety in 117 patients with West syndrome at Saitama Children's Medical Center from July 1993 to May 2016. Pyridoxal was administered at doses of 10-50 mg/kg/day. We evaluated seizure outcomes and electroencephalographic findings at 4 weeks after pyridoxal therapy. The responders were those with complete cessation of spasms for more than 4 weeks and those with resolution of hypsarrhythmia on EEG at 1-4 weeks after pyridoxal therapy. RESULTS: Five of the 117 patients (4.3%) were responders. The median duration between pyridoxal therapy to spasm cessation was 6 (5-13) days. Among the responders, four had hypsarrhythmia resolution, no spasm relapse, and no other seizure types more than 2 years after pyridoxal therapy. One responder had partial seizures and spasm relapse. No serious adverse effects occurred. There were no significant differences in sex, etiologies, complication, other seizure types preceding the spasms, onset age of spasms, age of pyridoxal therapy, treatment lag, initial and maintenance doses of pyridoxal, and adverse effects between pyridoxal responders and non-responders. CONCLUSIONS: The efficacy rate of pyridoxal monotherapy as first-line treatment for West syndrome was low. However, pyridoxal therapy showed a rapid response within 1 week and was safe. We consider pyridoxal therapy as a kind of challenge therapy during the evaluation period concerning differential diagnosis and etiologies of West syndrome and immunological risks before adrenocorticotrophic hormone therapy or vigabatrin therapy.

The effect of G3 PAMAM dendrimer conjugated with B-group vitamins on cell morphology, motility and ATP level in normal and cancer cells.

In a search for the safe vitamin carrier the PAMAM G3 dendrimer covalently substituted with 9 and 10 molecules of vitamin B7 (biotin) and B6 (pyridoxal), respectively (BC-PAMAM) was investigated. Dendrimer substitution with B-group vitamins significantly alters its biological properties as compared to native form. Observed effects on investigated cell parameters including morphology, adhesion, migration and ATP level were different for normal human fibroblasts (BJ) and squamous cell carcinoma (SCC-15) cell lines. BC-PAMAM revealed significantly less pronounced effects on investigated parameters, particularly at higher concentrations (5-50µM), which is relevant with its lower positive surface charge, as compared with native form. The bioconjugate, up to 50µM concentration, appeared to be a safe vitamin carrier to normal fibroblasts, without significant effect on their adhesion, shape and migration as well as on intracellular ATP level. In SCC-15 cells BC-PAMAM, at low concentrations (0.1-0.5µM), altered the cell shape and increase adhesion, whereas at higher concentrations opposite effects were seen. Measurements of cellular level of ATP showed that higher resistance of cancer cells to toxic effects of native PAMAM dendrimers may be due to higher energy supply of cancer cells.

Elevated maternal serum folate in the third trimester and reduced fetal growth: a longitudinal study.

This study aimed to examine the association of fetal growth and elevated third trimester maternal serum folate due to folic acid (FA) supplement intake. Dietary intake, use of FA supplements, weight, and blood biomarkers of B-vitamins (serum folate, pyridoxal, vitamin B(12), and plasma total homocysteine) were observed in 33 healthy pregnant women at the third trimester (average gestational age 35 wk). Birth outcomes were assessed through hospital birth records. Infant anthropometry and maternal blood biomarkers were followed up at 1 mo postpartum. Fourteen women were taking FA supplements at the third trimester. Dietary intake was similar among FA users and non-users, but serum folate and pyridoxal were significantly higher in users (11.6±6.7 vs. 6.1±3.2 ng/mL, and 13.8±21.7 vs. 3.2±1.4 ng/mL, respectively). Plasma total homocystein (tHcy) was higher in non-users compared to users, but not significantly. Nine FA users and eight non-users had low serum vitamin B(12) values (<203 pg/mL). Nine FA users and all non-users had low serum pyridoxal values (<7.0 ng/mL). Infant birthweight was significantly lower in users compared to non-users (2,894±318 vs. 3,154±230 g). At 1 mo postpartum, infant weight and length were similar between FA users and non-users, but infant weight gain was larger in users. Higher serum folate values due to FA use in the third trimester was related to reduced fetal size. Excess FA under low vitamin B(6) and B(12) status may affect fetal growth.

Influence of pyridoxylidene aminoguanidine on biomarkers of the oxidative stress and selected metabolic parameters of rats with diabetes mellitus.

Oxidative damage is considered to play an important role in the pathogenesis of several diseases, such as diabetes mellitus (DM), atherosclerosis, cardiovascular complications and chronic renal failure. DM is associated with the oxidative stress and formation of advanced glycation end products (AGEs). Different drugs inhibit oxidative stress and formation of advanced glycation end products. Aminoguanidine (AG) has been proposed as a drug of potential benefit in prophylaxis of the complications of DM. Recent reports show a pro-oxidant activity of AG. Therefore we examined the effect of structural analogue of AG, its Schiff base with pyridoxal-pyridoxylidene aminoguanidine (PAG) on the level of selected markers of oxidative stress. We found that PAG decreased total damage to DNA in controls as well as in diabetic group of rats. However, we also found that PAG supplementation increases susceptibility of lipoproteins to oxidation and formation of conjugated dienes in both, diabetic as well as control animals. Its administration to diabetic rats decreases antioxidant capacity of plasma. Therefore, it is necessary to search for other structural modifications of AG that would combine its higher anti-diabetic activity with less toxicity.

Pyridoxal isonicotinoyl hydrazone (PIH) and its analogs as protectants against anthracycline-induced cardiotoxicity.

The risk of cardiotoxicity is the main drawback of anthracycline antibiotics. However, these drugs remain among the most effective and frequently used anti cancer drugs. In this study we aimed to assess the cardioprotective effects of aroylhydrazone iron (FE) chelators: pyridoxal isonicotinoyl hydrazone (PIH) and its two analogs: salicyladehyde isonicotinoyl hydrazone (SIH) and pyridoxal o-chlorbenzoyl hydrazone (o-108). In rabbits, chronic treatment with daunorubicin (DAU) (3 mg/kg weekly for 10 weeks) induced mortality (33%) as well as left ventricular (LV) dysfunction. Co-administrations of PIH (25 mg/kg, i.p.), SIH hydrochloride [1 mg/kg, iv] as well as o-108 (10 mg/kg, i.p.), fully prevented premature deaths and most of the DAU-induced functional impairments were significantly suppressed. However, when 2- to 2.5-fold higher doses of the chelators were used, they led to rather paradoxical and mostly negative results regarding both cardioprotection and overall mortality.

Safety and tolerability of repeated administration of pyridoxal 2-chlorobenzoyl hydrazone in rabbits.

Recently, pyridoxal 2-chlorobenzoyl hydrazone (o-108) has been identified as an effective iron chelator [Link et al., Blood 2003; 101: 4172-79]. Since chronic treatment would be necessary in its potential indications, in the present study, the safety and tolerability of this agent after repeated administration was determined. Three doses of o-108 (25, 50, 100 mg/kg, in 10% Cremophor EL) were administered intraperitoneally, once weekly, for 10 weeks to three groups (n=5 each) of Chinchilla male rabbits. The effects on biochemical, haematological and cardiovascular parameters were examined during the experiment; histopathological examination was performed at the end of the experiment. Results were compared with control (saline 2 mL/kg, n=11) and vehicle groups (10% Cremophor EL, 2 mL/kg, n=12). No premature deaths occurred; the well-being of animals was evidenced by their body weight gain, although lower gain was observed with the highest dose (100 mg/kg). Significant elevations of cardiac troponin T plasma concentrations were observed with the highest dose of o-108, but no abnormalities were found in the cardiovascular function and only minor and inconsistent changes in haematological and biochemical parameters were observed. Histopathological examinations of selected organs revealed only weak and reversible changes through all studied groups. Thus, the data from this study suggest that o-108 remains a promising drug from the standpoint of the possibility of its repeated administration and warrants further investigation.

Iron chelation therapy.

Although iron chelation therapy with deferoxamine (DFO) has changed life expectancy in thalassemic patients, compliance with the rigorous requirements of long-term subcutaneous DFO infusions is unsatisfactory. This problem underlines the current efforts for developing alternative, orally effective chelators to improve compliance and treatment results. For the patient with transfusional iron overload in whom results of DFO treatment are unsatisfactory, several orally effective agents are now available. The most important of the new generation of oral chelators are deferiprone and ICL670. Total iron excretion with deferiprone is less than with DFO, but deferiprone has a better ability to penetrate cell membranes and may have a better cardioprotective effect than DFO. Current studies of the clinical efficacy and tolerability of ICL670 indicate that at a single oral dose of 20 mg/kg daily, it may be as effective as parenteral DFO used at the standard dose of 40 mg/kg daily. Combined chelation treatment, employing a weak chelator that penetrates cells better, and a stronger chelator with efficient urinary excretion, may result in improved therapeutic effect through iron shuttling between the two compounds. The efficacy of combined chelation treatment is additive and offers an increased likelihood of success in patients previously failing DFO or deferiprone monotherapy.

[Effects of nutritional intervention on brain functions and its related biochemical indexes in mice exposed to high +Gy].

OBJECTIVE: To study the effects of nutritional intervention on changes of monoamines in rats brain, certain amino acids in rats serum and maze behaviors caused by high +Gy exposure. METHOD: The mice were arranged into control group (Group A), +Gy group (Group B) and +Gy nutritional intervention group (group C). Group A was not exposed to +Gy. Both Group B and group C were exposed to +10 Gy for 8 min. Three hours before +Gy exposure distilled water was given to mice in group B by gavage. The day before exposure pyridoxal fortified water was given and 3 h before exposure mixed amino acids solution were given by gavage to group C. Maze test scores were recorded for all groups. After the maze test was completed, blood was collected through the eyes for serum amino acids and brain tissue was collected by decollation for monoamines and gamma-glutamyl transferase (GGT) activity determinations. RESULT: After +Gy exposure maze test scores and brain NE concentrations decreased and abnormal behaviors were found. While other monoamine transmitters increased significantly. In group C maze behaviors improved and biochemical changes induced by +Gy exposure alleviated. CONCLUSION: High +Gy exposure can induce changes of neural transmitters coming from nutritional metabolites in central nervous system. As a result, brain functions are affected. Nutritional intervention can alleviate this negative effect to some extent.

Pyridoxal supplementation reduces cell proliferation and DNA synthesis in estrogen-dependent and -independent mammary carcinoma cell lines.

In previous studies, decreased growth of tumor cells by vitamin B-6 treatment has been attributed to modulation of steroid hormone action. Therefore, the growth-inhibiting properties of pyridoxal (PL) supplementation were studied in estrogen receptor-positive, MCF-7 and T-47D, and estrogen receptor-negative, BT-20, breast cancer cell lines. Cell counting and [3H]thymidine incorporation into DNA were used to assess growth, and analysis of pS2 expression was used to determine whether PL supplementation affected estrogen action. Treatment with 100 or 300 mM PL resulted in dose-dependent decreases in total cell numbers in the absence (26-85% and 72-98%, respectively) and presence (38-42% and 88-98%, respectively) of estradiol in all cell lines studied compared with control cells cultured without PL supplementation. Similar decreases in DNA synthesis were observed in response to PL supplementation. Incorporation of [3H]thymidine into DNA of cells cultured with 100 or 300 microM PL was decreased by 30-90% and 96-99%, respectively, in the absence and by 32-40% and 82-99%, respectively, in the presence of estradiol. Northern analysis showed that expression of the estrogen-sensitive gene pS2 was not affected by either concentration of PL. These results indicate that PL supplementation regulates breast cancer cell growth in vitro via a mechanism that appears to be steroid independent.

Efficacy of pyridoxal treatment in controlling the growth of melanomas in cell culture and an animal pilot study.

We have demonstrated, using confocal laser scanning microscopy, that pyridoxal treatment of B16C3 murine melanoma cells inhibits triamcinolone acetonide induced translocation of the glucocorticoid receptor to the nucleus of intact cells. In addition to inhibiting glucocorticoid receptor nuclear translocation, pyridoxal kills B16C3 murine melanoma cells and WM983A human melanoma cells in culture. Cortexolone, a glucocorticoid antagonist, also kills cells in culture. This mechanism, however, appears to initiate in the glucocorticoid receptor signal transducing cascade at a point prior to the impact of pyridoxal treatment alone. The glucocorticoid antagonist RU486 has no detrimental effect on melanoma cell viability, however, in combination with pyridoxal, RU486 extends cell viability. Since pyridoxal kills melanoma cells in culture, a pilot study was carried out examining the efficacy of topical application of a pyridoxal cream to inhibit the growth and/or cause regression of (B16C3) xenograft melanoma tumors in an immunocompetent (Hairless Rhino-J3) and an immunocompromised (Crl: nu/nu (CD1)BR) murine animal model. The results of the study with immunocompetent animals are encouraging. While tumors are brought under control by pyridoxal treatment, further work is needed to determine the most efficacious treatment regimen and to establish formal concentrations for pyridoxal in topical ointments. Trials using immunocompromised animals indicated that although some qualitative differences may be detected between the control and experimental animals, tumor growth in these animals is so aggressive that multiple applications or higher concentrations of pyridoxal may be needed to obtain useful data.

Pyridoxal-5'-phosphate and pyridoxal biokinetics in male Wistar rats fed graded levels of vitamin B-6.

Biokinetic parameters of plasma pyridoxal-5'-phosphate (PLP) and pyridoxal (PL) disposition were studied in male Wistar rats (age 8 mo) fed a purified diet containing less than 0.5, approximately 3 or approximately 6 mg pyridoxine.HCl/kg diet from weaning, with animals fed the 6 mg/kg diet serving as the control group. Basal plasma PLP concentration was lower in both the less than 0.5 and 3 mg/kg diet groups than in control animals (98 +/- 12, 314 +/- 40 and 514 +/- 56 nmol/L, respectively). Basal plasma PL concentration was lower in the less than 0.5 mg/kg diet group only [60 nmol/L (measured in pooled samples), 190 +/- 73 and 235 +/- 63 nmol/L for less than 0.5, 3 and 6 mg/kg diet groups, respectively]. In both the less than 0.5 and 3 mg/kg diet groups, PLP clearance was lower than in control rats (0.158 +/- 0.025, 0.131 +/- 0.040 and 0.240 +/- 0.051 L.h-1.kg body weight-1, respectively). In the less than 0.5 mg/kg diet group, PLP synthesis was more efficient than in control animals (34.7 +/- 9.3, 12.1 +/- 2.5 and 16.7 +/- 11.4% for less than 0.5, 3 and 6 mg/kg diet groups, respectively). In both the less than 0.5 and 3 mg/kg diet groups, volume of distribution of PLP as well as of PL was larger than in controls. It is concluded that B-6 vitamer metabolism is influenced by vitamin B-6 status. The metabolic pathway involved (PLP synthesis and/or PLP degradation) was observed to depend on degree of vitamin B-6 deficiency.

Vitamin B-6 metabolism in premature infants.

The response of premature infants to intravenous pyridoxine or pyridoxal was studied by measuring serum and erythrocyte pyridoxal 5'-phosphate (PLP). In the first study serum PLP was measured in 28 infants periodically through day 28. Infants less than 30 wk gestational age (GA) had no serum PLP response to the administration of pyridoxine. Infants greater than or equal to 30 wk GA had significantly greater concentrations of PLP by day 3. In the second study there was a negligible response of serum PLP in nine infants less than or equal to 28 wk GA to supplementation of pyridoxine or pyridoxal. However, erythrocyte PLP and whole-blood total vitamin B-6 concentrations increased in both groups, indicating the presence of a substantial amount of the vitamin in the circulation of the infants. Whereas the functional significance of these observations is not known, it appears that in premature infants, serum PLP may not be an appropriate indicator of vitamin B-6 status.

Toxicological study of pyridoxal isonicotinoyl hydrazone: acute and subchronic toxicity.

Pyridoxal isonicotinoyl hydrazone (PIH) is a highly effective iron chelator. Acute toxicity testing was performed in mice and rats of both sexes, with 10 mice or rats/sex/group. The LD50 values of PIH in both species were 5 and 1 g/kg given orally and intraperitoneally, respectively. Microscopic examination of tissues from the highest oral dose (6 g/kg) animals that survived 7 days revealed fatty degeneration in the liver. Subchronic toxicity was tested in rats of both sexes, with 8 males and 8 females/group. PIH doses of 100, 400 and 800 mg/kg were given orally for 90 consecutive days. Water was given to the control group. Hematocrit and blood chemistries were analysed at weeks 3, 6, 10 and 13. There were no changes in hematocrit and BUN. PIH at doses of 800 mg/kg caused a significant increase in serum alkaline phosphatase and transaminase levels at week 13. Microscopic examination showed hepatic degeneration in a dose-related fashion. Vascular congestion of the kidney and spleen was also found. No histopathological changes were detected in sections from the stomach and intestine.

Pyridoxine (a vitamin B6) and its derivative pyridoxal as treatment for Albizia versicolor poisoning in guinea-pigs.

In the course of three experiments it was established that all the toxic effects of a lethal dose of Albizia versicolor pods (greater than 4.5 g/kg) in guinea-pigs could be countered by concurrent subcutaneous injection of pyridoxine (10 mg/kg). This treatment was also successful once severe symptoms had set in. Pyridoxal, on the other hand, was found to be ineffective as a therapeutic agent. The fact that pyridoxal does not counter the action of the toxin indicates an atypical site of action by the toxin as regards the normal pathways which require vitamin B6 as a co-factor.

Mechanism of in vivo iron chelation by pyridoxal isonicotinoyl hydrazone and other imino derivatives of pyridoxal.

The source of iron chelated in vivo by the new iron-chelating agent PIH and its mechanism of excretion have been studied in normal and hypertransfused rats. PIH is able to chelate iron from both parenchymal and RE iron stores. Unlike DF, which promotes both urinary and fecal iron excretion, in this model PIH-induced iron excretion is limited almost entirely to the gut. Response to PIH is directly related to dosage, and oral doses ranging from 125 to 500 mg/kg/day are well tolerated. Six additional imino derivatives of pyridoxal have been studied, but none of these new compounds was as effective as PIH. Our study indicates that oral PIH is comparable in efficiency with parenteral DF and is of potential usefulness in the management of iron overload.

Biliary iron excretion in rats following pyridoxal isonicotinoyl hydrazone.

Biliary excretion of iron after administration of pyridoxal isonicotinoyl hydrazone (PIH), a recently identified effective iron-chelating agent, was investigated in rats. PIH administered both intraperitoneally and orally was shown to increase significantly 59Fe excretion into bile of rats which had previously been injected with 59Fe-transferrin to label hepatic parenchymal cells. 59Fe-PIH appears in bile as early as 15 min after chelator administration and the peak of 59Fe-radioactivity in bile is seen 1--5 h following intraperitoneal PIH injection. PIH, administered intraperitoneally, 125--250 mg/kg, increased 24 h biliary radioiron excretion about 35 times and in addition increased urinary and faecal iron excretion. When PIH was given immediately before 59Fe-transferrin, 24 h cumulative biliary 59Fe excretion was even higher. PIH was also demonstrated to increase biliary excretion of radioiron released from 59Fe-haemoglobin catabolysed in reticuloendothelial cells. The effect of PIH was confirmed by estimation of biliary iron concentration using the method of atomic absorption spectrophotometry. Repeated PIH administration to rats decreased 59Fe radioactivity in liver and kidney and increased urinary and faecal iron excretion.

Absorbed dose estimation of some 99mTc-hepatobiliary agents.

The absorbed dose estimates of several organs after administration in humans of six new hepatobiliary agents (five 99mTc-Pyridoxal amino acid complexes and the 99mTc-HIDA) are presented in comparison with 131I-Rose-Bengal. The results indicated that the radiation doses absorbed by the total body and gonads as well as by the critical organ (upper part of the large intestine) are significantly lower than those of Rose Bengal. Therefore, the new 99mTc-agents can be safely applied to humans.