Effects of calcium supplementation on body weight reduction in overweight calcium stone formers

A randomized, placebo-controlled trial was conducted in overweight calcium stone-forming (CSF) patients, to evaluate the effect of calcium supplementation associated with a calorie-restricted diet on body weight (BW) and fat reduction and its potential changes upon serum and urinary parameters. Fifteen patients were placed on a hypocaloric diet for 3 months, supplemented with either calcium carbonate (CaCO(3), n = 8) or placebo (n = 7), 500 mg bid. Blood and 24-h urine samples were collected and body composition was assessed at baseline and after the intervention. At the end of the study, final BW was significantly lower vs baseline in both CaCO(3) (74 +/- A 14 vs. 80 +/- A 14 kg, P = 0.01) and placebo groups (80 +/- A 10 vs. 87 +/- A 9 kg, P = 0.02) but the mean percentage of loss of body weight and body fat did not differ between CaCO(3) and placebo (7.0 +/- A 2.0 vs. 8.0 +/- A 3.0%, P = 0.40 and 13.0 +/- A 7.0 vs. 13.0 +/- A 10.0%; P = 0.81, respectively). After CaCO(3) or placebo, no significant differences versus baseline were observed for urinary parameters in both CaCO(3) and placebo, except for a higher mean urinary citrate in placebo group. These data suggest that increasing calcium intake by calcium carbonate supplementation did not contribute to a further reduction of BW and fat in overweight CSF patients submitted to a hypocaloric diet nor altered urinary lithogenic parameters.

Gaining ligand selectivity in thyroid hormone receptors via entropy

Nuclear receptors are important targets for pharmaceuticals, but similarities between family members cause difficulties in obtaining highly selective compounds. Synthetic ligands that are selective for thyroid hormone (TH) receptor beta (TR beta) vs. TR alpha reduce cholesterol and fat without effects on heart rate; thus, it is important to understand TR beta-selective binding. Binding of 3 selective ligands (GC-1, KB141, and GC-24) is characterized at the atomic level; preferential binding depends on a nonconserved residue (Asn-331 beta) in the TR beta ligand-binding cavity (LBC), and GC-24 gains extra selectivity from insertion of a bulky side group into an extension of the LBC that only opens up with this ligand. Here we report that the natural TH 3,5,3`-triodothyroacetic acid (Triac) exhibits a previously unrecognized mechanism of TR beta selectivity. TR x-ray structures reveal better fit of ligand with the TR alpha LBC. The TR beta LBC, however, expands relative to TR alpha in the presence of Triac (549 angstrom(3) vs. 461 angstrom(3)), and molecular dynamics simulations reveal that water occupies the extra space. Increased solvation compensates for weaker interactions of ligand with TR beta and permits greater flexibility of the Triac carboxylate group in TR beta than in TR alpha. We propose that this effect results in lower entropic restraint and decreases free energy of interactions between Triac and TR beta, explaining subtype-selective binding. Similar effects could potentially be exploited in nuclear receptor drug design.

A multi-screening approach for marine-derived fungal metabolites and the isolation of cyclodepsipeptides from Beauveria felina

Extracts obtained from 57 marine-derived fungal strains were analyzed by HPLC-PDA, TLC and ¹H NMR. The analyses showed that the growth conditions affected the chemical profile of crude extracts. Furthermore, the majority of fungal strains which produced either bioactive of chemically distinctive crude extracts have been isolated from sediments or marine algae. The chemical investigation of the antimycobacterial and cytotoxic crude extract obtained from two strains of the fungus Beauveria felina have yielded cyclodepsipeptides related to destruxins. The present approach constitutes a valuable tool for the selection of fungal strains that produce chemically interesting or biologically active secondary metabolites.

Secondary metabolites produced by Propionicimonas sp (ENT-18) induce histological abnormalities in the sclerotia of Sclerotinia sclerotiorum

Sclerotinia sclerotiorum is a highly aggressive pathogen that causes great economic losses, especially in temperate climates. Several biological control agents are available, but actinobacteria have seldom been used to control this fungus. Our objective was to evaluate the efficiency and ultrastructural effects of the secondary metabolites produced by the ant-associated actinobacterium Propionicimonas sp. ENT-18 in controlling the sclerotia of S. sclerotiorum. We demonstrated total inhibition of sclerotia treated with 62.5 mu g/10 mu l of an ethyl acetate extract of compounds produced by ENT-18, and calculated an LC(50) of 1.69 mu g/sclerotia. Histological and ultrastructural analysis indicated that the cells of the treated sclerotia were severely damaged, suggesting direct action of the biomolecule(s) produced by the actinobacterium ENT-18 on the cell structure of the medullae and rind cell wall. This is the first report demonstrating a novel property of Propionicimonas sp.-antifungal activity against S. sclerotiorum.

Relationships between gene polymorphisms of folate-related proteins and vitamins and metabolites in pregnant women and neonates

Background: The methylenetetrahydrofolate reductase (MTHFR), glutamate carboxypeptidase II (GCPII) and reduced folate carrier (RFC1) gene polymorphisms were associated with folate status. We investigated the effects of these polymorphisms on serum folate (SF) and folate-related metabolites in mothers and their neonates. Methods: Cobalamin (Cbl), SF, total homocysteine (tHcy), methylmalonic acid (MMA), S-adenosylmethionine (SAM), and S-adenosylhomocysteine (SAH) were measured in 275 healthy women and their neonates. MTHFR C677T, GCPII C1561T and RFC1 A80G polymorphisms were determined by PCR-RFLP. Results: Maternal tHcy was affected individually by MTHFR C677T and GCPII C1561T polymorphisms and by combined genotypes MTHFR 677TT/GCPII 1561CC and MTHFR 677TT/RFC1 80AG. The MTHFR and RFC1 polymorphisms were not associated with variations in vitamins or SAM, SAH and MMA in neonates. Neonatal tHcy was predicted directly by maternal tHcy and inversely by maternal SF, neonatal Cbl and neonatal RFC1 80G allele (AG+GG genotypes). Maternal MMA and SAM/SAH were predicted by creatinine and Cbl, respectively. Neonatal MMA was predicted by maternal MMA and GCPII 1561T allele (CT+TT genotypes) and by neonatal Cbl. Conclusions: Maternal tHcy was affected by MTHFR C677T, RFC1 A80G and GCPII C1561T polymorphisms. Maternal GCPII C1561T variant was associated with neonatal MMA. Neonatal RFC1 A80G polymorphism influenced tHcy in neonates. (C) 2008 Elsevier B.V. All rights reserved.

Association between decreased vitamin levels and MTHFR, MTR and MTRR gene polymorphisms as determinants for elevated total homocysteine concentrations in pregnant women

Objectives: To examine the association between methylenetetrahydrofolate reductase (MTHFR) (C677T and A1298C), methionine synthase (MTR) A2756G and methionine synthase reductase (MTRR) A66G gene polymorphisms and total homocysteine (tHcy), methylmalonic acid (MMA) and S-adenosylmethionine/ S-adenosylhomocysteine (SAM/SAH) levels; and to evaluate the potential interactions with folate or cobalamin (Cbl) status. Subjects/ Methods: Two hundred seventy-five healthy women at labor who delivered full-term normal babies. Cbl, folate, tHcy, MMA, SAM and SAH were measured in serum specimens. The genotypes for polymorphisms were determined by PCR-restriction fragment length polymorphism ( RFLP). Results: Serum folate, MTHFR 677T allele and MTR 2756AA genotypes were the predictors of tHcy levels in pregnant women. Serum Cbl and creatinine were the predictors of SAM/SAH ratio and MMA levels, respectively. The gene polymorphisms were not determinants for MMA levels and SAM/SAH ratios. Low levels of serum folate were associated with elevated tHcy in pregnant women, independently of the gene polymorphisms. In pregnant women carrying MTHFR 677T allele, or MTHFR 1298AA or MTRR 66AA genotypes, lower Cbl levels were associated with higher levels of tHcy. Lower SAM/SAH ratio was found in MTHFR 677CC or MTRR A2756AA genotypes carriers when Cbl levels were lower than 142 pmol/l. Conclusions: Serum folate and MTHFR C677T and MTR A2576G gene polymorphisms were the determinants for tHcy levels. The interaction between low levels of serum Cbl and MTHFR (C677T or A1298C) or MTRR A66G gene polymorphisms was associated with increased tHcy.

Pentoxyphylline in association with vitamin E reduces cutaneous fibrosis in systemic sclerosis

Systemic sclerosis (SSc) is a disorder characterized by skin thickness and vasculopathy. The objective of the study was to evaluate the therapeutic effect and safety of the association of pentoxyphylline and vitamin E in SSc patients. Twelve SSc patients (American College of Rheumatology criteria) enrolled this 24-week open-label study. Patients received daily 800 mg of pentoxyphylline and 800 UI of vitamin E and were evaluated at 4-week interval. The primary efficacy endpoint was the change in Modified Rodnan Skin Score (MRSS) at week 24. Nine diffuse SSc patients treated 6 months with cyclophosphamide were used as a historical control group. The mean age of the treated group was 43.6 years, and ten of 12 (84%) patients were women. Their mean MRSS reduced from 25.7 to 18.7 (p = 0.03) at 16th week and remained significantly reduced throughout the study. In contrast, only a trend of MRSS reduction was observed in the historical control group (p = 0.06). Two patients started the study with active ischemic ulcers and ended with a complete healing of them. No serious side effects were reported. Pentoxyphylline and vitamin E might be an alternative therapeutic approach in SSc patients.

Vitamin E and tannic acid improve DNA damage in rats submitted chronic ethanol administration

Purpose - Chronic ethanol consumption induces lipid peroxidation by increasing free radicals or reducing antioxidants and may increase damage to hepatic DNA. Tannins are polyphenolic metabolites present in various plants and one of their effects is antioxidant activity that reduces lipoperoxidation, as is the case for vitamin E. This paper aims to assess the role of tannic acid and vitamin E in lipid peroxidation and in DNA damage in rats receiving ethanol. Design/methodology/approach - A total of 60 Wistar rats were divided into six groups: control + ethanol (0-24hs), tannic acid + ethanol (0-24 hs), and vitamin E + ethanol (0-24 hs). The animals were sacrificed immediately (0 hour) or 24 hours after a period of four weeks of ethanol administration and the following measurements were made: plasma vitamin E and liver glutathione, thiobarbituric acid resistant substances, and a-tocopherol. The comet test was also applied to hepatocytes. Findings - Ethanol administration led to an increase in DNA damage (148.67 +/- 15.45 versus 172.63 +/- 18.94) during a period of 24 hours which was not detected in the groups receiving tannic acid or vitamin E. Steatosis was lower in the groups receiving tannic acid. Originality/value - The paper highlights that antioxidant role of vitamin E and of tannic acid in biological systems submitted to oxidative stress should be reevaluated, especially regarding the protective role of tannic acid against hepatic steatosis.

Genetic dissection of vitamin E biosynthesis in tomato

Vegetables are critical for human health as they are a source of multiple vitamins including vitamin E (VTE). In plants, the synthesis of VTE compounds, tocopherol and tocotrienol, derives from precursors of the shikimate and methylerythritol phosphate pathways. Quantitative trait loci (QTL) for alpha-tocopherol content in ripe fruit have previously been determined in an Solanum pennellii tomato introgression line population. In this work, variations of tocopherol isoforms (alpha, beta, gamma, and delta) in ripe fruits of these lines were studied. In parallel all tomato genes structurally associated with VTE biosynthesis were identified and mapped. Previously identified VTE QTL on chromosomes 6 and 9 were confirmed whilst novel ones were identified on chromosomes 7 and 8. Integrated analysis at the metabolic, genetic and genomic levels allowed us to propose 16 candidate loci putatively affecting tocopherol content in tomato. A comparative analysis revealed polymorphisms at nucleotide and amino acid levels between Solanum lycopersicum and S. pennellii candidate alleles. Moreover, evolutionary analyses showed the presence of codons evolving under both neutral and positive selection, which may explain the phenotypic differences between species. These data represent an important step in understanding the genetic determinants of VTE natural variation in tomato fruit and as such in the ability to improve the content of this important nutriceutical.

Cytotoxic and genotoxic effects of tambjamine D, an alkaloid isolated from the nudibranch Tambja eliora, on Chinese hamster lung fibroblasts

Marine organisms have been shown to be potential sources of bioactive compounds with pharmaceutical applications. Previous chemical investigation of the nudibranch Tambja eliora led to the isolation of the alkaloid tambjamine D. Tambjamines have been isolated from marine sources and belong to the family of 4-methoxypyrrolic-derived natural products, which display promising immunosuppressive and cytotoxic properties. Their ability to intercalate DNA and their pro-oxidant activity may be related to some of the biological effects of the 4-methoxypyrrolic alkaloids. The aim of the present investigation was to determine the cytotoxic, pro-oxidant and genotoxic properties of tambjamine D in V79 Chinese hamster lung fibroblast cells. Tambjamine D displayed a potent cytotoxic effect in V79 cells (IC50 1.2 mu g/mL) evaluated by the MTT assay. Based on the MTT result, V79 cells were treated with different concentrations of tambjamine D (0.6. 1.2. 2.4 and 4.8 mu g/mL). After 24 h, tambjamine D reduced the number of viable cells in a concentration-dependent way at all concentrations tested. assessed by the trypan blue dye exclusion test. The hemolytic assay showed that the cytotoxic activity of tambjamine D was not related to membrane disruption (EC50 > 100 mu g/mL). Tambjamine D increased the number of apoptotic cells in a concentration-dependent manner at all concentrations tested according to acridine orange/ethidium bromide staining, showing that the alkaloid cytotoxic effect was related to the induction of apoptosis. MTT reduction was stimulated by tambjamine D, which may indicate the generation of reactive oxygen species. Accordingly, treatment of cells with tambjamine D increased nitrite/nitrate at all concentrations and TBARS production starting at the concentration corresponding to the IC50. Tambjamine D, also, induced DNA strand breaks and increased the micronucleus cell frequency as evaluated by comet and micronucleus tests, respectively, at all concentrations evaluated. showing a genotoxic risk induced by tambjamine D. (C) 2008 Elsevier Ireland Ltd. All rights reserved.

Use of Experimental Design for the Optimization of the Production of New Secondary Metabolites by Two Penicillium Species

A fractional factorial design approach has been used to enhance secondary metabolite production by two Penicillium strains. The method was initially used to improve the production of bioactive extracts as a whole and subsequently to optimize the production of particular bioactive metabolites. Enhancements of over 500% in secondary metabolite production were observed for both P. oxalicum and P. citrinum. Two new alkaloids, citrinalins A (5) and B (6), were isolated and identified from P. citrinum cultures optimized for production of minor metabolites.

Lesion of the subthalamic nucleus reverses motor deficits but not death of nigrostriatal dopaminergic neurons in a rat 6-hydroxydopamine-lesion model of Parkinson's disease

The objective of the present study was to determine whether lesion of the subthalamic nucleus (STN) promoted by N-methyl-D-aspartate (NMDA) would rescue nigrostriatal dopaminergic neurons after unilateral 6-hydroxydopamine (6-OHDA) injection into the medial forebrain bundle (MFB). Initially, 16 mg 6-OHDA (6-OHDA group) or vehicle (artificial cerebrospinal fluid - aCSF; Sham group) was infused into the right MFB of adult male Wistar rats. Fifteen days after surgery, the 6-OHDA and SHAM groups were randomly subdivided and received ipsilateral injection of either 60 mM NMDA or aCSF in the right STN. Additionally, a control group was not submitted to stereotaxic surgery. Five groups of rats were studied: 6-OHDA/NMDA, 6-OHDA/Sham, Sham/NMDA, Sham/Sham, and Control. Fourteen days after injection of 6-OHDA, rats were submitted to the rotational test induced by apomorphine (0.1 mg/kg, ip) and to the open-field test. The same tests were performed again 14 days after NMDA-induced lesion of the STN. The STN lesion reduced the contralateral turns induced by apomorphine and blocked the progression of motor impairment in the open-field test in 6-OHDA-treated rats. However, lesion of the STN did not prevent the reduction of striatal concentrations of dopamine and metabolites or the number of nigrostriatal dopaminergic neurons after 6-OHDA lesion. Therefore, STN lesion is able to reverse motor deficits after severe 6-OHDA-induced lesion of the nigrostriatal pathway, but does not protect or rescue dopaminergic neurons in the substantia nigra pars compacta.

Overview of the taxonomy and of the major secondary metabolites and their biological activities related to human health of the Laurencia complex (Ceramiales, Rhodophyta) from Brazil

In Brazil, the Laurencia complex is represented by twenty taxa: Laurencia s.s. with twelve species, Palisada with four species (including Chondrophycus furcatus now that the proposal of its transference to Palisada is in process), and Osmundea and Yuzurua with two species each. The majority of the Brazilian species of the Laurencia complex have been phylogenetically analyzed by 54 rbcL sequences, including five other Rhodomelacean species as outgroups. The analysis showed that the Laurencia complex is monophyletic with high posterior probability value. The complex was separated into five clades, corresponding to the genera: Chondrophycus, Laurencia, Osmundea, Palisada, and Yuzurua. A bibliographical survey of the terpenoids produced by Brazilian species showed that only six species of Laurencia and five of Palisada (including C. furcatcus) have been submitted to chemical analysis with 48 terpenoids (47 sesquiterpenes and one triterpene) isolated. No diterpenes were found. Of the total, 23 sesquiterpenes belong to the bisabolane class and eighteen to the chamigrene type, whose biochemical precursor is bisabolane, two are derived from lauranes and four are triquinols. Despite the considerable number of known terpenes and their ecological and pharmacological importance, few experimental biological studies have been performed. In this review, only bioactivities related to human health were considered.

Synthesis of novel O-acylated-D-ribono-1,5-lactones and structural assignment supported by conventional NOESY-NMR and x-ray analysis

A practical method for the structural assignment of 3,4-O-benzylidene-D-ribono-1,5-lactones and analogues using conventional NMR techniques and NOESY measurements in solution is described. 2-O-Acyl-3,4-O-benzylidene-D-ribono-1,5-lactones were prepared in good yields by acylation of Zinner’s lactone with acyl chlorides under mildly basic conditions. Structural determination of 2-O-(4-nitrobenzoyl)-3,4-O-benzylidene-D-ribono-1,5-lactone was achieved by single crystal x-ray diffraction, which supports the results based on spectroscopic data.

High resolution study of 104Pd(d,t)103Pd

Information collected in the present high resolution study of 104Pd(d,t)103Pd is interpreted within the systematics of the A ~ 100 region. The paper complements data previously presented by the S.Paulo Group, which were taken with the Pelletron-Enge-Spectrograph facility. A one-to-one correspondence to gamma ray results for 103Pd, collected by the Nuclear Data Sheets (NDS), was achieved and at least four open questions were settled. More reliable spectroscopic strengths were extracted in the present study.