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Previous studies reported that Pb exposure causes a negative association with delta-aminolevulinic acid dehydratase activity (δ-ALAD), but the impact of Pb exposure (dose and time), B vitamin deficiencies, and lifestyle factors needs to be explored. In this study, the impact of Pb exposure, B vitamin deficiencies, and lifestyle factors on δ-ALAD activity among workers exposed to Pb from the Pb-recycling process was evaluated. Blood lead levels (BLLs), B vitamins (B6, B9, and B12), hematological factors (Hb% and HCT), lifestyle factors, and δ-ALAD activity was assessed in 170 male Pb-exposed workers engaged in the Pb recycling process. BLLs are estimated using the ICP-OES method. B vitamins in serum samples from workers were determined using the ELISA method. The δ-ALAD activity in whole blood samples was determined using the spectrophotometer method. The lifestyle factors were collected using a standard questionnaire. The δ-ALAD activity was significantly decreased in workers with the habits of alcohol use, tobacco consumption, hematocrit < 41%, mild and moderate categories of anemia, vitamin B6 and B12 deficiency, and BLL categories of 10-30, 30-50, and > 50 µg/dL. Multiple regression analysis revealed that the independent variables of alcohol consumption (β = - 0.170; P = 0.025), BLLs (β = - 0.589; P = 0.001) and Hb% (β = 0.183; P = 0.001) significantly influenced the δ-ALAD activity with 44.2% (R 2  = 0.442). Among the workers exposed to Pb from the Pb recycling plant, δ-ALAD activity was considerably reduced by Pb exposure, B vitamin deficiency, hematological parameters, and lifestyle factors., (© 2024. The Author(s), under exclusive licence to Society for Biological Inorganic Chemistry (SBIC).)

δ-Aminolevulinic acid dehydratase (ALAD) is a key enzyme of the cytoplasmic heme biosynthesis pathway. The primary structure of the ALAD gene, the multimeric structure of the ALAD/hemB protein, and ALAD expression during the annual reproductive cycle were studied in the cold-water marine sponge Halisarca dujardinii. The results implicated the GATA-1 transcription factor and DNA methylation in regulating ALAD expression. Re-aggregation of sponge cells was accompanied by a decrease in ALAD expression and a change in the cell content of an active ALAD/hemB form. Further study of heme biosynthesis and the role of ALAD/hemB in morphogenesis of basal animals may provide new opportunities for treating pathologies in higher animals.

Corynebacterium glutamicum porphobilinogen synthase (PBGS) is a metal enzyme with a hybrid active site metal binding sequence. In this study, the porphobilinogen synthase gene of C. glutamicum was cloned and heterogeneously expressed in Escherichia coli. C. glutamicum PBGS was purified, and its enzymatic characteristics were analyzed. The results showed that C. glutamicum PBGS is a Zn 2+ -dependent enzyme, and Mg 2+ has allosteric regulation. The allosteric Mg 2+ plays a vital role in forming the quaternary structure of C. glutamicum PBGS. Based on the ab initio predictive structure modeling of the enzyme and the molecular docking model of 5-aminolevulinic acid (5-ALA), 11 sites were selected for site-directed mutagenesis. When the hybrid active site metal binding site of C. glutamicum PBGS is converted into a cysteine-rich motif (Zn 2+ -dependent) or an aspartic acid-rich motif (Mg 2+ /K + -dependent), the enzyme activity is basically lost. Four residues, D128, C130, D132, and C140, in the metal binding site, were the binding sites of Zn 2+ and the active center of the enzyme. The band migration, from the native PAGE, of five variants with mutations in the center of enzyme activity was the same as that of the variant enzymes as purified, individually adding two metal ion chelating agents. Their Zn 2+ active center structures were abnormal, and the quaternary structure equilibrium was altered. The destroyed active center affects the construction of its quaternary structure. The quaternary structural balance between octamer and hexamer through dimers was regulated by the allosteric regulation of C. glutamicum PBGS. The enzyme activity was also affected by the change of the active site lid structure and (α β) 8 -barrel structure caused by mutation. Structural changes in the variants were analyzed to understand C. glutamicum PBGS better., (© 2023. The Author(s), under exclusive licence to Springer Nature B.V.)

The aim of the current study was to determine the activity of the delta-aminolevulinate dehydratase (δ-ALA-D) enzyme, oxidative stress biomarkers and the expression of cytokines in those infected with influenza B virus (IBV). To evaluate the activity of the δ-ALA-D enzyme, lipid peroxidation was estimated as levels of thiobarbituric acid reactive substances, protein and non-protein thiol groups, ferric-reducing antioxidant power (FRAP), vitamin C concentration and cytokine levels in IBV-infected individuals (n  = 50) and a control group (n = 30). δ-ALA-D activity was significantly lower in IBV-infected individuals compared with controls, as well as levels of thiols, vitamin C and FRAP. Lipid peroxidation and cytokine levels of IL-6, IL-10, IL-17A and IFN-y were statistically higher in the IBV group. In conclusion, we found evidence of the generation of oxidants, the depletion of the antioxidant system, decrease in the activity of the δ-ALA-D enzyme and an increase in the synthesis of cytokines, thus contributing to a better understanding of oxidative and inflammatory pathways during IBV infection., (© The Author(s) 2023. Published by Oxford University Press on behalf of FEMS.)

The δ -aminolevulinic acid dehydratase (ALAD) enzyme is an intermediate in the biosynthetic pathway of tetrapyrroles. It combines two δ -aminolevulinic acid ( δ -ALA) molecules to form the pyrrole, porphobilinogen, an important precursor for plant pigments involved in photosynthesis, respiration, light-sensing, and nutrient uptake. Our recent efforts showed that, in citrus, silencing of ALAD gene via Citrus tristeza virus- induced gene silencing, caused yellow spots and necrosis in leaves and in developing new shoots. Silencing of ALAD gene reduced leaf pigments and altered leaf metabolites. Moreover, total phenolic content, H 2 O 2, and reactive oxygen species (ROS) increased, indicating that silencing of ALAD induced severe stress. Herein, we hypothesized that conditions including lower sucrose, elevated ROS, alteration of microRNA involved in RNAi regulatory protein Argonaute 1 (AGO1) and ROS lead to higher deposition of callose in phloem tissues. Using aniline blue staining and gene expression analysis of callose synthases, we showed significant deposition of callose in ALAD -silenced citrus.

Introduction: Oxidative stress is closely related to the pathophysiology of gestation, where the placenta is susceptible to oxidative damage, contributing to the onset of gestational complications. Currently, few studies evaluate the use of oxidative markers for prediction of risk of gestational complications. However, there are some reports that suggest these biomarkers as potential prognostic biomarkers. Therefore, the objective of this study was to compare the biomarkers of oxidative stress from gestations with and without complications, and also evaluate the delta of variation in these markers from the first gestational trimester., Material and Methods: A total of 45 pregnant women were evaluated during the three gestational trimesters, of whom 15 developed gestational complications by the end of gestation. The evaluated oxidative damage markers were thiobarbituric acid reactive substances and nitric oxide dosage. Evaluation of the antioxidant system was performed by the quantification of vitamin C, sulfhydryl groups, total antioxidant capacity, plasmatic iron reduction ability, the evaluation of catalase and delta-aminolevulinate dehydratase enzymatic activity., Results: According to the results, the markers of oxidative damage are increased, and the antioxidant profile decreased, in the third trimester of complicated pregnancies as compared to uncomplicated pregnancies. Moreover, the delta of variation in both oxidative damage markers and antioxidants was higher in complicated gestations as compared to uncomplicated gestations, thus suggesting a higher oxidative stress in pregnancies with complications., Conclusions: Oxidative stress parameters appear altered in pregnant women with gestational complications. The markers to oxidative stress can be possible biomarkers, helping in understanding mechanisms underlying the associations between complications during pregnancy and various health outcomes., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The aim of this study was to investigate the clinical and oxidative profile, including the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D), in women who acquired toxoplasmosis during pregnancy and used the triple regimen (sulfadiazine + pyrimethamine + folinic acid [SPFA]) as treatment. These parameters have not been evaluated in pregnant women with toxoplasmosis who used the triple regimen. A total of 53 pregnant women were recruited and divided into two groups: control (C; n = 27) and acute toxoplasmosis (AT; n = 26). Clinical data and blood samples were obtained from all patients. The clinical profile was analyzed by checking parameters such as body mass index, blood pressure, and complete blood count. Oxidative stress was evaluated by quantifying protein (P-SH) and non-protein (NP-SH) thiol groups, vitamin C, plasma iron reduction capacity (FRAP), δ-ALA-D enzyme activity, reactive substances to thiobarbituric acid (TBARS), and nitric oxide (NO). Changes in hematological parameters (increased red cell distribution width and decreased hemoglobin and mean corpuscular hemoglobin concentration), increased antioxidant system (P-SH, NP-SH, FRAP, δ-ALA-D enzyme activity), as well as damage markers (TBARS and NO), were significantly elevated in pregnant women with toxoplasmosis, compared to those in the control group. Pregnant women treated for this acute infection showed increased damage markers, as well as a significant increase in the antioxidant system, including the activity of the δ-ALA-D enzyme. Given this evidence, it is suggested that these changes occur as a form of compensation, with a possible contribution from drug therapy., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Aims: The objective of this study was to investigate the effect of the type of delivery (vaginal and cesarean) on the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D), which as yet has not been studied, and the markers of oxidative stress., Methods: Seventy-six mothers and their newborns were divided into two groups: normal birth (VD) and elective cesarean section (ECS). Samples of maternal and umbilical cord blood were collected up to 5 min after birth. Thiobarbituric acid reactive substances (TBARS), advanced oxidation protein products (AOPP), protein thiol (P-SH), nonprotein (NP-SH), the ferric reducing ability of plasma (FRAP), total antioxidant capacity (TAC), catalase, and δ-ALA-D enzyme activity were tested., Results: TBARS and AOPP were significantly higher in mothers of the VD group, while P-SH, NP-SH, FRAP and TAC were reduced. In newborns, TBARS and AOPP did not differ between the groups; however, in the VD group, there was a decrease in P-SH, NP-SH, FRAP, TAC, and catalase. The activity of the δ-ALA-D enzyme was decreased in mothers and neonates born by VD., Conclusions: Mothers undergoing VD had higher levels of free radicals and lower antioxidant defenses, while their newborns decreased antioxidant defenses likely to contain the oxidative imbalance. The inhibition of the δ-ALA-D enzyme in this scenario allows its use as a useful marker of oxidative stress in different obstetric settings.

Streptozotocin (STZ) is a substance used experimentally to induce a diabetes model, a metabolic disease associated with oxidative tissue damage. This study evaluated if 4-4'-dichloro-diphenyl diselenide ( p -ClPhSe) 2 modulates oxidative stress in peripheral tissues of diabetic mice. Male Swiss mice received a single STZ injection (i.p.) at a dose of 200 mg/kg or its vehicle and were treated with ( p -ClPhSe) 2 (7 days, 5 mg/kg) or metformin (200 mg/kg, twice per day). After, the mice were euthanized to collect liver, kidney, and skeletal muscle samples. In the liver, ( p -ClPhSe) 2 reduced thiobarbituric acid reactive substances (TBARS) and protein carbonyl levels and normalized the superoxide dismutase activity in STZ-treated mice. In the kidney, ( p -ClPhSe) 2 reversed the increase in the reactive species levels but not the catalase (CAT) activity reduction in STZ-treated mice. There was no evidence of oxidative damage in the skeletal muscle of STZ-treated mice, but an increase in the CAT activity and a reduction in non-protein thiol levels were found. ( p -ClPhSe) 2 did not reverse a decrease in hepatic and renal δ-aminolevulinic acid dehydratase activity in STZ-treated mice. The results show that the liver and kidney of STZ-treated mice were more susceptible to oxidative stress. This study reveals that ( p -ClPhSe) 2 modulated oxidative stress, which differently affected peripheral tissues of diabetic mice.

Givosiran is a small synthetic double-stranded siRNA (small interfering RNA) conjugated with N-acetyl-galactosamine (GalNAc) for specific hepatocyte targeting via the asialoglycoprotein receptor. A prospective randomized multicenter study (Envision) demonstrated the clinical efficacy of monthly subcutaneous injection of Givosiran for the prevention of attacks of acute hepatic porphyria (AHP). This leads to highly selective transcriptional inhibition of the key hepatic enzyme, aminolaevulinate synthase 1, that is overexpressed in AHP. The success of the Envision study has led to the approval of Givosiran in the US and Europe for the treatment of severe AHP. This innovative guided siRNA therapy has opened up the possibility to selectively inhibit the expression of any hepatocyte gene whose overexpression that causes pathology, which can be considered a milestone development in hepatology. However, currently this treatment with givosiran is very costly. Moreover, since some patients experience worsening of kidney function and elevated aminotransferases, monthly monitoring of these parameters is necessary in the first half year of treatment., Competing Interests: US hat Honorare für Beratungen der Firma Alnylam erhalten.DS hat Alnylam in den Jahren 2010–2013 beraten., (Thieme. All rights reserved.)

Previous studies have shown the porphobilinogen synthase (PBGS) zinc-binding mechanism and its conservation among the living cells. However, the precise molecular interaction of zinc with the active center of the enzyme is unknown. In particular, quantum chemistry techniques within the density functional theory (DFT) framework have been the key methodology to describe metalloproteins, when one is looking for a compromise between accuracy and computational feasibility. Considering this, we used DFT-based models within the molecular fractionation with conjugate caps scheme to evaluate the binding energy features of zinc interacting with the human PBGS. Besides, phylogenetic and clustering analyses were successfully employed in extracting useful information from protein sequences to identify groups of conserved residues that build the ions-binding site. Our results also report a conservative assessment of the relevant amino acids, as well as the benchmark analysis of the calculation models used. The most relevant intermolecular interactions in Zn2+-PBGS are due to the amino acids CYS0122, CYS0124, CYS0132, ASP0169, SER0168, ARG0221, HIS0131, ASP0120, GLY0133, VAL0121, ARG0209, and ARG0174. Among these residues, we highlighted ASP0120, GLY0133, HIS0131, SER0168, and ARG0209 by co-occurring in all clusters generated by unsupervised clustering analysis. On the other hand, the triple cysteines at 2.5 Å from zinc (CYS0122, CYS0124, and CYS0132) have the highest energy attraction and are absent in the taxa Viridiplantae, Sar, Rhodophyta, and some Bacteria. Additionally, the performance of the DFT-based models shows that the processing time-dependence is more associated with the choice of the basis set than the exchange-correlation functional., (© The Author(s) 2021. Published by Oxford University Press.)

Heme biosynthesis and iron-sulfur cluster (ISC) biogenesis are two major mammalian metabolic pathways that require iron. It has long been known that these two pathways interconnect, but the previously described interactions do not fully explain why heme biosynthesis depends on intact ISC biogenesis. Herein we identify a previously unrecognized connection between these two pathways through our discovery that human aminolevulinic acid dehydratase (ALAD), which catalyzes the second step of heme biosynthesis, is an Fe-S protein. We find that several highly conserved cysteines and an Ala306-Phe307-Arg308 motif of human ALAD are important for [Fe 4 S 4 ] cluster acquisition and coordination. The enzymatic activity of human ALAD is greatly reduced upon loss of its Fe-S cluster, which results in reduced heme biosynthesis in human cells. As ALAD provides an early Fe-S-dependent checkpoint in the heme biosynthetic pathway, our findings help explain why heme biosynthesis depends on intact ISC biogenesis.

The δ-aminolevulinic acid (δ-ALA) is an intermediate in the biosynthetic pathway of tetrapyrroles. Tetrapyrroles play vital roles in many biological processes such as photosynthesis, respiration, and light-sensing. ALA-dehydratase (ALAD) combines two molecules of δ-ALA to form porphobilinogen. In citrus, the silencing of ALAD caused discrete yellow spots and necrosis in leaves and stems. Additionally, it caused rapid death in developing new shoots. Herein, we hypothesize that the accumulation of δ-ALA results in severe stress and reduced meristem development. For that reason, we investigated the dynamic changes in the expression profiles of 23 microRNA (miRNA) identified through small RNA sequencing, from CTV-tALAD plants in comparison with healthy C. macrophylla and C. macrophylla infiltrated with CTV-wt. Furthermore, we reported the effect of ALAD silencing on the total phenolics, H 2 O 2, and reactive oxygen species (ROS) levels, to examine the possibilities of miRNAs involving the regulation of these pathways. Our results showed that the total phenolics content, H 2 O 2 , and O 2 - levels were increased in CTV-tALAD plants. Moreover, 63 conserved miRNA members belonging to 23 different miRNA families were differentially expressed in CTV-tALAD plants compared to controls. The identified miRNAs are implicated in auxin biosynthesis and signaling, axillary shoot meristem formation and leaf morphology, starch metabolism, and oxidative stress. Collectively, our findings suggested that ALAD silencing initiates stress on citrus plants. As a result, CTV-tALAD plants exhibit reduced metabolic rate, growth, and development in order to cope with the stress that resulted from the accumulation of δ-ALA. This cascade of events led to leaf, stem, and meristem necrosis and failure of new shoot development., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Purpose: To assess and understand the maternal oxidative stress in twin pregnancies, currently not studied, through ascertain indicators of oxidative damage in maternal blood in response of two fetuses, as well as the relation of placenta with or without the increase of oxidative stress in these gestations. Materials and methods: The activity of delta-aminolevulinate dehydratase (δ-ALA-D) was analyzed as an indirect marker of oxidative stress, as well as the quantification of thiobarbituric acid reactive substances (TBARS), protein thiol groups (P-SH) and nonprotein thiol groups (NP-SH), vitamin C (VIT C) and catalase activity (CAT) in maternal blood samples from twin ( n  = 30) and single ( n  = 30) pregnancies. This study was approved by the Human Ethics Committee UFSM (register by the number 49823015.4.0000.5346). Results: TBARS was significantly higher in twin pregnancies, while thiol groups, VIT C and CAT were decreased, asides from the reduced activity of δ-ALA-D in comparison to single fetus gestations. Conclusions: The study established an oxidative stress increased and an antioxidant ability decreased in twin pregnancies, suggesting a possible relation between the levels of oxidants and antioxidants with the complications in those gestations.

Autism is a neuropathology characterized by behavioral disorders. Considering that oxidative stress is involved in the pathophysiology of this disease, we evaluated the effects of quercetin, a flavonoid with antioxidant and neuroprotective properties, in an experimental model of autism induced by valproic acid (VPA). Twelve pregnant female rats were divided into four groups (control, quercetin, VPA, and VPA+quercetin). Quercetin (50 mg/kg) was administered orally to the animals from gestational days 6.5 to 18.5, and VPA (800 mg/kg) was administered orally in a single dosage on gestational day 12.5. Behavioral tests such as open field, social interaction, and tail flick nociceptive assays were performed on pups between 30 and 40 days old, after which the animals were euthanized. Cerebral cortex, hippocampus, striatum, and cerebellum were collected for evaluation of oxidative stress parameters. The pups exposed to VPA during the gestational period showed reduced weight gain, increased latency in the open field and tail flick tests, reduced time of social interaction, accompanied by changes in oxidative stress parameters mainly in the hippocampus and striatum. Prenatal treatment with quercetin prevented the behavioral changes and damage caused by oxidative stress, possibly due to its antioxidant action. Our findings demonstrated that quercetin has neuroprotective effects in an animal model of autism, suggesting that this natural molecule could be an important therapeutic agent for treatment of autism spectrum disorders (ASDs)., (© 2020 International Society for Developmental Neuroscience.)

Ulcerative dermatitis in laboratory mice remains an ongoing clinical problem and animal welfare issue. Many products have been used to treat dermatitis in mice, with varying success. Recently, the topical administration of healing clays, such as bentonite and green clays, has been explored as a viable, natural treatment. We found high concentrations of arsenic and lead in experimental samples of therapeutic clay. Given the known toxic effects of these environmental heavy metals, we sought to determine whether the topical administration of a clay product containing bioavailable arsenic and lead exerted a biologic effect in mice that potentially could introduce unwanted research variability. Two cohorts of 20 singly housed, shaved, dermatitis free, adult male CD1 mice were dosed daily for 2 wk by topical application of saline or green clay paste. Samples of liver, kidney and whole blood were collected and analyzed for total arsenic and lead concentrations. Hepatic and renal concentrations of arsenic were not different between treated and control mice in either cohort; however, hepatic and renal concentrations of lead were elevated in clay treated mice compared to controls in both cohorts. In addition, in both cohorts, the activity of δ-aminolevulinate acid dehydratase, an enzyme involved with heme biosynthesis and a marker of lead toxicity, did not differ significantly between the clay-treated mice and controls. We have demonstrated that these clay products contain high concentrations of arsenic and lead and that topical application can result in the accumulation of lead in the liver and kidneys; however, these concentrations did not result in measurable biologic effects. These products should be used with caution, especially in studies of lead toxicity, heme biosynthesis, and renal α2 microglobulin function.

Givosiran (Givlaari™) is an aminolevulinate synthase 1 (ALAS1)-directed small interfering RNA (siRNA) covalently linked to a ligand to enable specific delivery of the siRNA to hepatocytes. This results in downregulation of ALAS1 mRNA and prevents accumulation of neurotoxic δ-aminolevulinic acid and porphobilinogen levels that are associated with acute porphyria attacks. Givosiran is being developed by Alnylam Pharmaceuticals for the treatment of acute hepatic porphyria (AHP). In November 2019, givosiran was approved in the USA for the treatment of adults with AHP based on the positive results from the multinational, phase III ENVISION trial. In the EU, givosiran received a positive opinion in January 2020 for the treatment of AHP in adults and adolescents aged 12 years and older. This article summarizes the milestones in the development of givosiran leading to this first approval for the treatment of adults with AHP.

m-Trifluoromethyl-diphenyl diselenide [(m-CF 3 -PhSe) 2 ] is an organoselenium molecule that displays multiple pharmacological actions, including the antinociceptive effect. The current study investigated the (m-CF 3 -PhSe) 2 restorative properties in models of acute and chronic inflammatory pain induced by complete Freund's adjuvant (CFA). Male adult Swiss mice received an intraplantar injection of CFA in the hindpaw and 24 h (acute) or 14 days (subchronic) later they were treated with a single or repeated (m-CF 3 -PhSe) 2 schedule via intragastric route, respectively. The mechanical and thermal hypernociceptive behaviors were assessed by von Frey hair and hot plate tests. Samples of injected paw were collected to evaluate the tissue edema and myeloperoxidase (MPO) activity while cerebral contralateral cortex samples were used to determine the inflammatory proteins content (subchronic protocol). The acute (m-CF 3 -PhSe) 2 administration (1 and 10 mg/kg) reduced the hypernociceptive behavior and both paw thickness and MPO activity induced by CFA injection. In the subchronic protocol, the repeated administration with a low effective dosage of (m-CF 3 -PhSe) 2 reduced the mechanical and thermal hypernociception as well as restored the edema and MPO activity in paw samples. In addition, the repeated treatment schedule mitigated the increase in TNF-α, IL-1β and COX-2 content in cerebral contralateral cortex induced by CFA injection. Collectively, these data showed that (m-CF 3 -PhSe) 2 presents anti-inflammatory properties, which could be mediated by an interplay between peripheral and central mechanisms of action, reinforcing the potential biological properties of the compound., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 Elsevier B.V. All rights reserved.)

Porphobilinogen synthase (PBGS) is an essential enzyme that catalyzes an early step in heme biosynthesis. An unexpected human PBGS quaternary structure dynamic drove the definition of morpheeins, which are protein multimers that dissociate, change shape, and re-assemble differently with functional consequences. Each PBGS monomer has two domains that can reposition through a hinge motion. Human PBGS exists in an equilibrium among high activity octamer, low activity hexamer, and low mole-fraction dimer in which the hinge motion occurs. The dimer conformation dictates the multimer architecture. An octamer-specific inter-subunit interaction responds to pH, resulting in a pH-dependence to the octamer-hexamer equilibrium. An inborn error of metabolism, ALAD porphyria, is caused by single amino acid substitutions that stabilize the hexamer relative to octamer. Drugs that stabilize the PBGS hexamer result in a drug side effect that can exacerbate porphyria. PBGS is essential for all organisms that require respiration, photosynthesis, or methanogenesis. Consequently, phylogenetic variation in PBGS multimerization equilibria provides insight into how Nature has harnessed oligomeric variation in the control of protein function. The dynamic multimerization of PBGS revealed the morpheein mechanism for allostery, a structural basis for inborn errors of metabolism, a quaternary structure focus for drug discovery and/or drug side effects, and a pathway toward new antibiotics or herbicides. The fortuitous discovery of PBGS quaternary structure dynamics arose from characterization of a low-activity single amino acid variant that dramatically stabilized the hexamer, whose existence had previously gone unnoticed., (© 2020 Elsevier Inc. All rights reserved.)

Biomarkers allow an integrated risk assessment of heavy metal pollution effects in living organisms. In this study, the biochemical effects of Cd, Cr, Ni, Pb and Zn pollution in agricultural soil and their accumulation in Alium cepa L. (onion) were evaluated with ALA-D enzyme response as a biomarker, along with δ-aminolevulinic acid (ALA) and total chlorophyll contents in leaves of this plant. Soil samples were randomly selected from agricultural areas in two regions, Mitrovica and Obiliqi, which are considered the most industrially polluted regions in Kosovo. Results show that Pb and Zn concentrations in soil samples from Mitrovica (1953-2576 mg kg -1 ) and Obiliqi regions (138-179 mg kg -1 ) and their bioaccumulation levels in onion were significantly higher in comparison with the control group. There was an adverse negative correlation between Pb or Zn concentration and ALA-D activity and total chlorophyll content, and a positive correlation with ALA content. This study indicates that ALA-D activity can be used as a very sensitive biomarker for evaluation of heavy metal pollution. The bioaccumulation of heavy metals from soil polluted areas poses a threat for food contamination and public health.

The purpose is to determine markers of oxidative stress related to the longer and shorter duration of labor (DOL) of pregnant women in the umbilical cord blood of neonates, not yet studied. Blood samples from the umbilical cord were collected from pregnant women with normal delivery and classified according to DOL in two groups: a group with DOL less than 310 min ( n  = 33) and a group with DOL greater than or equal to 310 min ( n  = 35). The oxidative stress parameters were analyzed by the quantification of thiobarbituric acid reactive substances (TBARS), nitrate/nitrite (NOx), protein thiol groups (P-SH) and non-protein (NP-SH), vitamin C and plasma iron reduction capacity (FRAP), in addition to the activity of the enzyme delta-aminolevulinate dehydratase (δ-ALA-D). The activity of the δ-ALA-D enzyme was shown to be decreased in longer DOL, however, the oxidant parameters and antioxidants were higher in the longer DOL, with the exception of NP-SH that was lower. The longer maternal DOL time is related to the alteration of δ-ALA-D enzyme activity and other parameters in neonates, suggesting an increase in the passage of maternal oxidative markers by umbilical cord blood.

Porphobilinogen synthase (PBG synthase) gene from Pyrobaculum calidifontis was cloned and expressed in E. coli. The recombinant enzyme was purified as an octamer and was found by mass spectrometry to have a subunit M r of 37676.59 (calculated, 37676.3). The enzyme showed high thermal stability and retained almost all of its activity after incubation at 70 °C for 16 h in the presence of β-mercaptoethanol (β-ME) and zinc chloride. However, in the absence of the latter the enzyme was inactivated after 16 h although it regained full activity in the presence of β-ME and zinc chloride. The protein contained 4 mol of tightly bound zinc per octamer. Further, 4 mol of low affinity zinc could be incorporated following incubation with exogenous zinc salts. The enzyme was inactivated by incubation with levulinic acid followed by treatment with sodium borohydride. Tryptic digest of the modified enzyme and mass spectrometric analysis showed that Lys 257 was the site of modification, which has previously been shown to be the site for the binding of 5-aminolevulinic acid giving rise to the propionate-half of porphobilinogen. P. calidifontis PBG synthase was inactivated by 5-chlorolevulinic acid and the residue modified was shown to be the central cysteine (Cys 127 ) of the zinc-binding cysteine-triad, comprising Cys 125, 127, 135 . The present results in conjunction with earlier findings on zinc containing PBG synthases, are discussed which advocate that the catalytic role of zinc in the activation of the 5-aminolevulinic acid molecule forming the acetate-half of PBG is possible., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Impaired liver function is associated with decreased hepatic delta-aminolevulinic acid dehydratase (δ-ALAD) activity in diabetes mellitus. Hence, this study described the effect of dietary jute leaf (Corchorus olitorius) on hepatic δ-ALAD activity in high-fat fed combined with low-dose streptozotocin administered diabetic rats. Animals were fed diets containing 35% fat for 14 days prior to a single administration of low-dose (35 mg/kg body weight) streptozotocin to induce diabetes. Thereafter, the animals were randomly placed in groups and fed 100 mg/g jute leaf-supplemented diets for 30 days. The result showed that jute leaf supplementation significantly (p < 0.05) reversed the decreased hepatic δ-ALAD activity, increased hepatic catalase and SOD activity accompanying the decrease in serum AST and AST activities. This finding suggests that restoration of hepatic δ-ALAD activity, modulation of hepatic function biomarkers, and increase in antioxidant status could be possible underlying events mediating the hepatoprotective effect of jute leaf in diabetic conditions. PRACTICAL APPLICATIONS: Decrease in hepatic δ-ALAD activity has been associated with diabetes-induced hepatotoxicity arising from prolonged and uncontrolled hyperglycemia. Therefore, increased δ-ALAD activity represents improved hepatic function in diabetic situations. Antidiabetic properties of jute leaf have been demonstrated but information on its effect on hepatic δ-ALAD is lacking. Thus, this study revealed that dietary supplementation of jute leaf restored hepatic δ-ALAD activities and improved liver antioxidant status in diabetic rats which is an indication of its hepatoprotective properties., (© 2019 Wiley Periodicals, Inc.)

Purpose: Determining the post-mortem interval (PMI) is one of the challenging tasks in forensic science due to the lack of quick and inexpensive methods. Our objective is to develop innovative and alternative means for PMI evaluation. Methods: The relationship between PMI and enzymatic modifications in mice tissues was described. After being sacrificed, Swiss mice were randomly divided into groups according to the time elapsed since death. The activities of catalase (CAT) and δ-aminolevulinate dehydratase (δ-ALA-D) were determined in hepatic, renal, skeletal muscle and cerebral tissues. Results: CAT activity increased in kidney and brain 6 h after death and this increase remained for up to 24 h in the brain and 48 h in the kidney. δ-ALA-D had its activity decreased in the liver and kidneys in 6 h. In the skeletal muscle, δ-ALA-D activity was reduced only 48 h after death. Conversely, an increase on δ-ALA-D activity was observed in the brain at 6 h, followed by its decrease at 24 and 48 h. Conclusion: With the association of this set of results, it is possible to provide an estimate of PMI. Additionally, these results can be used as an auxiliary parameter associated with other methods to estimate PMI.

Pregnancy is characterized by changes in various organs, triggering changes in the use of energy substrates and increased oxygen consumption. In addition, gestation is an oxidative event that can be assessed by the relationship between free radicals and antioxidants produced by the body. Excessive production of free radicals has detrimental effects such as damage to enzymes, carbohydrates, and DNA. Thus, the objective of this study was to evaluate the oxidative status and antioxidant responses throughout pregnancy through a longitudinal study. Reactive oxygen species were analyzed by means of thiobarbituric acid reactive substances and nitric oxide, the antioxidant system through vitamin C, sulfhydryl groups, total antioxidant capacity, and ferric reducing ability of plasma as well as enzymes such as catalase and delta-aminolevulinate-dehydratase in pregnant women in the three gestational trimesters ( n = 30). According to the results, the markers of oxidative damage showed significant differences in the different gestational trimesters where they were increased in the second trimester when compared to the first trimester. The antioxidant defenses responded differently in each gestational trimester, suggesting a response pattern to try to combat the damage caused by free radicals, in order to stabilize the increase of oxidative stress caused in the second gestational trimester., Competing Interests: The authors declare no conflict of interest.

N,N`-Bis[(1,2-didehydro-1-hydroxy-2-thioxopyrid-4-yl)-carbonyl]- L-lysine (HTPL) is a novel newly synthesized compound intended to be used for the chelation of lead in intoxicated animals. Subchronic lead intoxication experiments were carried out on Wistar male rats; these rats were intoxicated with lead and then treated with HTPL. Results were compared with those obtained with known compounds used for lead chelation therapy, such as disodium ethylnediaminetetraacetic acid (CaNa 2 EDTA) and meso-2,3-dimercaptosuccininc acid (DMSA), using different routes of administration. Biological samples of whole blood and urine were collected and analyzed for urinary proporphyrins, δ-aminolevulinic acid dehydratase, and zinc protoporphyrin. Results revealed that HTPL can remarkably reverse the toxic effects of lead intoxication at biochemical levels. Additionally, results showed that this agent is as good or even more potent than calcium disodium ethylnediaminetetraacetic acid (CaNa 2 EDTA) and meso-2,3-dimercaptosuccininc acid (DMSA) in reversing the toxic effect of lead. More importantly, HTPL was found effective when administrated intraperitoneally and orally., (Copyright © 2018 Elsevier GmbH. All rights reserved.)

The aim of this study was to explore the effects of lead exposure on the antioxidant and immune responses of Crucian carp. Three hundred sixty healthy Crucian carp were randomly grouped into four groups and exposed to different doses of lead (0, 0.05, 0.5, and 1 mg/L). Fish were sampled at 30 and 60 days, respectively, and antioxidant capability, immune parameters, ALAD activity, and immune-related genes were assessed. The results showed that T-AOC and GSH activities of the liver were significantly increased in 60 days (P < 0.05); the activities of SOD, CAT, T-AOC, and GSH were significantly increased (P < 0.05) compared to the control in the kidney in 60 days. With an increase in Pb dose, the activity and expression of lysozyme and the content of immunoglobulin M were significantly decreased compared to the control. Compared with the control group, the activity of ALAD in the lead-exposed group decreased significantly (P < 0.05). The expression of the HSP70, tumor necrosis factor-α (TNF-α), interleukins (IL-10), and immunoglobulin M genes was all enhanced in lead-exposed group, whereas lysozyme gene expression was decreased. The results indicated that lead induced oxidative stress and had immunotoxic effects on Crucian carp.

Objectives: This study aimed to evaluate the activity of delta-aminolevulinate dehydratase (δ-ALA-D) and oxidative stress biomarkers in pregnant women with gestational diabetes mellitus (GDM), in order to demonstrate the involvement of oxidative stress in this condition, which presents pathophysiology still undetermined., Methods: δ-ALA-D activity, lipid peroxidation estimated as the levels of thiobarbituric acid reactive substances (TBARS), protein (P-SH) and non-protein thiol (NP-SH) content, catalase (CAT) activity and concentration of vitamin C (VIT C) in samples of pregnant women with GDM (n = 48) and in healthy pregnant women (n = 30), who constituted the control group., Results: The δ-ALA-D activity was significantly lower in pregnant women with GDM compared to controls, as well as levels of thiols, VIT C and CAT activity. Lipid peroxidation was higher in GDM group., Discussion: The results suggest that the main factor for the increase in oxidative stress and reduced δ-ALA-D activity in diabetic pregnant women is gestational hyperglycemic environment, which changed the redox balance and interfered on mechanism of the δ-ALA-D activity in relation to normoglycemic pregnant women.

Although cisplatin (CIS) has been associated with serious adverse effects, such as hepatotoxicity and nephrotoxicity in adult rats, there is few reports on its use in newborn rats. The aim of this study was to evaluate acute toxic effects of CIS in newborn rats. Adult and newborn Wistar rats received CIS by the i. p. route, at the dose of 5 or 10 mg/kg. After 24 h of treatment, blood, kidney, and liver were excised from the animals and parameters of renal and hepatic functions, oxidative stress markers were determined. Acute administration of CIS caused an increase of AST activity and urea levels, suggesting hepatorenal toxicity in newborn and adult rats. However, the pattern and intensity of damage was different between ages and tissues. Newborn rats showed more pronouncedly oxidative stress damage, characterized by an increase in reactive species and protein carbonyl levels, lower NPSH content and highest inhibition in δ-ALA-D and CAT activities. Besides that, it was observed a faster molecular response in protein levels involved with apoptosis and oxidative stress response; whereas in the beginning the damage was less severe in the kidney than in the liver of adult rats. Thus, the present study shows that there are body response differences between adult and newborn rats to CIS acute exposure being that newborn rats are more susceptible than adults., (Copyright © 2018. Published by Elsevier B.V.)

Lead is an environmental hazard with great public health concern and has been known to inhibit delta-aminolevulinate dehydratase (ALAD) activity involved in the heme biosynthetic pathway. The study aimed to investigate the influence of ALAD polymorphism (G177C) on retention of Pb-B levels and ALAD activity on occupationally exposed lead workers. In the present study, we enrolled 561 lead exposed and 317 non-occupationally exposed subjects and performed a comprehensive analysis of Pb-B levels along with ALAD activity and genotyping. The frequency of ALAD variants observed in the total subjects (n = 878) was 70.04% for ALAD 1-1, 27.44% for heterozygous ALAD 1-2 and 2.5% for homozygous mutant ALAD 2-2. Our study revealed that ALAD 1-2 carriers presented higher Pb-B levels compared to wild type ALAD 1-1 carriers. Further, a significant difference was observed in the activity of ALAD between ALAD 1-2/ 2-2 and ALAD 1-1 carriers of non-occupationally exposed group indicating that the polymorphic nature of the enzyme may contribute to altered activity of ALAD irrespective of lead exposure. Hence, ALAD 2 allele might contribute to increased susceptibility to high Pb-B retention, and genotyping of ALAD in lead exposed subjects might be used as a prediction marker to impede tissue/organ damage due to lead toxicity., (Copyright © 2018. Published by Elsevier B.V.)

Mammalian δ-aminolevulinate dehydratase (δ-ALA-D) is a metalloenzyme, which requires Zn(II) and reduced thiol groups for catalytic activity, and is an important molecular target for the widespread environmental toxic metals. The δ-ALA-D inhibition mechanism by metals of Group 10 (Ni, Pd, and Pt) and 11 (Cu, Ag, and Au) of the periodic table has not yet been determined. The objective of this study was to characterize the molecular mechanism of δ-ALA-D inhibition caused by the elements of groups 10 and 11 using in vitro (δ-ALA-D activity from human erythrocytes) and in silico (docking simulations) methods. Our results showed that Ni(II) and Pd(II) caused a small inhibition (~ 10%) of the δ-ALA-D. Pt(II) and Pt(IV) significantly inhibited the enzyme (75% and 44%, respectively), but this inhibition was attenuated by Zn(II) and dithiothreitol (DTT). In group 11, all metals inhibited δ-ALA-D with great potency (~ 70-90%). In the presence of Zn(II) and DTT, the enzyme activity was restored to the control levels. The in silico molecular docking data suggest that the coordination of the ions Pt(II), Pt(IV), Cu(II), Ag(I), and Au(III) with thiolates groups from C135 and C143 residues from the δ-ALA-D active site are crucial to the enzyme inhibition. The results indicate that a possible mechanism of inhibition of δ-ALA-D by these metals may involve the replacement of the Zn(II) from the active site and/or the cysteinyl residue oxidation.

Introduction: Arsenic and fluoride are recognized globally as the most serious inorganic contaminants in drinking water. As there is no safe and effective treatment for the cases of fluoride poisoning and combined arsenic-fluoride toxicity, the present study was planned to assess (i) the mechanism of combined exposure to arsenic and fluoride via biochemical and spectroscopic data; (ii) the effect of a thiol chelating agent, meso-2,3-dimercaptosuccinic acid (DMSA), either individually or in combination with the antioxidant vitamin C in reversing arsenic-fluoride toxicity; and (iii) whether combination therapy enhances arsenic and fluoride removal from blood and soft tissues., Methods: Rats were exposed to arsenic (50 mg l-1) and fluoride (50 mg l-1) individually and in combination for 9 months and later administered DMSA (50 mg kg-1) via an i.p. route and vitamin C (25 mg kg-1) orally for 5 days. Biochemical parameters suggestive of alterations in the heme synthesis pathway, oxidative stress in blood, the liver and the kidneys, and concentrations of arsenic and fluoride in blood and soft tissues were studied. We also studied the infrared (IR) spectra of DNA extracted from the livers and kidneys of the normal and exposed animals., Results: It was found that chronic arsenic and fluoride exposure led to an increased oxidative stress condition and impaired heme synthesis (67% inhibition in δ-aminolevulinic acid dehydratase activity and 38% increase in δ-aminolevulinic acid synthetase activity). The decreased antioxidant defense mechanism was marked by a 2.25 fold increased concentration of Reactive Oxygen Species (ROS) and a 28% decrease in the Glutathione (GSH) level. Interestingly, concomitant exposure to arsenic and fluoride did not lead to antagonistic effects as the toxic effects were the same as those seen during the individual exposure to both the toxicants. It suggests that toxicity depends on the dose and duration of exposure. Combination therapy with DMSA and vitamin C showed a better efficacy than monotherapy in terms of reducing the arsenic and fluoride burden (more than 70% in blood and soft tissues) as well as reversal in the altered biochemical variables indicative of oxidative stress and tissue damage (80-85%). The infrared (IR) spectra of DNA isolated from the liver and kidneys suggested that the treatment with vitamin C and DMSA had no beneficial effects in terms of reversing DNA damage., Conclusion: On the basis of the above observations, we suggest that the combinational therapy of DMSA and vitamin C would be more effective in arsenic and/or fluoride toxicity; however, more detailed studies are required to address recoveries in DNA damage.

Fluoride (F - ) is becoming an ineluctable environmental pollutant causing deleterious effects in humans. In the present study, we examined whether tamarind seed coat extract (TSCE) is beneficial against the F - -induced systemic toxicity and hematological changes. Wistar rats were randomly grouped as follows: group I served as control; group II intoxicated with sodium fluoride (NaF, 300 ppm) in drinking water; group III was administered through oral intubation with TSCE (100 mg/kg bw); group IV was treated with NaF (300 ppm) in association with TSCE (100 mg/kg bw) for 30 days. The results indicated that F - exposure induced oxidative stress as evidenced by elevated levels of reactive oxygen species and lipid peroxidation in the brain, liver, and kidney. F - administration modulates hematological indices-WBC, RBC, and mean corpuscular volume. Moreover, aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, acetylcholinesterase, and monoamine oxidase significantly increased on F - exposure. Conversely, δ-aminolevulinic acid dehydratase and glutathione/reduced glutathione ratio were decreased. Activity of antioxidants-superoxide dismutase, catalase, glutathione peroxidase, and vitamin C-was also significantly decreased due to F - administration. Treatment with TSCE effectively mitigated the alterations through its antioxidant potential. The data suggested that the TSCE had beneficial effects in alleviating the F - -induced toxicity and hence can serve as a promising neutraceutical agent.

The mechanism of lead (Pb) modulated heme synthesis pathway induced oxidative stress mediated genotoxicity using standard (ST) and high bioactivation (HB) crosses of Drosophila melanogaster was addressed in the present study. Third instar larvae derived from the ST or HB crosses were reared in sub lethal concentrations of lead acetate (PbAc) treated food media and showed that Pb was readily taken up and accumulated in the said crosses. Pb modulated heme synthesis was evident by significant reductions of δ-aminolevulinic acid dehydratase (δ-ALA-D) and cytochrome P450 (CYP450) and increased accumulation of δ-aminolevulinic acid (δ-ALA). The results have also demonstrated that Pb induced oxidative stress by overproducing reactive oxygen species (ROS) and lipid peroxidation (LPO) and depletion of the antioxidant enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) and glutathione-s-transferase (GST). Wing somatic mutation and recombination test (SMART) using ST and HB crosses revealed that Pb is mutagenic and weakly recombinogenic. By employing larval hemocytes, there was an increase in percent of tail DNA in alkaline comet compared to that of neutral comet revealing the DNA single strand breaks were the products of Pb modulated heme synthesis pathway induced oxidative free radicals. Based on these findings, it can be concluded that Pb modulated heme synthesis pathway induces oxidative stress that mediates the genotoxicity in D. melanogaster., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Lead (Pb) is a non-essential metal. Its occurrence in the environment is related principally to anthropogenic contamination. Pb is toxic to aquatic organisms and can provoke damage to membranes and inhibit the activity of essential enzymes. The filter-feeding, Manila clam Ruditapes philippinarum is widely used as a biomonitor organism to assess metal toxicity. Among biomarkers related to the Pb toxicity, the enzymatic activity of δ-aminolevulinic acid dehydratase (δ-ALAD) has been adopted as a specific tool. Metallothionein (MT), lipid peroxidation (LPO) and antioxidant enzymes activities, such as catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR) and glutathione S-transferase (GST) and superoxidase dismutase (SOD) have also been employed to assess the toxic effect of metals. Two target tissues, the gills and the digestive gland, were selected to examine biomarker responses. In order to assess the effects of Pb accumulation and the mechanisms involved in the recovery from it, clams were exposed at two Pb levels (10 and 100 µg/L) for 7 days and were later maintained in clean water for 7 days as a depuration period. Pb accumulation was dependent on the exposure concentration and higher Pb levels were observed in the gills compared to the digestive gland. Inhibition of δ-ALAD, GST and SOD and the induction of MT and LPO over the exposure period were observed in the gills and the digestive gland of R. philippinarum. The depuration period showed a continuous inhibition of the δ-ALAD activity and induction of MT and LPO in both tissues. These results demonstrate that lead induced an exposure effect and the 7 days of depuration were not sufficient to recover the basal health status of the clams., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The present study was designed to investigate the effects of lithium treatment on red blood cells which were given arsenic exposure. Long-term lithium therapy is being extensively used for the treatment of bipolar disorders. Arsenic is a group I carcinogen and a major toxic pollutant in drinking water that affects millions of people worldwide. Male SD rats were segregated into four groups, viz. normal control, lithium treated, arsenic treated, and lithium + arsenic treated. Lithium was supplemented as lithium carbonate at a dose level of 1.1 g/kg diet for a period of 8 weeks. Arsenic was given in the form of sodium arsenite at a dose level of 100 ppm in drinking water, ad libitum, for the same period. Lysates of red blood cells were used to investigate the effects of lithium and arsenic treatments on anti-oxidant enzymes, reduced glutathione (GSH), and lipid peroxidation (LPO) levels. Various hematological parameters, activities of Na + K + ATPase and delta-aminolevulinic acid dehydratase (δ-ALAD) were also assessed. A significant reduction was observed in the activities of antioxidant enzymes, GSH levels, total erythrocyte counts, Na + K + ATPase, and ALAD enzyme activities in lysates of red blood cells when exposed either to lithium or arsenic. In addition, a significant increase in the levels of malondialdehyde (MDA), lymphocytes, neutrophils, and total leukocytes was also observed following lithium as well as arsenic treatments. However, when arsenic-treated rats were subjected to lithium treatment, a pronounced alteration was noticed in all the above parameters. Therefore, we conclude that lithium supplementation to the arsenic-treated rats enhances the adverse effects on red blood cells and therefore use of lithium may not be medicated to patients who are vulnerable to arsenic exposure through drinking water. It can also be inferred that adverse effects of lithium therapy may get aggravated in patients thriving in the arsenic-contaminated area.

Hexachloronaphthalenes (HxCNs) are the most toxic congeners of polychlorinated naphthalenes, a group of compounds lately included into the list of persistent organic pollutants (POPs). This study presents the effects of 90-day intragastric administration of HxCN to female Wistar rats at doses of 0.03, 0.1, and 0.3 mg/kg body weight. The study examined selected parameters of the heme synthesis pathway, oxidative stress, hepatic cytochromes level, and basic hematology indicators. A micronucleus test was also performed. The subchronic exposure of rats to HxCN resulted in disruption of heme biosynthesis, hematological disturbances, and hepatotoxicity. The highest dose of HxCN inhibited aminolevulinic acid dehydratase (ALA-D) and uroporphyrinogen decarboxylase (URO-D). Accumulation of higher carboxylated porphyrins in the liver and increased excretion of 5-aminolevulinic acid in the urine was observed after a dose of 0.1 mg/kg body weight. The most sensitive effect of HxCN in rats was very strong induction of hepatic CYP1A1 activity, which was observed after the lowest dose. The highest dose of HxCN induced significant thrombocytopenia, thymic atrophy and hepatotoxicity, expressed as hepatomegaly and hepatic steatosis., (© 2018 Wiley Periodicals, Inc.)

Previous studies have shown that the mammalian δ-aminolevulinic acid dehydratase (δ-ALAD) is inhibited by selenides and selenoxides, which can involve thiol oxidation. However, the precise molecular interaction of selenides and selenoxides with the active center of the enzyme is unknown. Here, we try to explain the interaction of selenides and the respective selenoxides with human δ-ALAD by in silico molecular docking. The in silico data indicated that Se atoms of selenoxides have higher electrophilic character than their respective selenides. Further, the presence of oxygen increased the interaction of selenoxides with the δ-ALAD active site by O…Zn coordination. The interaction of S atom from Cys124 with the Se atom indicated the importance of the nucleophilic attack of the enzyme thiolate to the organoselenium molecules. These observations help us to understand the interaction of target proteins with organoselenium compounds., (© 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

The widespread use of lead (Pb) shot in shooting activities, including at former shooting ranges, continues to pose environmental risks. The La Crosse River Marsh (located in Wisconsin, USA) is a biologically diverse urban riparian wetland with a legacy of Pb-contaminated sediment resulting from its use as a trap shooting range from 1929-1963. Within the shot fall zone, shot densities exceed 43,000 pellets/m 2 and surface sediments exceed 25,000 mg/kg in some areas. This study used the Zebrafish as a model to determine the acute toxicity of these contaminated sediments. Zebrafish were exposed to sediments containing approximately 13 to 13,450 mg/kg Pb for 5 days (8-120 hr post-fertilization). The toxic responses to sediments were non-monotonic. Only exposure to sediments containing "mid-range" concentrations of Pb (4580 mg/kg) induced mild skeletal malformations and a sluggish C-start response indicating that Pb was marginally bioavailable. Expression of δ-aminolevulinic acid dehydratase (ALA-D) also indicated the potential for uptake of Pb from sediments. Our findings suggest that Pb within the La Crosse River Marsh sediments is not readily bioavailable to Zebrafish, and while this metal poses a minimal acute toxicological risk, toxicity due to chronic exposure of low concentrations of Pb is possible. Further, our data demonstrated that induction of ALA-D gene expression in Zebrafish embryos shows promise as an alternative to ALA-D enzyme activity as a biomarker for acute Pb exposure under lab conditions.

Osmotic stress induced with 1 M sorbitol inhibited δ-aminolevulinic acid dehydratase (ALAD) and aminolevulinic acid (ALA) synthesizing activities in etiolated maize leaf segments during greening; the ALAD activity was inhibited to a greater extent than the ALA synthesis. When the leaves were exposed to light, the ALAD activity increased for the first 8 h, followed by a decrease observed at 16 and 24 h in both sorbitol-treated and untreated leaf tissues. The maximum inhibition of the enzyme activity was observed in the leaf segments incubated with sorbitol for 4 to 8 h. Glutamate increased the ALAD activity in the in vitro enzymatic preparations obtained from the sorbitol-treated leaf segments; sorbitol inhibited the ALAD activity in the preparations from both sorbitol-treated and untreated leaves. It was suggested that sorbitol-induced osmotic stress inhibits the enzyme activity by affecting the ALAD induction during greening and regulating the ALAD steady-state level of ALAD in leaf cells. The protective effect of glutamate on ALAD in the preparations from the sorbitol-treated leaves might be due to its stimulatory effect on the enzyme.

Objectives: This study investigated the potential anti-inflammatory effect of hesperidin against carrageenan induced pleurisy in rat model., Methods: Twenty-four adult female Wistar rats (350 - 450g) were grouped as follows: Group I: rats were administered saline solution only (Normal control group); Group II: rats were administered saline solution (NaCl 0.9%) orally and injected with carrageenan (Inflammation control group); Group III: rats were administered hesperidin only (Hesperidin group); Group IV: rats were administered hesperidin orally and intrapleurally injected with 2% carrageenan (Inflammation treated with hesperidin group). The exudate volume, total leukocyte count, reactive oxygen species (ROS), myeloperoxidase (MPO),δ-aminolevulinate dehydratase (δ-ALA-D), catalase (CAT), superoxide dismutase (SOD), activities as well as non-protein thiol group (NPSH) and thiobarbituric acid reactive substances (TBARS) levels were determined., Results: Pretreatment with hesperidin at a dose of 80 mg/kg orally per day for 21 days, minimized the increase in pleural exudate volume and leucocyte count and modulated the activities of MPO, SOD and CAT, as well as the levels of ROS, NPSH and TBARS in carrageenan-induced rats., Conclusion: Our results suggest that hesperidin can elicit its anti-inflammatory action by blocking exudate and leukocyte influx into pleural cavity, inhibiting MPO activity and preventing oxidative damage.

Lead is an environmental pollutant having nephrotoxic effects even at low level. Its continuous exposure is associated with increased serum uric acid level that resulting in renal insufficiency. This research was conducted to see the effects of delta-aminolevulinic acid dehydratase (ALAD) and vitamin D receptor (VDR) genotypes on biochemical parameters and blood pressure (BP) of automobile workers having low blood lead level (BLL) with continuous lead exposure. Automobile paints workers with ALAD 1-2 genotype showed the positive association of BLL with diastolic BP (p<0.05) whereas, a genotypic combination of ALAD 1-2/VDR BB showed the negative association of serum uric acid with BLL (p<0.05). Similarly negative effects of VDR BB genotype (p<0.01) and ALAD 1-2 genotype (p<0.05) were observed in the association of serum uric acid with BLL at the mean age ≥30 years. This suggests that automobile paint workers having ALAD 1-2 genotypes are at the risk of increased diastolic BP. The research also foretells that combination of ALAD 1-2/VDR BB may play a significant role against lead induced nephrotoxicity at low BLL with continuous lead exposure.

Aim: To determine if SNPs located within the 3'-UTR of δ-aminolevulinic acid dehydratase (ALAD) can alter the risk of lead poisoning and the ALAD gene expression., Materials & Methods: A case-control study was carried out to find the SNPs in miRNA target region. Luciferase reporter gene assay, qRT-PCR and Western blot was used to determine the relationship between miRNA and SNPs., Results: We found a significant association between rs818708 and the risk of lead poisoning. miR-545-5p was influenced by rs818708 variant and might result in a significant change in ALAD expression., Conclusion: rs818708 T > C can weaken the binding capability between miR-545-5p and 3'-UTR of ALAD and thus may alter the risk of lead poisoning.

Programmed cell death (PCD) is an important form to protect plants from pathogen attack. However, plants must precisely control the PCD process under microbe attacks to avoid detrimental effects. The complexity of how plants balance the defense activation and PCD requires further clarification. Lesion mimic mutants constitute an excellent material to study the crosstalk between them. Here, we identified a Gossypium hirsutum (cotton) lesion mimic mutant ( Ghlmm ), which exhibits necrotic leaf damage and enhanced disease resistance. Map-based cloning demonstrated that GhLMMD , encoding 5-aminolevulinic acid dehydratase and located on chromosome D5, was responsible for the phenotype. The mutant was resulted from a nonsense mutation within the coding region of GhLMMD It exhibited an overaccumulation of the 5-aminolevulinic acid, elevated levels of reactive oxygen species and salicylic acid, along with constitutive expression of pathogenesis-related genes and enhanced resistance to the Verticillium dahliae infection. Interestingly, GhLMM plays a dosage-dependent role in regulating PCD of cotton leaves and resistance to V. dahliae infection. This study provides a new strategy on the modulation of plant immunity, particularly in polyploidy plants., (© 2017 American Society of Plant Biologists. All Rights Reserved.)

Myeloperoxidase (MPO) is an inducible heme peroxidase responsive to some stress situations. It is already known that its activity is stimulated in neurodegenerative disorders and in the animal model of parkinson's disease (PD) induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP). By contrast, the role of δ-aminolevulinate dehydratase (δ-ALA-D), an essential enzyme for heme synthesis, has not been investigated in the MPTP model. The aim of this study was to investigate the involvement of striatal δ-ALA-D activity in an acute model of PD, induced by MPTP, in C57Bl/6 mice and its correlation with MPO activity. Animals received four MPTP injections (20 mg/kg, i.p.) or saline (vehicle) to induce a PD model. 7 days after MPTP administration, the motor function was evaluated through rotarod and challenging beam tests in mice. Afterward, mice were killed, and the striata were removed for biochemical analyses. MPTP-treated mice showed impairment in motor skills, such as balance and motor coordination. Furthermore, there was a reduction of tyrosine hydroxylase levels in these animals, which characterizes the dopaminergic lesion. Striatal δ-ALA-D activity was stimulated by MPTP, as well as the MPO activity, and a significant positive correlation between δ-ALA-D and MPO activities was also demonstrated. These data suggest that δ-ALA-D activity could be stimulated due to the requirement of heme groups by peroxidases. Therefore, this study demonstrated for the first time the involvement of striatal δ-ALA-D activity in the MPTP model and its correlation with the MPO activity.

Organoselenium compounds and isoquinoline derivatives have their toxicity linked to induction of pro-oxidant situations. δ-Aminolevulinate dehydratase (δ-ALA-D) and Na + , K + -ATPase have sulfhydryl groups susceptible to oxidation. Thus, we investigated toxicological effects of 4-organoseleno-isoquinoline derivatives, cerebral monoamine oxidase B inhibitors, on rat cerebral δ-ALA-D and Na + , K + -ATPase activities and the involvement of sulfhydryl groups in vitro. Compounds substituted with fluoro (4-(4-fluorophenylseleno)-3-phenylisoquinoline), chloro (4-(4-chlorophenylseleno)-3-phenylisoquinoline) and trifluoro (4-(3-trifluoromethylphenylseleno)-3-phenylisoquinoline) at the selenium-bonded aromatic ring inhibited δ-ALA-D (IC 50 values: 78.42, 92.27, 44.98 µM) and Na + , K + -ATPase (IC 50 values: 41.36, 89.43, 50.66 µM) activities, possibly due to electronic effects induced by these groups. 3-Phenyl-4-(phenylseleno) isoquinoline (without substitution at the selenium-bonded aromatic ring) and 4-(4-methylphenylseleno)-3-phenylisoquinoline (with a methyl group substituted at the selenium-bonded aromatic ring) did not alter the activity of these enzymes. Dithiothreitol, a reducing agent, restored the enzymatic activities inhibited by 4-(4-fluorophenylseleno)-3-phenylisoquinoline, 4-(4-chlorophenylseleno)-3-phenylisoquinoline and 4-(3-trifluoromethylphenylseleno)-3-phenylisoquinoline, suggesting the involvement of sulfhydryl residues in this effect. However, the release of essential zinc seems not to be related to the δ-ALA-D inhibition by these compounds. According to these data, the effect of oral administration (300 mg/kg, intragastric) of 3-phenyl-4-(phenylseleno) isoquinoline on markers of systemic toxicity in Wistar rats was evaluated. None signs of toxicity was observed during or after treatment. This study suggests that the insertion of electron-withdrawing groups in the aromatic ring bonded to the selenium atom of isoquinolines tested increased its inhibitory effect on sulfhydryl enzymes in vitro. 3-Phenyl-4-(phenylseleno) isoquinoline, which has documented pharmacological properties, had no toxicological effects on the parameters evaluated in this study. J. Cell. Biochem. 118: 1144-1150, 2017. © 2016 Wiley Periodicals, Inc., (© 2016 Wiley Periodicals, Inc.)

Purpose of Review: Many studies over the past decade have together identified new genes including modifier genes and new regulation and pathophysiological mechanisms in inherited inborn diseases of the heme biosynthetic pathway. A new porphyria has been characterized: X-linked protoporphyria and the perspective to have innovative treatment at very short-term became a reality. We will summarize how recent data on both ALAS1 and ALAS2 have informed our understanding of disease pathogenesis with an emphasis on how this information may contribute to new therapeutic strategies., Recent Findings: The development of clinical and biological porphyria networks improved the long-term follow up of cohorts. The ageing of patients have allowed for the identification of novel recurrently mutated genes, and highlighted long-term complications in acute hepatic porphyrias. The treatment of hepatic porphyrias by an RNAi-targeting hepatic ALAS1 is actually tested and may lead to improve the management of acute attacks.In erythropoietic porphyrias, the key role of ALAS2 as a gate keeper of the heme and subsequently hemoglobin synthesis has been demonstrated. Its implication as a modifier gene in over erythroid disorders has also been documented., Summary: The knowledge of both the genetic abnormalities and the regulation of heme biosynthesis has increased over the last 5 years and open new avenues in the management of erythropoietic and acute hepatic porphyrias.

Blood lead levels (BLLs) and delta-aminolevulinic acid dehydratase (ALAD) activity are considered biomarkers of lead exposure and lead toxicity, respectively. The present study was designed to investigate the association between BLLs and ALAD activity in pregnant women from Durango, Mexico. A total of 633 pregnant women aged 13-43 years participated in this study. Blood lead was measured by a graphite furnace atomic absorption spectrometer. ALAD activity was measured spectrophotometrically. Mean blood lead was 2.09 ± 2.34 µg/dL; and 26 women (4.1%) crossed the Centers for Disease Control (CDC) recommended level of 5 µg/dL. ALAD activity was significantly lower in women with levels of lead ≥5 µg/dL compared to those with BLLs < 5 µg/dL ( p = 0.002). To reduce the influence of extreme values on the statistical analysis, BLLs were analyzed by quartiles. A significant negative correlation between blood lead and ALAD activity was observed in the fourth quartile of BLLs (r = -0.113; p < 0.01). Among women with blood lead concentrations ≥2.2 µg/dL ALAD activity was negatively correlated with BLLs (r = -0.413; p < 0.01). Multiple linear regression demonstrated that inhibition of ALAD in pregnant women may occur at levels of lead in blood above 2.2 µg/dL.

Delta-aminolevulinate dehydratase (ALAD) catalyzes the second step in the biosynthesis of heme and is also an endogenous inhibitor of the 26S proteasome. The role of ALAD in breast cancer progression is still unclear. In this study, we found that the expression of ALAD was downregulated in breast cancer tissues compared with adjacent normal breast tissues. Enhanced ALAD expression was associated with a favorable outcome in patients with breast cancer. Overexpression of ALAD suppresses breast cancer cell proliferation and invasion and inhibits the epithelial-mesenchymal transition phenotype. Furthermore, we found that ALAD regulates transforming growth factor-β-mediated breast cancer progression. This finding suggests that ALAD might be a potential biomarker for breast cancer that suppresses breast cancer progression by regulating transforming growth factor-β-mediated epithelial-mesenchymal transition., (© 2017 The Authors. Cancer Science published by John Wiley & Sons Australia, Ltd on behalf of Japanese Cancer Association.)

The present investigation was undertaken to evaluate the ameliorative activity of Allium sativum against lead-induced oxidative stress in the brain, liver, and kidney of male rats. Four groups of male Wistar strain rats (100-120 g) were taken: group 1 received 1000 mg/L sodium acetate and group 2 was given 1000 mg/L lead acetate through drinking water for 2 weeks. Group 3 and 4 were treated with 250 mg/kg body weight/day of A. sativum and 500 mg/kg body weight/day of A. sativum, respectively, by oral intubation for a period of 2 weeks along with lead acetate. The rats were sacrificed after treatment and the brain, liver, and kidney were isolated on ice. In the brain, four important regions namely the hippocampus, cerebellum, cerebral cortex, and brain stem were separated and used for the present investigation. Blood was also drawn by cardiac puncture and preserved in heparinized vials at 4 °C for estimation of delta-aminolevulinic acid dehydratase (ALAD) activity. The results showed a significant (p < 0.05) increase in reactive oxygen species (ROS), lipid peroxidation products (LPP), total protein carbonyl content (TPCC), and lead in the selected brain regions, liver, and kidney of lead-exposed group compared with their respective controls. Blood delta-ALAD activity showed a significant (p < 0.05) decrease in the lead-exposed rats. However, the concomitant administration of A. sativum resulted in tissue-specific recovery of oxidative stress parameters namely ROS, LPP, and TPCC. A. sativum treatment also restored the blood delta-ALAD activity back to control. Overall, our results indicate that A. sativum administration could be an effective antioxidant treatment strategy for lead-induced oxidative insult.