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Venoms are evolutionary novelties that have real-world implications due to their impact upon human health. However, relative to the abundant studies of elapid and viperid snake venoms, fewer investigations have been undertaken on those of rear-fanged snakes as they are more problematic for obtaining venom. While most rear-fanged venomous snakes are not considered to be of great medical importance, several species are capable of producing fatalities. Most notable among these are snakes from the genus Rhabdophis, the Asian "keelback" snakes. Prior work have described potent procoagulant toxicity suggesting Factor X and prothrombin activation, but did not investigate the ability to activate other clotting factors. Here we show that in addition to activating both Factor X and prothrombin (with prothrombin twice that of FX), the venom of Rhabdophis subminiatus is able to more potently activate Factor VII (ten times that of prothrombin), while also activating FXII and FIX equipotently to prothrombin, and with FXI also activated but at a much lower level. The ability to activate FVII represents a third convergent evolution of this trait. The Australian elapid clade of [Oxyuranus (taipans) + Pseudonaja (brown snakes)] was the first identified to have evolved this trait. and only recently was it shown to be independently present in another lineage (the Central American viperid species Porthidium volcanicum). In addition, the abilities to activate FXI and FXII are also convergent between R. subminiatus and P. volcanicum, but with R. subminiatus being much more potent. By testing across amphibian, avian, and mammalian plasmas we demonstrate that the venom is potently procoagulant across diverse plasma types. However, consistent with dietary preference, R. subminiatus venom was most potent upon amphibian plasma. While a Rhabdophis antivenom is produced in Japan to treat R. tigrinus envenomings, it is scarce even within Japan and is not exported. As this genus is very wide-ranging in Asia, alternate treatment options are in need of development. Hence we tested the ability of candidate, broad-spectrum enzyme inhibitors to neutralize R. subminiatus venom: marimastat was more effective than prinomastat but both marimastat and prinomastat were significantly more effective than DMPS (2,3-Dimercapto-1-propanesulfonic acid). The findings of this study shed light on the evolution of these fascinating rear-fanged snakes as well as explored their systemic effects upon blood coagulation and point to potential treatment options for the rare, but potentially lethal encounters., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests:, (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Objective: To explore the expulsion effect of sodium dimercaptopropanesulfonate (DMPS) on mercury in different organs of mercury poisoning and the therapeutic effect of glutathione (GSH) combined with antioxidant therapy on mercury poisoning. Methods: In February 2019, 50 SPF male SD rats were randomly divided into 5 groups, 10 rats in each group: A (saline negative control group) , B (HgCL2 positive control group) , treatment group (C: intramuscular injection of DMPS 15 mg/kg treatment, D: intramuscular injection of DMPS30 mg/kg treatment, E: intramuscular injection of DMPS 15 mg/kg and intraperitoneal injection of GSH200 mg/kg treatment) . Rats in group B, C, D and E were subcutaneously injected with mercury chloride solution (1 mg/kg) to establish a rat model of subacute mercury poisoning kidney injury. Rats in group A were subcutaneously injected with normal saline. After the establishment of the model, rats in the treatment group were injected with DMPS and GSH. Rats in group A and group B were injected with normal saline. At 21 d (treatment 7 d) and 28 d (treatment 14 d) after exposure, urine and blood samples of 5 rats in each group were collected. Blood biochemistry, urine mercury, urine microalbumin and mercury content in renal cortex, cerebral cortex and cerebellum were detected. Results: After exposure to mercury, the contents of mercury in renal cortex, cerebrum and cerebellum of rats in group B, C, D and E increased, and urine microalbumin increased. Pathology showed renal tubular injury and renal interstitial inflammation. Compared with group B, urinary mercury and renal cortex mercury in group C, D and E decreased rapidly after DMPS treatment, and there was no significant decrease in mercury levels in cerebellum and cerebral cortex of rats, accompanied by transient increase in urinary albumin after DMPS treatment ( P <0.05) ; the renal interstitial inflammation in group E was improved after GSH treatment. There was a positive correlation between urinary mercury and the contents of mercury in renal cortex, cerebral cortex and cerebellum ( r= 0.61, 0.47, 0.48, P <0.05) . Conclusion: DMPS mercury expulsion treatment can significantly reduce the level of metal mercury in the kidney, and there is no significant change in the level of metal mercury in the cortex and cerebellum.

The increasing antibiotic resistance is a clinical problem worldwide. Numerous Gram-negative bacteria have already become resistant to the most widely used class of antibacterial drugs, β-lactams. One of the main mechanisms is inactivation of β-lactam antibiotics by bacterial β-lactamases. Appearance and spread of these enzymes represent a continuous challenge for the clinical treatment of infections and for the design of new antibiotics and inhibitors. Drug repurposing is a prospective approach for finding new targets for drugs already approved for use. We describe here the inhibitory potency of known detoxifying antidote 2,3-dimercaptopropane-1-sulfonate (unithiol) against metallo-β-lactamases. Unithiol acts as a competitive inhibitor of meropenem hydrolysis by recombinant metallo-β-lactamase NDM-1 with the K I of 16.7 µM. It is an order of magnitude lower than the K I for l-captopril, the inhibitor of angiotensin-converting enzyme approved as a drug for the treatment of hypertension. Phenotypic methods demonstrate that the unithiol inhibits natural metallo-β-lactamases NDM-1 and VIM-2 produced by carbapenem-resistant K. pneumoniae and P. aeruginosa bacterial strains. The 3D full atom structures of unithiol complexes with NDM-1 and VIM-2 are obtained using QM/MM modeling. The thiol group is located between zinc cations of the active site occupying the same place as the catalytic hydroxide anion in the enzyme-substrate complex. The sulfate group forms both a coordination bond with a zinc cation and hydrogen bonds with the positively charged residue, lysine or arginine, responsible for proper orientation of antibiotics upon binding to the active site prior to hydrolysis. Thus, we demonstrate both experimentally and theoretically that the unithiol is a prospective competitive inhibitor of metallo-β-lactamases and it can be utilized in complex therapy together with the known β-lactam antibiotics.

Palearctic vipers are medically significant snakes in the genera Daboia, Macrovipera, Montivipera , and Vipera which occur throughout Europe, Central Asia, Near and Middle East. While the ancestral condition is that of a small-bodied, lowland species, extensive diversification has occurred in body size, and niche specialization. Using 27 venom samples and a panel of in vitro coagulation assays, we evaluated the relative coagulotoxic potency of Palearctic viper venoms and compared their neutralization by three antivenoms (Insoserp Europe, VIPERFAV and ViperaTAb) and two metalloprotease inhibitors (prinomastat and DMPS). We show that variation in morphology parallels variation in the Factor X activating procoagulant toxicity, with the three convergent evolutions of larger body sizes ( Daboia genus, Macrovipera genus, and Vipera ammodytes uniquely within the Vipera genus) were each accompanied by a significant increase in procoagulant potency. In contrast, the two convergent evolutions of high altitude specialization (the Montivipera genus and Vipera latastei uniquely within the Vipera genus) were each accompanied by a shift away from procoagulant action, with the Montivipera species being particularly potently anticoagulant. Inoserp Europe and VIPERFAV antivenoms were both effective against a broad range of Vipera species, with Inoserp able to neutralize additional species relative to VIPERFAV, reflective of its more complex antivenom immunization mixture. In contrast, ViperaTAb was extremely potent in neutralizing V. berus but, reflective of this being a monovalent antivenom, it was not effective against other Vipera species. The enzyme inhibitor prinomastat efficiently neutralized the metalloprotease-driven Factor X activation of the procoagulant venoms. In contrast, DMPS (2,3-dimercapto-1-propanesulfonic acid), which as been suggested as another potential treatment option in the absence of antivenom, DMPS failed against all venoms tested. Overall, our results highlight the evolutionary variations within Palearctic vipers and help to inform clinical management of viper envenomation., Competing Interests: ML was employed by the company Ophirex, MA by Micropharm, and RS by Inosan Biopharma, all of which made products tested in this manuscript. However, the companies had no input in experimental design or reviewing of results before publication. The remaining authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Chowdhury, Zdenek, Lewin, Carter, Jagar, Ostanek, Harjen, Aldridge, Soria, Haw and Fry.)

Objective: A randomized-controlled trial comparing study of the changes in brain sensitive-weighted imaging (SWI) of Wilson disease (WD) patients during the treatment with metal chelator was done., Methods: 100 untreated WD patients (80 cases of cerebral type, 20 cases of hepatic type, age 20.13 ± 9.12 years old) and 20 normal controls were selected. Neurological symptoms were scored using the modified Young scale. Liver function tests and copper indices were collected. All study objects received SWI test of the brain. The values of corrected phase (CP) were calculated on SWI. Cerebral-type WD patients were treated with D-penicillamine (DPA) (group 1) or Dimercaptopropane Sulfonate (DMPS) + Dimercaptosuccinic Acid (DMSA) (group 2). Hepatic-type WD patients were treated with DPA (group 3). All patients received annual neurological symptom score, liver function, copper indices, and SWI examination., Results: At the first year of treatment, score of the modified Young scale in group 2 was lower than that in group 1 (P = 0.023) and lower than that before treatment (P = 0.040). After 2 years of treatment, the score of the modified Young scale in group 1 was lower than that before treatment (P = 0.012). At the second year after treatment, the urinary copper in group 2 was higher than that in group 1 (P = 0.014). Urinary copper was maintained at 200 µg/day in group 1 and 300 µg/day in group 2 after 3 years of treatment. At the first year of treatment, serum copper in group 1 was lower than that in group 2 (P = 0.032). At the first year of treatment, CP values of the pallidum and substantia nigra in group 2 were higher than those in group 1 (P = 0.026, 0.040). At the second year of treatment, CP value of substantia nigra in group 2 was higher than that in group 1 (P = 0.037). After 3 years of treatment, there was no difference in CP values between WD patients and normal controls., Conclusions: Therapy with DMPS and DMSA improves neurological symptoms of WD patients more quickly and leads to less aggravation, compared with therapy with DPA. The metal content in the brain of WD patients was at a low level after 3 years of treatment. DMPS and DMSA can remove metal from brain tissue faster than DPA.

: High arsenic (As) levels in food and drinking water, or under some occupational conditions, can precipitate chronic toxicity and in some cases cancer. Millions of people are exposed to unacceptable amounts of As through drinking water and food. Highly exposed individuals may develop acute, subacute, or chronic signs of poisoning, characterized by skin lesions, cardiovascular symptoms, and in some cases, multi-organ failure. Inorganic arsenite(III) and organic arsenicals with the general formula R-As 2+ are bound tightly to thiol groups, particularly to vicinal dithiols such as dihydrolipoic acid (DHLA), which together with some seleno-enzymes constitute vulnerable targets for the toxic action of As. In addition, R-As 2+ -compounds have even higher affinity to selenol groups, e.g., in thioredoxin reductase that also possesses a thiol group vicinal to the selenol. Inhibition of this and other ROS scavenging seleno-enzymes explain the oxidative stress associated with arsenic poisoning. The development of chelating agents, such as the dithiols BAL (dimercaptopropanol), DMPS (dimercapto-propanesulfonate) and DMSA (dimercaptosuccinic acid), took advantage of the fact that As had high affinity towards vicinal dithiols. Primary prevention by reducing exposure of the millions of people exposed to unacceptable As levels should be the prioritized strategy. However, in acute and subacute and even some cases with chronic As poisonings chelation treatment with therapeutic dithiols, in particular DMPS appears promising as regards alleviation of symptoms. In acute cases, initial treatment with BAL combined with DMPS should be considered., Competing Interests: The authors declare no conflicts of interest.

In light of the recent lead contamination of the water in Flint, Michigan and its potential adverse outcomes, much research and media attention has turned towards the safety profile of commonly used chelators. Dimercapto-1-propanesulfonic acid (DMPS) typically used in the treatment of lead, mercury and arsenic poisoning also displays a high affinity towards transition metals such as zinc and copper, essential for biological functioning. It is given in series of dosages (0.2-0.4g/day) over a long period, and has the ability to enter cells. In this work, we investigated the mechanism through which increasing concentrations of DMPS alter oocyte quality as judged by changes in microtubule morphology (MT) and chromosomal alignment (CH) of metaphase II mice oocyte. The oocytes were directly exposed to increasing concentration of DMPS (10, 25, 50, 100 and 300μM) for four hours (time of peak plasma concentration after administration) and reactive oxygen species (mainly hydroxyl radical and superoxide) and zinc content were measured. This data showed DMPS plays an important role in deterioration of oocyte quality through a mechanism involving zinc deficiency and enhancement of reactive oxygen species a major contributor to oocyte damage. Our current work, for the first time, demonstrates the possibility of DMPS to negatively impact fertility. This finding can not only help in counseling reproductive age patients undergoing such treatment but also in the development of potential therapies to alleviate oxidative damage and preserve fertility in people receiving heavy metal chelators., (Copyright © 2017 Elsevier Inc. All rights reserved.)

Previously, we reported that specific lower dose of sodium 2,3-dimercapto-1-propanesulfonic acid (DMPS) which is an antidote to heavy metal intoxication, inversely enhanced cisplatin (CDDP)-induced antitumor activity to S-180 cell-bearing mouse. This activity was only weak with meso-2,3-dimercaptosuccinic acid (DMSA), however. This study investigated the effects of lower doses of DMPS or DMSA on the nephrotoxicity and kinetics of CDDP. Kidney and blood isolated from female mice which received CDDP with or without DMPS or DMSA once daily for 4 days were provided for measuring levels of blood urea nitrogen (BUN) and transporter proteins (OCT2: organic cation transporter; MATE1: multidrug and toxin extrusion) mRNA, and CDDP-originated platinum, and TUNEL staining of renal tubular cells. DMPS or DMSA reduced effectively CDDP-induced BUN, and caused a moderate reduction of platinum in kidney. Additionally, both dimercapto-compounds restored the CDDP-reduced mRNA levels of transporter proteins (OCT2 and MATE1), and apparently suppressed the CDDP-induced apoptosis. These results suggest that DMPS, as well as DMSA, at approximate 17-fold dose (μmol/kg) of CDDP, has an enough potential to reverse the CDDP nephrotoxicity, and concomitant use of DMPS considering both dose and timing for administration is potentially useful for preventing nephrotoxicity and enhancing antitumor activity during CDDP chemotherapy., (Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.)

Zinc concentrations strongly influence aflatoxin accumulation in laboratory media and in food and feed crops. The presence of zinc stimulates aflatoxin production, and the absence of zinc impedes toxin production. Initial studies that suggested a link between zinc and aflatoxin biosynthesis were presented in the 1970s. In the present study, we utilized two zinc chelators, N,N,N',N'-tetrakis (2-pyridylmethyl) ethane-1,2-diamine (TPEN) and 2,3-dimercapto-1-propanesulfonic acid (DMPS) to explore the effect of zinc limitation on aflatoxin synthesis in Aspergillus parasiticus. TPEN but not DMPS decreased aflatoxin biosynthesis up to six-fold depending on whether A. parasiticus was grown on rich or minimal medium. Although we observed significant inhibition of aflatoxin production by TPEN, no detectable changes were observed in expression levels of the aflatoxin pathway gene ver-1 and the zinc binuclear cluster transcription factor, AflR. Treatment of growing A. parasiticus solid culture with a fluorescent zinc probe demonstrated an increase in intracellular zinc levels assessed by increases in fluorescent intensity of cultures treated with TPEN compared to controls. These data suggest that TPEN binds to cytoplasmic zinc therefore limiting fungal access to zinc. To investigate the efficacy of TPEN on food and feed crops, we found that TPEN effectively decreases aflatoxin accumulation on peanut medium but not in a sunflower seeds-derived medium. From an application perspective, these data provide the basis for biological differences that exist in the efficacy of different zinc chelators in various food and feed crops frequently contaminated by aflatoxin.

In this study we have tested an idea on the important role of amine oxidases (semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase) as an additional source of oxidative/carbonyl stress under glycerol-induced rhabdomyolysis, since the enhanced formation of reactive oxygen species and reactive carbonyl species in a variety of tissues is linked to various diseases. In our experiments we used the sensitive fluorescent method devised for estimation of amine oxidases activity in the rat kidney and thymus as targeted organs under rhabdomyolysis. We have found in vivo the multiple rises in activity of semicarbazide-sensitive amine oxidase, diamine oxidase, polyamine oxidase (2-4.5 times) in the corresponding cell fractions, whole cells or their lysates at the 3-6th day after glycerol injection. Aberrant antioxidant activities depended on rhabdomyolysis stage and had organ specificity. Additional treatment of animals with metal chelator ‘Unithiol’ adjusted only the activity of antioxidant enzymes but not amine oxidases in both organs. Furthermore the in vitro experiment showed that Fenton reaction (hydrogen peroxide in the presence of iron) products alone had no effect on semicarbazide-sensitive amine oxidase activity in rat liver cell fraction whereas supplementation with methylglyoxal resulted in its significant 2.5-fold enhancement. Combined action of the both agents had additive effect on semicarbazide-sensitive amine oxidase activity. We can assume that biogenic amine and polyamine catabolism by amine oxidases is upregulated by oxidative and carbonyl stress factors directly under rhabdomyolysis progression, and the increase in catabolic products concentration contributes to tissue damage in glycerol-induced acute renal failure and apoptosis stimulation in thymus.

Autophagy plays a key role in human health and disease, especially in cancer and neurodegeneration. Many autophagy regulators are developed for therapy. Diverse nanomaterials have been reported to induce autophagy. However, the underlying mechanisms and universal rules remain unclear. Here, for the first time, we show a reliable and general mechanism by which nanoparticles induce autophagy and then successfully modulate autophagy via tuning their dispersity. Various well-designed univariate experiments demonstrate that nanomaterials induce autophagy in a dispersity-dependent manner. Aggregated nanoparticles induce significant autophagic effect in comparison with well-dispersed nanoparticles. As the highly stable nanoparticles may block autophagic degradation in autolysosomes, endocytosis and intracellular accumulation of nanoparticles can be responsible for this interesting phenomenon. Our results suggest dispersity-dependent autophagic effect as a common cellular response to nanoparticles, reveal the relationship between properties of nanoparticles and autophagy, and offer a new alternative way to modulate autophagy.

The results of experiments on noninbred albino rats showed that the acute intoxication with carbon tetrachloride (CT) at a dose of 1 LD50 reduced the parameters of cellular immune response and function of Th1 cells more significantly than the levels of humoral immune response and Th2-lymphocyte function, decreases the blood content of immunoregulatory cytokines IFN-g, IL-2, IL-4 and anti-inflammatory cytokine IL-13, while not changing the concentration of anti-inflammatory cytokine IL-10 and increasing the concentration of pro-inflammatory cytokine IL-6. The application of unithiol, tocopherol acetate, and combinations partially restores the parameters examined. The combined effects of drugs during intoxication with CT does not exceed their separate action.

Dimercaptopropanesulfonic acid (DMPS) has been approved for the treatment of arsenic poisoning through promoting arsenic excretion and modulating arsenic species. To clarify how DMPS regulates the excretion of arsenic species, we investigated the effects of DMPS on the biomethylation of arsenite (As(3+)) in HepG2 cells. In the experiments, we found that DMPS at low concentrations dramatically decreased the content of arsenic in HepG2 cells and inhibited the cellular methylation of As(3+). Three aspects, the expression of human arsenic (III) methyltransferase (hAS3MT), the accumulation of cellular reactive oxygen species (ROS) and the in vitro enzymatic methylation of arsenic, were considered to explain the reasons for the inhibition of DMPS in arsenic metabolism. The results suggested that DMPS competitively coordinated with As(3+) and monomethylarsonous acid (MMA(3+)) to inhibit the up-regulation of arsenic on the expression of hAS3MT and block arsenic involving in the enzymatic methylation. Moreover, DMPS eliminated arsenic-induced accumulation of ROS, which might contribute to the antidotal effects of DMPS on arsenic posing., (Copyright © 2014 Elsevier B.V. and Société française de biochimie et biologie Moléculaire (SFBBM). All rights reserved.)

Inorganic arsenic is a known human carcinogen, inducing tumors of the skin, urinary bladder and lung. It is metabolized to organic methylated arsenicals. 2,3-Dimercaptopropane-1-sulfonic acid (DMPS), a chelating agent, is capable of reducing pentavalent arsenicals to the trivalent state and binding to the trivalent species, and it has been used in the treatment of heavy metal poisoning in humans. Therefore, we investigated the ability of DMPS to inhibit the cytotoxicity and regenerative urothelial cell proliferation induced by arsenate administration in vivo. Female rats were treated for 4 weeks with 100 ppm As(V). DMPS (2800 ppm) co-administered in the diet significantly reduced the As(V)-induced cytotoxicity of superficial cells detected by scanning electron microscopy (SEM), and the incidence of simple hyperplasia observed by light microscopy and the bromodeoxyuridine (BrdU) labeling index. It also reduced the total concentration of arsenicals in the urine and the methylation of arsenic. There were no differences in oxidative stress as assessed by immunohistochemical staining for 8-hydroxy-2'-deoxyguanosine (8OHdG) of the bladder urothelium. No differences were detected in urine sediments between groups. These data suggest that DMPS has the ability to inhibit both arsenate-induced acute toxicity and regenerative proliferation of the rat bladder epithelium, most likely by decreasing exposure of the urothelium to trivalent arsenicals excreted in the urine. These data provide additional evidence that the effects of arsenate exposure in vivo do not appear to be related to oxidative effects on dG in DNA., (Copyright © 2012. Published by Elsevier Ireland Ltd.)

Lumen-to-cell transport, cellular accumulation, and toxicity of L-cysteine (Cys), glutathione (GSH) and N-acetylcysteine (NAC) S-conjugates of methylmercury (CH(3)Hg(+)) were evaluated in isolated, perfused rabbit proximal tubular segments. When these conjugates were perfused individually through the lumen of S(2) segments of the proximal tubule it was found that Cys-S-CH(3)Hg and GSH-S-CH(3)Hg were transported avidly, while NAC-S-CH(3)Hg was transported minimally. In addition, 95% of the (203)Hg taken up by the tubular cells was associated with precipitable proteins of the tubule, while very little was found in the acid-soluble cytosol. No visual cellular pathological changes were observed during 30min of study. Luminal uptake of Cys-S-CH(3)Hg was temperature-dependent and inhibited significantly by the amino acids L-methionine and l-cystine. Rates of luminal uptake of GSH-S-CH(3)Hg were twice as great as that of Cys-S-CH(3)Hg and uptake was inhibited significantly (74%) by the presence of acivicin. When 2,3-bis(sulfanyl)propane-1-sulfonate (DMPS) was added to the bathing or luminal fluid, luminal uptake of Cys-S-CH(3)Hg was diminished significantly. Overall, our data indicate that Cys-S-CH(3)Hg is likely a transportable substrate of one or more amino acid transporters (such as system B(0,+) and system b(0,+)) involved in luminal absorption of L-methionine and L-cystine along the renal proximal tubule. In addition, GSH-S-CH(3)Hg appears to be degraded enzymatically to Cys-S-CH(3)Hg, which can then be taken up at the luminal membrane. By contrast NAC-S-CH(3)Hg and Cys-S-CH(3)Hg (in the presence of DMPS) are not taken up avidly at the luminal membrane of proximal tubular cells, thus promoting the excretion of CH(3)Hg(+) into the urine., (Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.)

To support the key role of glutathione (GSH) in the mechanisms of tolerance and accumulation of arsenic in plants, this work examines the impact of several effectors of GSH synthesis or action in the response of maize (Zea mays L.) to arsenic. Maize was exposed in hydroponics to iso-toxic rates of 150 μM arsenate or 75 μM arsenite for 9 days and GSH effectors, flurazole (an herbicide safener), l-buthionine-sulfoximine (BSO, a known inhibitor of GSH biosynthesis), and dimercaptosuccinate (DMS) and dimercaptopropanesulfonate (DMPS) (two thiols able to displace GSH from arsenite-GSH complexes) were assayed. The main responses of plants to arsenic exposure consisted of a biomass reduction (fresh weight basis) of about 50%, an increase of non-protein thiol (NPTs) levels (especially in the GSH precursor γ-glutamylcysteine and the phytochelatins PC₂ and PC₃) in roots, with little effect in shoots, and an accumulation of between 600 and 1000 ppm of As (dry weight basis) in roots with very little translocation to shoots. Growth inhibition caused by arsenic was partially or completely reversed in plants co-treated with flurazole and arsenate or arsenite, respectively, highly exacerbated in plants co-treated with BSO, and not modified in plants co-treated with DMS or DMPS. These responses correlated well with an increase of both NPTs levels in roots and glutathione transferase activity in roots and shoots due to flurazole treatment, the decrease of NPTs levels in roots caused by BSO and the lack of effect on NPT levels caused by both DMS and DMPS. Regarding to arsenic accumulation in roots, it was not modified by flurazole, highly reduced by BSO, and increased between 2.5- and 4.0-fold by DMS and DMPS. Therefore, tolerance and accumulation of arsenic by maize could be manipulated pharmacologically by chemical effectors of GSH., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

The antioxidant properties of sulfur-containing substances have been experimentally studied in vitro. Unithiol exhibits a wide spectrum us radicals. For this reason, unithiol can be considered, along with ascorbic acid, as a universal drug for the reduction of free radical reactions.

Accumulation of β amyloid (Aβ) peptides to nerve cells should be associated with the onset of Alzheimer's disease (AD). We prepared hybrid liposomes (HL) composed of 90 mol% phospholipids having various charged head groups (cationic L-α-dimyristoyltrimethyl ammonium propane (DMTAP), anionic L-α-dimyristoylphosphatidylserine (DMPS) or zwitterionic L-α-dimyristoylphosphatidylcholine (DMPC)) and 10 mol% polyoxyethylene(23) dodecyl ether (C(12)(EO)(23))), and investigated the inhibitory effects of HL on the accumulation of Aβ(1-40) peptides into human neuroblastoma (SH-SY5Y) cells in vitro. It is noteworthy that remarkable inhibitory effects on the accumulation of Aβ(1-40) peptides were observed for SH-SY5Y cells treated with anionic HL-DMPS, though the accumulation was not inhibited by cationic HL-DMTAP. On the other hand, the immediate fusion of HL-DMTAP into SH-SY5Y cells was confirmed using a confocal laser microscope. Interestingly, the specific interactions between anionic HL-DMPS and Aβ(1-40) peptides were observed using the thioflavin T (ThT) assay. In addition, the cytotoxicity of Aβ(1-42) peptides on the SH-SY5Y cells decreased after the treatment with HL-DMPS. These results suggest that anionic HL-DMPS could be used as a novel medicine for AD in the future.

In vitro activity of interferon-alpha-2b in combination with various antioxidants against the influenza virus and Herpes simplex was studied. The standard strains and a clinical strain of Herpes simplex isolated from a patient with resistance to acyclovir were used. The in vitro studie showed that antioxidants, such as alpho-tocoferol acetate (vitamin E), Unithiol and ascorbic acid had a significant antiinfluenzae and antiherpetic action on the influenza virus A/H5N1 and Herpes simplex variants. They protected up to 100% of the cell monolayer from the virus cytopathic effect. The taurin solutions had no antiviral activity irrespective of the infection dose. Combinations of interferon-alpha-2b with alpha-tocopherol acetate (vitamin E), Unithiol or ascorbic acid showed a significant synergistic effect: the antiviral activity of interferon increased several times. The antiinfluenza activity of interferon-a-2b in the presence of various concentrations of taurin did not change.

Objective: to investigate the changes of γ-aminobutyric acid (GABA) and glutamate (Glu) in the cerebral cortex following acute bromoxynil intoxication in mice and the protective effect of sodium dimercaptopropane sulfonate (Na-DMPS)., Methods: 30 ICR mice were randomly divided into blank control group (10), exposure group (10) and Na-DMPS protection group (10). The levels of GABA and Glu in the cerebral cortex were measured by RP-HPLC. The glutamine (Gln) level and the glutamine synthetase (GS), glutamate decarboxylation enzyme (GAD), γ-aminobutyric acid transaminase (GABA-T) activity in the cerebral cortex were determined by UV colorimetric., Results: compared with the control group [GABA: (3.41 ± 0.12) micromol/g, Glu (14.00 ± 0.16) micromol/g, Gln (1.25 ± 0.19) micromol/g, GAD (13.50 ± 0.25) micromol × g(-1) × h(-1), GABA-T (25.51 ± 0.21) micromol × g(-1) × h(-1), GS(142.19 ± 1.31) U/mg pro], the level of GABA [(3.14 ± 0.14) micromol/g] was decreased (P < 0.05), whereas the level of Glu [(17.54 ± 0.40) micromol/g] and Gln [(3.35 ± 0.27) micromol/g] were increased (P < 0.05), the activity of GAD [(11.93 ± 0.15 micromol × g(-1) × h(-1)], GABA-T [(24.15 ± 0.22) micromol × g(-1) × h(-1)], GS [(140.75 ± 1.01) U/mg pro] was decreased (P < 0.05) in acute intoxication group; Compared with the acute intoxication group, the level of GABA [(3.52 ± 0.30) micromol/g] was increased (P < 0.05), whereas the level of Glu [(14.20 ± 0.32) micromol/g] and Gln [(1.32 ± 0.17) micromol/g] were decreased (P < 0.05), the activity of GAD [(13.01 ± 0.45 micromol × g(-1) × h(-1)], GABA-T [(25.19 ± 0.26) micromol × g(-1) × h(-1), GS [(142.35 ± 1.20) U/mg pro] was increased (P < 0.05); In contrast, the levels of GABA, Glu, Gln and the activity of GAD, GABA-T, and GS in Na-DMPS protection group were not significantly different in comparison with control group (P > 0.05)., Conclusion: the central toxic effects of mice with acute bromoxynil intoxication may be related to the changes of GABA and Glu content in the cerebral cortex;Na-DMPS can protect mice from bromoxynil-induced central toxic effects and GABA and Glu abnormal change in the cerebral cortex.

This investigation was aimed to study the effect of 2,3-dimercapto-1-propanesulfonic acid (DMPS) on mercuric chloride (HgCl(2))-induced alterations in urinary excretion of various carnitine fractions including free carnitine (FC), acylcarnitine (AC), and total carnitine (TC). Different groups of Wistar male rats were treated with HgCl(2) at the doses of 0.1, 0.5, 1.0, 2.0, and 3.0 mg/kg body weight, and the animals were sacrificed at 24 hours following HgCl(2) injection. A separate batch of animals received HgCl(2) (2 mg/kg) with or without DMPS (100 mg/kg) and sacrificed at 24 or 48 hours after dosing. Administration of HgCl(2) resulted in statistically significant and dose-dependent increase in the urinary excretion of FC, AC, and TC in rats. However, the ratio of urinary AC:FC was significantly decreased by HgCl(2). Pretreatment with DMPS offered statistically significant protection against HgCl(2)-induced alterations in various urinary carnitine fractions in rats.

Objective: To investigate the expression of angiotensin converting enzyme (ACE) and ACE2 Gene in lung of paraquat poisoning rats and the protection of sodium dimercaptopropane sulfonate (Na-DMPS)., Methods: One hundred SD male rats were randomly equally divided into 4 groups:normal control group (10 rats), drug control group (40 rats), paraquat poisoning group (40 rats) and drug intervention group(40 rats). The paraquat poisoning and drug intervention group rats were injected intraperitoneally by paraquat (20 mg/kg). The rats in drug intervention group rats were protected by intraperitoneal injection with Na-DMPS (200 mg/kg) 15 min before exposure of paraquat. Behavioral changes of the rats and histological changes of lung tissues under light microscope were observed. And the expression of ACE and ACE2 mRNA in lung tissues of rats both in paraquat poisoned group and drug intervention group were measured by RT-PCR at different time of 6 h, 24 h, 3 and 7 d after poisoning., Results: The poisoning symptoms of shortness of breath, cramps appeared and deteriorated progressively in rats after paraquat exposure and the protection of NA-DMPS could delay and reduce these symptoms significantly. Histological appearance of disorganization of pulmonary capillary and alveolus, exudation in alveolar space, pulmonary edema, severe bleeding, and inflammatory cells infiltration were obvious in lungs of rats after paraquat poisoning, whereas the histological changes were extenuated by protection of NA-DMPS. As compared with normal control group (NC group), the expressions of ACE, ACE2 mRNA in lung tissue decreased, and the lowest level of ACE mRNA expressions appeared at 24 h (0.457 +/- 0.262), on 3 d (0.385 +/- 0.179) after Paraquat exposure (P < 0.05), while lowest level of ACE2 mRNA expressions appeared on 3 d (0.415 +/- 0.247), 7 d (0.365 +/- 0.215) (P < 0.05). As compared with paraquat poisoned group, the expressions of ACE mRNA in lung tissue of rats in NA-DMPS protected group increased significantly at 24 h (0.739 +/- 0.558) and 3 d (0.749 +/- 0.414) (P < 0.05), while the expressions of ACE2 mRNA increased markedly on 3 d (0.584 +/- 0.345) and 7 d (0.493 +/- 0.292) (P < 0.05). But the expression of ACEmRNA and ACE2 mRNA in lungs had no statistical significance between normal control group and drug intervention group (P > 0.05)., Conclusion: The expressions of ACE and ACE2 mRNA in lung tissue of the rats with paraquat poisoning are decreased. Na-DMPS can effectively improve the balance of RAS in local lung tissue and reduce the pathological changes of lung tissue, delay the poisoning symptoms and show protective effects for acute lung injury induced by paraquat.

In the present study, we evaluated the disposition of inorganic mercury (Hg(2+)) in sham-operated and 75% nephrectomized (NPX) Wistar and transport-deficient (TR(-)) rats treated with saline or the chelating agent meso-2,3-dimercaptosuccinic acid (DMSA). Based on previous studies, DMSA and TR(-) rats were used as tools to examine the potential role of multidrug-resistance protein 2 (MRP2) in the disposition of Hg(2+) during renal insufficiency. All animals were treated with a low dose (0.5 mumol/kg i.v.) of mercuric chloride (HgCl(2)). At 24 and 28 h after exposure to HgCl(2), matched groups of Wistar and TR(-) rats received normal saline or DMSA (intraperitoneally). Forty-eight hours after exposure to HgCl(2), the disposition of Hg(2+) was examined. A particularly notable effect of 75% nephrectomy in both strains of rats was enhanced renal accumulation of Hg(2+), specifically in the outer stripe of the outer medulla. In addition, hepatic accumulation, fecal excretion, and blood levels of Hg(2+) were enhanced in rats after 75% nephrectomy, especially in the TR(-) rats. Treatment with DMSA increased both the renal tubular elimination and urinary excretion of Hg(2+) in all rats. DMSA did not, however, affect hepatic content of Hg(2+), even in the 75% NPX TR(-) rats. We also show with real-time polymerase chain reaction that after 75% nephrectomy and compensatory renal growth, expression of MRP2 (only in Wistar rats) and organic anion transporter 1 is enhanced in the remaining functional proximal tubules. We conclude that MRP2 plays a significant role in the renal and corporal disposition of Hg(2+) after a 75% reduction of renal mass.

In vitro synergistic antiviral effect of interferon alpha-2b in combination with unithiol (an antioxidant) on diverse variants of Herpes simplex, including the clinical acyclovir-resistant isolates, was demonstrated. Unithiol showed immediate antiherpes activity in the cell culture. However, its activity was lower than that of ascorbic acid, another highly active antioxidant. It was also observed that the specific antiherpes activity of interferon alpha-2b in the presence of unithiol increased several times. The data could be useful in the clinical practice, since the drugs combinations or complex formulations provide higher efficacy of the herpetic infection therapy with the use of the same concentrations of the available agents.

Objective: to study the oxidative stress of rats with acute paraquat poisoning and the intervention of Sodium Dimercaptopropane Sulfonate (NA-DMPS)., Methods: Eighty male SD rats were randomizedly divided into: the normal control group (n=8), NA-DMPS control group (n=8), the PQ group (n=32, the rats were intraperitoneally injected with 1% PQ solution at the dosage of 20 mg/kg) and the NA-DMPS protected group (n=32). The rats in the groups of normal and NA-DMPS control were sacrificed 1d after administration of NS or NA-DMPS. And the rats in the PQ group and the NA-DMPS protected group were sacrificed at 6h, 1, 3, 7d after poisoning. Samples of serum, bronchoalveolar lavage fluid (BALF) and lung tissue were gathered. The MDA and CAT in serum, BALF and lung homogenate, the glutathione (GSH) in serum and BALF were measured. And the expression of Nuclear factor E2-related factor 2 (Nrf2) mRNA in lung was tested with RT-PCR., Results: Compared with the normal control group, the activities of MDA and CAT in serum, BALF and lung homogenate are higher in both groups of PQ and NA-DMPS protected. And compared with the PQ group, the activities of MDA in serum, BALF and lung homogenate of the NA-DMPS protected group decreased significantly at 6h, 1d after poisoning, whereas the activities of CAT are higher at 6h, 1, 3d in serum and 1, 3d in BALF and lung homogenate (P<0.05 or P<0.001). The serum GSH at 6h, 3d of the NA-DMPS protected group [(730.07 +/- 16.23), (793.66 +/- 7.40)] were higher than those in the PQ group. And the BALF GSH at 1, 3d of the NA-DMPS protected group [(609.75 +/- 6.74), (631.83 +/- 12.03)] were also markedly higher than the PQ group (P<0.05 or P<0.001). The expression of NRF2 mRNA of the lung at 1, 3, 7d in the PQ group [(0.71 +/- 0.061), (1.023 +/- 0.158), (0.969 +/- 0.046)] and the NA-DMPS protected group [(1.005 +/- 0.06), (1.464 +/- 0.166), (1.066 +/- 0.191)] were significantly higher than those in the control groups. Compared with the PQ group, the expression of NRF2 mRNA of the lung increased markedly in the NA-DMPS protected group at 1, 3d (P<0.01)., Conclusion: Na-DMPS decreases the activity of MDA and increases the activity of CAT, GSH and the expression of Nrf2 mRNA. NA-DMPS can protected rats from PQ intoxication by improving the balance of redox reaction.

The effect of combined therapy with diphenyl diselenide (PhSe)(2) and sodium 2,3-dimercapto-propane-1-sulphonate (DMPS) against alterations induced by mercury (Hg(2+)) was evaluated. Mice were exposed to mercuric chloride (HgCl(2)) (1mg/kg, subcutaneously) for two weeks. After that, mice received (PhSe)(2) (15.6 mg/kg), or DMPS (12.6 mg/kg), or a combination of both for one week. Thiobarbituric acid-reactive substances (TBARS), ascorbic acid and Hg(2+) levels and glutathione S-transferase (GST) and catalase (CAT) activities were carried out in kidney. Hematological parameters, plasmatic bilirubin, uric acid, urea and creatinine levels as well as lactate dehydrogenase (LDH) activity were determined. (PhSe)(2) or DMPS restored the increase in LDH activity and TBARS, bilirubin, uric acid, urea and creatinine levels caused by HgCl(2). The levels of erythrocytes, hemoglobin and hematocrit reduced by HgCl(2) exposure were restored by (PhSe)(2) or DMPS administration in mice. Leukocyte and platelet counts modified by HgCl(2) exposure were restored by (PhSe)(2) or DMPS therapy. DMPS restored the increase in Hg(2+) levels induced by exposure to HgCl(2). Concomitant administration of (PhSe)(2) and DMPS reduced the effectiveness of DMPS in restoring damage induced by HgCl(2). Combined therapy with (PhSe)(2) and DMPS was less effective than isolated therapies in restoring the damage induced by HgCl(2) in mice.

Chelation therapy for the treatment of acute, high dose exposure to heavy metals is accepted medical practice. However, a much wider use of metal chelators is by alternative health practitioners for so called "chelation therapy". Given this widespread and largely unregulated use of metal chelators it is important to understand the actions of these compounds. We tested the effects of four commonly used metal chelators, calcium disodium ethylenediaminetetraacetate (CaNa2EDTA), D-penicillamine (DPA), 2,3 dimercaptopropane-1-sulfonate (DMPS), and dimercaptosuccinic acid (DMSA) for their effects on heavy metal neurotoxicity in primary cortical cultures. We studied the toxicity of three forms of mercury, inorganic mercury (HgCl2), methyl mercury (MeHg), and ethyl mercury (thimerosal), as well as lead (PbCl2) and iron (Fe-citrate). DPA had the worst profile of effects, providing no protection while potentiating HgCl2, thimerosal, and Fe-citrate toxicity. DMPS and DMSA both attenuated HgCl2 toxicity and potentiated thimerosal and Fe toxicity, while DMPS also potentiated PbCl2 toxicity. CaNa2EDTA attenuated HgCl2 toxicity, but caused a severe potentiation of Fe-citrate toxicity. The ability of these chelators to attenuate the toxicity of various metals is quite restricted, and potentiation of toxicity is a serious concern. Specifically, protection is provided only against inorganic mercury, while it is lacking against the common form of mercury found in food, MeHg, and the form found in vaccines, thimerosal. The potentiation of Fe-citrate toxicity is of concern because of iron's role in oxidative stress in the body. Potentiation of iron toxicity could have serious health consequences when using chelation therapy.

Cysteine (Cys) and homocysteine (Hcy)-S-conjugates of inorganic mercury (Hg2+) are transportable species of Hg2+ that are taken up readily by proximal tubular cells. The metal chelators, 2,3-dimercaptopropane-1-sulfonic acid (DMPS) and meso-2,3-dimercaptosuccinic acid (DMSA), have been used successfully to extract Hg2+ from these cells, presumably via the multidrug resistance protein (Mrp2). In the current study, we tested the hypothesis that Mrp2 is involved in the DMPS- and DMSA-mediated extraction of Hg2+ following administration of Hg2+ as an S-conjugate of Cys or Hcy. To test this hypothesis, control and TR(-) (Mrp2-deficient) rats were injected with 0.5 micromol/kg HgCl2 (containing 203Hg2+) conjugated to 1.25 micromol/kg Cys or Hcy. After 24 and 28 h, rats were treated with saline or 100 mg/kg DMPS or DMSA. Tissues were harvested 48 h after Hg2+ exposure. The renal and hepatic burden of Hg2+ was greater in saline-injected TR- rats than in corresponding controls. Accordingly, the content of Hg2+ in the urine and feces was less in TR- rats than in controls. Following treatment with DMPS or DMSA, the renal content of Hg2+ in both groups of rats was reduced significantly and the urinary excretion of Hg2+ was increased. In liver, the effect of each chelator appeared to be dependent upon the form in which Hg2+ was administered. In vitro experiments provide direct evidence indicating that DMPS and DMSA-S-conjugates of Hg2+ are substrates for Mrp2. Overall, these data support our hypothesis that Mrp2 is involved in the DMPS and DMSA-mediated extraction of the body burden of Hg2+.

Anionic lipids like phosphatidylserine are known to significantly enhance electroporation mediated transepidermal transport of polar solutes of molecular weights up to 10kDa. The underlying mechanism of the effect of anionic lipids on transdermal transport is not fully understood. The main barrier to transdermal transport lies within the intercellular lipid matrix (ILM) of the stratum corneum (SC) and our previous studies indicate that dimyristoyl phosphatidylserine (DMPS) can perturb the packing of this lipid matrix. Here we report on our investigation on water retention in the SC following electroporation in the presence and the absence of DMPS. The water content in the outer most layers of the SC of full thickness porcine skin was determined using ATR-FTIR-spectroscopy. The results show that in the presence of DMPS, the SC remains in a state of enhanced hydration for longer periods after electroporation. This increase in water retention in the SC by DMPS is likely to play an important role in trans-epidermal transport, since improved hydration of the skin barrier can be expected to increase the partitioning of polar solutes and possibly the permeability.

Current therapies for inorganic mercury (Hg(2+)) intoxication include administration of a metal chelator, either 2,3-dimercaptopropane-1-sulfonic acid (DMPS) or meso-2,3-dimercaptosuccinic acid (DMSA). After exposure to either chelator, Hg(2+) is rapidly eliminated from the kidneys and excreted in the urine, presumably as an S-conjugate of DMPS or DMSA. The multidrug resistance protein 2 (Mrp2) has been implicated in this process. We hypothesize that Mrp2 mediates the secretion of DMPS- or DMSA-S-conjugates of Hg(2+) from proximal tubular cells. To test this hypothesis, the disposition of Hg(2+) was examined in control and Mrp2-deficient TR(-) rats. Rats were injected i.v. with 0.5 mumol/kg HgCl(2) containing (203)Hg(2+). Twenty-four and 28 h later, rats were injected with saline, DMPS, or DMSA. Tissues were harvested 48 h after HgCl(2) exposure. The renal and hepatic burden of Hg(2+) in the saline-injected TR(-) rats was greater than that of controls. In contrast, the amount of Hg(2+) excreted in urine and feces of TR(-) rats was less than that of controls. DMPS, but not DMSA, significantly reduced the renal and hepatic content of Hg(2+) in both groups of rats, with the greatest reduction in controls. A significant increase in urinary and fecal excretion of Hg(2+), which was greater in the controls, was also observed following DMPS treatment. Experiments utilizing inside-out membrane vesicles expressing MRP2 support these observations by demonstrating that DMPS- and DMSA-S-conjugates of Hg(2+) are transportable substrates of MRP2. Collectively, these data support a role for Mrp2 in the DMPS- and DMSA-mediated elimination of Hg(2+) from the kidney.

Chelating therapy has been reported as a useful approach for counteracting mercurial toxicity. Moreover, 2,3-dimercapto-1-propanesulfonic acid (DMPS), a tissue-permeable metal chelator, was found to increase urinary mercury excretion and decrease mercury content in rat brain after methylmercury (MeHg) exposure. We evaluated the capability of DMPS to reduce MeHg-induced motor impairment and cerebellar toxicity in adult mice. Animals were exposed to MeHg (40 mg/L in drinking water, ad libitum) during 17 days. In the last 3 days of exposure (days 15-17), animals received DMPS injections (150 mg/kg, i.p.; once a day) in order to reverse MeHg-induced neurotoxicity. Twenty-four hours after the last injection (day 18), behavioral tests related to the motor function (open field and rotarod tasks) and biochemical analyses on oxidative stress-related parameters (cerebellar glutathione, protein thiol and malondyaldehyde levels, glutathione peroxidase and glutathione reductase activities) were carried out. Histological analyses for quantifying cellular damage and mercury deposition in the cerebellum were also performed. MeHg exposure induced a significant motor deficit, observed as decreased locomotor activity in the open field and decreased falling latency in the rotarod apparatus. DMPS treatment displayed an ameliorative effect toward such behavioral parameters. Cerebellar glutathione and protein thiol levels were not changed by MeHg or DMPS treatment. Conversely, the levels of cerebellar thiobarbituric acid reactive substances (TBARS), a marker for lipid peroxidation, were increased in MeHg-exposed mice and DMPS administration minimized such phenomenon. Cerebellar glutathione peroxidase activity was decreased in the MeHg-exposed animals, but DMPS treatment did not prevent such event. Histological analyses showed a reduced number of cerebellar Purkinje cells in MeHg-treated mice and this phenomenon was completely reversed by DMPS treatment. A marked mercury deposition in the cerebellar cortex was observed in MeHg-exposed animals (granular layer>Purkinje cells>molecular layer) and DMPS treatment displayed a significant ameliorative effect toward these phenomena. These findings indicate that DMPS displays beneficial effects on reversing MeHg-induced motor deficits and cerebellar damage in mice. Histological analyses indicate that these phenomena are related to its capability of removing mercury from cerebellar cortex.

Objective: To observe the effect of Gandou Decoction IV (GDIV) on serum indexes of hepatic fibrosis and liver function in patients with Wilson's disease (WD)., Methods: Sixty-one WD patients were assigned to two groups, 30 patients in the sodium dimercaptosulphonate (DMPS) group and 31 patients in the GD IV group. Both groups received 8 courses of DMPS treatment with 6 days as one course, and the GD IV group was given GD IV additionally. Serum indexes of liver function were examined, serum matrix metalloproteinase-1 (MMP-1) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were detected by double antibody sandwish ABC enzyme-linked immunosorbent assay (ELISA), and serum hyaluronic (HA), laminin (LN), procollagen III (PC III) and collagen type IV (C-IV) were determined by radioimmunoassay (RIA)., Results: After treatment, all indexes of hepatic fibrosis and liver function had no significant change in the DMPS group, while in the GD IV group, the serum TIMP-1 level markedly decreased (P <0.05), the ratio of MMP-1/TIMP-1 significantly increased (P <0.01), and serum indexes of liver function markedly decreased (P < 0.05), but the changes in serum levels of HA, LN and PCIII, as well as in serum MMP-1 and C-IV were insignificant (P> 0.05), though they showed a trend of decreasing or increasing, respectively., Conclusion: Short-term decopper-ing treatment with DMPS alone has no significant effect on hepatic function and serum fibrosis indexes in WD patients, while combined with GD IV, it can improve liver function and display an anti-fibrosis effect through inhibiting the serum TIMP-1 level and increasing the ratio of MMP-1/TIMP-1.

Objective: To study the effects of BSO, GSH, Vit-C and DMPS on the nephrotoxicity of mercury., Methods: The rats in groups 1, 2 and 3 were sc injected with 0.75, 1.5 and 2.5 mg/kg HgCl2, respectively. Fourth group rats were ip injected with 0.5 mmol/kg BSO and 4h later sc administrated with 0.75 mg/kg HgCl2. The rats in groups 5, 6 and 7 were ip injected with 3 mmol/kg GSH, 4 mmol/kg Vit-C, 200 micromol/kg DMPS, respectively, and 2 h later sc administrated with 2.5 mg/kg HgCl2. Eighth group rats were sc injected with saline as a control. Mercury concentrations in the liver, renal cortex and urine, urinary NAG, ALP, LDH activities, protein and BUN contents were determined., Results: Urinary NAG, ALP activities, protein and BUN contents in the rats of BSO pretreatment group were significantly higher than that of 0.75 mg/kg HgCl2 alone group and control group. As compared with 2.5 mg/kg HgCl2 alone group, urinary NAG, ALP, LDH activities, urinary protein and BUN contents decreased significantly., Conclusion: BSO pretreatment could enhance the renal toxicity of mercury and GSH, Vit-C and DMPS pretreatment had antagonistic effects on nephrotoxicity of mercury.

Mercuric chloride (HgCl(2)) is a highly toxic compound, which can cause nephrotoxic damage. In the present study effects of HgCl(2) on mitochondria integrity and energy metabolism, as well as antidotal effects of 2,3-dimercaptopropane-1-sulfonate (DMPS) were investigated in the opossum kidney derived cell line (OK). OK cell monolayers were incubated during 0, 1, 3, 6, and 9 h in serum-free culture medium containing 15 microM HgCl(2), either in the absence or in the presence of 60 microM DMPS in a 1:4 ratio. Intracellular ATP content, MTT reduction, and HSP70/HSP90 induction were studied; confocal, transmission electron microscopy, and light microscopy studies were also performed. For confocal analysis, a mitochondrial selective probe (MitoTracker Red CMXH2Ros) was used. Antioxidant activity of DMPS was also studied by the scavenging of the free radical 2, 2-diphenyl-1-picrylhydrazyl (DPPH) technique. A decrease of ATP content, an impaired ability to reduce tetrazolium, and dramatic changes on cellular and mitochondrial morphology, and energetic levels were found after either 6 or 9 h of HgCl(2) exposure. Increased expression of HSP90 and HSP70 were also seen. When OK cells were co-incubated with HgCl(2) and DMPS, cellular morphology, viability, intracellular ATP, and mitochondrial membrane potential were partially restored; a protective effect on mitochondrial morphology was also seen. DMPS also showed potent antioxidant activity in vitro. Mitochondrial protection could be the cellular mechanism mediated by DMPS in OK cells exposed to a toxic concentration of HgCl(2).

The effect of cadmium (Cd(2+)) on delta-aminolevulinate dehydratase (delta-ALA-D) activity from rat lung in vitro was investigated. delta-ALA-D activity, a parameter for metal intoxication, has been reported as a target of Cd(2+) in different tissues. The protective effect of monotherapies with dithiol chelating (meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercaptopropane-1-sulfonic acid (DMPS)) or antioxidant agents (ascorbic acid, diphenyl diselenide (PhSe)(2), and N-acetylcysteine (NAC)) was evaluated. The effect of a combined therapy (dithiol chelatingxantioxidant agent) was also studied. Zinc chloride (ZnCl(2)) and dithiothreitol (DTT) were used to investigate the mechanisms involved in cadmium, chelating and antioxidant effects on delta-ALA-D activity. Cadmium inhibited rat lung delta-ALA-D activity at low concentrations. DTT (3mM), but not ZnCl(2) (100microM), protected the inhibition of enzyme activity caused by Cd(2+). Chelating agents were not effective in restoring the enzyme activity. DMPS and DMSA presented inhibitory effect on enzyme activity. DTT restored the inhibition caused by both chelating agents, but ZnCl(2) restored only the inhibitory effect induced by DMSA. These compounds caused a marked potentiation of delta-ALA-D inhibition induced by Cd(2+). ZnCl(2) did not restore inhibition of enzyme activity caused by Cd(2+) plus chelating agents. Conversely, DTT restored the inhibition induced by Cd(2+)/DMSA, but not by Cd(2+)/DMPS. Antioxidants were not effective in ameliorating delta-ALA-D inhibition induced by Cd(2+), whereas ascorbic acid potentiated the enzyme inhibition induced by this metal. A combined effect of Cd(2+)xDMPSx(PhSe)(2) and Cd(2+)xDMPSxNAC was observed. There was no combined effect of Cd(2+)xchelatorxantioxidants when DMSA was used. This study demonstrated that Cd(2+)inhibited delta-ALA-D activity and chelating and antioxidant agents, alone or combined, did not restore the enzyme activity. In contrast, these compounds potentiated the inhibition induced by Cd(2+) in rat lung.

In a highly mercury-burdened, small scale gold mining area in the Philippines, spontaneous urine samples were taken from 75 Hg intoxicated volunteers before (U1), and 2-3 hours after (U2) the oral application of 200 mg DMPS (2,3-Dimercapto-1-propanesulfonic acid, Dimaval). In the urine samples, the concentrations of organic and inorganic bound mercury were determined separately by CV-AAS. In U1, median concentrations of 15.7 microg inorganic Hg/g crea. and 2.2 microg organic Hg/g crea. were found. In U2, these values increased to 262 for inorganic Hg and 14.5 for organic Hg. Maximum concentrations (microg/g crea.) as high as 7,593 for inorganic Hg and 2,011 for organic Hg were observed after DMPS. The mean (median) increasing factor (U2/U1) was 16.0 for inorganic Hg and 5.1 for organic Hg. There was a trend that females responded better to DMPS than males. It was concluded that DMPS increases the renal excretion of organic bound Hg as it does for inorganic Hg, but to a lesser extent.

Acute effects of mercuric chloride (HgCl2) were evaluated on mice. Mice received a single dose of HgCl2 (4.6 mg/kg, subcutaneously) for three consecutive days. Thirty minutes after the last injection with HgCl2, mice received one single injection of 2,3-dimercapto-1-propanesulfonic acid (DMPS) or N-acetylcysteine (NAC) or diphenyl diselenide (PhSe)2. DMPS, NAC and (PhSe)2 were utilized as therapy against mercury exposure. At 24 h after the last HgCl2 injection, blood, liver and kidney samples were collected. delta-Aminolevulinate dehydratase (delta-ALA-D) and Na+, K- (+) ATPase activities, thiobarbituric acid-reactive substances (TBARS), non-protein thiols (NPSH) and ascorbic acid concentrations were evaluated. Plasma aspartate (AST) and alanine (ALT) aminotransferase activities, as well as urea and creatinine levels were determined. The group of mice exposed to Hg + (PhSe)2 presented 100% of lethality. Exposure with HgCl2 caused a decrease on the body weight gain and treatments did not modify this parameter. delta-ALA-D, AST and ALT activities, TBARS, ascorbic acid levels and NPSH (hepatic and erythrocytic) levels were not changed after HgCl2 exposure. HgCl2 caused an increase in renal NPSH content and therapies did not modify these levels. Mice treated with (PhSe)2, Hg + NAC and Hg + DMPS presented a reduction in plasma NPSH levels. Creatinine and urea levels were increased in mice exposed to Hg + NAC, while Hg + DMPS group presented an increase only in urea level. Na+, K- (+) ATPase activity was inhibited in mice exposed to Hg + DMPS and Hg + NAC. In conclusion, therapies with (PhSe)2, DMPS and NAC following mercury exposure must be better studied because the formation of more toxic complexes with mercury, which can mainly damage renal tissue.

Although the sulfate/anion transporter (sat-1; SLC26A1) was isolated from a rat liver cDNA library by expression cloning, localization of sat-1 within the liver and its contribution to the transport of sulfate and organo sulfates have remained unresolved. In situ hybridization and immunohistochemical studies were undertaken to demonstrate the localization of sat-1 in liver tissue. RT-PCR studies on isolated hepatocytes and liver endothelial and stellate cells in culture were performed to test for the presence of sat-1 in these cells. In sulfate uptake and efflux experiments, the substrate specificity of sat-1 was evaluated. Sat-1 mRNA was found in hepatocytes and endothelial cells. Sat-1 protein was localized in sinusoidal membranes and along the borders of hepatocytes. The canalicular region and bile capillaries were not stained. Sulfate uptake was only slightly affected by sulfamoyl diuretics or organo sulfates. Sulfate efflux from sat-1-expressing oocytes was enhanced in the presence of bicarbonate, indicating sulfate/bicarbonate exchange. Estrone sulfate was not transported by sat-1. Sat-1 may be responsible for the uptake of inorganic sulfate from the blood into hepatocytes to enable sulfation reactions. In hepatocytes and endothelial cells, sat-1 may also supply sulfate for proteoglycan synthesis.

We investigated the effects of dimercaprol (BAL), meso-2,3-dimercaptosuccinic acid (DMSA) and 2,3-dimercapto-1-propanesulphonic acid (DMPS) on human blood delta-aminolevulinate dehydratase (delta-ALA-D) activity, the most reliable indicator of lead intoxication in humans, in the presence of lead in vitro. Furthermore, we studied the effects of the chelating agents, administered subcutaneously, on delta-ALA-D activity in blood and tissues of mice submitted to sub-acute lead exposure (50 mg/kg for 15 consecutive days, subcutaneously). In vitro results demonstrated that human blood delta-ALA-D activity was significantly inhibited (62%) by lead acetate. Lead acetate (1-1000 microM) pre-incubated with human blood increased the inhibitory potency of this compound on delta-ALA-D when compared to the assay without pre-incubation (89%). Chelating agents caused a marked potentiation of delta-ALA-D inhibition induced by lead, in vitro. One of the most notable observations in the present study was the correspondence between in vitro and ex vivo effects. In fact, BAL and DMPS increase the inhibitory effect of lead on delta-ALA-D activity from mice blood. The complexes formed (lead and chelators) were more inhibitory than lead alone in kidney and liver enzyme activity, ex vivo.

We demonstrated that 5-amino-3-(3,4-dichlorophenyl)1,2,3,4-oxatriazolium (GEA3162), a nitric oxide (NO)-releasing agent, stimulated [Ca2+]i rise in rat neutrophils. This Ca2+ response was prevented by the thiol reducing agents, 2-mercaptoethanol, N-acetyl-L-cysteine, dithiothreitol, 2,3-dimercaptopropane-1-sulfonic acid (DMPS) and tris-(2-carboxyethyl)phosphine (TCEP), but slightly reduced by the antioxidant, 6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid (Trolox). GEA3162 also increased the formation of cellular reactive oxygen intermediates and decreased the cellular content of low molecular thiols. These responses were greatly reduced by Trolox, dithiothreitol and N-acetyl-L-cysteine. GEA3162 stimulated the protein tyrosine phosphorylation in neutrophils. The [Ca2+]i rise caused by formyl-Met-Leu-Phe (fMLP) and cyclopiazonic acid (CPA) was suppressed by GEA3162. TCEP prevented the inhibition of fMLP-induced [Ca2+]i rise by GEA3162. In the absence of external Ca2+, GEA3162 inhibited the CPA-induced [Ca2+]i rise, whereas it only slightly affected the fMLP-induced mobilization of the Ca2+ store. Application of GEA3162 after the stimulation with fMLP or CPA suppressed the robust Ca2+ entry followed by the readdition of Ca2+ into medium. Moreover, the Ca2+ entry was more susceptible to inhibition by treatment with GEA3162 prior to than after the fMLP stimulation. GEA3162 had no effect on the mitochondrial membrane potential. GEA3162 induced actin reorganization and condensed filament network at the cell periphery. These results indicate that GEA3162 exerted both the stimulation of Ca2+ entry and the inhibition of the store-operated Ca2+ entry in rat neutrophils. The dual effects of GEA3162 on the regulation of the external Ca2+ entry are mainly through the thiol modification of target protein(s) residing on the outside of the plasma membrane.

Background: The present study was undertaken to study the effect of mercuric chloride (HgCl2) on the collagen metabolism in rats and the protective effect of 2, 3-dimercapto-1-propane sulfonic acid (DMPS) in HgCl2-treated rats., Material/methods: The experimental groups studied were (i) a control group (ii) rats injected with a single intraperitoneal (ip) dose of 2 mg of HgCl2/kg body weight (HgCl2-treated group, n=10 rats), (iii) Rats injected with a single dose (ip) of 100 mg of DMPS/kg body weight (DMPS group, n=10 rats), (iv) rats injected with a single dose (ip) of 100 mg of DMPS/kg body weight followed by a single dose (ip) of 2 mg of HgCl2/kg body weight 1 hour after a 100-mg DMPS injection (DMPS + HgCl2-treated group, n=10 rats). Half of the rats from each group were sacrificed after 24 hours and the other half after 48 hours of treatment., Results: A dose of 2.0 mg HgCl2/kg body weight caused an impairment of glomerular function, which was reflected by significant increases in the levels of serum creatinine and serum urea nitrogen in HgCl2-treated rats compared with control rats. Administration of 2.0 mg of HgCl2/kg body weight significantly increased urinary excretion of free hydroxyproline in HgCI2-treated rats compared with the control rats, reflecting increased collagen breakdown., Conclusions: Administration of DMPS one hour before HgCl2 treatment caused the restoration of altered parameters to near normal levels.

The deleterious effect of acute cadmium-intoxication in mice testes was evaluated. Animals received a single dose of CdCl2 (2.5 or 5 mg/kg, intraperitoneally) and a number of toxicological parameters in mice testes were examined, such as delta-aminolevulinic acid dehydratase (delta-ALA-D) activity, lipid peroxidation, hemoglobin and ascorbic acid contents. Furthermore, the parameters that indicate tissue damage such as plasma alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were also determined. Thus, a possible protective effect of 2,3-dimercapto-1-propane-sulfonic acid (DMPS) and diphenyl diselenide (PhSe)2 were studied. The results demonstrated an inhibition of delta-ALA-D activity, a reduction of ascorbic acid and an increase of lipid peroxidation induced by cadmium, indicating testes damage. Furthermore, we observed an increase of plasma LDH, AST and ALT activities. DMPS (400 mol/kg) and (PhSe)2 (100 micromol/kg) partially protected from the inhibitory effect of 2.5 mg/kg CdCl2 on delta-ALA-D and from the increase of TBARS (thiobarbituric acid reactive species) levels. (PhSe)2 therapy was effective in ameliorate ascorbic acid content when the cadmium dose was 2.5 mg/kg. Treatment with DMPS and (PhSe)2, individually or combined, was inefficient in reducing cadmium-induced plasma LDH and ALT activity increase. The use of combined therapy (DMPS plus (PhSe)2) proved to be efficient in decreasing cadmium levels in testes and in ameliorating plasma AST activity from animals that received the highest dose of cadmium.

Objective: To study the renal toxicity caused by mercury administrated once and to observe the effects of buthionine sulfoximine (BSO), gluthionein (GSH), vitamin C (VC), and sodium 2,3-dimercato-1-propanesulfonate (DMPS) pretreatment on the nephrotoxicity of mercury., Methods: Sixty-four Wistar rats were divided randomly into eight groups, i. e., control group, low, middle and high dose mercury groups and BSO, GSH, VC, DMPS pretreatment groups. The low, middle, and high dose mercury group rats were subcutaneously (sc) injected with 0.75, 1.5, and 2.5 mg/kg HgCl2, respectively. The BSO pretreatment group rats were intraperitoneally (ip) injected with 0.5 mmol/kg BSO and four hours later sc administrated with 0.75mg/kg HgCl2. The GSH, VC and DMPS pretreatment group rats were ip injected with 3 mmol/kg GSH, 4mmol/kg VC, 200 micromol/kg DMPS, respectively, and two hours later sc administrated with 2.5 mg/kg HgCl2. The control group rats were sc injected with saline at corresponding time. The volume of injection was 5 ml/kg body weight. The 12 h urine samples were collected after 12 hours. After 48 hours, the blood samples were collected and then centrifuged to get the serum. The liver and renal cortex were also removed. Mercury contents in the liver, renal cortex, and urine samples were measured. Urinary NAG, ALP, LDH activities, urinary protein and BUN contents were also determined., Results: Mercury concentrations in the liver, renal cortex, and urine samples increased with mercury dose increasing. Mercury contents in the renal cortex presented evident dose-effect relationship. Mercury concentrations in the liver of high-dose mercury group were higher significantly than that of low, middle-dose mercury group, and control group. The concentrations of urinary mercury in the middle and high dose mercury groups were higher significantly than that of control group. Compared with 0.75mg/kg HgCl2 alone group, BSO pretreatment increased mercury concentrations in the liver, but decreased the concentrations in the renal cortex and urine. Mercury concentrations in the liver of GSH, VC and DMPS pretreatment groups were lower than that of 2.5 mg/kg HgCl2 alone group. Urinary NAG, ALP, LDH activities, urinary protein and BUN contents increased with mercury dose increasing, and the values in the animals of 2.5 mg/kg HgCl2 mercury group were higher significantly than that of control, 0.75 and 1.5 mg/kg HgCl2 groups. Urinary NAG, ALP activities, urinary protein and BUN contents in the rats of BSO pretreatment were higher than that of 0.75 mg/kg HgCl2 alone group and control group. Compared with 2.5 mg/kg HgCl2 alone group, urinary NAG, ALP, LDH activities, urinary protein and BUN contents decreased significantly., Conclusion: Mercury concentrations in the liver, renal cortex, and urine of the rats increased with mercury dose increasing. BSO pretreatment could enhance the renal toxicity induced by mercury, however, GSH, VC, and DMPS pretreatment had antagonistic effects on nephrotoxicity of the mercury.

Alpha-particle immunotherapy by targeted alpha-emitters or alpha-emitting isotope generators is a novel form of extraordinarily potent cancer therapy. A major impediment to the clinical use of targeted actinium-225 (225Ac) in vivo generators may be the radiotoxicity of the systemically released daughter radionuclides. The daughters, especially bismuth-213 (213Bi), tend to accumulate in the kidneys. We tested the efficacy of various pharmacologic agents and the effect of tumor burden in altering the pharmacokinetics of the 225Ac daughters to modify their renal uptake. Pharmacologic treatments in animals were started before i.v. administration of the HuM195-225Ac generator. 225Ac, francium-221 (221Fr), and 213Bi biodistributions were calculated in each animal at different time points after 225Ac generator injection. Oral metal chelation with 2,3-dimercapto-1-propanesulfonic acid (DMPS) or meso-2,3-dimercaptosuccinic acid (DMSA) caused a significant reduction (P < 0.0001) in the renal 213Bi uptake; however, DMPS was more effective than DMSA (P < 0.001). The results with DMPS were also confirmed in a monkey model. The renal 213Bi and 221Fr activities were significantly reduced by furosemide and chlorothiazide treatment (P < 0.0001). The effect on renal 213Bi activity was further enhanced by the combination of DMPS with either chlorothiazide or furosemide (P < 0.0001). Competitive antagonism by bismuth subnitrate moderately reduced the renal uptake of 213Bi. The presence of a higher target-tumor burden significantly prevented the renal 213Bi accumulation (P = 0.003), which was further reduced by DMPS treatment (P < 0.0001). Metal chelation, diuresis with furosemide or chlorothiazide, and competitive metal blockade may be used as adjuvant therapies to modify the renal accumulation of 225Ac daughters.

Hydrobionta species of Daphnia magna Straus were used as a test objects for in vivo evaluation of the antioxidant activity of three hydrophilic thiol compounds: reduced gluthatione, unithiol, and cysteine. These compounds exhibited significant differences in activity under oxidative stress conditions, in the dynamics of observed effects, and in the probability of inversion from anti- to pro-oxidant action. The main advantage of the proposed test objects in comparison to the conventional in vitro experiments (where the antioxidant effect is evaluated over a period of time from several minutes to several hours) is that the development of drug activity (pro- and antioxidant effects) can be monitored over a prolonged period of time (up to several days). In comparison to the tests on mammals, the new method is much simpler and allows the entire antioxidant protection (rather than separate systems) to be evaluated. It is recommended to use Daphnia magna Straus species for comparative evaluation of the antioxidant action of water-soluble preparations in vivo.

Mercuric chloride (HgCl2) disturbs the collagen metabolism in the body which is reflected by altered hydroxyproline fractions in the serum. The aim of the present investigation was to study the effect of HgCl2 treatment on various hydroxyproline (Hyp) fractions in rat serum and the effect of 2,3-dimercapto-1-propane sulfonic acid (DMPS) treatment on serum Hyp fractions in HgCl2 treated rats. Other parameters studied included body weight, food intake, water intake and kidney weight. Doses of HgCl2 used were 0.1, 0.5, 1.0, 2.0, 3.0 mg/kg body weight and that of DMPS was 100 mg DMPS/kg body weight. All the doses of HgCl2 used caused significant (p < 0.01) alterations in free, peptide-bound and protein-bound Hyp in the serum when compared with control rats but a dose of 2 mg/kg body weight caused significant (p < 0.001) alteration even in the total serum Hyp when compared to control rats. Administration of DMPS prior HgCl2 treatment of rats sacrificed 24 h after the treatment caused a significant decrease of 52% (p < 0.01) in free Hyp when compared to similar HgCl2 treated rats. DMPS treatment with HgCl2 also caused an increase of 61% (p < 0.001) and 114% (p < 0.001) in peptide- and protein-bound Hyp respectively, when compared to HgCl2 treated rats sacrificed 24 h after mercuric chloride and DMPS treatment. Administration of DMPS followed by HgCl2 to rats which were sacrificed 48 h later caused no significant change in the total and free Hyp when compared to HgCl2 treated rats which were sacrificed 48 h after the treatment. But there was a significant decrease of 40% (p < 0.001) in peptide-bound Hyp and an increase in of 77% (p < 0.001) in protein-bound Hyp when compared to HgCl2 treated rats sacrificed 48 h after the treatment. The present study shows that HgCl2 treatment caused significant alterations in serum Hyp fractions reflecting disturbed composition of connective tissues which were not reversed by DMPS treatment.

Two chelating agents meso-2,3-dimercaptosuccinic acid (DMSA) and sodium 2,3-dimercapto-propane-1-sulphonate (DMPS) were tested for their efficiency in mercury removal from the body of rats in the presence and in the absence of selenium. Female Wistar rats were given a single intraperitoneal injection of mercuric chloride or an equimolar mixture of mercuric chloride and sodium selenite (1.5 micromol/kg body weight). The chelating agents were given orally, in excess (500 micromol DMSA/kg body weight; 300 micromol DMPS/kg body weight), 30 min after the administration of mercury and selenium. The animals were euthanized 24 h after the treatment and mercury in the kidney, liver, and 24 h urine was determined using cold vapour atomic absorption spectrometry (CV-AAS). The simultaneous administration of mercuric chloride and sodium selenite led to a redistribution of mercury in the organs, so that accumulation of mercury in the kidneys was decreased and in the liver increased. Selenite also caused decrease in the level of urinary mercury excretion. Both chelating agents were effective in mercury removal from the body, by increasing its urinary excretion. However, when animals were simultaneously treated with mercury and selenite, the rise of mercury excreted in the urine due to the treatment with chelating agents was lower when compared to animals receiving mercury without selenite. It is concluded that sodium selenite decreases the efficiency of DMSA and DMPS in mercury removal from the body of rats.

Heme distribution in subcellular fractions of rat liver was studied first hours under the action of several agents causing oxidative stress in vivo. Total and post-mitochondrial heme content in liver was found to depend on both the level of hemolysis products in blood and agent's capacity to modify heme and hemoproteins. The increase of activity of 5-aminolevulinate synthase (ALAS) and/or heme accumulation in mitochondria was accompanied by increase of tryptophan-2,3-dioxygenase (TDO) heme saturation. Membrane stabilisation by tocopherol or prevention of early ALAS induction by cycloheximide prevented both mitochondrial heme accumulation and increase of TDO heme saturation. Modification of heme fully prevented the alterations of total heme content even under severe hemolysis as well as the increase of TDO heme saturation if no increase of heme synthesis occurred. Thus heme synthesis can greatly contribute to heme intracellular redistribution under oxidative stress.