Way Of Detoxification Research Articles

Comprehensive Toxicological Assessment of Halobenzoquinones in Drinking Water at Environmentally Relevant Concentration.

Halobenzoquinones (HBQs), an emerging unregulated category of disinfection byproduct (DBP) in drinking water, have aroused an increasing concern over their potential health risks. However, the chronic toxicity of HBQs at environmentally relevant concentrations remains largely unknown. Here, the occurrence and concentrations of 13 HBQs in drinking water from a northern megacity in China were examined using ultrahigh performance liquid chromatography coupled with triple-quadrupole tandem mass spectrometry (UHPLC-MS/MS). Four HBQs, including 2,6-dichloro-1,4-benzoquinone (2,6-DCBQ), 2,6-dibromo-1,4-benzoquinone (2,6-DBBQ), 2,3,6-trichloro-1,4-benzoquinone (TriCBQ), and 2,5-dibromo-1,4-benzoquinone (2,5-DBBQ), were detected beyond 50% occurrence frequency and at median concentrations from 4 to 50 ng/L. The chronic toxicity of these four HBQs to normal human colon and liver cells (FHC and THLE-2) was investigated at these concentrations. After 90 days of exposure, 2,5-DBBQ and 2,6-DCBQ induced the highest levels of oxidative stress and deoxyribonucleic acid (DNA) damage in colon and liver cells, respectively. Moreover, 2,5-DBBQ and 2,6-DCBQ were also found to induce epithelial-mesenchymal transition (EMT) in normal human liver cells via the extracellular signal regulated kinase (ERK) signaling pathway. Importantly, heating to 100 °C (boiling) was found to efficiently reduce the levels of these four HBQs in drinking water. These results suggested that environmentally relevant concentrations of HBQs could induce cytotoxicity and genotoxicity in normal human cells, and boiling is a highly efficient way of detoxification for HBQs.

Aluminum localization in tissues of Eriophorum vaginatum and its effect on root growth and recovery

Previous observations of Eriophorum vaginatum L. growing in its natural habitats suggest that this perennial graminoid is highly tolerant of aluminum (Al). Eriophorum vaginatum is unusually productive in the bogs surrounding Sudbury (Ontario, Canada) where many years of intensive mining and industrial activities resulted in strong acidification of the environment and wide-scale deposition of metals including highly phytotoxic Al, which in acidic soils is readily available for biological uptake. The ability to accumulate Al within the plant body might be the way of detoxification and can play an important role in Al tolerance by E. vaginatum. To detect Al distribution in leaves, corms and roots of E. vaginatum, plants were collected from a highly polluted site and the fluorescence intensity from the Al-lumogallion complex was observed using a confocal laser scanning microscopy (CLSM). A strong fluorescence signal was detected, demonstrating dense Al accumulation mainly within the cell walls of the analysed plant tissues. It suggests that E. vaginatum can sequester the phytotoxic Al away from the metabolically active tissues so it cannot interfere with the normal cellular activity. Additionally, a hydroponics study was conducted to examine Al effects on root growth and recovery using in vitro regenerated E. vaginatum plants not previously exposed to Al. Root growth was stimulated by 5 and 10 µM Al, but was inhibited by 50 and 100 µM Al. However, all roots returned to control growth rates within 48 h after being transferred to Al-free media, regardless of initial exposure concentration. Based on the ability of this species to tolerate and sequester Al, our results support investigation into E. vaginatum to phytoremediate metal polluted wetlands.

Fresh herbs for stimulating immunity

The immune system is the defense mechanism developed and maintained by the human body to repel germs, viruses and other foreign substances. After the disease, returning to agood health is difficult and sometimes very slow. The best way to regain energy is the process of cleaning the entire system of toxins that have accumulated in the body. The natural way of detoxification is to clean the entire colon and liver, so it is advisable to spare the digestive system of heavy food by replacing them with fresh juices. The objective of the case study was to analyze the influence of ionizing radiation on the content in biologically active compounds (polyphenolcarboxylic acids, flavonic derivatives, polyunsaturated fatty acids, “like SOD” vegetal enzymes) existing in white sea buckthorn fruit powder, as well as its antioxidant activity.

Selenocoumarins as new multitarget antiproliferative agents: Synthesis, biological evaluation and in silico calculations

Herein we report a straightforward preparation of new antiproliferative agents based on the hybridization of a coumarin skeleton and an organoselenium motif. Three families were obtained: isoselenocyanate, selenocarbamates and selenoureas. The main purpose of these hybrid structures is the development of new antiproliferative agents with a multitarget mode of action.A strong correlation between the nature of the organosenium scaffold and the antiproliferative activity was observed. Thus, whereas selenocarbamates proved to be inactive, or moderate antiproliferative agents, isoselenocyanate and most of the selenoureas behaved as strong antiproliferative agents, with GI50 values within the low micromolar range. Interestingly, a good selectivity toward tumor cell lines was found for some of the compounds. Moreover, an increase in the ROS level was observed for tumor cells, and accordingly, these pro-oxidant species might be involved in their mode of action. Overall, title compounds were found not to be substrates for P-glycoprotein, which is overexpressed in many cancer cells as a way of detoxification, and thus, to develop drug resistance.In silico calculations revealed that the selenoderivatives prepared herein might undergo a strong interaction with the active site of HDAC8, and therefore, be potential inhibitors of histone deacetylase 8. In vitro assessment against HDAC8 revealed a strong inhibition of such enzyme exerted by selenoureas, particularly by symmetrical coumarin-containing selenourea.Two compounds showed good antiproliferative data and appear as plausible leads for further testings. The symmetrical coumarin 6 displays the best in vitro inhibition of HDAC8, but is affected by P-gp. In contrast, the N-butyl selenourea coumarin derivative 5a escapes P-gp resistance but has lower HDAC8 inhibition activity.

Comparative study between chemical, physical and enzymatic methods for Jatropha curcas kernel meal phorbol ester detoxification

Detoxification of protein rich Jatropha kernel cake to eliminate the phorbol esters is a great challenge for its industrial utilization in food processing. Several methods either chemical or physical have been previously applied trying to degrade phorbol esters in Jatropha curcas seed cake, which are the main toxic compound with thermo-stable properties. The objective of this study was to compare the different methods to get rid of phorbol esters (PE) including, chemical treatments (0.1 M NaOH/90 % methanol, 85 % ethanol, 90 % methanol & 85 % ethanol (50:50) for 8 h), physical treatments (microwave, ultrasonic and microwave + ultrasonic) and enzymatic treatment by crude germinated Jatropha seed lipase (CGJS). The results showed that the elimination of phorbol esters content chemically treated either by 0.1 M NaOH/90 % methanol or ethanol 85% had effectively decreased by 98.04 % and 98.17 %, respectively compared to control. The treatment by methanol 90% and ethanol 85% (50:50) gave degradation percentage of 95.43% of phorbol esters. The enzymatic elimination of phorbol esters by crude germinated Jatropha seed (CGJS) lipase proved high efficiency of detoxification by reducing the percentage to 98.43%. On the other hand, physical detoxification of Jatropha seed kernel showed good results with microwave treatment by reducing phorbol esters content to 86.29 %. Treatment by ultrasound has detoxified the phorbol esters content by 87.60 % in Jatropha curcas seed. While, combination between microwave & ultrasound increased the percentage of phorbol esters degradation to 88.38 %. In conclusion, enzymatic degradation of phorbol esters is a safe method for degradation as it is both an un-expensive and easy way for detoxification.

Mycotoxin management through transformations – A review

Mycotoxins are toxic secondary metabolic products of various fungi, mainly belonging to the genera Fusarium (Trichothecenes, Zearalenone), Aspergillus (Aflatoxin) and Penicillium (Ochratoxin) and can be found in almost 25% of the world’s agricultural commodities. These compounds are toxic to humans, animals and plants and therefore, efforts should be made to avoid mycotoxin contamination in food and feed. It has been estimated that at least 300 of these fungal metabolites are potentially toxic to animals and humans. In India 50% losses of agricultural commodities are due to postharvest losses. A number of physical and chemical approaches have already been taken to reduce the effect of mycotoxins, but due to certain limitations of physical and chemical strategies prompted search for other solutions to the mycotoxin hazards. Thus, there is an increasing public pressure for a safer and eco-friendly alternative to control these organisms. Consequently, a new approach is applied for managing mycotoxins through transformations that offer specific, efficient and eco-friendly way for detoxification of mycotoxins. This review aims to brings about the up-to-date management strategies mainly through transformation (genetic and bio) to pre-vent or reduce post harvest damages to the crops caused by storage fungi and the contamination of food and feed by mycotoxins. It will make aware of the new technologies or management methods for mycotoxins through transformation. The transformation methods may become the technology of choice, as they offer a specific, irreversible, efficient and environment friendly way of detoxification that leaves neither toxic residues nor any undesirable by-products.

In vitro study on antagonism mechanism of glutathione, sodium selenite and mercuric chloride

It has been broadly recognized that the antagonism between selenium (Se) and mercury (Hg) can reduce the toxicity of mercury in organism. Glutathione (GSH) can participate in the metabolism of Se and Hg in vivo and promote the formation of low-toxic Hg-Se complexes, which is a vital way of detoxification for Hg. In this paper, the reaction mechanism of GSH-Se(IV) binary system, GSH-Hg(II) binary system and GSH-Se(IV)-Hg(II) ternary system were systematically studied from the aspects of stoichiometry, thermodynamics and kinetics, via hyphenated techniques including high performance liquid chromatography (HPLC)-ultraviolet (UV) detection, HPLC-inductively coupled plasma mass spectrometry (ICP-MS) and HPLC-electrospray ionization mass spectrometry (ESI-MS). For GSH-Se(IV) binary system, selenodiglutathione (GSSeSG) was the crucial intermediate; the reaction was exothermic and irreversible at constant pressure; it followed second-order kinetics with a fast kinetics (rate constant (k)=4534.2mol−1Ls−1). For GSH-Se(IV)-Hg(II) ternary system, GSSeSeSG would form by the extremely weak dissociation of two molecules of GSSeSG; Hg(II) would rapidly coordinate with GSSeSeSG to generate (HgxSey)n(GS)m precipitates. The mechanism of GSH-Se(IV)-Hg(II) antagonism system involves two processes, the competitive combination of Hg and Se with GSH and the formation of (HgxSey)n(GS)m complexes.

Bioprospecting of Medicinal Plants for Detoxification of Aflatoxins

Aflatoxin contamination of foods is a major concern worldwide as aflatoxin B1 is implicated in the etiology of hepatic cancer in humans. The aflatoxins are a group of secondary metabolites mainly produced by Aspergillus flavus and Aspergillus parasiticus when they grow on a wide range of agricultural commodities. Once the food commodities are contaminated with aflatoxin, removal of the toxin is extremely difficult as the toxin is highly stable. Several approaches for detoxification of aflatoxins have been proposed; however, each method has its own shortcomings. Natural plant products are of interest as a source of safe and alternative way for detoxification of aflatoxins. This paper summarizes some of the recent developments in the detoxification of aflatoxins by using plant products.

Long-term ferrocyanide application via deicing salts promotes the establishment of Actinomycetales assimilating ferrocyanide-derived carbon in soil.

SummaryCyanides are highly toxic and produced by various microorganisms as defence strategy or to increase their competitiveness. As degradation is the most efficient way of detoxification, some microbes developed the capability to use cyanides as carbon and nitrogen source. However, it is not clear if this potential also helps to lower cyanide concentrations in roadside soils where deicing salt application leads to significant inputs of ferrocyanide. The question remains if biodegradation in soils can occur without previous photolysis. By conducting a microcosm experiment using soils with/without pre‐exposition to road salts spiked with 13C‐labelled ferrocyanide, we were able to confirm biodegradation and in parallel to identify bacteria using ferrocyanide as C source via DNA stable isotope probing (DNA‐SIP), TRFLP fingerprinting and pyrosequencing. Bacteria assimilating 13C were highly similar in the pre‐exposed soils, belonging mostly to Actinomycetales (Kineosporia, Mycobacterium, Micromonosporaceae). In the soil without pre‐exposition, bacteria belonging to Acidobacteria (Gp3, Gp4, Gp6), Gemmatimonadetes (Gemmatimonas) and Gammaproteobacteria (Thermomonas, Xanthomonadaceae) used ferrocyanide as C source but not the present Actinomycetales. This indicated that (i) various bacteria are able to assimilate ferrocyanide‐derived C and (ii) long‐term exposition to ferrocyanide applied with deicing salts leads to Actinomycetales outcompeting other microorganisms for the use of ferrocyanide as C source.

Metallothionein modulation in relation to cadmium bioaccumulation and age-dependent sensitivity of Chironomus riparius larvae.

The goal of this study was to contribute to understanding of the mechanisms behind sensitivity differences between early and late instar larvae of Chironomus riparius and to address the influence of the differences in standard testing approaches on the toxicity evaluation. A 10-day contact sediment toxicity test was carried out to assess sensitivity to cadmium exposure in relation to different age and laboratory culture line origin of test organisms. Chironomid larvae of early (OECD 218 method) and late instar (US-EPA600/R-99/064 method) differed substantially in sensitivity of traditional endpoints (OECD: LOEC 50 and 10μg Cd/g dry weight (dw); US-EPA: LOEC > 1000 and 100μg Cd/g dw for survival and growth, respectively). Bioaccumulated cadmium and metallothioneins (MTs) concentrations were analyzed to investigate the role of MTs in reduced sensitivity to cadmium in late instar larvae. Metallothioneins were induced after treatment to greater Cd concentrations, but their levels in relation to cadmium body burdens did not fully explain low sensitivity of late instars to cadmium, which indicates some other effective way of detoxification in late instars. This study brings new information related to the role of MTs in age-dependent toxicant sensitivity and discusses the implications of divergence in data generated by chironomid sediment toxicity tests by standardized methods using different instars.

Microbial reduction and precipitation of vanadium by mesophilic and thermophilic methanogens

Vanadium is a trace element required by microorganisms, but it is toxic at high concentrations. Some microorganisms are able to reduce vanadium as a way of detoxification or to utilize it as an electron acceptor in respiration. To date, all reported vanadium-reducing microbes belong to either bacteria or eukaryote and no archaeal strain has been reported to possess this capability. To explore the potential of archaea in vanadium reduction, we studied microbial reduction of vanadate (V5+) by a mesophilic (Methanosarcina mazei with the optimal temperature of 37°C) and a thermophilic (Methanothermobacter thermautotrophicus, with the optimum temperature of 65°C) methanogen in both growth and non-growth media. These two methanogens reduced up to 10mM and 5mM of V5+, respectively, in a growth medium. However, in a non-growth medium both methanogens did not even reduce 2mM V5+. Methanogenesis was inhibited by V5+ bioreduction, possibly due to diversion of electrons from methanogenesis to vanadate reduction. Bioreduction of V5+ in a growth medium induced biogenic solid precipitation. Scanning electron microscopy (SEM) observations revealed the relationship between methanogenic cells and solid precipitates. Transition electron microscopy (TEM) with electron energy loss spectroscopy (EELS) and electron paramagnetic resonance (EPR) spectroscopy determined that the oxidation state of reduced vanadium in biogenic precipitates was +4. These data collectively demonstrated that both mesophilic and thermophilic methanogens were capable of reducing V5+ to vanadyl under a variety of conditions.

Investigation of Thai traditional way for detoxification of aloe

In Thai traditional medicine, dried juice extract (DJE) of Aloe vera (L.) Burm has been used in many formulations for a long time [1]. The Thai traditional way recommends detoxifying the aloe DJE before combining with other herbal constituents. The reason for detoxification is to decrease the gastrointestinal tract irritation of aloe. The traditional method to detoxify aloe is adding small amount of water into the DJE powder and heating in clay pot until the dried and crispy mixture is formed. The objective of this study is to verify the chemical conversion of major ingredients in aloe DJE using HPTLC analysis (Silica gel 60 GF254, solvent system; ethyl acetate: methanol: water 100: 13.5: 10, detection at 420nm). Our study found that the amount of a major compound aloin (Rf 0.43) in the DJE was decreased after heating while the amount of its aglycone aloe-emodin (Rf 0.80) was increased from 50µg/mL to 473.2µg/mL. This result explains that hydrolysis and oxidation reactions can occur and some aloin is conversed to aloe-emodin resulted in decreasing anthraquinone glycoside intensity, which can cause irritation of the gastrointestinal tract and increase the chance for gripping action [2]. Further study of other glycosides and aglycones in the DJE of aloe is in progress.

Changes in carbohydrate metabolism in fine roots of the native European black poplar (Populus nigra L.) in a heavy-metal-polluted environment

Effects of copper-smelter-related deposition of heavy metals in the soil on carbohydrate metabolism of fine roots of the native European black poplar were investigated in spring and autumn. Total soluble non-structural carbohydrates in fine roots from trees growing in the polluted habitat were lower than in a control site, but this was directly associated only with a lower raffinose concentration. Neither glucose nor fructose concentrations differed significantly between polluted and unpolluted sites. In contrast, the galactose concentration was higher in the presence of heavy metals, especially in autumn. Also the stachyose concentration was higher in the polluted site, but only in autumn, suggesting it could be an alternative way of detoxification of galactose. No difference between control and polluted stands was observed in sucrose concentration. However, estimates of sucrolytic activity revealed markedly higher activities of sucrose synthase (SuSy), soluble acid (AI) and neutral (NI) invertases in the polluted stand than in the control. In contrast, the estimated glycolytic enzyme activities were not affected by the presence of heavy metals in soil.

Accurate determination of Cd, Cr, Cu and Ni in woodlice and their skins—is moulting a means of detoxification?

Cd, Cr, Cu and Ni were determined in two different species of woodlice: Porcellio scaber and Porcellio dilatatus. Both P. scaber and P. dilatatus were cultivated under standardized conditions in a climatic chamber. Moreover, skins of the cultivated animals were collected and analysed separately to examine whether moulting is a way of detoxification from these elements. After drying and grinding both animal and skin samples, they were pooled to obtain enough sample material for each species. The pooled samples were digested in pure concentrated nitric acid using microwave-assisted high pressure digestion and, finally, analysed by ICP-OES. Special emphasis was given to quality control. To match the matrix of the samples very closely, the reference materials Dorm-2, Dogfish Muscle ( Squalus acanthias) and SRM 1577b Bovine Liver were used to evaluate the whole analytical process including sample digestion. Analyses of the elements in the reference materials were carried out using three different wavelengths for each element simultaneously to check for spectral interferences and to select the wavelengths which were best suited for the analyses. Concentrations of Cd, Cr, Cu and Ni in woodlice and their skins indicated that moulting is a possible means of detoxification in the case of Cr and Ni.

Structural characterization of metabolites after the microbial degradation of type A trichothecenes by the bacterial strain BBSH 797

Contamination of feed with trichothecenes, a group of Fusarium mycotoxins, leads to losses in performance due to their immunosupressive effects and the negative effect on the gastrointestinal system in animal production. A possible way of detoxification is microbial degradation, which was the focus of this study. A bacterial strain — BBSH 797 — which can degrade some mycotoxins of the trichothecene group, has already been isolated. It transforms deoxynivalenol (DON) into its metabolite DOM-1, the non-toxic deepoxide of DON. Analogous to the microbial degradation of DON, the transformation of six different type A trichothecenes was observed. The metabolites appearing were characterized by GC-MS after derivatization with TRI-SIL®TBT. Two metabolites were additionally identified by liquid chromatography-mass spectrometry with particle beam interface (LC-PB-MS) with electron impact (EI)-ionization mode. The major finding was that scirpentriol was completely transformed into its non-toxic metabolite deepoxy scirpentriol, while the mycotoxin T-2 triol underwent a more complicated metabolism. According to the study, T-2-triol was degraded into its non-toxic deepoxy form and into T-2 tetraol, which was then further metabolized to deepoxy T-2 tetraol. GC-MS after derivatization with TRI-SIL®TBT was suitable for the structural characterization of trichothecenes and their degradation products. Besides the mass spectra of already known degradation products, spectra of new metabolites could be recorded by LC-PB-MS.

EmrE, a small Escherichia coli multidrug transporter, protects Saccharomyces cerevisiae from toxins by sequestration in the vacuole.

In this report we describe the functional expression of EmrE, a 110-amino-acid multidrug transporter from Escherichia coli, in the yeast Saccharomyces cerevisiae. To allow for phenotypic complementation, a mutant strain sensitive to a series of cationic lipophilic drugs was first identified. A hemagglutinin epitope-tagged version of EmrE (HA-EmrE) conferring resistance to a wide variety of drugs, including acriflavine, ethidium, methyl viologen, and the neurotoxin 1-methyl-4-phenylpyridinium (MPP+), was functionally expressed in this strain. HA-EmrE is expressed in yeast at relatively high levels (0.5 mg/liter), is soluble in a mixture of organic solvents, and can be functionally reconstituted in proteoliposomes. In bacterial cells, EmrE removes toxic compounds by active transport through the plasma membrane, lowering their cytosolic concentration. However, yeast cells expressing HA-EmrE take up 14C-methyl viologen as well as control cells do. Thus, we investigated the basis of the enhanced resistance to the above compounds. Using Cu2+ ions or methylamine, we could selectively permeabilize the plasma membrane or deplete the proton electrochemical gradients across the vacuolar membrane, respectively. Incubation of yeast cells with copper ions caused an increase in 14C-methyl viologen uptake. In contrast, treatment with methylamine markedly diminished the extent of uptake. Conversely, the effect of Cu2+ and methylamine on a plasma membrane uptake system, proline, was essentially the opposite: while inhibited by the addition of Cu2+, it remained unaffected when cells were treated with methylamine. To examine the intracellular distribution of HA-EmrE, a functional chimera between HA-EmrE and the green fluorescent protein (HA-EmrE-GFP) was prepared. The pattern of HA-EmrE-GFP fluorescence distribution was virtually identical to that of the vacuolar marker FM 4-64, indicating that the transporter is found mainly in this organelle. Therefore, HA-EmrE protects yeast cells by lowering the cytoplasmic concentrations through removal of the toxin to the vacuole. This novel way of detoxification has been previously suggested to function in organisms in which a large vacuolar compartment exists. This report represents the first molecular description of such a mechanism.

DEVELOPMENT AND DESIGN OF A LIQUID MEMBRANE ENZYME REACTOR FOR THE DETOXIFICATION OF BLOOD

Abstract Liver failure causes the enrichment of different lipophilic metabolites: phenol derivatives, mercaptans and short-chain fatty acids in blood. The removal of these toxines from blood is necessary to avoid death and to support the liver's self-regeneration. The liquid surfactant membrane technique with consecutive chemical reaction is used for this purpose. Liquid membranes were developed for the extraction of fatty acids. Enhancement of mass transfer is achieved by an instantaneous chemical reaction inside the emulsion globules, selectivity is obtained by using a suitable carrier. Essential fatty acids are not affected. Phenolic compounds are removed by extraction and consecutive enzymatic reaction inside the liquid membrane globules. This way of detoxification is identical with elimination in the living organism. Furthermore, a new model is being developed to describe the results of phenol extraction. This model makes possible the simulation of the detoxification process in the human organism. A ...