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1.
J Agric Food Chem ; 71(1): 884-894, 2023 Jan 11.
Article in English | MEDLINE | ID: mdl-36584355

ABSTRACT

α-Asarone (αA) and ß-asarone (ßA) are often used as flavoring agents for alcoholic beverages and food supplements. They possess a double bond in the side chain with different configurations. Double bonds are a class of alert chemical group, due to their metabolic epoxidation to the corresponding epoxides eliciting liver injury. Little is known about changes of configuration on metabolic activation and related toxicity. Here, we report the insight into the mechanisms of hepatotoxicity of asarone with different configurations. In vitro and in vivo comparative studies demonstrated ßA displayed higher metabolic activation effectiveness. Apparently, the major metabolic pathway of ßA underwent epoxidation at C-1' and C-2', while αA was mainly metabolized to the corresponding alcohol resulting from the hydroxylation of C-3'. CYP1A2 dominated the metabolism of αA and ßA. The molecular simulation studies showed that the orientation of ßA at the active site of CYP1A2 favored the epoxidation of ßA over that of αA. These findings not only remind us that configuration is another important factor for toxicities but also facilitate the understanding of the mechanisms of toxic action of asarone. Additionally, these findings would benefit the risk assessment of αA and ßA exposure from foods.


Subject(s)
Allylbenzene Derivatives , Anisoles , Chemical and Drug Induced Liver Injury , Humans , Allylbenzene Derivatives/toxicity , Anisoles/toxicity , Chemical and Drug Induced Liver Injury/etiology , Cytochrome P-450 CYP1A2
2.
Chemosphere ; 308(Pt 2): 136421, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36108757

ABSTRACT

Anisole (methoxybenzene) represents an important marker compound of lignin pyrolysis and a starting material for many chemical products. In this study, secondary organic aerosols (SOA) formed by anisole via various atmospheric processes, including homogeneous photooxidation with varying levels of OH• and NOx and subsequent heterogeneous NO3• dark reactions, were investigated. The yields of anisole SOA, particle-bound organoperoxides, particle-induced oxidative potential (OP), and cytotoxicity were characterized in view of the atmospheric fate of the anisole precursor. Anisole SOA yields ranged between 0.12 and 0.35, depending on the reaction pathways and aging degrees. Chemical analysis of the SOA suggests that cleavage of the benzene ring is the main reaction channel in the photooxidation of anisole to produce low-volatility, highly oxygenated small molecules. Fresh anisole SOA from OH• photooxidation are more light-absorbing and have higher OP and organoperoxide content. The high correlation between SOA OP and organoperoxide content decreases exponentially with the degree of OH• aging. However, the contribution of organoperoxides to OP is minor (<4%), suggesting that other, non-peroxide oxidizers play a central role in anisole SOA OP. The particle-induced OP and particulate organoperoxides yield both reach a maximum value after ∼2 days' of photooxidation, implicating the potential long impact of anisole during atmospheric transport. NOx-involved photooxidation and nighttime NO3• reactions facilitate organic nitrate formation and enhance particle light absorption. High NOx levels suppress anisole SOA formation and organoperoxides yield in photooxidation, with decreased aerosol OP and cellular oxidative stress. In contrast, nighttime aging significantly increases the SOA toxicity and reactive oxygen species (ROS) generation in lung cells. These dynamic properties and the toxicity of anisole SOA advocate consideration of the complicated and consecutive aging processes in depicting the fate of VOCs and assessing the related effects in the atmosphere.


Subject(s)
Air Pollutants , Nitrates , Aerosols/analysis , Air Pollutants/analysis , Anisoles/analysis , Anisoles/toxicity , Benzene/analysis , Lignin/analysis , Nitrates/chemistry , Oxidation-Reduction , Reactive Oxygen Species/analysis
3.
Toxicol In Vitro ; 79: 105290, 2022 Mar.
Article in English | MEDLINE | ID: mdl-34861381

ABSTRACT

Potential consequences of combined exposure to the selected food-borne alkenylbenzenes safrole and estragole or their proximate carcinogenic 1'-hydroxy metabolites were evaluated in vitro and in silico. HepG2 cells were exposed to 1'-hydroxyestragole and 1'-hydroxysafrole individually or in equipotent combination subsequently detecting cytotoxicity and DNA adduct formation. Results indicate that concentration addition adequately describes the cytotoxic effects and no statistically significant differences were shown in the level of formation of the major DNA adducts. Furthermore, physiologically based kinetic modeling revealed that at normal dietary intake the concentration of the parent compounds and their 1'-hydroxymetabolites remain substantially below the Km values for the respective bioactivation and detoxification reactions providing further support for the fact that the simultaneous presence of the two carcinogens or of their proximate carcinogenic 1'-hydroxy metabolites may not affect their DNA adduct formation. Overall, these results point at the absence of interactions upon combined exposure to selected food-borne alkenylbenzenes at realistic dietary levels of intake.


Subject(s)
Allylbenzene Derivatives/toxicity , Anisoles/toxicity , Safrole/analogs & derivatives , Safrole/toxicity , Allylbenzene Derivatives/pharmacokinetics , Anisoles/pharmacokinetics , Carcinogens/pharmacokinetics , Carcinogens/toxicity , DNA Adducts/drug effects , Hep G2 Cells , Humans , Risk Assessment , Safrole/pharmacokinetics
6.
Int J Mol Sci ; 22(14)2021 Jul 17.
Article in English | MEDLINE | ID: mdl-34299276

ABSTRACT

1-cyclohexyl-x-methoxybenzene is a novel psychoactive substance (NPS), first discovered in Europe in 2012 as unknown racemic mixture of its three stereoisomers: ortho, meta and para. Each of these has structural similarities with the analgesic tramadol and the dissociative anesthetic phencyclidine. In light of these structural analogies, and based on the fact that both tramadol and phencyclidine are substances that cause toxic effects in humans, the aim of this study was to investigate the in vitro and in vivo pharmacodynamic profile of these molecules, and to compare them with those caused by tramadol and phencyclidine. In vitro studies demonstrated that tramadol, ortho, meta and para were inactive at mu, kappa and delta opioid receptors. Systemic administration of the three stereoisomers impairs sensorimotor responses, modulates spontaneous motor activity, induces modest analgesia, and alters thermoregulation and cardiorespiratory responses in the mouse in some cases, with a similar profile to that of tramadol and phencyclidine. Naloxone partially prevents only the visual sensorimotor impairments caused by three stereoisomers, without preventing other effects. The present data show that 1-cyclohexyl-x-methoxybenzene derivatives cause pharmaco-toxicological effects by activating both opioid and non-opioid mechanisms and suggest that their use could potentially lead to abuse and bodily harm.


Subject(s)
Analgesics, Opioid/toxicity , Anisoles/toxicity , Benzene Derivatives/toxicity , Hallucinogens/toxicity , Phencyclidine/toxicity , Psychotropic Drugs/toxicity , Receptors, Opioid/metabolism , Tramadol/toxicity , Analgesics, Opioid/chemistry , Animals , Anisoles/chemistry , Benzene Derivatives/chemistry , Cells, Cultured , Cricetinae , Hallucinogens/chemistry , In Vitro Techniques , Male , Mice , Mice, Inbred ICR , Models, Animal , Phencyclidine/chemistry , Psychotropic Drugs/chemistry , Tramadol/chemistry
7.
Food Chem Toxicol ; 153: 112253, 2021 Jul.
Article in English | MEDLINE | ID: mdl-34015424

ABSTRACT

Estragole and anethole are secondary metabolites occurring in a variety of commonly used herbs like fennel, basil, and anise. Estragole is genotoxic and carcinogenic in rodents, which depends on the formation of 1'-sulfoxyestragole after hydroxylation and subsequent sulfoconjugation catalyzed by CYP and SULT, respectively. It was hypothesized recently that anethole may be bioactivated via the same metabolic pathways. Incubating estragole with hepatic S9-fractions from rats and humans, specific adducts with hemoglobin (N-(isoestragole-3-yl)-valine, IES-Val) and DNA (isoestragole-2'-deoxyguanosine and isoestragole-2'-deoxyadenosine) were formed. An isotope-dilution technique was developed for the quantification of IES-Val after cleavage with fluorescein isothiocyanate (FITC) according to a modified Edman degradation. The same adducts, albeit at lower levels, were also detected in reactions with anethole, indicating the formation of 3'-hydroxyanethole and the reactive 3'-sulfoxyanethole. Finally, we conducted a pilot investigation in which IES-Val levels in human blood were determined during and after the consumption of an estragole- and anethole-rich fennel tea for four weeks. A significant increase of IES-Val levels was observed during the consumption phase and followed by a continuous decrease during the washout period. IES-Val may be used to monitor the internal exposure to the common reactive genotoxic metabolites of estragole and anethole, 1'-sulfoxyestragole and 3'-sulfoxyanethole, respectively.


Subject(s)
Allylbenzene Derivatives/toxicity , Anisoles/toxicity , DNA Adducts/chemistry , Foeniculum/chemistry , Hemoglobins/chemistry , Allylbenzene Derivatives/metabolism , Animals , Anisoles/metabolism , Beverages/analysis , Biomarkers/blood , Humans , Rats
8.
Environ Toxicol Chem ; 40(6): 1713-1725, 2021 06.
Article in English | MEDLINE | ID: mdl-33646621

ABSTRACT

The present study investigates the bioaccumulation of the insensitive munition compounds 2,4-dinitroanisole (DNAN) and 3-nitro-1,2,4-triazol-5-one (NTO), developed for future weapons systems to replace current munitions containing sensitive explosives. The earthworm Eisenia andrei was exposed to sublethal concentrations of DNAN or NTO amended in Sassafras sandy loam. Chemical analysis indicated that 2- and 4-amino-nitroanisole (2-ANAN and 4-ANAN, respectively) were formed in DNAN-amended soils. The SumDNAN (sum of DNAN, 2-ANAN, and 4-ANAN concentrations) in soil decreased by 40% during the 14-d exposure period. The SumDNAN in the earthworm body residue increased until day 3 and decreased thereafter. Between days 3 and 14, there was a 73% decrease in tissue uptake that was greater than the 23% decrease in the soil concentration, suggesting that the bioavailable fraction may have decreased over time. By day 14, the DNAN concentration accounted for only 45% of the SumDNAN soil concentration, indicating substantial DNAN transformation in the presence of earthworms. The highest bioaccumulation factor (BAF; the tissue-to-soil concentration ratio) was 6.2 ± 1.0 kg/kg (dry wt) on day 3 and decreased to 3.8 ± 0.8 kg/kg by day 14. Kinetic studies indicated a BAF of 2.3 kg/kg, based on the earthworm DNAN uptake rate of 2.0 ± 0.24 kg/kg/d, compared with the SumDNAN elimination rate of 0.87 d-1 (half-life = 0.79 d). The compound DNAN has a similar potential to bioaccumulate from soil compared with trinitrotoluene. The NTO concentration in amended soil decreased by 57% from the initial concentration (837 mg NTO/kg dry soil) during 14 d, likely due to the formation of unknown transformation products. The bioaccumulation of NTO was negligible (BAF ≤ 0.018 kg/kg dry wt). Environ Toxicol Chem 2021;40:1713-1725. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.


Subject(s)
Explosive Agents , Oligochaeta , Soil Pollutants , Animals , Anisoles/analysis , Anisoles/toxicity , Bioaccumulation , Explosive Agents/toxicity , Kinetics , Soil/chemistry , Soil Pollutants/analysis , Soil Pollutants/toxicity
9.
Neurobiol Dis ; 150: 105244, 2021 03.
Article in English | MEDLINE | ID: mdl-33385516

ABSTRACT

There is a growing body of evidence demonstrating the significant involvement of the sigma-1 chaperone protein in the modulation of seizures. Several sigma-1 receptor (Sig1R) ligands have been demonstrated to regulate the seizure threshold in acute and chronic seizure models. However, the mechanism by which Sig1R modulates the excitatory and inhibitory pathways in the brain has not been elucidated. The aim of this study was to compare the susceptibility to seizures of wild type (WT) and Sig1R knockout (Sig1R-/-) mice in intravenous pentylenetetrazol (PTZ) and (+)-bicuculline (BIC) infusion-induced acute seizure and Sig1R antagonist NE-100-induced seizure models. To determine possible molecular mechanisms, we used quantitative PCR, Western blotting and immunohistochemistry to assess the possible involvement of several seizure-related genes and proteins. Peripheral tissue contractile response of WT and Sig1R-/- mice was studied in an isolated vasa deferentia model. The most important finding was the significantly decreased expression of the R2 subunit of the GABA-B receptor in the hippocampus and habenula of Sig1R-/- mice. Our results demonstrated that Sig1R-/- mice have decreased thresholds for PTZ- and BIC-induced tonic seizures. In the NE-100-induced seizure model, Sig1R-/- animals demonstrated lower seizure scores, shorter durations and increased latency times of seizures compared to WT mice. Sig1R-independent activities of NE-100 included downregulation of the gene expression of iNOS and GABA-A γ2 and inhibition of KCl-induced depolarization in both WT and Sig1R-/- animals. In conclusion, the results of this study indicate that the lack of Sig1R resulted in decreased expression of the R2 subunit of the GABA-B receptor and increased susceptibility to seizures. Our results confirm that Sig1R is a significant molecular target for seizure modulation and warrants further investigation for the development of novel anti-seizure drugs.


Subject(s)
Convulsants/toxicity , Habenula/metabolism , Hippocampus/metabolism , Receptors, GABA-B/genetics , Receptors, sigma/genetics , Seizures/genetics , Animals , Anisoles/toxicity , Bicuculline/toxicity , Gene Expression/drug effects , Gene Expression/genetics , Genetic Predisposition to Disease , Habenula/drug effects , Hippocampus/drug effects , Mice , Mice, Knockout , Nitric Oxide Synthase Type II/drug effects , Nitric Oxide Synthase Type II/genetics , Pentylenetetrazole/toxicity , Propylamines/toxicity , Receptors, GABA-A/drug effects , Receptors, GABA-A/genetics , Receptors, GABA-B/metabolism , Seizures/chemically induced , Sigma-1 Receptor
10.
Life Sci ; 264: 118675, 2021 Jan 01.
Article in English | MEDLINE | ID: mdl-33127513

ABSTRACT

Among the bacterial resistance mechanisms, efflux pumps are responsible for expelling xenobiotics, including bacterial cell antibiotics. Given this problem, studies are investigating new alternatives for inhibiting bacterial growth or enhancing the antibiotic activity of drugs already on the market. With this in mind, this study aimed to evaluate the antibacterial activity of Estragole against the RN4220 Staphylococcus aureus strain, which carries the MsrA efflux pump, as well as Estragole's toxicity in the Drosophila melanogaster arthropod model. The broth microdilution method was used to perform the Minimum Inhibitory Concentration (MIC) tests. Estragole was used at a Sub-Inhibitory Concentration (MIC/8) in association with erythromycin and ethidium bromide to assess its combined effect. As for Estragole's toxicity evaluation over D. melanogaster, the fumigation bioassay and negative geotaxis methods were used. The results were expressed as an average of sextuplicate replicates. A Two-way ANOVA followed by Bonferroni's post hoc test was used. The present study demonstrated that Estragole did not show a direct antibacterial activity over the RN4220 S. aureus strain, since it obtained a MIC ≥1024 µg/mL. The association of estragole with erythromycin demonstrated a potentiation of the antibiotic effect, reducing the MIC from 512 to 256 µg/mL. On the other hand, when estragole was associated with ethidium bromide (EtBr), an antagonism was observed, increasing the MIC of EtBr from 32 to 50.7968 µg/mL, demonstrating that estragole did not inhibited directly the MsrA efflux pump mechanism. We conclude that estragole has no relevant direct effect over bacterial growth, however, when associated with erythromycin, this reduced its MIC, potentiating the effect of the antibiotic.


Subject(s)
Anisoles/toxicity , Anti-Bacterial Agents/toxicity , Drug Resistance, Multiple, Bacterial/drug effects , Staphylococcus aureus/drug effects , Allylbenzene Derivatives , Animals , Anisoles/administration & dosage , Anti-Bacterial Agents/administration & dosage , Dose-Response Relationship, Drug , Drosophila melanogaster , Drug Resistance, Multiple, Bacterial/physiology , Erythromycin/administration & dosage , Flavoring Agents/administration & dosage , Flavoring Agents/toxicity , Microbial Sensitivity Tests/methods , Staphylococcus aureus/physiology
11.
J Appl Toxicol ; 41(8): 1166-1179, 2021 08.
Article in English | MEDLINE | ID: mdl-33236787

ABSTRACT

Asarone isomers are naturally occurring in Acorus calamus Linné, Guatteria gaumeri Greenman, and Aniba hostmanniana Nees. These secondary plant metabolites belong to the class of phenylpropenes (phenylpropanoids or alkenylbenzenes). They are further chemically classified into the propenylic trans- and cis-isomers α-asarone and ß-asarone and the allylic γ-asarone. Flavoring, as well as potentially pharmacologically useful properties, enables the application of asarone isomers in fragrances, food, and traditional phytomedicine not only since their isolation in the 1950s. However, efficacy and safety in humans are still not known. Preclinical evidence has not been systematically studied, and several pharmacological effects have been reported for extracts of Acorus calamus and propenylic asarone isomers. Toxicological data are rare and not critically evaluated altogether in the 21st century yet. Therefore, within this review, available toxicological data of asarone isomers were assessed in detail. This assessment revealed that cardiotoxicity, hepatotoxicity, reproductive toxicity, and mutagenicity as well as carcinogenicity were described for propenylic asarone isomers with varying levels of reliability. The toxicodynamic profile of γ-asarone is unknown except for mutagenicity. Based on the estimated daily exposure and reported adverse effects, officials restricted or published recommendations for the use of ß-asarone and preparations of Acorus calamus. In contrast, α-asarone and γ-asarone were not directly addressed due to a limited data situation.


Subject(s)
Allylbenzene Derivatives/toxicity , Anisoles/toxicity , Allylbenzene Derivatives/pharmacokinetics , Animals , Anisoles/pharmacokinetics , Carcinogens/toxicity , Cardiotoxicity/etiology , Chemical and Drug Induced Liver Injury/etiology , Humans , Isomerism , Reproduction/drug effects
12.
Toxicol Lett ; 337: 1-6, 2021 Feb 01.
Article in English | MEDLINE | ID: mdl-33189830

ABSTRACT

Accumulation of N2-(trans-isoestragol-3'-yl)-2'-deoxyguanosine (E-3'-N2-dG) DNA adducts derived from the alkenylbenzene estragole upon repeated dose exposure was investigated since the repair of this adduct was previously shown to be inefficient. To this end human HepaRG cells were exposed to repeating cycles of 2 h exposure to 50 µM estragole followed by 22 h repair to mimic daily exposure. The E-3'-N2-dG DNA adduct levels were quantified by LC-MS/MS after each cycle. The results show accumulation of E-3'-N2-dG DNA adducts at a rate of 17.53 adducts/108 nts/cycle. This rate at the dose level calculated by physiologically based kinetic (PBK) modeling to result in 50 µM was converted to a rate expected at average human daily intake of estragole. The predicted time estimated to reach adduct levels reported at the BMD10 of the related alkenylbenzene methyleugenol of 10-100 adducts /108 nts upon average human daily intake of estragole amounted to 8-80 (in rat) or 6-57 years (in human). It is concluded that the persistent nature of the E-3'-N2-dG DNA adducts may contribute to accumulation of substantial levels of DNA adducts upon prolonged dietary exposure.


Subject(s)
Anisoles/toxicity , DNA Adducts/drug effects , Liver/metabolism , Allylbenzene Derivatives , Animals , Anisoles/pharmacokinetics , Cell Line , DNA/genetics , DNA/isolation & purification , Diet , Eugenol/analogs & derivatives , Eugenol/toxicity , Hepatocytes/drug effects , Humans , Kinetics , Liver/drug effects , Liver/pathology , Models, Biological , Rats
13.
Toxicology ; 444: 152566, 2020 11.
Article in English | MEDLINE | ID: mdl-32853702

ABSTRACT

Estragole is a natural constituent in herbs and spices and in products thereof such as essential oils or herbal teas. After cytochrome P450-catalyzed hydroxylation and subsequent sulfation, estragole acts as a genotoxic hepatocarcinogen forming DNA adducts in rodent liver. Because of the genotoxic mode of action and the widespread occurrence in food and phytomedicines a refined risk assessment for estragole is needed. We analyzed the time- and concentration-dependent levels of the DNA adducts N2-(isoestragole-3'-yl)-2'-desoxyguanosine (E3'N2dG) and N6-(isoestragole-3'-yl)-desoxyadenosine (E3'N6dA), reported to be the major adducts formed in rat liver, in rat hepatocytes (pRH) in primary culture after incubation with estragole. DNA adduct levels were measured via UHPLC-ESI-MS/MS using stable isotope dilution analysis. Both adducts were formed in pRH and could already be quantified after an incubation time of 1 h (E3'N6dA at 10 µM, E3'N2dG at 1µM estragole). E3'N2dG, the main adduct at all incubation times and concentrations, could be detected at estragole concentrations < 0.1 µM after 24 h and < 0.5 µM after 48 h. Adduct levels were highest after 6 h and showed a downward trend at later time-points, possibly due to DNA repair and/or apoptosis. While the concentration-response characteristics of adduct formation were apparently linear over the whole concentration range, strong indication for marked hypo-linearity was obtained when the modeling was based on concentrations < 1 µM only. In the micronucleus assay no mutagenic potential of estragole was found in HepG2 cells whereas in HepG2-CYP1A2 cells 1 µM estragole led to a 3.2 fold and 300 µM to a 7.1 fold increase in micronuclei counts. Our findings suggest the existence of a 'practical threshold' dose for DNA adduct formation as an initiating key event of the carcinogenicity of estragole indicating that the default assumption of concentration-response-linearity is questionable, at least for the two major adducts studied here.


Subject(s)
Anisoles/toxicity , Carcinogens/toxicity , DNA Adducts , Hepatocytes/drug effects , Allylbenzene Derivatives , Animals , Cells, Cultured , Cytochrome P-450 CYP1A2/genetics , Hepatocytes/metabolism , Humans , Male , Micronucleus Tests , Rats, Wistar
14.
Food Chem Toxicol ; 145: 111585, 2020 Nov.
Article in English | MEDLINE | ID: mdl-32702506

ABSTRACT

In 2015, the Expert Panel of the Flavor and Extract Manufacturers Association initiated the safety re-evaluation of over 250 natural flavor complexes (NFCs) used as flavor ingredients. This publication, 4th in a series focusing on the safety evaluation of NFCs, presents an evaluation of NFCs rich in hydroxyallylbenzene and hydroxypropenylbenzene constituents using a procedure initially published in 2005 and updated in 2018 that evaluates the safety of naturally occurring mixtures for their intended use as flavoring ingredients. The procedure requires the characterization of the chemical composition for each NFC and subsequent organization of the constituents into defined congeneric groups. The safety of each NFC is evaluated using the conservative threshold of toxicological concern (TTC) approach together with studies on absorption, metabolism and toxicology of the NFC and its constituent congeneric groups. By the application of this procedure, seven NFCs, derived from clove, cinnamon leaf and West Indian bay leaf were affirmed as "generally recognized as safe (GRAS)" under their conditions of intended use as flavor ingredients. An eighth NFC, an oleoresin of West Indian bay leaf, was affirmed based on its estimated intake, which is below the TTC of 0.15 µg/person per day for compounds with structural alerts for genotoxicity.


Subject(s)
Cinnamomum zeylanicum/chemistry , Flavoring Agents/toxicity , Laurus/chemistry , Syzygium/chemistry , Allylbenzene Derivatives , Animals , Anisoles/chemistry , Anisoles/toxicity , Consumer Product Safety , Escherichia coli/drug effects , Eugenol/chemistry , Eugenol/toxicity , Female , Flavoring Agents/chemistry , Humans , Male , Mice , Mutagenicity Tests , No-Observed-Adverse-Effect Level , Plant Oils/chemistry , Plant Oils/toxicity , Rats , Safrole/chemistry , Safrole/toxicity , Salmonella typhimurium/drug effects
16.
Food Chem Toxicol ; 142: 111484, 2020 Aug.
Article in English | MEDLINE | ID: mdl-32526244

ABSTRACT

The phenylpropenes α-asarone and ß-asarone are widely spread in the marsh plant Acorus calamus. Both isomers are classified as carcinogenic in rodents. However, the respective genotoxic mechanisms are not elucidated so far. The present study gives deeper insights into the genotoxic effects of asarone isomers as well as their known oxidative phase I metabolites, (E)-3'-oxoasarone and asarone epoxide. We show that asarone metabolites highly increase DNA strand breaks after 1 h of incubation, markedly metabolic activation contributes to their carcinogenic mode of action. All test compounds act as aneugens and potently enhance the amounts of micronuclei in binuclear cells. However, a prolonged incubation time of 24 h results in a decrease of DNA damage. This work suggests that asarone metabolites also induce DNA double strand breaks , why we put a strong focus on homologous recombination and non-homologous end joining. The obtained results herein indicate that asarone epoxide-induced DNA strand breaks are repaired via a homologous repair pathway.


Subject(s)
Anisoles/toxicity , DNA Breaks, Double-Stranded/drug effects , Mutagens/toxicity , Activation, Metabolic , Allylbenzene Derivatives , Anisoles/chemistry , Anisoles/metabolism , Hep G2 Cells , Humans , Isomerism , Mutagens/chemistry
17.
Arch Toxicol ; 94(4): 1349-1365, 2020 04.
Article in English | MEDLINE | ID: mdl-32185416

ABSTRACT

Estragole, naturally occurring in a variety of herbs and spices, can form DNA adducts after bioactivation. Estragole DNA adduct formation and repair was studied in in vitro liver cell models, and a molecular dynamics simulation was used to investigate the conformation dependent (in)efficiency of N2-(trans-isoestragol-3'-yl)-2'-deoxyguanosine (E-3'-N2-dG) DNA adduct repair. HepG2, HepaRG cells, primary rat hepatocytes and CHO cells (including CHO wild-type and three NER-deficient mutants) were exposed to 50 µM estragole or 1'-hydroxyestragole and DNA adduct formation was quantified by LC-MS immediately following exposure and after a period of repair. Results obtained from CHO cell lines indicated that NER plays a role in repair of E-3'-N2-dG adducts, however, with limited efficiency since in the CHO wt cells 80% DNA adducts remained upon 24 h repair. Inefficiency of DNA repair was also found in HepaRG cells and primary rat hepatocytes. Changes in DNA structure resulting from E-3'-N2-dG adduct formation were investigated by molecular dynamics simulations. Results from molecular dynamics simulations revealed that conformational changes in double-stranded DNA by E-3'-N2-dG adduct formation are small, providing a possible explanation for the restrained repair, which may require larger distortions in the DNA structure. NER-mediated enzymatic repair of E-3'-N2-dG DNA adducts upon exposure to estragole will be limited, providing opportunities for accumulation of damage upon repeated daily exposure. The inability of this enzymatic repair is likely due to a limited distortion of the DNA double-stranded helix resulting in inefficient activation of nucleotide excision repair.


Subject(s)
Anisoles/toxicity , Carcinogens/toxicity , Flavoring Agents/toxicity , Allylbenzene Derivatives , Animals , Chromatography, Liquid , Cricetinae , Cricetulus , DNA , DNA Adducts , DNA Repair , Deoxyguanosine , Hepatocytes , Mass Spectrometry , Molecular Dynamics Simulation , Rats , Toxicity Tests
18.
Toxicol Lett ; 324: 1-11, 2020 May 15.
Article in English | MEDLINE | ID: mdl-32035120

ABSTRACT

α-asarone is a natural phenylpropene found in several plants, which are widely used for flavoring foods and treating diseases. Previous studies have demonstrated that α-asarone has many pharmacological functions, while some reports indicated its toxicity. However, little is known about its cardiovascular effects. This study investigated developmental toxicity of α-asarone in zebrafish, especially the cardiotoxicity. Zebrafish embryos were exposed to different concentrations of α-asarone (1, 3, 5, 10, and 30 µM). Developmental toxicity assessments revealed that α-asarone did not markedly affect mortality and hatching rate. In contrast, there was a concentration-dependent increase in malformation rate of zebrafish treated with α-asarone. The most representative cardiac defects were increased heart malformation rate, pericardial edema areas, sinus venosus-bulbus arteriosus distance, and decreased heart rate. Notably, we found that α-asarone impaired the cardiac function of zebrafish by prolonging the mean QTc duration and causing T-wave abnormalities. The expressions of cardiac development-related key transcriptional regulators tbx5, nkx2.5, hand2, and gata5 were all changed under α-asarone exposure. Further investigation addressing the mechanism indicated that α-asarone triggered apoptosis mainly in the heart region of zebrafish. Moreover, the elevated expression of puma, cyto C, afap1, caspase 3, and caspase 9 in treated zebrafish suggested that mitochondrial apoptosis is likely to be the main reason for α-asarone induced cardiotoxicity. These findings revealed the cardiac developmental toxicity of α-asarone, expanding our knowledge about the toxic effect of α-asarone on living organisms.


Subject(s)
Abnormalities, Drug-Induced/etiology , Anisoles/toxicity , Apoptosis/drug effects , Electrocardiography/drug effects , Heart Defects, Congenital/chemically induced , Mitochondria, Heart/drug effects , Allylbenzene Derivatives , Animals , Cardiotoxicity/etiology , Embryo, Nonmammalian/drug effects , Mitochondria, Heart/pathology , Zebrafish
19.
Reprod Toxicol ; 93: 99-105, 2020 04.
Article in English | MEDLINE | ID: mdl-32004625

ABSTRACT

Anethole is a natural anisole derivative that has been widely used in food and daily chemical industries, agricultural applications and the traditional medicine. It is closely related to aspects of daily life, and humans can easily be exposed to it. Although the reproductive toxicity of anethole was shown in the rat, its effect on human reproduction remains unknown. In this study, we examined the effect of anethole on human sperm in vitro. Different anethole doses (0.1, 1, 10, and 100 µM) were applied to ejaculated human sperm. Fertilization-essential functions, as well as the intracellular calcium concentration ([Ca2+]i) and tyrosine phosphorylation, two vital factors for regulating sperm function, were measured. The results indicated that 10 and 100 µM anethole significantly reduced the motility, hyperactivation, and penetration ability of human sperm (P < 0.05) and inhibited the increase in human sperm functions induced by progesterone, a hormone essential for sperm function activation. Additionally, 10 and 100 µM anethole decreased both basal and progesterone-increased tyrosine phosphorylation, [Ca2+]i, and the current of CATSPER, a cation channel of sperm predominant for Ca2+ influx. These results suggest that anethole inhibits human sperm functions by reducing sperm [Ca2+]i through CATSPER and suppressing tyrosine phosphorylation in vitro, raising the fact that the caution is needed when overtaking anethole.


Subject(s)
Anisoles/toxicity , Calcium/metabolism , Spermatozoa/drug effects , Tyrosine/metabolism , Adult , Allylbenzene Derivatives , Humans , Male , Phosphorylation/drug effects , Sperm Motility/drug effects , Spermatozoa/metabolism , Spermatozoa/physiology , Young Adult
20.
Bull Entomol Res ; 110(3): 406-416, 2020 Jun.
Article in English | MEDLINE | ID: mdl-31813390

ABSTRACT

Sitophilus zeamais is a key pest of stored grains. Its control is made, usually, using synthetic insecticides, despite their negative impacts. Botanical insecticides with fumigant/repellent properties may offer an alternative solution. This work describes the effects of Anethum graveolens, Petroselinum crispum, Foeniculum vulgare and Cuminum cyminum essential oils (EOs) and (S)-carvone, cuminaldehyde, estragole and (+)-fenchone towards adults of S. zeamais. Acute toxicity was assessed by fumigation and topical application. Repellence was evaluated by an area preference bioassay and two-choice test, using maize grains. LC50 determined by fumigation ranged from 51.8 to 535.8 mg L-1 air, with (S)-carvone being the most active. LD50 values for topical applications varied from 23 to 128 µg per adult for (S)-carvone > cuminaldehyde > A. graveolens > C. cyminum > P. crispum. All EOs/standard compounds reduced significantly the percentage of insects attracted to maize grains (65-80%) in the two-choice repellence test, whereas in the area preference bioassay RD50 varied from 1.4 to 45.2 µg cm-2, with cuminaldehyde, (S)-carvone and estragole being strongly repellents. Petroselinum crispum EO and cuminaldehyde affected the nutritional parameters relative growth rate, efficiency conversion index of ingested food and antifeeding effect, displaying antinutritional effects toward S. zeamais. In addition, P. crispum and C. cyminum EOs, as well as cuminaldehyde, showed the highest acetylcholinesterase inhibitory activity in vitro (IC50 = 185, 235 and 214.5 µg mL-1, respectively). EOs/standard compounds exhibited acute toxicity, and some treatments showed antinutritional effects towards S. zeamais. Therefore, the tested plant products might be good candidates to be considered to prevent damages caused by this pest.


Subject(s)
Apiaceae/chemistry , Oils, Volatile/pharmacology , Weevils/drug effects , Allylbenzene Derivatives , Animals , Anisoles/pharmacology , Anisoles/toxicity , Benzaldehydes/pharmacology , Benzaldehydes/toxicity , Camphanes/pharmacology , Camphanes/toxicity , Cyclohexane Monoterpenes/pharmacology , Cyclohexane Monoterpenes/toxicity , Cymenes/pharmacology , Cymenes/toxicity , Feeding Behavior/drug effects , Fumigation , Insect Repellents/pharmacology , Insecticides/pharmacology , Norbornanes/pharmacology , Norbornanes/toxicity , Oils, Volatile/toxicity , Plant Oils/pharmacology , Plant Oils/toxicity
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