Anti-Sporothrix activity of novel copper-itraconazole complexes

A series of new metal complexes, [Cu(ITZ)2Cl2]·5H2O (1), [Cu(NO3)2(ITZ)2] ·3H2O·C4H10O and [Cu(ITZ)2)(PPh3)2]NO3·5H2O (3) were synthesized by a reaction of itraconazole (ITZ) with the  respective copper salts under reflux. The metal complexes were characterized by elemental analyses, molar conductivity, 1H and 13C{1H} nuclear magnetic resonance, UV-Vis, infrared and EPR spectroscopies. The antifungal activity of these metal complexes was evaluated against the main sporotrichosis agents: Sporothrix brasiliensis, Sporothrix schenkii, and Sporothrix globosa. All three new compounds inhibited the growth of S. brasiliensis and S. schenckii at lower concentrations than the free azole, with complex 2 able to kill all species at 4 µM and induce more pronounced alterations in fungal cells. Complexes 2 and 3 exhibited higher selectivity and no mutagenic effect at the concentration that inhibited fungal growth and affected fungal cells. The strategy of coordinating itraconazole (ITZ) to copper was successful, since the corresponding metal complexes were more effective than the parent drug. Particularly, the promising antifungal activity of the Cu-ITZ complexes makes them potential candidates for the development of an alternative drug to treat mycoses.

Antimutagenic and antitumor activities of a water-soluble fraction of soursop (syn Graviola, Annona muricata L.) fruit pulp

Soursop (Annona muricata) is a tropical tree whose decoction derived from bark, root, seed, or leaf has been used for medicinal uses. In addition, the fruit itself is considered a food, and the juice is utilized to treat heart and liver diseases. The aim of this study was to determine the phenolic content. In addition, a water-soluble fraction of the soursop fruit pulp (WSSP) was examined for the following properties: antioxidant, mutagenic, and antimutagenicity. UV-visible spectrophotometry determined total phenolic content by the Folin-Ciocalteu method to be 11.22 ± 0.6 mg of gallic acid equivalent per gram dried extract, and free-radical scavenging activity by the 2,2'-diphenyl-1-picryl-hydrazyl (DPPH•) showed an EC50 of 1032 µg/ml. In the Salmonella/microsome assay, no marked mutagenicity was induced following WSSP treatment, and a chemopreventive capacity was observed in the antimutagenic assay. The cytotoxicity assays were carried out using the water-soluble tetrazolium salt and lactate dehydrogenase (LDH) assays demonstrated that WSSP induced significant cytotoxicity in MCF-7 and Caco-2 cells, indicating greater effectiveness of cytotoxic action by destroying cell membrane integrity. Data suggest that WSSP may exert beneficial effects as a DNA chemopreventive and antitumor agent.

Marketable 1,3-dimethylamylamine and caffeine-based thermogenic supplements: Regulatory genotoxicity assessment through in vitro and in silico approaches

The consumption of dietary supplements to enhance physical performance has increased significantly in the last century, especially thermogenic pre-workout supplements. Nevertheless, this industry has faced criticism for inadequate safety measures surveillance in regulatory issues regarding their products. The aims of our study were to investigate two pre-workout supplements with respect to (1) mutagenicity utilizing Salmonella/microsome assay; (2) genotoxicity employing cytokinesis-block micronucleus (CBMN) assay protocols; and (3) hepatocytoxicity using WST cell proliferation, activities of lactate dehydrogenase (LDH) and alkaline phosphatase using human liver carcinoma (HepG2) and mouse fibroblast (F C3H) cells. Oxidative stress was determined through glutathione (GSH) measurement and in silico for predictions of pharmacokinetics and toxicity for the most abundant isolated substances present in these supplements. Both supplements induced mutagenicity in all examined bacterial strains, especially in the presence of exogenous metabolism. Further, tested supplements significantly elevated the formation of micronuclei (MN) as well as other cellular phenomena. Concentration- and time-dependent curves were observed for hepatotoxicity in both studied cell lines. In addition, both supplements decreased levels of intracellular and extracellular GSH. In silico predictions showed that the isolated individual compounds failed to induce the observed outcomes. Our findings provide contributions to the molecular mechanisms underlying two pre-workout supplement-induced toxicity and the need for surveillance.

Echinodorus macrophyllus: Acute toxicological evaluation of hydroxycinnamoyl derivatives from SF1 subfractions

ETHNOPHARMACOLOGICAL RELEVANCE

Echinodorus macrophyllus (Kunth.) Micheli (Alismataceae), known as chapéu-de-couro in Brazil, is popularly used to treat inflammatory diseases. We have previously demonstrated a significant reduction in the acute inflammation for the aqueous extract of E. macrophyllus (AEEm) and its ethanolic fraction (Fr20) and described that hydroxycinnamoyl derivatives present in SF1 (Fr20 subfraction) showed higher anti-inflammatory properties by mechanisms that include a reduction of TNF-α, IL-1β, CKCL1/KC, LTB4, and PGE2 levels in exudate.

AIM OF THE STUDY

This work describes the acute toxicological effect of SF1 subfraction on SW mice treated orally for five days in the air pouch model by evaluating the hematological and biochemical determinations on the blood samples; the relative organ weight and its histopathological analysis; the liver genotoxicity assessment and the activity of liver enzymes from xenobiotic metabolism.

MATERIALS AND METHODS

Fr20 was earlier fractionated on the Sephadex LH-20 column, yielding mainly four subfractions, including SF1. The SF1 toxicity was evaluated in mice challenged with carrageenan on the air pouch inflammation model and orally treated for five days. The body weight was monitored daily, and the organs were weighed after the euthanasia. Hematological and biochemical determinations were carried out using specific commercial kits and following the protocols provided by the manufacturers. The organs were fixed, sectioned, processed for hematoxylin and eosin staining, and analyzed by light microscopy. Genotoxicity assessment was performed by the alkaline single-cell gel electrophoresis. Livers were processed for ethoxyresorufin-O-deethylase (EROD) and Glutathione S-transferase (GST) assays.

RESULTS

SF1 exhibited low toxicity, as no significant discrepancy was observed in the relative weight of the body organs of mice. Moreover, the daily treatment with SF1 did not alter the number and percentage of red blood cells or hemoglobin concentration in the blood. The treatment with SF1 did not affect the creatinine concentration, but the 25 mg/kg dose reduced the plasma urea level and uric acid, suggesting its use in treating acute renal failure. The parameters analyzed did not present biochemical alterations indicative of liver disease. Regarding serum triglyceride and cholesterol levels, a significant decrease was detected in both parameters in mice treated with SF1. In addition, the histopathological analysis showed that inflammatory focus in the livers seemed more relevant in the control groups than in those treated. There were no significant changes in the renal or splenic tissues of animals treated with SF1. Treatment with SF1 also does not have a genotoxic effect on liver cells.

CONCLUSION

Treatment with SF1 showed no toxicity in mice at doses equivalent to those recommended for humans, which provides evidence of the safety of the therapeutic use of this subfraction.

In vitro chemopreventive and cytotoxic effects of Amazon mosses Leucobryum martianum (Hornsch.) and Leucobryum laevifolium (Broth) extracts

Several bioactive compounds, such as polyphenols, demonstrate low toxicity and prominent effects on cancer cells with antioxidant, anti-inflammatory, and antitumor activities. Such compounds can be found in Amazon mosses Leucobryum martianum (Hornsch.) Hampe ex Müll. Hal. (Hornsch.) and Leucobryum laevifolium (Broth). Antimutagenic assay with Salmonella enterica serovar Typhimurium and cytotoxicity with different eukaryotic cell lines were carried out to screen aqueous, hydroalcoholic, and ethanolic extracts of those Amazon mosses for anticancer potential. The results indicate the capacity of all extracts of both mosses to exert chemopreventive effects against 4-nitroquinoline-N-oxide (4NQO) and 2-aminoanthracene (2-AA), which are direct or indirect mutagens. In particular, the ethanolic and aqueous extract from L. martianum. The ethanolic extract from L. martianum induces significant cytotoxicity by mitochondrial metabolism and cell membrane disruption pathways to tumor or non-tumor cells. The aqueous extract from L. martianum showed a mainly cytotoxic response in the HepG2 cells, a human liver carcinoma, reaching ~90% cytotoxicity. The same extract did not induce significant damage to normal liver cells (F C3H cells) by membrane interaction pathway. The selective cytotoxicity in the aqueous extract of L. martianum makes it a candidate against liver cancer. Further studies, including in vivo models, are necessary to validate the efficacy and safety of the aqueous extract of L. martianum.

UHPLC-MS metabolomic profile and in silico pharmacokinetic approach of Kalanchoe daigremontiana Raym.-Hamet & H. Perrier aqueous extracts

Throughout humanity's development, the medicinal use of plants has evolved as an observational and empirical matter; Yorubá culture uses Kalanchoe sp. as universal antidotes. They are believed to be "ewé òdúndún" or plants of goodness and are traditionally and religiously used in preparations to treat diseases and physiological disorders. Our main goals were to determine the comparative phytochemical composition panel of two Kalanchoe daigremontiana Raym.-Hamet & H. Perrier aqueous extracts through UHPLC-MS metabolomic approaches and highlight the drug-likeness properties of the most abundant compounds in the complex mixture prepared according to its traditional uses. K. daigremontiana leaf aqueous extracts were prepared by cold water maceration (Kd1) or decoction (Kd2). The metabolomics analysis of the extracts was performed through UHPLC-ESI-MS/MS acquisition in positive and negative modes. An in-house database was built with molecules found in plants from the Crassulaceae family and was applied to the annotation step. Our analysis identified 132 compounds, showcasing variations between negative (ESI(-)) and positive (ESI(+)) ionization modes. Notably, flavonoids such as quercetin and kaempferol glycosides, known for their potent antioxidant properties, were abundant in both extracts. Additionally, bufadienolides, associated with diverse biological activities, were present. Both extracts presented similar phytochemical compositions in terms of the number of compounds. Differential analysis revealed significantly higher intensities for specific molecules in both Kd1 and Kd2 extracts. Considering the relative abundance, Kd1 showed a significant amount of Fatty Acids and Steroids concerning Kd2. Additionally, the 15 most abundant compounds were analyzed using in silico pharmacokinetic and toxicity algorithms (SwissADME, pkCSM, and LAZAR) to predict their drug-likeness profile. The fifteen most abundant molecules (Corchorifatty acid F; 9,12,13-TriHOME; Acetylsagittatin A; Apiin; Kaempferol; L-Malic acid; 19-Oxodesacetylcinobufagin; Lucyoside Q; (12 S,13 S)-Epoxylinolenic acid; Isocitric acid; 4''-O-Acetylafzelin; Hellebrigenin; Senedigitalene; Blumenol C and Sativoside R2) had their ADMET in silico profiles predicted using computational tools. Importantly, our in silico assessments pinpointed six promising compounds with favorable absorption, pharmacokinetics, and drug-likeness properties, suggesting their potential as bioactive agents. This finding underscores the significance of these traditional aqueous extracts in folk medicine. In conclusion, our study not only supports the traditional use of Kalanchoe spp. but also sheds light on the safety and pharmacological potential of these extracts. By exploring different extraction methods and employing metabolomics, we have gained valuable insights into the bioactivity and safety of plant extracts, which can guide future research in this field.

Anti-Trypanosoma cruzi Activity, Mutagenicity, Hepatocytotoxicity and Nitroreductase Enzyme Evaluation of 3-Nitrotriazole, 2-Nitroimidazole and Triazole Derivatives

Chagas disease (CD), which is caused by Trypanosoma cruzi and was discovered more than 100 years ago, remains the leading cause of death from parasitic diseases in the Americas. As a curative treatment is only available for the acute phase of CD, the search for new therapeutic options is urgent. In this study, nitroazole and azole compounds were synthesized and underwent molecular modeling, anti-T. cruzi evaluations and nitroreductase enzymatic assays. The compounds were designed as possible inhibitors of ergosterol biosynthesis and/or as substrates of nitroreductase enzymes. The in vitro evaluation against T. cruzi clearly showed that nitrotriazole compounds are significantly more potent than nitroimidazoles and triazoles. When their carbonyls were reduced to hydroxyl groups, the compounds showed a significant increase in activity. In addition, these substances showed potential for action via nitroreductase activation, as the substances were metabolized at higher rates than benznidazole (BZN), a reference drug against CD. Among the compounds, 1-(2,4-difluorophenyl)-2-(3-nitro-1H-1,2,4-triazol-1-yl)ethanol (8) is the most potent and selective of the series, with an IC50 of 0.39 µM and selectivity index of 3077; compared to BZN, 8 is 4-fold more potent and 2-fold more selective. Moreover, this compound was not mutagenic at any of the concentrations evaluated, exhibited a favorable in silico ADMET profile and showed a low potential for hepatotoxicity, as evidenced by the high values of CC50 in HepG2 cells. Furthermore, compared to BZN, derivative 8 showed a higher rate of conversion by nitroreductase and was metabolized three times more quickly when both compounds were tested at a concentration of 50 µM. The results obtained by the enzymatic evaluation and molecular docking studies suggest that, as planned, nitroazole derivatives may utilize the nitroreductase metabolism pathway as their main mechanism of action against Trypanosoma cruzi. In summary, we have successfully identified and characterized new nitrotriazole analogs, demonstrating their potential as promising candidates for the development of Chagas disease drug candidates that function via nitroreductase activation, are considerably selective and show no mutagenic potential.

Antiplasmodial, Trypanocidal, and Genotoxicity In Vitro Assessment of New Hybrid α,α-Difluorophenylacetamide-statin Derivatives

BACKGROUND

Statins present a plethora of pleiotropic effects including anti-inflammatory and antimicrobial responses. A,α-difluorophenylacetamides, analogs of diclofenac, are potent pre-clinical anti-inflammatory non-steroidal drugs. Molecular hybridization based on the combination of pharmacophoric moieties has emerged as a strategy for the development of new candidates aiming to obtain multitarget ligands.

METHODS

Considering the anti-inflammatory activity of phenylacetamides and the potential microbicidal action of statins against obligate intracellular parasites, the objective of this work was to synthesize eight new hybrid compounds of α,α-difluorophenylacetamides with the moiety of statins and assess their phenotypic activity against in vitro models of Plasmodium falciparum and Trypanosoma cruzi infection besides exploring their genotoxicity safety profile.

RESULTS

None of the sodium salt compounds presented antiparasitic activity and two acetated compounds displayed mild anti-P. falciparum effect. Against T. cruzi, the acetate halogenated hybrids showed moderate effect against both parasite forms relevant for human infection. Despite the considerable trypanosomicidal activity, the brominated compound revealed a genotoxic profile impairing future in vivo testing.

CONCLUSIONS

However, the chlorinated derivative was the most promising compound with chemical and biological profitable characteristics, without presenting genotoxicity in vitro, being eligible for further in vivo experiments.

In silico and in vitro assessment of anti-Trypanosoma cruzi efficacy, genotoxicity and pharmacokinetics of pentasubstituted pyrrolic Atorvastatin-aminoquinoline hybrid compounds

Atorvastatin (AVA) is a third-generation statin with several pleiotropic effects, considered the last synthetic pharmaceutical blockbuster. Recently, our group described the effects of AVA on DNA damage prevention and against Trypanosoma cruzi infection. In this study, our aim was to evaluate the efficacy, safety, and in silico pharmacokinetic profile of four hybrids of aminoquinolines with AVA 4a-d against T. cruzi using in vitro and in silico models. These synthetic compounds were designed by hybridization of the pentapyrrolic moiety of AVA with the aminoquinolinic unit of chloroquine or primaquine. Pharmacokinetics (ADME) and toxicity parameters were predicted by SwissADME, admetSAR and LAZAR in silico algorithms. The trypanocidal activity of AVA-quinoline hybrids were evaluated in vitro against amastigotes and trypomastigotes of T. cruzi, from Y (Tc II) and Tulahuen (Tc VI) strains. In vitro cardiocytotoxicity was assessed using primary cultures of mouse embryonic cardiac cells and in vitro hepatocytotoxicity on bidimensional and 3D-cultured HepG2 cells. Genotoxicity was evaluated by Ames test and micronucleus assay. Despite the overall good in silico ADMET profile, all tested compounds were predicted to be hepatotoxic. All hybrid derivatives presented high trypanocidal activity, against both trypomastigote and intracellular forms of T. cruzi, presenting EC₅₀'s lower than 1 µM besides superior selectivity than the reference drug, without evidences of cardiotoxicity in vitro. The compounds 4a and 4b presented a time-dependent toxicity in monolayer culture of HepG2 but no detectable toxic effects in their spheroids, opposing to the in silico prediction. We can conclude that the AVA-aminoquinoline hybrids presented a hit profile as antiparasitic agents in synthetic pharmaceutical innovation platforms.

Antioxidant Capacity, Antitumor Activity and Metabolomic Profile of a Beetroot Peel Flour

In this study, a beetroot peel flour was made, and its in vitro antioxidant activity was determined in aqueous (BPFw) and ethanolic (BPFe) extracts. The influence of BPFw on breast cancer cell viability was also determined. A targeted betalain profile was obtained using high-resolution Q-Extractive Plus Orbitrap mass spectrometry (Obrtitrap-HRMS) alongside untargeted chemical profiling of BPFw using Ultra-High-Performance Liquid Chromatography with High-Resolution Mass Spectrometry (UHPLC-HRMS). BPFw and BPFe presented satisfactory antioxidant activities, with emphasis on the total phenolic compounds and ORAC results for BPFw (301.64 ± 0.20 mg GAE/100 g and 3032.78 ± 55.00 µmol T/100 g, respectively). The MCF-7 and MDA-MB-231 breast cancer cells presented reductions in viability when treated with BPFw, showing dose-dependent behavior, with MDA-MB-231 also showing time-dependent behavior. The chemical profiling of BPFw led to the identification of 9 betalains and 59 other compounds distributed amongst 28 chemical classes, with flavonoids and their derivates and coumarins being the most abundant. Three forms of betalain generated via thermal degradation were identified. However, regardless of thermal processing, the BPF still presented satisfactory antioxidant and anticancer activities, possibly due to synergism with other identified molecules with reported anticancer activities via different metabolic pathways.

In vitro genotoxicity assessment of graphene quantum dots nanoparticles: A metabolism-dependent response

Nanomaterials are progressively being applied in different areas, including biomedical uses. Carbon nanomaterials are relevant for biomedical sciences because of their biocompatibility properties. Graphene quantum dots (GQD) have a substantial potential in drug-delivery nanostructured biosystems, but there is still a lack of toxicological information regarding their effects on human health and the environment. We thus evaluated the mutagenicity, cytotoxicity and genotoxicity of this nanomaterial using alternative methods applied in regulatory toxicology guidelines. The Ames test was carried out in the presence and absence of exogenous metabolization. Salmonella enterica serovar Typhimurium strains TA97a, TA98, TA100, TA102, TA104, and TA1535 were exposed to GQD with concentrations ranging from 1 to 1000 μg/plate. The mammal cell viability assays were carried out with HepG2 and 3T3BalbC cell lineages and the in vitro Cytokinesis-Block Micronucleus assay (CBMN) was applied for 24 h of exposure in non-cytotoxic concentrations. Mutagenicity was induced in the TA97a strain in the absence of exogenous metabolization, but not in its presence. Mutagenicity was also detected in the TA102 strain in the assay with exogenous metabolization, suggesting redox misbalance mutagenicity. The WST-1 and LDH assays demonstrated that GQD decreased cell viability, especially in 3T3BalbC cells, which showed more sensitivity to the nanomaterial. GQD also increased micronuclei formation in 3T3BalbC and caused a cytostatic effect. No significant impact on HepG2 micronuclei formation was observed. Different metabolic systems interfered with the mutagenic, cytotoxic, and genotoxic effects of GQD, indicating that liver metabolism has a central role in the detoxification of this nanomaterial.

Toxicogenetic assessment of a pre-workout supplement: In vitro mutagenicity, cytotoxicity, genotoxicity and glutathione determination in liver cell lines and in silico ADMET approaches

The benefits of practicing physical activity, such as weight loss and control, are commonly associated with caloric restriction diets and may be improved by the ingestion of thermogenic and ergogenic supplements. However, there is a lack of safety data on commonly marketed nutritional supplements. Therefore, this investigation aims to evaluate a pre-workout supplement for mutagenicity using the Ames test, hepatocytoxicity in HepG2 and F C3H cells after 24 h, 48 h and 72 h, genotoxicity using the CBMN assay, determination of gluthatione activity and computational prediction of the three major isolated compounds present in the supplement. The mutagenicity test showed a mutagenic response in TA98 His⁺ revertants of 5 mg/plate in the presence of metabolic activation, cytotoxicity in TA98 of 5 mg/plate in the absence of metabolic conditions, and in TA102 of 0.5 mg/plate both in the presence and absence of metabolic activation. In our in vitro eukaryotic cell viability, WST-1, LDH and alkaline phosphatase assays, the supplement showed hepatocytotoxicity both dose-dependently and time-dependently. In the cytokinesis blocking micronuclei assay, the supplement induced micronuclei, nuclear buds, nucleoplasmatic, bridge formation, and a decreased in nuclear division. In addition, the supplement decreased intra and extracellular GSH. Computational analysis showed that the three isolated compounds most present in the supplement have the potential to cause hepatotoxicity. In the present investigation, the pre-workout supplement induced mutagenic, genotoxic, and cytotoxic responses and GSH decrease. Thus, considering food safety and public health sanitary vigilance, the consumption of this pre-workout supplement may harm the health of its consumers.

In vitro and in vivo cytotoxicity assessment of glyphosate and imazethapyr-based herbicides and their association

Resistance to glyphosate herbicide has initiated usage of combined application of herbicides as a weed control measure. Imazethapyr-based herbicides associated with glyphosate herbicide seem to be an alternative to suppress weed resistance. The aim of this study was to examine the adverse effects of Glyphosate Atanor 48® (ATN) and Imazethapyr Plus Nortox® (IMZT) formulations in both single forms and mixtures using HepG2 cells and zebrafish early-life stages models. Data demonstrated cytotoxicity due to exposure to ATN, IMZT for both models, as follows: (1) ATN (0.5 mg/L), IMZT (5 mg/L), and M3 (0.05 mg/L ATN + 5 mg/L IMZT) increased cytotoxicity by disturbing the mitochondrial activity of HepG2 cells 24 hr after exposure; (2) ATN and IMZT (5 mg/L), and M3 (0.05 mg/L ATN + 5 mg/L IMZT) also decreased the integrity of the membrane of HepG2 cells after 24 hr incubation; (3) only ATN and IMZT (5 mg/L) in their single forms diminished the mitochondrial potential of zebrafish; (4) ATN (single form) at 0.5 mg/L induced apoptosis in zebrafish larvae. In conclusion, these herbicides in their single forms appeared to produce greater cytotoxicity to HepG2 cells and zebrafish compared to the herbicide mixtures.

A novel naphthoquinone derivative shows selective antifungal activity against Sporothrix yeasts and biofilms

Sporotrichosis is a subcutaneous mycosis that affects humans and animals, with few therapeutic options available in the pharmaceutical market. We screened the in vitro antifungal activity of fourteen 1,4-naphthoquinones derivative compounds against Sporothrix brasiliensis and Sporothrix schenckii, the main etiological agents of sporotrichosis in Latin America. The most active compound was selected for further studies exploring its antibiofilm activity, effects on yeast morphophysiology, interaction with itraconazole, and selectivity to fungal cells. Among the fourteen 1,4-naphthoquinones tested, naphthoquinone 5, a silver salt of lawsone, was the most active compound. Naphthoquinone 5 was able to inhibit Sporothrix biofilms and induced ROS accumulation, mitochondrial disturbances, and severe plasmatic membrane damage in fungal cells. Furthermore, naphthoquinone 5 was ten times more selective towards fungal cells than fibroblast, and the combination of itraconazole with naphthoquinone 5 improved the inhibitory activity of the azole. Combined, the data presented here indicate that the silver salt naphthoquinone 5 exerts promising in vitro activity against the two main agents of sporotrichosis with important antibiofilm activity and a good toxicity profile, suggesting it is a promising molecule for the development of a new family of antifungals.

Plinia cauliflora (Mart.) Kausel (Jaboticaba) leaf extract: In vitro anti-Trypanosoma cruzi activity, toxicity assessment and phenolic-targeted UPLC-MSE metabolomic analysis

ETHNOPHARMACOLOGICAL RELEVANCE

Plinia cauliflora (Mart.) Kausel, known as Brazilian grape or jaboticaba, is widely used in Brazilian traditional medicine to treat infectious and inflammatory disorders. However, several aspects of its biological potential remain unclear, such as toxicity and effects on pathogenic protozoa.

AIM OF THE STUDY

Investigate the phenolic composition, the in vitro and in silico toxicity profile, and the anti-Trypanosoma cruzi activity of the phenolics-enriched hydromethanolic extract of P. cauliflora leaf.

MATERIAL AND METHODS

Phytochemical analysis was performed ultra-performance liquid chromatography-mass spectrometry (UPLC-MS^E). Mutagenicity, genotoxicity and eukaryotic cytotoxicity was evaluated by Ames test, cytokinesis-block micronucleus and colorimetric assays, respectively, alongside with a computational prediction of the major compound's pharmacokinetics and toxicity. Anti-T. cruzi activity was investigated on T. cruzi bloodstream trypomastigotes.

RESULTS

A total of 14 phenolic compounds were identified, including 11 flavonoids and 2 phenolic acids. No positive response regarding mutagenic potential was detected in Salmonella strains TA97, TA98, TA100, TA102, TA104, both in absence or presence of metabolic activation. The extract induced significant dose-response reduction on nuclear division indexes of HepG2 cells, suggesting cytostatic effects, with no micronuclei induction on cytokinesis-block micronucleus assay. Likewise, it also presented cytotoxic effects, inducing HepG2 and F C3H dose and time dependently cell death through cell membrane damage and more evidently by mitochondrial dysfunction. A dose-response curve of in vitro trypanocidal activity was observed against T. cruzi bloodstream trypomastigotes after 2 and 24 h of exposure. In silico predictions of most abundant compounds' structural alerts, pharmacokinetics and toxicity profile indicates a moderately feasible druglikeness profile and low toxicity for them, which is compatible with in vitro results.

CONCLUSIONS

The present study demonstrated that P. cauliflora leaf extract is a potential source of antiparasitic bioactive compounds, however it presents cytotoxic effects in liver cell lines.

In vitro biochemical characterization and genotoxicity assessment of Sapindus saponaria seed extract

ETHNOPHARMACOLOGICAL RELEVANCE

Sapindus saponaria, also popularly known as soapberry, has been used in folk medicinal values because of its therapeutic properties and several compounds in its composition, which represent a target in potential for drug discovery. However, few data about its potential toxicity has been reported.

AIM OF THE STUDY

Plant proteins can perform essential roles in survival, acting as defense mechanism, as well functioning as important molecular reserves for its natural metabolism. The aim of the current study was to investigate the in vitro toxicity profile of protein extract of S. saponaria and detect protein potentially involved in biological effects such as collagen hydrolysis and inhibition of viral proteases.

MATERIALS AND METHODS

Protein extract of soapberry seeds was investigated for its cytotoxic and genotoxic action using the Ames test. The protein extract was also subjected to a partial purification process of a protease and a protease inhibitor by gel chromatography filtration techniques and the partially isolated proteins were characterized biochemically.

RESULTS

Seed proteins extract of S. saponaria was evaluated until 100 μg/mL concentration, presenting cytotoxicity and mutagenicity in bacterial model mostly when exposed to exogenous metabolic system and causing cytotoxic and genotoxic effects in HepG2 cells. The purification and partial characterization of a serine protease (43 kDa) and a cysteine protease inhibitor (32.8 kDa) from protein extract of S. Saponaria, corroborate the idea of ​​the biological use of the plant as an insecticide and larvicide. Although it shows cytotoxic, mutagenic and genotoxic effects.

CONCLUSION

The overall results of the present study provide supportive data on the potential use of proteins produced in S. saponaria seeds as pharmacological and biotechnological agents that can be further explored for the development of new drugs.

Risk assessment of coffees of different qualities and degrees of roasting

During the coffee beans roasting process, occurs the formation of polycyclic aromatic hydrocarbons, which are associated with the incidence of cancer in humans. This study aimed to evaluate the influence of coffee bean quality and roasting degree regarding mutagenicity, cytotoxicity and genotoxicity. Six samples of coffee drink made with roasted and ground Coffea arabica beans from different qualities and roast degrees were used after freeze-drying. Both commercial and special quality grains suffered light, medium and dark roasting. According to the Salmonella/microsome assay, the highest concentration of commercial grain sample (dark roast) significantly increased the number of revertants of the TA98 strain in the absence of metabolization. All the samples induced cytotoxicity to HepG2 cells. These effects can be ranked in the following order from most to least toxic: medium roast - special grain > light roast - special grain > dark roast - commercial grain > dark roast - special grain > light roast - commercial grain > medium roast - commercial grain. None of the samples induced genotoxicity in HepG2 cells. Our findings show that the harmful effects of coffee depend not only on the degree of roasting but also on the grain quality.

Nanotechnology activities: environmental protection regulatory issues data

Nanotechnology is a fascinating technology that is revolutionizing science and bringing countless benefits to the population. The economic side linked to nanotechnology has grown in recent years, as have the lines of research. However, nanoparticles can be toxic when released into the environment. In this work, a scientometric study was carried out in order to identify and describe scientific research on environmental protection involving nanotechnology with respect to regulatory studies. The research period was from 2003 to 2020, the database selected was Scopus and the software used for the study was Microsoft Excel and VOSviewer. According to specified keywords, the result presented by Scopus was a total of 106 publications. The clustering figures shown by VOSviewer showed that nanotoxicity studies were mostly aimed at protecting human health, to the detriment of environmental protection. Another interesting fact is that toxicity of nanomaterials has been studied from the perspective of risk assessment, including by the regulatory sector.

Metabolomic analysis of Cyrtopodium glutiniferum extract by UHPLC-MS/MS and in vitro antiproliferative and genotoxicity assessment

ETHNOPHARMACOLOGICAL RELEVANCE

Extracts of orchids have been traditionally used as human phytotherapeutics. Cyrtopodium flavum, for example, due to the analgesic and anti-inflammatory properties, beside the capacity of heal skin lesions has been focus of research. Also Cyrtopodium glutiniferum, an orchid found in the Brazilian southeastern rainforest, is known to synthesize anti-inflammatory glucomannans in the pseudobulbs, as other potentially therapeutic compounds.

AIM OF THE STUDY

We have reported the first metabolomic analysis focused on the phenols expression of the neotropical orchid Cyrtopodium glutiniferum Raddi, besides free radical scavenging, anti-inflammatory and antiproliferative activities, and the genotoxicity properties of the aqueous extract.

MATERIAL AND METHODS

The metabolomics of C. glutiniferum aqueous extract was performed through UHPLC-MSⁿ acquisition. We have detected the scavenging potential of the extract using DPPH assay. The genotoxic potential was performed by Ames Test (0-5000 μg mL^-1) and micronucleous assay (0-5000 μg mL^-1) in RAW264.7 cells. The cytotoxic potential of the extract against RAW264.7 was tested by WST-1 assay (0-500 μg mL^-1). And after all, the RAW264.7 cells were treated with non-cytotoxic concentrations of C. glutiniferum (0-50 μg mL^-1) to evaluate the antiproliferative and anti-inflammatory potential, besides the mitochondrial activity.

RESULTS

From the 55 molecules identified, 45.5% belonged to the phenolic compounds database from Phenol Explorer, 29% to an in-house Orchidaceae molecules database, and 25.5% to both. Among the identified phenolic compounds, 18 subclasses were discriminated, being phenanthrenes the most abundant. Doses-dependent of C. glutiniferum extracts were able to induce DPPH free radicals scavenging and also to increase TA100 His⁺ revertants, in metabolic environment, showing mutagenicity just in the highest concentration, of 5 mg/plate. On Eukaryotic cell models, the extract also has induced dose-response and time-response cytotoxicity against RAW264.7 macrophages, mainly after 48 h and 72 h, even though the extract has not been able to induce the increase of micronucleated cells and mitotic index alteration on Micronucleus assay. The activation and proliferation of macrophages cultures were downregulated after 24 h and 48 h by the non-cytotoxic concentrations of the extract in a dose-dependent manner.

CONCLUSIONS

The Cyrtopodium glutiniferum metabolomics, anti-inflammatory and anti-proliferative properties observed in this study suggest a therapeutic efficacy of the orchid extract applied in folk medicine.

Anti-inflammatory potential of invasive sun corals (Scleractinia: Tubastraea spp.) from Brazil: alternative use for management?

OBJECTIVES

The objective was to analyse the anti-inflammatory potential of the invasive coral species Tubastraea coccinea and Tubastraea tagusensis.

METHODS

Methanolic extracts, fractions and synthesized compounds were evaluated for their anti-inflammatory ability, and their composition was elucidated through chemical analysis.

KEY FINDINGS

The genus Tubastraea (Order Scleractinia, Family Dendrophylliidae) (known as sun corals) presents compounds with pharmacological value. The introduction of these azooxanthellate hard corals into Brazil, initially in Rio de Janeiro state, occurred through their fouling of oil and gas platforms from the Campos oil Basin. The two invasive species have successfully expanded along the Brazilian coast and threaten endemic species and biodiversity. The HPLC-MS and GC-MS data suggest the presence of aplysinopsin analogues (alkaloids). Anti-inflammatory activity was observed in all samples tested in in-vivo assays, especially in T. coccinea. The ethyl acetate fraction from this sample was more effective in in-vitro assays for anti-inflammatory activity. Depending on the concentration, this fraction showed cytotoxic responses.

CONCLUSIONS

These species have potential pharmacological use, and considering their invasive nature, this study presents a potential alternative use, which may enhance the management of this biological invasion.

Evaluation of the acute toxicity, phototoxicity and embryotoxicity of a residual aqueous fraction from extract of the Antarctic moss Sanionia uncinata

Background

Ultraviolet (UV) radiation is the main exogenous inductor of skin damage and so photoprotection is important to control skin disorders. The Antarctic moss Sanionia uncinata is an important source of antioxidants and the photoprotective activity of its organic extracts has been investigated. This study aimed to evaluate the potential photoprotection, cytotoxicity and embryotoxicity of residual aqueous fraction (AF) from the moss S. uncinata.

Methods

UV-visible spectrum and SPF (sun protection factor) were determined by spectrophotometry. Embryotoxicity potential was evaluated by Fish embryo-larval toxicity test using zebrafish (Danio rerio) as organism model. Cell death assays by water-soluble tetrazolium salt (WST-1) and lactate dehydrogenase (LDH) were investigated using HaCaT keratinocyte cell line cultured in monolayers and three dimensions (3D). Phototoxicity and association with UV-filters were performed by 3T3 neutral red uptake test.

Results

The AF showed sharp absorption bands in the UV region and less pronounced in the visible region. The SPF was low (2.5 ± 0.3), but the SPF values of benzophenone-3 and octyl-methoxycinnamate increased ~ 3 and 4 times more, respectively, in association with AF. The AF did not induce significant lethal and sublethal effects on zebrafish early-life stages. In monolayers, the HaCaT cell viability, evaluated by WST-1, was above 70% by ≤0.4 mg AF/mL after 48 and 72-h exposure, whereas ≤1 mg AF/mL after 24-h exposure. The LDH assay showed that the cell viability was above 70% by ≤0.4 mg AF/mL even after 72-h exposure, but ≤1 mg/mL after 24 and 48-h exposure. In 3D cell culture, an increased cell resistance to toxicity was observed, because cell viability of HaCaT cell by WST-1 and LDH was above ~ 90% when using ≤1 and 4 mg AF/mL, respectively. The AF demonstrated values of photo irritation factor < 2 and of photo effect < 0.1, even though in association with UV-filters.

Conclusions

The residual AF absorbs UV-vis spectrum, increased SPF values of BP-3 and OMC and does not induce embryotoxicity to zebrafish early life-stage. The cell death assays allowed establishing non-toxic doses of AF and phototoxicity was not detected. AF of S. uncinata presents a good potential for skin photoprotection against UV-radiation.

Mutagenic, genotoxic and cytotoxic studies of invasive corals Tubastraea coccinea and Tubastraea tagusensis

The high diversity of species in the marine environment gives rise to compounds with unique structural patterns not found as natural products in other systems and with great potential for pharmacological, cosmetic and nutritional use. The genus Tubastraea (Class Anthozoa, Order Scleractinia, Family Dendrophylliidae) is characterized as a hard coral without the presence of zooxanthellae. In species of this genus alkaloids derived from the compound aplysinopsin with pharmacological activity are known. In Brazil T. coccinea and T. tagusensis are characterized as non-indigenous and invasive and are currently found along the Brazilian coast, from Santa Catarina to Bahia states. This study aims to analyze the mutagenic, cytotoxic and genotoxic potential of methanolic and ethanolic extracts from T. coccinea and T. tagusensis collected in Ilha Grande Bay, Rio de Janeiro state, Brazil. Bacterial reverse mutation assay on the standard strains TA97, TA98, TA100, TA102 and TA104, in vitro micronucleus formation test and colorimetric assays for cytotoxic signals on the cell lines HepG2 and RAW264.7 were used. We also synthesized an oxoaplysinopsin derivate alkaloid (APL01) for comparative purposes. No mutagenic (250; 312.5; 375; 437.5 and 500 μg/plate) or genotoxic (0.05; 0.5; 5.0; 50 and 500 μg/mL) effects were observed in any sample tested for all measured concentrations. Cytotoxic responses were observed for eukaryotic cells in all tested samples at 500 and 5000 μg/mL concentrations. Cytotoxicity found in the WST-1 assay was independent of the metabolism of substances present in samples compositions. The cytotoxicity observed in the LDH release assay depended on metabolism.

Toxicological evaluation of nail polish waste discarded in the environment

Nail polish has been widely used around the world. However, the hazards of nail polishes discarded in the environment are still poorly investigated. Thus, the toxicogenetic effects of solubilized (SE) and leached (LE) extracts from nail polishes were investigated, simulating their disposal on water and landfill, respectively, and identifying their physicochemical properties and chemical constituents. Organic compounds and metals were detected in both extracts. SE and LE only induced mutagenic effects in TA98 Salmonella strain in the presence and absence of exogenous metabolic activation. Although both extracts did not significantly increase the frequency of micronucleated HepG2 cells, the cell viability was affected by 24-h exposure. No DNA damage was observed in gonad fish cells (RTG-2) exposed to both extracts; however, the highest SE and LE concentrations induced significant lethal and sublethal effects on zebrafish early-life stages during 96-h exposure. Based on our findings, it can be concluded that if nail polishes enter aquatic systems, it may cause negative impacts to the environment.

Protection against UV-induced oxidative stress and DNA damage by Amazon moss extracts

Amazon mosses, such as Holomitriopsis laevifolia and Leucobryum sp. are naturally exposed to high levels of solar ultraviolet (UV) radiation. Theoretically, under environmental stress conditions these mosses have developed protective chemical and metabolic strategies against UV damage, by way of biosynthesis of secondary metabolites, such as flavonoids. The present paper aimed to evaluate the free-radical scavenging activity, and the photoprotective, mutagenic and photomutagenic potencies of the methanolic (ME), aqueous (AE), hydroalcoholic (HE), ethanolic (EE) extracts of H. laevifolia and Leucobryum sp. The phenolic contents were evaluated by spectrophotometry and by High-Performance Liquid Chromatography (HPLC). The present findings showed that the AE and HE of H. laevifolia and the AE of Leucobryum sp. presented the highest phenolic contents. The HPLC analysis indicated the presence mainly of phenolic and cinnamic acids, flavonols, flavones and flavanones. The AE and EE of H. laevifolia and the AE and HE of Leucobryum sp. efficiently scavenged the 2,2'-diphenyl-1-picrylhydrazyl (DPPH) radical. All extracts showed significant values of in vitro Sun Protection Factor alone, and HE of Leucobryum sp. showed a synergistic effect in association with benzophenone-3. None of the extracts induced mutagenicity in the auxotrophic strains for histidine of Salmonella typhimurium, and photomutagenicity of the TA102 and TA104 strains was not detected after exposure to UV-A radiation. Besides, all extracts showed photoprotective activity against UV-A radiation for the TA104 strain, including synergistic protection in association with BP-3. Thus, the constituents in H. Laevifolia and Leucobryum sp. could be good candidates for cosmetic and dermatological applications, particularly in association with synthetic UV filters, since the concentration of the filters in the final product could be reduced.

New hydrazides derivatives of isoniazid against Mycobacterium tuberculosis: Higher potency and lower hepatocytotoxicity

Tuberculosis (TB) is one of the leading causes of death worldwide. The emergence of multi-drug resistant strains of Mycobacterium tuberculosis (Mtb) and TB-HIV co-infection are major public health challenges. The anti-TB drugs of first choice were developed more than 4 decades ago and present several adverse effects, making the treatment of TB even more complicated and the development of new chemotherapeutics for this disease imperative. In this work, we synthesized two series of new acylhydrazides and evaluated their activity against different strains of Mtb. Derivatives of isoniazid (INH) showed important anti-Mtb activity, some being more potent than all anti-TB drugs of first choice. Moreover, three compounds proved to be more potent than INH against resistant Mtb. The Ames test showed favorable results for two of these substances compared to INH, one of which presented expressly lower toxicity to HepG2 cells than that of INH. This result shows that this compound has the potential to overcome one of the main adverse effects of this drug.

Impacts of discarded coffee waste on human and environmental health

Coffee is one of the most widely consumed beverages throughout the world. So far, many studies have shown the properties of coffee beverages, but little is known about its impacts on human and environmental health from its discard in the environment. So, the present work aims to investigate the mutagenic, genotoxic, cytotoxic and ecotoxic effects of leached (LE) and solubilized (SE) extracts from coffee waste, simulating the disposal of this residue in landfills and via sewage systems, respectively. Chemical analyses were also carried out. LE and SE induced mutagenicity in the TA98 Salmonella strain with and without exogenous metabolization (S9). In the TA100 only SE induced mutagenicity, what was observed without S9. An increase in the frequency of micronuclei was observed in HepG2 cell line after 3 and 24h of exposure to both extracts. No cytotoxic effects were observed in HepG2 cells by WST-1 assay. The EC50 values for the LE and SE were 1.5% and 11.26% for Daphnia similis, 0.12% and 1.39% for Ceriodaphnia dubia and 6.0% and 5.5% for Vibrio fischeri, respectively. Caffeine and several transition metals were found in both extracts. Coffee waste discarded in the environment may pose a risk to human and environmental health, since this compound can cause DNA damage and present toxicity to aquatic organisms.

Investigation of the mutagenic and genotoxic activities of LLL-3, a STAT3 inhibitor

LLL-3, an anthracene derived compound, has been shown to be a promising therapeutic agent for the treatment of some kinds of cancer such as chronic myeloid leukemia and glioblastoma. However, no data regarding the toxic properties of this compound have yet been described in the literature. The present work aimed to investigate the mutagenic and genotoxic activities of LLL-3 using the TA97, TA98, TA100, TA102 and TA104 Salmonella/microsome strains for the Ames test and the micronucleus assay with the mouse macrophage cell line RAW 264.7. The findings showed that LLL-3, at doses of 0.001, 0.01, 0.1, 1.0 and 10.0 μg/plate, did not induce mutagenic activity in the Salmonella strains used under the conditions tested, and nor did it present genotoxicity in RAW 264.7 cells, at 10.0, 100.0 and 1000.0 μg/mL doses. Moreover, it is important to point out that the mitotic index of the cells decreased after exposure to LLL-3 under the same conditions tested, which may suggest some cytostatic effect, since this compound acts by inhibiting STAT3. Since most drugs used in the treatment of cancer present mutagenic activity as an adverse effect, these results suggest that LLL-3 is a promising drug for cancer therapy.

Pharmacokinetic and Toxicological Evaluation of a Zinc Gluconate-Based Chemical Sterilant Using In Vitro and In Silico Approaches

Sclerosing agents as zinc gluconate-based chemical sterilants (Infertile®) are used for chemical castration. This solution is injected into the animal testis, but there are not enough evidences of its safety profiles for the receivers. The present work aimed to establish the pharmacokinetics and toxicological activity of Infertile, using in vitro and in silico approaches. The evaluation at the endpoint showed effects in a dose-dependent manner. Since necrosis is potentially carcinogenic, the possible cell death mechanism could be apoptosis. Our data suggested that Infertile at 60 mM presented risk for animal health. Even though Infertile is a licensed product by the Brazilian Ministry of Agriculture, Livestock and Supply, it presented a high mutagenic potential. We suggest that the optimal dose must be less than 6 mM, once, at this concentration, no mutagenicity or genotoxicity was observed.

Differential toxicity of an organic PM2.5 extract to human lung cells cultured in three dimensions (3D) and monolayers

Several epidemiological studies have associated PM2.5 (particulate matter, aerodynamic diameter 2.5 µm) exposure with an increase in morbidity and mortality attributed to cardiopulmonary diseases. Based upon these observations and the growing effort to replace the use of animals in research, in vitro A549 cells cultured in three dimensions (3D), an alternative method to the use of animals, as well as monolayers were investigated to examine whether organic PM2.5 extract induced equivalent cytotoxic changes in vitro as compared to in vivo. PM2.5 was collected on Brazil Avenue, Rio de Janeiro, Brazil, from November 2010 to May 2011, except March, and analyzed for the ability to induce cytotoxicity in A549 cells using various established assays. Samples collected in all months significantly decreased viability of A549 cells using both types of cell death assays, and those collected in November showed lower cytotoxicity. It is worthwhile noting that for samples collected in all months except for April, PM2.5 induced greater toxicity in cells grown in monolayers than in 3D. Data demonstrated that cell behavior varied based upon type of culture system employed. Since the 3D cell culture mimics the architecture of in vivo tissue to a greater extent than monolayers, it is suggested that data from 3D studies resemble more closely human exposure conditions and thus may provide more reliable findings to be utilized in risk assessment following PM exposure than results obtained in traditional culture system.

Studies of genotoxicity and mutagenicity of nitroimidazoles: demystifying this critical relationship with the nitro group

Nitroimidazoles exhibit high microbicidal activity, but mutagenic, genotoxic and cytotoxic properties have been attributed to the presence of the nitro group. However, we synthesised nitroimidazoles with activity against the trypomastigotes of Trypanosoma cruzi, but that were not genotoxic. Herein, nitroimidazoles (11-19) bearing different substituent groups were investigated for their potential induction of genotoxicity (comet assay) and mutagenicity (Salmonella/Microsome assay) and the correlations of these effects with their trypanocidal effect and with megazol were investigated. The compounds were designed to analyse the role played by the position of the nitro group in the imidazole nucleus (C-4 or C-5) and the presence of oxidisable groups at N-1 as an anion receptor group and the role of a methyl group at C-2. Nitroimidazoles bearing NO2 at C-4 and CH3 at C-2 were not genotoxic compared to those bearing NO 2 at C-5. However, when there was a CH3 at C-2, the position of the NO2 group had no influence on the genotoxic activity. Fluorinated compounds exhibited higher genotoxicity regardless of the presence of CH3 at C-2 or NO2 at C-4 or C-5. However, in compounds 11 (2-CH3; 4-NO2; N-CH2OHCH2Cl) and 12 (2-CH3; 4-NO2; N-CH2OHCH2F), the fluorine atom had no influence on genotoxicity. This study contributes to the future search for new and safer prototypes and provide.

Photoprotective and toxicological activities of extracts from the Antarctic moss Sanionia uncinata

Background:

The Antarctic moss Sanionia uncinata (Hedw.) Loeske has shown high ultraviolet (UV)-absorbers content after exposition to high levels of UV-B radiation and can be an important source of antioxidants.

Objective:

The aim was to investigate photoprotection and mutagenicity by the aqueous extract (AE) and hydroethanolic extract (HE) from the Antarctic moss S. uncinata.

Materials and Methods:

Photoprotective activities were determined through survival curves of Escherichia coli strains, after UV irradiation in an aqueous solution of thymine and in vitro sun protection factor (SPF). The Salmonella/microsome assays were applied to assess the mutagenicity.

Results:

Both extracts induced photoprotection against UV-C radiation. The AE showed a higher protection than the hydroethanolic one against UV-induced thymine dimerization. The SPFs were low in both extracts. In association to benzophenone-3 a significant increase in the SPF was detected for the AE, and a significant decrease was induced by the HE. No mutagenicity was found in the both extracts. Furthermore, it was observed absence of cytotoxicity.

Conclusion:

Water-extractable compounds seem to contribute on photoprotection of this Antarctic moss.

Reactive oxygen species mediate lethality induced by far-UV inEscherichia colicells

The involvement of reactive oxygen species (ROS) in the induction of DNA damage to Escherichia coli cells caused by UVC (254 nm) irradiation was studied. We verified the expression of the soxS gene induced by UVC (254 nm) and its inhibition by sodium azide, a singlet oxygen (1O2) scavenger. Additional results showed that a water-soluble carotenoid (norbixin) protects against the lethal effects of UVC. These results suggest that UVC radiation can also cause ROS-mediated lethality.

Genotoxicity of polycyclic aromatic hydrocarbons and nitro-derived in respirable airborne particulate matter collected from urban areas of Rio de Janeiro (Brazil)

Air pollution toxic effects are mainly attributed to small inhalable particulates with an aerodynamic diameter of less than 2.5 µ m (PM 2.5). Our objective was to investigate mutagenic and clastogenic activity in PM samples collected in Rio de Janeiro. Samples were collected using a high-volume sampler at three sites: with low traffic and (2) and (3) with a heavy traffic. Six polycyclic aromatic hydrocarbons (PAHs) were quantified by gas chromatography/mass spectrometry (GC/MS). Salmonella typhimurium TA98 and the derivative strains YG1021 and YG1024 were used in mutagenicity assays in the presence of organic extracts (10-50 µ g/ plate) with and without exogenous metabolization. Allium cepa test was performed to evaluate possible cytotoxic and clastogenic activities. The highest PM 2.5 µ m (132.73 µ m/m(3)) and PAH values (1.22 ng/m(3) for benzo(a)pyrene) were detected at site 3. High mutagenic frameshift responses in absence and presence of metabolic activation were detected at site 3. The participation of nitroarenes and dinitroarenes was detected in the total mutagenicity of the extracts studied. The cytotoxic effect and the abnormalities detected by Allium cepa test can be attributed to the PAH nitroderivatives in the organic extracts. Evaluation of the genotoxicity of urban airborne particulate matter is important as a basis for decision making by regulatory authorities.

Prediction of health risk due to polycyclic aromatic hydrocarbons present in urban air in Rio de Janeiro, Brazil

Risk assessment can provide a comprehensive estimate of potential effects of contaminants under specific, well-defined, and well-described circumstances, providing quantitative relationships between exposure and effects to identify and to define areas of concern. We investigated the mutagenic activity of particulate matter in air samples collected from three sites in Rio de Janeiro city. Samples were collected using a high-volume sampler at Avenida Brasil, at Campus of Universidade do Estado do Rio de Janeiro, and at Rebouças Tunnel. Six polycyclic aromatic hydrocarbons were quantified by gas chromatography/mass spectrometry. Salmonella typhimurium TA98 and the derivative strains TA98/1.8-DNP(6), YG1021, and YG1024, commonly used in mutagenicity assays, were treated (10-50 µg/plate), with and without exogenous metabolization. The highest values for the polycyclic aromatic hydrocarbons were detected at Rebouças Tunnel. For chrysene, as an example, the concentration was nearly 200 times higher than that established by the US Environmental Protection Agency. Frequent traffic jams can place bus drivers who go through the Rebouças Tunnel at risk of exposure to up to 0.69 ng/m(3) benzo(a) pyrene. Independent of exogenous metabolization, mutagenicity was detected in strains YG1021 and YG1024 at all the sites, suggesting nitro and amino derivatives of polycyclic aromatic hydrocarbons. Rebouças Tunnel air samples gave the highest values for rev/µg and rev/m(3). This could be due to the fact that the long, enclosed passageway through a mountain restricts ventilation. The cancer risk estimate in this study was 10(-3) for the benzo(a)pyrene, at the two sites, indicating a high risk.

The role of Fpg protein in UVC-induced DNA lesions

We previously demonstrated that reactive oxygen species (ROS) could be involved in ultraviolet-C (UVC)-induced DNA damage in Escherichia coli cells. In the present study, we evaluated the involvement of the GO system proteins in the repair of the 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxoG, GO) lesion, which is ROS-induced oxidative damage. We first found that the mutant strain Δfur, which produces an accumulation of iron, and the cells treated with 2,2'-dipyridyl, a iron chelator, were both as resistant to UVC-induced lethality as the wild strain. The 8-oxoG could be mediated by singlet oxygen ((1)O(2)). The Fpg protein repaired this lesion when it was linked to C (cytosine), whereas the MutY protein repaired 8-oxoG when it was linked to A (adenine). The survival assay showed that the Fpg protein, but not the MutY protein, was important to UVC-induced lethality and interacted with the UvrA protein, a nucleotide excision repair (NER) protein involved in UVC repair. The GC-TA reversion assay in the mutant strains from the '8-oxoG-repair' GO system showed that UVC-induced mutagenesis in the fpg mutants, but not in the MutY strain. The transformation assay demonstrated that the Fpg protein is important in UVC repair. These results suggest that UVC could also cause indirect ROS-mediated DNA damage and the Fpg protein plays a predominant role in repairing this indirect damage.

Mutagenicity induced by UVC in Escherichia coli cells: reactive oxygen species involvement

We previously demonstrated that reactive oxygen species (ROS) could be involved in the DNA damage induced by ultraviolet-C (UVC). In this study, we evaluated singlet oxygen ((1)O(2)) involvement in UVC-induced mutagenesis in Escherichia coli cells. First, we found that treatment with sodium azide, an (1)O(2) chelator, protected cells against UVC-induced lethality. The survival assay showed that the fpg mutant was more resistant to UVC lethality than the wild-type strain. The rifampicin mutagenesis assay showed that UVC mutagenesis was inhibited five times more in cells treated with sodium azide, and stimulated 20% more fpg mutant. These results suggest that (1)O(2) plays a predominant role in UVC-induced mutagenesis. (1)O(2) generates a specific mutagenic lesion, 8-oxoG, which is repaired by Fpg protein. This lesion was measured by GC-TA reversion in the CC104 strain, its fpg mutant (BH540), and both CC104 and BH540 transformed with the plasmid pFPG (overexpression of Fpg protein). This assay showed that mutagenesis was induced 2.5-fold in the GC-TA strain and 7-fold in the fpg mutant, while the fpg mutant transformed with pFPG was similar to GC-TA strain. This suggests that UVC can also cause ROS-mediated mutagenesis and that the Fpg protein may be involved in this repair.

In vitro and in vivo toxicological evaluation of extract and fractions from Baccharis trimera with anti-inflammatory activity

ETHNOPHARMACOLOGICAL RELEVANCE

Baccharis trimera (Less) DC. (Asteraceae), popularly known in Brazil as "carqueja", have been used in folk medicine to treat gastrointestinal, hepatic and renal diseases, and inflammatory processes as rheumatism.

AIM OF THE STUDY

To evaluate the in vitro and in vivo toxicological effects of anti-inflammatory Baccharis trimera aqueous extract and fractions.

MATERIALS AND METHODS

Aqueous extract of Baccharis trimera (AEBt) was produced by infusion in boiling water. After lyophylization AEBt was extracted with 80% ethanol, originating the ethanolic supernatant fraction (EFBt) and the aqueous sediment fraction (AFBt). Anti-inflammatory properties of AEBt, EFBt or AFBt (3, 30 or 300 μg/kg b.w.) were evaluated by the carrageenan-induced mouse paw edema using indomethacin (10mg/kg) as positive control. The growth of rat hepatoma cells (HTC) and human embryo kidney epithelial cells (HEK) was determined by protein staining assay. Cytotoxicity was assayed by the tetrazolium salt (MTT) reduction. Cyclosporin was used as reference cytotoxic drug for spleen cells and doxorubicin for HTC and HEK cells. For in vivo toxicological evaluation SW male mice were daily and oral (gavage) treated with extract/fractions at 4.2mg/kg or 42 mg/kg during 15 days. After treatment liver or kidney cells were submitted to comet assay to determine the DNA damage index, and the glutathione S-transferase activity was assayed towards ETHA (class Pi) and CDNB (several classes). Mutagenicity was evaluated by the Ames test using Salmonella typhimurium strains TA97, TA98, TA100, and TA102.

RESULTS

The anti-inflammatory effects of EFBt were higher than those of AEBt or AFBt. Mice treatment (3-300 μg/kg) with AFBt reduced the paw edema (3h) at lower levels (29.2-37.3%; P<0.01), than those observed for AEBt (44.7-54.2%; P<0.001), EFBt (49.3-58.2%; P<0.001) or indomethacin (64.6%, P<0.001, 10mg/kg). The growth of kidney cells (HEK) was inhibited by AEBt (IC(50) 182.6 μg/ml), EFBt (IC(50) 78.1 μg/ml) and AFBt (IC(50) 86.2 μg/ml), with lower effects on HTC hepatic cell (IC(50) 308.8 μg/ml, 396.5 μg/ml and 167.9 μg/ml, respectively). As evaluated by MTT test, AFBt exhibited cytotoxicity for HEK cells (IC(50) 372.5 μg/ml), but none for HTC ones; by the way, AFBt stimulated spleen cells (EC(50) 2.2 μg/ml) while cyclosporine, a cytotoxic reference drug inhibited them with IC(50) of 0.42 μg/ml; the IC(50) for doxorubicin for HEK and HTC cells was 0.28 μg/ml and 14.4 μg/ml, respectively, at 96h. No mutagenic potential was observed. Mice treatment with AEBt or AFBt at 42 mg/kg for 15 days altered the kidney relative weight, but not at 4.2mg/kg. Baccharis trimera did not change liver, spleen or popliteal lymph node relative weight. DNA damage index of kidney cells was observed on mice treated with AEBt/AFBt, but not on animals treated with EFBt, while DNA lesions were detected on liver cells only after AFBt treatment. The general activities of hepatic GST and Pi GST were reduced by EFBt and AFBt treatment, respectively.

CONCLUSIONS

Baccharis trimera did not show mutagenicity, inhibited the GST activity, a hepatic detoxification enzyme, and induced in vivo (genotoxicity) and in vitro toxicological effects to kidney cells.

Effects of Sanionia uncinata extracts in protecting against and inducing DNA cleavage by reactive oxygen species

When mosses are exposed to increased quantities of ultraviolet (UV) radiation, they produce more secondary metabolites. Antarctica moss Sanionia uncinata (Hedw.) Loeske has presented high carotenoid contents in response to an increase in UVB radiation. This moss has been recommended as a potential source of antioxidants. In the present work, the protective and enhancing effects of aqueous (AE) and hydroalcoholic (HE) extracts of S. uncinata on the cleavage of supercoiled DNA were evaluated through topological modifications, quantified by densitometry after agarose gel electrophoresis. Total phenolic contents reached 5.89 mg/g. Our data demonstrated that the extract does not induce DNA cleavage. Furthermore, both extracts showed antioxidant activity that protected the DNA against cleavage induced by (i) O(2)(•-), 89% (AE) and 94% (HE) (P<0.05), and (ii) (.)OH, 17% (AE) and 18% (HE). However, the extracts intensified cleavage induced by Fenton-like reactions: (i) Cu(2+)/H(2)O(2), 94% (AE) and 100% (HE) (P<0.05), and (ii) SnCl(2), 62% (AE) and 56% (HE). DNA damages seem to follow different ways: (i) in the presence of Fenton-like reactions could be via reactive oxygen species generation and (ii) with HE/Cu(2+) could have also been triggered by other mechanisms.

N-nitrosodiethylamine genotoxicity evaluation: a cytochrome P450 induction study in rat hepatocytes

In rats, N-nitrosodiethylamine (NDEA) induces tumors mainly in the liver. This could be because various enzymes are responsible for the metabolic activation of NDEA, besides the hepatic NDEA metabolizing enzyme, CYP2E1. We examined NDEA genotoxicity and cytotoxicity in primary cultures of female rat hepatocytes; we also looked at how it affected CYP mRNA expression. Single incubation with 0.9% NaCl resulted in a mean of 0.2% apoptotic cells, which doubled with 105 μg NDEA/mL. The frequency of necrosis with NDEA treatment was also doubled. Besides the cytotoxic effects, there was also a 4-fold decrease in mitotic index and a 3-fold decrease in the percentage of cells with micronuclei. A significant increase in micronucleus cells when hepatocytes were incubated with 2.1 μg NDEA/mL suggests that DNA repair was inactive. The chromosomal aberration evaluation revealed a discrete dose-response curve. Treatment with NDEA induced increases in CYP mRNA: CYP2B2 (1.8 times) and CYP2E1 (1.6 times) with non-cytotoxic NDEA concentrations (0.21-21 μg/mL). CYP2B1 mRNA levels decreased at 0.21 μg NDEA/mL (2.5-fold), while CYP4A3 mRNA decreased 1.3-fold. NDEA treatment at 2.1 μg/ mL induced a 1.9-fold increase in CYP3A1 mRNA. Understanding the cumulative effects in target cells during precarcinogenesis is crucial to understanding the mode of action of potential carcinogens and in order to develop comprehensive chemical toxicity profiles.