In this paper, we report the synthesis and biological evaluation of picolylamide-based diselenides with the aim of developing a new series of diselenides with O···Se non-bonded interactions. The ...synthesis of diselenides was performed by a simple and efficient synthetic route. All the products were obtained in good yields and their structures were determined by 1H-NMR, 13C-NMR and HRMS. All these new compounds showed promising activities when tested in different antioxidant assays. These amides exhibited strong thiol peroxidase-like (TPx) activity. In fact one of the compounds showed 4.66 times higher potential than the classical standard i.e., diphenyl diselenide. The same compound significantly inhibited iron (Fe)-induced thiobarbituric acid reactive species (TBARS) production in rat's brain homogenate. In addition, the X-ray structure of the most active compound showed non-bonded interaction between the selenium and the oxygen atom that are in close proximity and may be responsible for the increased antioxidant activity. The present study provides evidence about the possible biochemical influence of nonbonding interactions on organochalcogens potency.
Drug resistance in the treatment of neglected parasitic diseases, such as leishmaniasis and trypanosomiasis, has led to the search and development of alternative drugs from plant origins. In this ...context, the essential oil extracted by hydro-distillation from Lantana camara leaves was tested against Leishmania braziliensis and Trypanosoma cruzi. The results demonstrated that L. camara essential oil inhibited T. cruzi and L. braziliensis with IC50 of 201.94 μg/mL and 72.31 μg/mL, respectively. L. camara essential oil was found to be toxic to NCTC929 fibroblasts at 500 μg/mL (IC50 = 301.42 μg/mL). The composition of L. camara essential oil analyzed by gas chromatography-mass spectrometry (GC/MS) revealed large amounts of (E)-caryophyllene (23.75%), biciclogermacrene (15.80%), germacrene D (11.73%), terpinolene (6.1%), and sabinene (5.92%), which might be, at least in part, responsible for its activity. Taken together, our results suggest that L. camara essential oil may be an important source of therapeutic agents for the development of alternative drugs against parasitic diseases.
4-Vinylcyclohexene (VCH) is a dimer of 1,3-butadiene produced as a by-product of pesticides, plastic, rubber, flame retardants, and tire production. Although, several studies have reported the ...ovotoxicity of VCH, information on a possible involvement of oxidative stress in the toxicity of this occupational chemical is scarce. Hence, this study was carried out to investigate further possible mechanisms of toxicity of VCH with a specific emphasis on oxidative stress using a Drosophila melanogaster model. D. melanogaster (both genders) of 1 to 3 days old were exposed to different concentrations of VCH (10µM–1mM) in the diet for 5 days. Subsequently, the survival and negative geotaxis assays and the quantification of reactive oxygen species (ROS) generation were determined. In addition, we evaluated RT-PCR expressions of selected oxidative stress and antioxidant mRNA genes (HSP27, 70, and 83, SOD, Nrf-2, MAPK2, and catalase). Furthermore, catalase, glutathione-S-transferase (GST), delta aminolevulinic acid dehydratase (δ-ALA-D), and acetylcholinesterase (AChE) activities were determined. VCH exposure impaired negative geotaxic behavior and induced the mRNA of SOD, Nrf-2, and MAPK2 genes expressions. There were increases in catalase and ROS production, as well as inhibitions of GST, δ-ALA-D, and AChE activities (P<0.05). Our results suggest that the VCH mechanism of toxicity is associated with oxidative damage, as evidenced by the alteration in the oxidative stress-antioxidant balance, and possible neurotoxic consequences due to decreased AChE activity, and impairments in negative geotaxic behavior. Thus, we conclude that D. melanogaster is a useful model for investigating the toxicity of VCH exposure, and here, we have provided further insights on the mechanism of VCH-induced toxicity.
•The involvement of oxidative stress in a D. melanogaster model of 4-vinylcyclohexene (VCH) toxicity was investigated.•VCH impaired climbing behavior and inhibited AChE activity in D. melanogaster.•VCH up-regulates mRNA expressions of SOD, Nrf-2, and MAPK2 genes in D. melanogaster.•VCH induced ROS production, changes in antioxidant balance, and inhibition of δ-ALA-D activity in D. melanogaster, therefore, suggesting involvement of oxidative stress.
Rhaphiodon echinus is a weed plant used in the Brazilian folk medicinal for the treatment of infectious diseases. In this study, the essential oil of R. echinus leaf was investigated for its ...antimicrobial properties.
The chemical constituents of the essential oil were characterized by GC-MS. The antimicrobial properties were determined by studying by the microdilution method the effect of the oil alone, and in combination with antifungal or antibiotic drugs against the fungi Candida albicans, Candida krusei and Candida tropicalis and the microbes Escherichia coli, Staphylococcus aureus and Pseudomonas. In addition, the iron (II) chelation potential of the oil was determined.
The results showed the presence of β-caryophyllene and bicyclogermacrene in major compounds, and revealed a low antifungal and antibacterial activity of the essential oil, but a strong modulatory effect on antimicrobial drugs when associated with the oil. The essential oil showed iron (II) chelation activity.
The GC-MS characterization revealed the presence of monoterpenes and sesquiterpenes in the essential oil and metal chelation potential, which may be responsible in part for the modulatory effect of the oil. These findings suggest that essential oil of R. echinus is a natural product capable of enhancing the antibacterial and antifungal activity of antimicrobial drugs.
Raphiodon echinus (R. echinus) is used in Brazilian folk medicine for the treatment of inflammation, coughs, and infectious diseases. However, no information is available on the potential ...antioxidant, cytotoxicity and genotoxicity of this plant. In this study, the polyphenolic constituents, antioxidant capacity and potential toxic effects of aqueous and ethanolic extracts of R. echinus on human erythrocytes and leukocytes were investigated for the first time. R. echinus extracts showed the presence of Gallic, chlorogenic, caffeic and ellagic acids, rutin, quercitrin and quercetin. Aqueous and ethanolic extracts of R. echinus exhibited antioxidant activity in DPPH radical scavenging with IC50 = 111.9 μg/mL (EtOH extract) and IC50 = 227.9 μg/mL (aqueous extract). The extracts inhibited Fe(2+) (10 μM) induced thiobarbituric acid reactive substances (TBARS) formation in rat brain and liver homogenates. The extracts (30-480 μg/mL) did not induce genotoxicity, cytotoxicity or osmotic fragility in human blood cells. The findings of this present study therefore suggest that the therapeutic effect of R. echinus may be, in part, related to its antioxidant potential. Nevertheless, further in vitro and in vivo studies are required to ascertain the safety margin of its use in folk medicine.
Gastric ulcers affect many people around the world and their development is a result of the imbalance between aggressive and protective factors in the gastric mucosa. Scutia buxifolia, commonly known ...as coronilha, has attracted the interest of the scientific community due to its pharmacological properties and its potential therapeutic applications. In this study, the preventive effects of the crude extract of Scutia buxifolia (ceSb) against gastric ulcer induced by 70% ethanol were evaluated in male Wistar rats. In addition, the composition of ceSb was clarified by high-performance liquid chromatography (HPLC). S. buxifolia extract (100, 200 and 400 mg/kg body weight) attenuated oxidative and histopathological features induced by ethanol. Moreover, all evaluated doses of ceSb caused significant (P<0.001 and P<0.0001) and dose-dependent increase in sulfhydryl groups (NPSH) levels, catalase (CAT) and superoxide dismutase (SOD) activities. Furthermore, the administration of ceSb reversed the increase in lipid peroxidation produced by ethanol. The protective effect of the extract could be attributed to antioxidant compounds present in the ceSb, such as flavonoids and phenolic acids, which were quantified by HPLC. Thus, an antioxidant effect of the extract leads to a protection on gastric tissue. These results indicate that S. buxifolia could have a beneficial role against ethanol toxicity by preventing oxidative stress and gastric tissue injury.
Background. Duguetia furfuracea is popular plant used in popular medicine. Hypothesis/Purpose. This claim evaluated the phytochemical composition of the hydroethanolic extract (HEDF), fractions of ...Duguetia furfuracea, and antioxidant and antifungal activity. Methods. The chemical profile was carried out by HPLC-DAD. The total phenolic contents and flavonoid components were determined by Folin-Ciocalteu and aluminium chloride reaction. The antioxidant activity was measured by scavenging of 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical and ferric reducing ability of plasma (FRAP) methods. The antifungal activity was determined by microdilution assay. Results. HPLC analysis revealed caffeic acid and rutin as major compounds (HEDF), caffeic acid and quercitrin (Mt-OH fraction), and quercitrin and isoquercitrin (Ac-OEt fraction). The highest levels of phenols and total flavonoids were found for Ac-OEt fraction, and the crude extract showed higher in vitro antioxidant potential. The antifungal activity showed synergic effect with fluconazole and EHDF against C. krusei, fluconazole and Mt-OH against C. krusei and C. tropicalis, and Ac-OE and fluconazole against C. albicans. Conclusion. The highest levels of phenols and total flavonoids were marked with antioxidant effect. This is the first report of bioactivity of the synergic effect of HEDF and fractions. More studies would be required to better clarify its mechanism of synergic action.
RESUMO O mel é um produto natural que apresenta várias propriedades benéficas para a saúde, tais como atividade antinflamatória, antioxidante e antimicrobiana, as quais dependem de sua composição. ...Neste contexto, as propriedades físico-químicas (cor, pH, conteúdo de cinzas, umidade, açúcares e compostos fenólicos totais) e a atividade antioxidadente (capacidade de remoção do radical DPPH) de méis de abelhas Apis mellifera de Santarém, na principal região de produção de mel na Amazônia Oriental, Brasil, foram avaliadas. A maioria das amostras teve cor escura e apresentaram-se ácidas. Os teores de cinzas e a umidade variaram de 0,112 a 0,318 e de 14,751 a 17,514, respectivamente. O teor de açúcares redutores vairou entre 62,873 e 91,563%. O teor total de compostos fenólicos foi mais elevado que os já reportados na literatura, variando entre 15,22 e 16,51 mg g−1 e 17,70 e 18,94 mg g−1 para amostras de mel protegidas e expostas à radiação UV, respectivamente. A quercetina foi encontrada apenas no mel que foi protegido da luz, com teores variando entre 0,24 e 0,43 mg g−1. A ausência de quercetina nas amostras de mel expostas à luz sugere que a radiação UV pode ter degradado esse composto. Todas as amostras apresentaram máxima capacidade de remover o radical DPPH próxima a 50%. Houve correlação inversa entre a cor e o pH, cinzas, açúcares redutores e teor de umidade, e correlação positiva entre a cor e o teor de composto fenólicos e a atividade antioxidante.
•Melissa officinalis (MO) showed strong DPPH radical scavenging activity.•MO inhibited deoxyribose degradation and exhibited reducing power property.•MO showed apparent Fe(II) chelation and ...maintained Fe(II) in a Fe(III) state.•The extract was neither genotoxic nor cytotoxic to leukocytes cells.•The antioxidant activity is correlated with the polyphenolic content of the plant.
The antioxidant activity of Melissa officinalis (MO) was evaluated to understand the mechanism of its pharmacological properties as well as its potential genotoxic and cytotoxic effects in human leukocytes. The results showed that MO scavenged DPPH radical in a concentration dependent-manner with IC50 values of 48.76±1.94μg/mL. MO showed strong reducing power and exhibited a significant inhibition of deoxyribose degradation. MO interfered with the formation of 1,10-phenanthroline–Fe2+ complex, suggesting that it has chelating activity and captures Fe2+ before 1,10-phenanthroline. The addition of 5mM ascorbic acid to the reaction mixture dramatically reduced Fe3+ (formed during the incubation time) to Fe2+ indicating that it was an “apparent” chelation. MO was neither genotoxic nor cytotoxic at the concentrations tested, indicating that the popular use of the extract might possibly not result in any genotoxic or cytotoxic effects. Our results suggest that MO is a potential source of natural antioxidants, and could be relevant for the management of oxidative stress. Of particular importance, for neurodegenerative diseases, the capacity of MO to “chelate” and to maintain Fe2+ in a Fe3+ state can contribute to its neurotherapeutic effects, because iron plays a central role in brain damage.
the widely studied species, and
the less studied species of the genus
are both used in traditional medicine for the same purpose (anti-asthma, anti-ulcer, anti-tumor, etc). However, little is known ...about the toxicity of
and there is limited information on its chemical constituents. Here, we investigated for the first time the genotoxicity and cytotoxicity of the ethanolic (EtOH) and aqueous extracts from the leaves of
in human leukocytes, as well as their possible interaction with human erythrocyte membranes
. The antioxidant activities of both extracts were also investigated in chemical and biological models. Treatment of leukocytes with EtOH or aqueous extracts (1-480 µg/mL) did not affect DNA damage index, but promoted cytotoxicity at higher concentrations (240-480 µg/mL). Both extracts did not modify the osmotic fragility of human erythrocytes. The extracts scavenged DPPH radical and prevented Fe
-induced lipid peroxidation in rat's brain and liver homogenates, and this was likely not attributed to Fe (II) chelation. The HPLC analysis of the extracts showed different amounts of polyphenolic compounds (isoquercitrin, gallic acid, catechin, ellagic acid, apigenin, kaempferol, caffeic acid, rutin, quercitrin, quercetin, chlorogenic acid, luteolin) that may have contributed to these effects. These results supported information on the functional use of
in folk medicine.
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