In vivo and in vitro genotoxicity studies of aqueous extract of Xanthium spinosum

The use of plants as a source of palliative or cure for pathological conditions is quite common worldwide. Xanthium spinosum (Asteraceae), popularly known in Brazil as 'espinho de carneiro', is an annual weed from South America, which has been used by empiric medicine to treat neoplasias. Owing to the extensive use of the above-mentioned plant and to the lack of reports about the real effects of its infusion, current study evaluated the genotoxic potential of its aqueous extract at concentrations 0.02 g L-1, 0.1 g L-1 and 0.2 g L-1 by fish micronucleus test and by comet human leukocytes assay. The micronucleus test featured at least 50 cells with micronuclei to every 2,000 cells scored, as a mutagenic parameter. The comet assay was used as a parameter for assessing the level of cell damage and the damage index. Since no significant changes in strain cells exposed to the aqueous extract in the comet and micronucleus assays were reported, it seems that no genotoxicity evidence is extant at the concentrations and in the assays performed.Em diversos lugares do mundo a utilização de plantas como fonte paliativa ou de cura para determinadas condições patológicas é bastante comum. No Brasil, essa prática não se torna diferente devido à ampla biodiversidade da fauna e flora presentes no País. Nesse contexto, surge a Xanthium spinosum (Asteraceae), conhecida popularmente como "espinho-de-carneiro", um arbusto anual introduzido na América do Sul, o qual tem sido utilizado empiricamente no tratamento de neoplasias. Sabendo do extensivo uso dessa planta em contrapartida com nenhum estudo reportando os reais efeitos de sua infusão, o objetivo do estudo foi avaliar a genotoxicidade do extrato aquoso nas concentrações de 0,02 g L-1, 0,1 g L-1 e 0,2 g L-1, através do ensaio do micronúcleo písceo e do ensaio cometa em leucócitos de sangue humano. O ensaio do micronúcleo tem como parâmetro mutagênico a presença de no mínimo 50 células com micronúcleo em uma contagem de 2.000 células por amostra, enquanto o ensaio cometa utiliza como parâmetro o nível de dano e o índice de dano. Os resultados mostram que não foi possível observar mudanças significativas nas células expostas ao extrato aquoso, em ambos os testes, o que sugere não existir evidência de genotoxicidade nas concentrações utilizadas no ensaio

Safety assessment and antioxidant activity of Lantana montevidensis leaves

Lantana camara, the widely studied species, and L. montevidensis, the less studied species of the genus Lantana 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 L. montevidensis 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 Lantana montevidensis in human leukocytes, as well as their ossible interaction with human erythrocyte membranes in vitro. 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 Fe2+-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 L. mon-tevidensis in folk medicine

Phytochemical Composition, Antifungal and Antioxidant Activity of Duguetia furfuracea

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

ASPECTOS ETNOBOTÂNICOS, FITOQUÍMICOS, TOXICOLÓGICOS E FARMACOLÓGICOS DA Euphorbia Tirucalli L.: DOS RISCOS ÀS POSSIBILIDADES

Nas últimas décadas, as pesquisas envolvendo plantas com potenciais propriedades medicinais têm se intensificado na aldeia global. A Euphorbia tirucalli L., conhecida popularmente como Aveloz, é uma planta que vem ganhando destaque. Originariamente da África, esta Euphorbiaceae vem se popularizando na América e América Latina, tanto pela aplicação medicinal quanto pela ornamental. Em sua constituição são encontrados muitos triterpenoides e diterpenoides, em especial ésteres de forbol, que, aparentemente, são os principais constituintes do Aveloz e responsáveis por suas atividades in vivo e in vitro. Além da cicatrização de feridas, a planta é recomendada pela medicina popular para o tratamento de várias doenças ou quadros de agravo à saúde, como hiperplasias, cânceres, lesões hepáticas, reumatismo, asma, infecções e doenças parasitárias, diarreia, distúrbios do trato geniturinário masculino, dores e processos inflamatórios. A presente revisão tenta fornecer informações sobre algumas características etnobotânicas, fitoquímicas, toxicológicas e farmacológicas do Aveloz e alguns de seus compostos, através de dados e evidências acumuladas ao longo dos anos pela comunidade científica. Palavras Chaves: Euphorbia tirucalli L.; etnobotânica; fitoquímica; toxicologia; farmacologia

Cytotoxicity and Genotoxicity Evaluation of Organochalcogens in Human Leucocytes: A Comparative Study between Ebselen, Diphenyl Diselenide, and Diphenyl Ditelluride

Organochalcogens, particularly ebselen, have been used in experimental and clinical trials with borderline efficacy. (PhSe)2 and (PhTe)2 are the simplest of the diaryl dichalcogenides and share with ebselen pharmacological properties. In view of the concerns with the use of mammals in studies and the great number of new organochalcogens with potential pharmacological properties that have been synthesized, it becomes important to develop screening protocols to select compounds that are worth to be tested in vivo. This study investigated the possible use of isolated human white cells as a preliminary model to test organochalcogen toxicity. Human leucocytes were exposed to 5–50 μM of ebselen, (PhSe)2, or (PhTe)2. All compounds were cytotoxic (Trypan’s Blue exclusion) at the highest concentration tested, and Ebselen was the most toxic. Ebselen and (PhSe)2 were genotoxic (Comet Assay) only at 50 μM, and (PhTe)2 at 5–50 μM. Here, the acute cytotoxicity did not correspond with in vivo toxicity of the compounds. But the genotoxicity was in the same order of the in vivo toxicity to mice. These results indicate that in vitro genotoxicity in white blood cells should be considered as an early step in the investigation of potential toxicity of organochalcogens

Synthesis and Biological Evaluation of 2-Picolylamide-Based Diselenides with Non-Bonded Interactions

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

Chemical Characterization and Trypanocidal, Leishmanicidal and Cytotoxicity Potential of Lantana camara L. (Verbenaceae) Essential Oil

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

In vitro antioksidativni učinak kore stabljike biljke Trichilia catigua Adr. Juss

Antioxidant activity of the ethanolic extract and fractions from the stem bark of T. catigua was investigated. IC50 (for DPPH scavenging) by T. catigua varied from 9.17 ± 0.63 to 76.42 ± 5.87 μg mL1 and total phenolic content varied from 345.63 ± 41.08 to 601.27 ± 42.59 µg GAE g1 of dry extract. Fe2+-induced lipid peroxidation was significantly reduced by ethanolic extract and fractions. Mitochondrial Ca2+-induced dichlorofluorescein oxidation was significantly reduced by the ethanolic extract in a concentration-dependent manner. Ethanolic extract reduced mitochondrial Δψm only at high concentrations (40100 μg mL1), which indicates that its toxicity does not overlap with its antioxidant effects. Results suggest involvement of antioxidant activities of T. catigua in its pharmacological properties.U radu je opisano ispitivanje antioksidativnog učinka etanolnog ekstrakta i pojedinih frakcija kore stabljike biljke T. catigua. IC50 (za DPPH test) varirao je između 9,17 ± 0,63 i 76,42 ± 5,87 μg mL1, a ukupni sadržaj fenola od 345,63 ± 41,08 i 601,27 ± 42,59 µg GAE po gramu suhog ekstrakta. Etanolni ekstrakt i frakcije značajno su reducirale Fe2+-induciranu lipidnu peroksidaciju. Nadalje, reducirana je oksidacija diklorfluoresceina inducirana ionima kalcija u mitohondrijima, a redukcija je ovisila o dozi etanolnog ekstrakta. Etanolni ekstrakt smanjio je mitohondrijsku Δψ samo pri visokim koncentracijama (40100 μg mL1), što ukazuje da se toksičnost ne preklapa s antioksidativnim učinkom. Rezultati pokazuju da u farmakološko djelovanje T. catigua treba uključiti i antioksidativni učinak