Environmental parameters modulate lead chloride toxicity on Artemia salina

Different environmental conditions can influence the effects of toxic agents on living beings. Recently, a series of experiments performed in Artemia salina submitted to different kinds of intoxication have shown that both, isotherapic and succussed watercan change Artemia salina ́s bio resilience at different levels. Moreover, it seems to vary according to the circalunar cycle. Objective:To verify if circalunar phases and water agitation can modify the toxicity of lead chloride on Artemia salina in vitro. Methodology:Artemia salina cysts were exposed to seawater containing 0.04% of lead chloride (equal to EC10 or 10% effective concentration, previously determined in a pilot study) in 96-well culture plates. Thirty-six experimental repetitions were performed in four series to observe the possible effects of adding stirred water, the so-called succussed water, and the moon phases. The hatched cysts were recorded after 48 hours using a digital microscope (1000x magnification) to identify the hatching percentage and the viability and mobility of the born nauplii. Results:The exposition of cysts to PbCl2 led to an increase in the hatching rate, and it was more evident during the full moon (p = 0.00014) The addition of succussed water into the seawater medium reduced this effect to the baseline levels. An increase in mobility was seen in nauplii born from exposed cysts during the full moon (p = 0.00077), but this effect was not affected by the treatment with succussed water. Discussion:Although the effects of lead chloride EC10 on the increase of nauplii hatching were expected, two environmental variables changed the sensitivity of cysts to this harmful stimulus. The circalunar cycle varied the hatching rate according to the moon phase, even in laboratory conditions, and the addition of succussed water into the medium reduced the hatching rate, even with different intensities according to the moon phase. The organization of nano and microbubbles generated after the succussion of water could be related to this protective effect and can explain, at least partially the effects of high diluted preparations on this biological context. Conclusion:Environmental factors, such as the circalunar cycle and products of water agitation, can modulate the adaptative control of hatching in Artemia salina exposed to lead chloride at EC10.

Mercury chloride toxicity attenuation of the Brine Shrimp Artemia Salinaafter treatment with Mercurius corrosivusas isotherapic

Isotherapics preparedfromtoxic substances have been described as attenuation factors for heavy metal intoxicationin aquatic animals. Herein, Artemia salinaand mercury chloride were usedas a model to identify treatment-related bioresilience. The aim was to describe the effects of Mercurius corrosivus(MC) in different potencies on Artemia salinacyst hatching and on mercury bioavailability. Artemia salinacysts were exposed to 5.0 µg/mL of mercury chloride during the hatching phase. MC6cH, 30cH, and 200cHwere prepared and poured into artificial seawater. Different controls were used (nonchallenged cysts and challenged cysts treated with water, succussed water, and Ethilicum 1cH). Four series of nine experiments were performed for4 weeks to evaluate the percentage of cyst hatchingconsidering all moon phases. Soluble total mercury (THg) levels and precipitated mercury content were also evaluated. Solvatochromic dyes were used to check for eventual physicochemical markers of MCbiological activity. Two-way analysis of variance (ANOVA) with mixed modelswas used for evaluating the effect of different treatments andthe simultaneous influence of the moon phases on the cystshatching rate, at both observation times (24 and 48 hours).When necessary, outliers were removed, using the Tukeycriterion.Thelevel of significance αwas set at 5%. Significant delay (p<0.0001) in cyst hatching was observed after treatment with MC30cH, compared with the controls. An increase inTHg concentration in seawater (p<0.0018) and of chlorine/oxygen ratio (p<0.0001) in suspended micro-aggregateswas also seen, with possiblerelation with mercury bioavailability. Specific interaction of MC30cH with the solvatochromic dye ET33 (p<0.0017) was found. The other observed potencies of Mercurius corrosivus6 and 200 cH were not significant in relation to the observed groups.The results werepostulated as being protective effects of MC30cH on Artemia salina, by improving its bioresilience.

Preliminary analysis of Brazilian Amazonian plant extracts using bench-top assays in a through-put basis aiming the identification of potential antioxidant natural product

Plants are a source of compounds that are used for the treatment of human and veterinary diseases. Brazil is one of the richest countries in the world in terms of biodiversity. The present study evaluated extracts using thin-layer chromatography to identify antioxidant activity and determine the presence of groups of compounds, in a large-scale basis. A total of 1,260 aqueous and organic extracts were obtained from plants that were collected in the Amazon and Atlantic rain forests. Thin-layer chromatography was performed to evaluate the presence of alkaloids, anthraquinones, cardioactive glicosides, terpenes, and phenolics and determine antioxidant and radical scavenging activity using the following reagents: Dragendorff's reagent, KOH, Kedde's reagent, sulphuric acid, NP reagent, ß-carotene, and 2,2-diphenyl-1-picrylhydrazyl (DPPH). Of the 1,260 extracts, 837 (66.43%) presented a ß-carotene/bleaching response, and 1,205 (95.63%) presented a radical scavenging response. Alkaloids were found in 203 extracts (16.11%). Anthraquinones were found in 14 extracts (1.11%), cardenolides were found in eight extracts (0.63%). The present findings shows the importance of the Brazilian Amazon plants as sources of antioxidant and radical scavenging active compounds.(AU)

Can mouth washes containing chlorhexidine 0.12% be used as synonym of a water solution of chlorhexidine 0.12%? / Pode lavagens da boca contendo 0.12 % de clorexidina ser utilizado como sinónimo de uma solução aquosa de cloro-hexidina 0.12 % ?

Chlorhexidine digluconate (CHX) is a gold standard drug in dentistry and is widely used as a reference in both in vitro and in vivoexperiments. Due to ease of access, mouth washes containing CHX 0.12% are used as a substitute for aqueous CHX 0.12% solution in laboratory experiments. Additionally, it is well known that for product flavor purposes, volatile compounds are added to mouth washes formulations. Volatiles added to CHX 0.12% may improve wash's antibacterial ability. Volatiles add potency to the mouth wash formulation. Compared with an aqueous CHX 0.12% solution, it is proposed that CHX solutions and Periogard^® would have antimicrobial activity. Antimicrobial activity was assessed in the present study via disk diffusion assays against Streptococcus mutans, Streptococcus sanguinisand Escherichia coli. Periogard^® showed a significantly higher antibacterial activity in relation to CHX 0.12% (p<0.05) and a similar activity in relation to CHX 1% (p>0.05). Periogard^(r) volatiles were analyzed by gas-chromatography/mass spectrometry (GCMS) and the presence of antibacterial menthol, menthone, isomenthol, menthyl acetate, trans-anethol and eugenol was verified. Finally, the use of Periogard^® as a synonym of CHX 0.12% must be avoided, because its antibacterial activity is closely related to CHX 1%...

Gluconato de clorexidina (CHX) é um fármaco considerado padrão ouro, em Odontologia, amplamente usado como referência em estudos in vitro e in vivo. Em razão da facilidade de acesso, enxaguatórios bucais que contêm CHX 0,12% são usados em substituição à solução aquosa de clorexidina (CHX 0,12%), em experimentos laboratoriais. É sabido que devido à palatabilidade do produto, os mesmos enxaguatórios bucais contêm compostos voláteis em sua formulação, além da CHX 0.12%. Visto que voláteis adicionados podem acrescentar poder antibacteriano à formulação, a comparação da resposta antibacteriana da solução aquosa de CHX em diferentes concentrações e de Periogard^® é proposta no presente artigo. Para tanto, utilizou-se o ensaio do disco de difusão em ágar com inóculos de Streptococcus mutans, Streptococcus sanguinis e Escherichia coli. Periogard^® mostrou atividade antibacteriana significativa contra as três cepas analisadas, quando comparada à atividade de CHX 0.12% (p<0,05) e atividade similar à CHX diluída a 1% (p>0,05). A presença de compostos voláteis no Periogard^® foi analisada por GC-MS e observou-se que mentol, mentona, isomentol, acetato de mentila, trans-anetol e eugenol estão presentes na formulação. Deste modo, o uso de Periogard^(r) como sinônimo de CHX 0,12% deve ser evitado, uma vez que sua atividade se assemelha àquela da CHX diluída a 1%...

Impacto causado por Escherichia coli na produção de animais de corte no Brasil: revisão da literatura / Impact caused by livestock colibacillosis in Brazil: literature review

O Brasil é um dos maiores exportadores de produtos de origem animal. Porém, sua produção sofre impacto causado pela bactéria Escherichia coli, que é capaz de acarretar prejuízos econômicos inestimáveis e gerar preocupação à saúde pública, na bovinocultura, avicultura e suinocultura. A utilização indiscriminada de antimicrobianos tanto no tratamento como aditivos melhoradores de desempenho zootécnico gera o aparecimento de resistência bacteriana. Por conta disso, há a necessidade de se introduzir novos medicamentos que sejam eficazes e estejam dentro dos limites máximos de resíduo estabelecidos nacional e internacionalmente pelo mercado consumidor. Diante deste fato, é imprescindível que haja a busca racional de novos antimicrobianos que apresentem eficácia e um baixo índice residual. Os compostos de origem natural são apontados como alternativas para serem usados na prática veterinária.

Brazil is one of the biggest exporters of animal products. However, its production is constantly being threatened by the bacterium Escherichia coli which can cause economic losses and generate invaluable public health concern in cattle, poultry, and swine culture. The indiscriminate use of antimicrobials in the treatment of farm animals and their use as growth promoters lead to the appearance of bacterial resistance, but the presence of drug residues is still a concern related to meat exportation. For that reason, it is essential to rationally seek new antimicrobials of natural origin to be used in veterinary practice.

The influence of Brazilian plant extracts on Streptococcus mutans biofilm

Nineteen plant extracts obtained from plants from the Brazilian Amazon showed activity against planktonic Streptococcus mutans, an important bacterium involved in the first steps of biofilm formation and the subsequent initiation of several oral diseases. Objective: Our goal was to verify whether plant extracts that showed activity against planktonic S. mutans could prevent the organization of or even disrupt a single-species biofilm made by the same bacteria. Material and Methods: Plant extracts were tested on a single-bacteria biofilm prepared using the Zürich method. Each plant extract was tested at a concentration 5 times higher than its minimum inhibitory concentration (MIC). Discs of hydroxyapatite were submersed overnight in brain-heart infusion broth enriched with saccharose 5%, which provided sufficient time for biofilm formation. The discs were then submersed in extract solutions for one minute, three times per day, for two subsequent days. The discs were then washed with saline three times, at ten seconds each, after each treatment. Supports were allowed to remain in the enriched medium for one additional night. At the end of the process, the bacteria were removed from the discs by vortexing and were counted. Results: Only two of 19 plant extracts showed activity in the present assay: EB1779, obtained from Dioscorea altissima, and EB1673, obtained from Annona hypoglauca. Although the antibacterial activity of the plant extracts was first observed against planktonic S. mutans, influence over biofilm formation was not necessarily observed in the biofilm model. The present results motivate us to find new natural products to be used in dentistry. .

In vitro activity of Amazon plant extracts against Enterococcus faecalis

Previous studies analyzing 2,200 plant extracts indicated anti-enterococcal activity in 25 extracts obtained from Brazilian forests' plants. In the present study, these extracts were subjected to microdilution broth assay (MDBA) and disk diffusion assay (DDA) using planktonic Enterococcus faecalis ATCC® 29212TM and were submitted to phytochemical analysis in TLC and HPLC. Three extracts obtained from Ipomoea alba (MIC < 40 µg/mL), Diclinanona calycina (MIC < 40 µg/mL) and Moronobea coccinea (40 < MIC < 80 µg/mL; MBC = 80 µg/mL) showed significant bactericidal activity in the MDBA and four extracts obtained from I. alba (14.04 ± 0.55 mm diameter) S. globulifera (14.43 ± 0.33 mm and 12.18 ± 0.28 mm diameter) and Connarus ruber var. ruber (13.13 ± 0.18 mm diameter) were active in DDA. Residues H2O obtained from Psidium densicomum (mean of 16.78 mm diameter) and from Stryphnodendron pulcherrimum (mean of 15.97 mm diameter) have shown an improved antibacterial activity after fractionation if compared to that obtained from the respective crude extracts. Antioxidant activity was observed in some residues of the active extracts. TLC analysis showed that phenolic compounds are likely to be found in active extracts. Three molecules were isolated from S. globulifera and were identified by 13C NMR lupeol, α-amyrin and 3β-hydroxyglutin-5-ene. The present chemical and biological findings suggest that these extracts are a potential source of new anti-Enterococcus compounds to be introduced in endodontic therapy.

Anti-Streptococcal activity of Brazilian Amazon Rain Forest plant extracts presents potential for preventive strategies against dental caries

Caries is a global public health problem, whose control requires the introduction of low-cost treatments, such as strong prevention strategies, minimally invasive techniques and chemical prevention agents. Nature plays an important role as a source of new antibacterial substances that can be used in the prevention of caries, and Brazil is the richest country in terms of biodiversity. Objective: In this study, the disk diffusion method (DDM) was used to screen over 2,000 Brazilian Amazon plant extracts against Streptococcus mutans. Material and Methods: Seventeen active plant extracts were identified and fractionated. Extracts and their fractions, obtained by liquid-liquid partition, were tested in the DDM assay and in the microdilution broth assay (MBA) to determine their minimal inhibitory concentrations (MICs) and minimal bactericidal concentrations (MBCs). The extracts were also subjected to antioxidant analysis by thin layer chromatography. Results: EB271, obtained from Casearia spruceana, showed significant activity against the bacterium in the DDM assay (20.67±0.52 mm), as did EB1129, obtained from Psychotria sp. (Rubiaceae) (15.04±2.29 mm). EB1493, obtained from Ipomoea alba, was the only extract to show strong activity against Streptococcus mutans (0.08 mg/mL<MIC<0.16 mg/mL; MBC=0.16 mg/mL) in the MBA. Conclusions: The active extracts, discovered in the Amazon rain forest, show potential as sources of new antibacterial agents for use as chemical coadjuvants in prevention strategies to treat caries. .

Effects of exposure to glyphosate in male and female mice behavior in pubertal period / Efeitos comportamentais da esposição na piberdade de camundongos machos e fêmeas ao glifosato

The present study aims to investigate the effects of pre-pubertal exposure of male and female mice to a commercial formulation of glyphosate on sexual dimorphism observed in animal models of emotionality, anxiety and depression. For this, mice were exposed from 23 days of age (PND) until PND 45 to glyphosate (50 mg/kg, per os) or saline solution, and, ten days after the end of treatments, male and female mice were observed in the open field (OF), elevated plus maze (EPM) or forced swimming test (FWT). Results showed that exposure to glyphosate: 1) reduced the locomotion frequency of male mice similarly to female mice in the OF and female mice had an increase in rearing behavior and in the immobility time; 2) reduced in male mice the motor activity both in the OF and EPM, while no effects were observed in female mice; 3) in the SWT male mice had a decreased time of float similarly female mice. We concluded that pre-pubertal exposure to glyphosate reduced in male mice the capacity of exploration in the OF and EPM tests suggesting that the herbicide interfered with the central mechanism related to brain masculinization of exploratory and anxiety behavioral models. In the FWT it was observed a decreased depressive response in male mice while in female an increased response was detected.

O presente estudo teve como objetivo investigar em camundongos machos e fêmeas o efeito da exposição a uma formulação comercial de glifosato durante o período de pré-pubere em modelos comportamentais de emocionalidade, ansiedade e depressão. Para isto, camundongos foram expostos a partir de 23 dias de idade (dia pós-natal-PND) até o PND 45 ao glifosato (50 mg/kg, via oral) ou solução salina. Dez dias após o término do tratamento, os animais, machos e fêmeas, foram observados no campo aberto (OF), labirinto em cruz elevado (EPM) ou teste de natação forçada (FWT). Os resultados mostraram que a exposição ao glifosato: 1) reduziu de forma similar a frequência de locomoção dos camundongos em ambos os sexos; 2) reduziu a atividade motora tanto no OF como no PM em camundongos machos, sem alterações observadas em fêmeas; 3) no SWT os camundongos machos apresentaram redução no tempo de flutuação similar ao das fêmeas. Concluiu-se que a exposição pré-pubere ao glifosato reduziu em machos a capacidade de exploração no OF e EPM e no tempo de flutuação no FWT sugerindo que o herbicida interferiu com mecanismos centrais relacionados com masculinização do cérebro ligados à exploração e ansiedade. No FWT observou-se menor depressão em machos e exacerbação da resposta em fêmeas.

New trends in dentistry: plant extracts against Enterococcus faecalis. The efficacy compared to chlorhexidine

Enterococcus faecalis is an important pathogen associated with endodontic diseases, and its elimination and control are of paramount importance, as it represents one of the major causes of failure in the treatment of endodontic disease. Twenty-five plant extracts obtained from Brazilian forests were found to be effective against planktonic E. faecalis and were subjected to two traditional antibacterial assays, the microdilution broth assay (MDBA) and the disk diffusion assay (DDA), using chlorhexidine (CHX) as a control. Seven out of 25 extracts showed significant antibacterial activity and were tested in a biofilm assay, and three of these extracts were subjected to chemical fractionation. Residues were tested for their antibacterial activity, and the first chemical findings were described based on thin layer chromatography (TLC). Extracts obtained from Ipomoea alba, Symphonia globulifera and Moronobea coccinea showed significant bactericidal activity in the MDBA. The same I. alba and S. globulifera extracts, as well as the extract obtained from Connarus ruber var. ruber, showed significant activity in the DDA. RH2O obtained from Psidium densicomum and Stryphnodendron pulcherrimum showed better antibacterial activity compared to the respective crude extracts and CHX. TLC analysis showed that phenolic compounds and triterpenes represent the first findings of chemical groups that may occur in all species. The results of the present study include the discovery of six active extracts against planktonic E. faecalis and support further testing via assays involving biofilm formation, as well as the determination of the compounds' chemical profiles, as their activity was significantly better than that observed for CHX.

Evaluation of the effect of an organic extract obtained from Ipomoea alba L. on experimental periodontitis in rats

The aim of this study was to evaluate the effect of an organic extract obtained from Ipomoea alba L. (Convolvulaceae or OE 1493), on experimental periodontal disease in rats. Periodontitis was induced in thirty six Wistar rats: a first mandibular molar was randomly assigned to receive a ligature, whereas the contralateral molar was left unligated. Animals were randomly assigned to two groups and treated topically, three times a day, for 11 days, as follows: Control Group - vehicle-treated (n = 18), and Test Group - OE 1493-treated (n = 18). The rats were sacrificed on the 12th day. Morphometrical measurements from the cementoenamel junction to the bone crest were performed to determine alveolar bone loss, using standardized photographs. Single- and multi-dose acute toxicity assays were carried out after OE 1493 treatment. Morphometrical analysis demonstrated that topically-administered OE 1493 showed no effect on reducing bone loss when compared with the control group (p > 0.05). In addition, OE 1493 did not present toxicity. Within the limits of this investigation, it may be concluded that OE 1493 did not show any positive influence on the progression of ligature-induced periodontitis in rats, when administered according to the regimen used in the present study.

Behavioral effects of acute glyphosate exposure in male and female Balb/c mice / Efeitos comportamentais da exposição aguda ao gliposato em camundongos Balb/c machos e fêmeas

We investigated the behavioral effects induced by an acute exposure to a commercial formulation of glyphosate (GF) in a dose that was about double the concentration of the no observed adverse effect level (NOAEL) in male and female BALB/c mice. The acute neurotoxicity induced by GF exposure was determined through analysis of general activity, the sensory system, the psychomotor system, the central nervous system and the autonomous nervous system in both male and female mice. The behavioral effects on exploration, anxiety and depression induced by GF exposure were determined with the open field, elevated plus maze and tail suspension tests, respectively. GF induced few signs of acute neurotoxicity. Locomotion in the open field was decreased in only female mice. No signs of anxiety were detected in the plus maze test in both sex, however, a reduced exploration was observed in male mice in this apparatus. In the tail suspension test, both male and female mice showed an increased immobility time. No interaction between sex and treatment was detected. In conclusion, GF exposure at about a dose twice that of the NOAEL induced few signs of neurotoxicity and no sexual dimorphism in all behavioral models employed.

Neste trabalho investigou-se em camundongos BALB/c, machos e fêmeas, os efeitos comportamentais da exposição aguda a uma formulação comercial do glifosato (GF) em uma dose duas vezes maior que a dose sem efeito observado (NOAEL). A neurotoxicidade aguda ao GF foi determinada por meio da análise da atividade geral, de parâmetros sensoriais, psicomotores, do sistema nervoso central e autônomo em machos e fêmeas. Os efeitos exploratório, de ansiedade e depressão induzidos pelo GF foram observados no campo aberto, labirinto em cruz elevado e no teste da suspensão da cauda, respectivamente. O GF promoveu poucos sinais de neurotoxicidade. A capacidade exploratória de fêmeas foi reduzida no campo aberto. Nenhum sinal de ansiedade foi detectado tanto em machos como em fêmeas no labirinto em cruz elevado porém, notou-se redução da exploratória neste aparelho. No teste de suspensão da cauda tanto as fêmeas como machos mostraram aumento no tempo de imobilidade. Não foi observado neste caso interação entre sexo e tratamento. Concluiu-se que a exposição ao dobro da dose da NOAEL do GF induziu poucos sinais de neurotoxicidade e poucos efeitos sexualmente dimórficos em camundongos machos e fêmeas.

In vitro cytotoxic effects of Brazilian plant extracts on squamous cell carcinoma of the oral cavity

Squamous cell carcinoma (SCC) is the most prevalent cancer of the oral cavity and the fifth most prevalent of all malignancies in males. Many researchers have attempted to develop new treatments that will improve the prognosis of SCC patients. Over 20 percent of the world's biodiversity is located within the Brazilian forests, but little is known about the chemical and/or pharmacological potential of these plants. Certain extracts obtained from Amazon and Atlantic Forest plants have previously been shown to have cytotoxic activity against various cancers. The aim of this study was to screen these extracts for cytotoxic activity against oral SCC cells. The extracts were analyzed for activity against the KB-ADL#12 cell line at various concentrations up to a maximum dose of 100 µg/mL. Comparisons with a control group were performed using one-way ANOVA. Significant cytotoxicity was induced by the extracts obtained from the aerial parts of Picrolemma sprucei (Simaroubaceae), from the leaves and stems of Laetia suaveolens (Salicaceae), from the aerial parts of Abarema auriculata (Fabaceae-Mimosoideae) and from the stem of A. auriculata.

Toxicidade de Neem, Azadirachta indica A. Juss. (Meliaceae), em Artemia sp: comparação da preparação comercial e do óleo puro / Neem Azadirachta indica A. Juss. (Meliaceae) toxicity in Artemia sp: comparison of a commercial preparation and the pure oil

Introdução - Azadirachta indica A. Juss. (Meliaceae) é conhecida popularmente por Neem (nim) ou margosa e é caracterizada por ser uma frondosa árvore, presente em regiões tropicais sendo, provavelmente, originada da Ásia. É empregada há tempos não só em medicina e cosmética como também na agricultura, sendo empregada como praguicida. A azadirachtina é a substância ativa presente no óleo responsável por seu efeito praguicida. O presente trabalho comparou os efeitos tóxicos de uma formulação comercial e do óleo puro de Azadirachta indica A. Juss. em Artemia sp. Material e Métodos - Foram utilizadas artêmias no estágio náuplio I ou II as quais foram submetidas a diferentes concentrações do óleo puro e do produto formulado, tendo sido computada a presença de morte após 24 e 48 horas da exposição. Resultados - A formulação comercial empregada apresentou-se significativamente (p < 0.05) mais tóxica do que o óleo puro da planta. Conclusão - Desde que o produto formulado é aquele empregado na agricultura, existe um risco maior se comparado ao óleo puro, quando atinge animais que habitem um corpo de água.

Introdution - Azadirachta indicates A. Juss. (Meliaceae), is popularly knows as Neem or margosa. It is characterized by a leafy tree, present in tropical areas, probably originated from Asia. It is popularly used not only in medicine and cosmetic, but also in the agriculture, as a pesticide. The azadirachtin is the active substance of the oil and is the responsible for its pesticide effect. The current study compared the toxic effects of a commercial formulation made with the Neem oil and the pure Neem oil against Artemia sp. Material and Methods - The artemias employed here were in the nauplii I or II stage. These animals were submitted to different concentrations of the pure oil or of the formulated product. Death was assessed at 24 and 48 hours after the exposure. Results - Results showed that the commercial formulation was significantly (p < 0.05) more toxic when compared to the pure oil. Conclusion - Since the formulated product is employed as agricultural pesticide, it would be represent a great risk when animals from aquatic environment were attained than the pure oil of the plant.

Concentração inibitória mínima e concentração bactericida mínima de três extratos vegetais antibacterianos selecionados da Floresta Amazônica e da Mata Atlântica brasileiras / Minimal inhibitory concentration and minimal bactericidal concentration results from three selected antibacterial plant extracts from the Amazon and Atlantic Brazilian rain forests

Introdução - Em trabalho prévio, 705 extratos vegetais oriundos de plantas amazônicas e da Mata Atlântica foram triados no teste antibacteriano da microdiluição em caldo. No presente trabalho, os extratos ativos foram identificados e submetidos à avaliação da concentração mínima inibitória e da concentração bactericida mínima usando o mesmo modelo experimental. Material e Métodos - Foi utilizado o ensaio da microdiluição em caldo, que consiste em se avaliar a susceptibilidade das bactérias aos extratos vegetais em meio ágar caldo, em microplacas de 96 poços. Resultados = Os extratos orgânicos obtidos de Rapanea parvifolia (MY841), Smilax rufescens (SM53) e Ruizterania retusa (VO581) mostraram atividade antibacteriana. MY841 e SM53 mostraram atividade contra Enterococcus faecalis CIM = 30 ?g/ml; CBM = 60 ?g/ml e CIM = 80 ?g/ml; CBM = 90 ?g/ml, respectivamente) e VO581 mostrou atividade contra Staphylococcusaureus (CIM = 140 ?g/ml; CBM = 160 ?g/ml) e leve atividade contra Pseudomonas aeruginosa (CIM = 200 ?g/ml; CBM = 380 ?g/ml). Conclusões - Estes três extratos apresentaram atividade importante contra as bactérias testadas, devendo, portanto, ser fracionados e os compostos majoritários avaliados.

Introduction - Up to 705 plant extracts from Amazon Rain Forest and Atlantic Rain Forest were screened against bacteria using the microdilution broth assay. In the present work, minimal inhibitory concentration and minimal bactericidal concentration were obtained from the three selected active extracts. Material and Methods - The microdilution broth assay used in the present analysis consists in evaluating small amounts of extract against the bacteria in agar broth medium in 96 well microplates. Results - Three organic extracts obtained from Rapanea parvifolia (MY841), Smilax rufescens (SM53) and Ruizterania retusa (VO581) showed antibacterial activity. MY841 and SM53 showed activity against Enterococcus faecalis MIC = 30 mg/ml; MBC = 60 mg/ml and MIC = 80 mg/ml; MBC = 90 mg/ml, respectively) and VO581 showed activity against Staphylococcus aureus (MIC = 140 mg/ml; MBC = 160 mg/ml) and a mild activity against Pseudomonas aeruginosa (MIC = 200 mg/ml; MBC = 380 mg/ml). Conclusions - The three extracts showed important activity against the bacteria, and they are going to be fractionated and the fractions evaluated against the antibacterial model. The major compounds are going to be isolated as well.

Discovery of new antitumoral and antibacterial drugs from brazilian plant extracts using high throughput screening: [review]

Plants have played a significant role in the treatment of cancer and infectious diseases for the last four decades. The discovery and introduction to market of paclitaxel, the vinca alkaloids, etoposide, and many antibacterial drugs support drug discovery programs based on natural products. Natural products have been rediscovered as important tools for drug development despite advances in combinatorial chemistry, due to the complex molecular structures able to interact with mammalian cell targets. The Brazilian flora, the most diverse in the world, has become an interesting spot to prospect for new chemical leads or hits due to its species diversity and associated chemical richness. Screening programs have been established in Brazil as a strategy to identify potentially active substances. High throughput screening techniques allow for the analysis of large numbers of extracts in a relatively short period of time, and can be considered one of the most efficient ways of finding new leads from natural products. An updated review of the current status of the biological screening program is presented and recent results from new antitumoral and antibacterial chemical leads are discussed.

Plantas são uma importante fonte de novos protótipos há pelo menos quatro décadas. A descoberta e introdução no mercado de paclitaxel, dos alcalóides da vinca, etoposídeo e muitos agentes antibacterianos têm servido de apoio ao desenvolvimento de programas de descobrimento de novos fármacos baseados em produtos naturais. Produtos naturais foram recentemente redescobertos como importante ferramenta na descoberta de novos fármacos devido às estruturas moleculares complexas capazes de interagir com alvos em células de mamíferos. A flora brasileira, a mais rica do mundo, tornou-se um importante sítio para prospecção de novos protótipos em decorrência da riqueza de espécies vegetais relacionada a uma possível diversidade química. Programas de triagem têm sido introduzidos no Brasil contrapondo a devastação de florestas relacionadas a atividades rurais, extrativismo madeireiro e mineral. Ensaios em larga escala permitem a análise de um grande número de amostras em um tempo relativamente pequeno, e pode ser considerado como o método mais eficaz para a descoberta de novos fármacos a partir de plantas. Dados atualizados relativos a programas de triagem que objetivam a identificação de novos protótipos antitumorais e antibacterianos são comentados.

Antibacterial activity of Brazilian Amazon plant extracts

Infections caused by multiresistant bacteria are a widespread problem, especially in intensive care units. New antibiotics are necessary, and we need to search for alternatives, including natural products. Brazil is one of the hottest spots in the world in terms of biodiversity, but little is known about the chemical and pharmacological properties of most of the plants found in the Amazon rain forest and the Atlantic Forest. We screened 1,220 organic and aqueous extracts, obtained from Amazon and Atlantic rain forest plants, against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa and E. coli. Seventeen organic and aqueous extracts obtained from 16 plants showed activity against both Gram-positive bacteria. None of the extracts showed relevant activity against the Gram-negative E. coli and Pseudomonas aeruginosa.

Antibacterial activity of Apocynaceae extracts and MIC of Tabernaemontana angulata stem organic extract

Trinta e oito extratos orgânicos e aquosos obtidos de 11 espécies de Apocynaceae foram submitidos a triagem utilizando o método da microdiluiçäo em caldo contra Staphylococcus aureus, Pseudomonas aeruginosa e Candida albicans. O extrato orgânico obtido do caule de Tabernaemontana angulata apresentou atividade contra a bactéria Gram positiva S. aureus. A concentraçäo inibitória mínima verificada para esse extrato variou de 2,50 a 1,25 mg/mL. Cloranfenicol foi utilizado como antimicrobiano padräo. A análise fitoquímica indicou a presença de triterpenos e alcalóides no extrato ativo.

Determinação da atividade citotóxica a artemia de extratos de Annonaceae

A família das Annonaceae pertence à classe Magnoliopsida, subclasse Magnoliidae e ordem Magnoliales. Estima-se que existam entre 2.000 e 2.300 espécies1,2, sendo a maior de sua Ordem1. As espécies de Annonaceae são encontradas nos trópicos e são especialmente características de florestas sempre verdes de planícies em grande parte dos trópicos do velho mundo2. No Brasil, encontram-se amplamente distribuídas.

Avaliaçäo da atividade citotóxica, antiviral e antimicrobiana de Apocynaceae amazônicas / Evaluation of the activity cytotoxic, antiviral and antimicrobial of Apocynaceae Amazonian

A necessidade de se introduzir novos fármacos quimioterápicos é patente. Para tanto, a modelagem molecular, a terapia gênica e os produtos naturais têm sido os caminhos escolhidos para a obtenção de novas moléculas. As florestas brasileiras estão entre os principais celeiros de biodiversidade, grande parte não estudada do ponto de vista fitoquímico e farmacológico. Isso implica em grandes possibilidades de identificação de novos fármacos, uma vez que a riqueza da biodiversidade biológica pode ser refletida na riqueza da biodiversidade química. Trinta e oito extratos provenientes de espécies de Apocynaceae foram submetidos a um estudo de triagem farmacológica antiviral, antimicrobiana e citotoxicidade, in vitro...