ABSTRACT
Chagas disease is one of the main public health problems in Latin America. Since the available treatments for this disease are not effective in providing cure, the screening of potential antiprotozoal agents is essential, mainly of those obtained from natural sources. This study aimed to provide an evaluation of the trypanocidal activity of 92 ethanol extracts from species belonging to the families Annonaceae, Apiaceae, Cucurbitaceae, Lamiaceae, Lauraceae, Moraceae, Nyctaginaceae, and Verbenaceae against the Y and Bolivia strains of Trypanosoma cruzi. Additionally, cytotoxic activity on LLCMK2 fibroblasts was evaluated. Both the trypanocidal activity and cytotoxicity were evaluated using the MTT method, in the following concentrations: 500, 350, 250, and 100 µg/mL. Benznidazole was used for positive control. The best results among the 92 samples evaluated were obtained with ethanol extracts of Ocotea paranapiacabensis (Am93) and Aegiphila lhotzkiana (Am160). Am93 showed trypanocidal activity against epimastigote forms of the Bolivia strain and was moderately toxic to LLCMK2 cells, its Selectivity Index (SI) being 14.56, while Am160 showed moderate trypanocidal activity against the Bolivia strain and moderate toxicicity, its SI being equal to 1.15. The screening of Brazilian plants has indicated the potential effect of ethanol extracts obtained from Ocotea paranapiacabensis and Aegiphila lhotzkiana against Chagas disease.
ABSTRACT
In vitro activity of the essential oil from Piper diospyrifolium leaves was tested using disk diffusion techniques. The antifungal assay showed significant potencial antifungal activity: the oil was effective against several clinical fungal strains. The majority compounds in the essential oil were identified as sesquiterpenoids by GC-MS and GC-FID techniques.
Subject(s)
Antifungal Agents , In Vitro Techniques , Plant Structures , Piper/growth & development , Piper/genetics , Piperaceae/genetics , Sesquiterpenes/analysis , Trees , Atlantic Ocean , Methods , Oils, Volatile , Plant Leaves , Plant Preparations , MethodsABSTRACT
A necessidade da introdução de novos agentes quimioterápicos é uma realidade no controle de doenças infecciosas. O Brasil é o país mais rico em biodiversidade, e o Laboratório de Extração da Universidade Paulista tem coletado plantas na Amazônia e Mata Atlântica com a finalidade de identificar extratos vegetais antibacterianos e antitumorais. Estudos prévios demonstraram que a fração etanólica obtida do extrato bruto orgânico do caule de Tabernaemontana angulata Mart. ex Müll. Arg. apresentou atividade antimicrobiana significante contra Staphylococcus aureus ATCC6538, no ensaio de diluição em caldo. Verificou-se por cromatografia em camada delgada que os compostos majoritários presentes na fração ativa eram alcalóides. No presente trabalho, foi obtida a fração de alcalóides totais a partir do extrato bruto, da qual os compostos majoritários foram isolados por sucessivas cromatografias e, posteriormente, identificados por CG-EM e ¹H-RMN como os alcalóides indólicos coronaridina e voacangina. As frações obtidas do isolamento foram testadas no ensaio biológico, porém não demonstraram atividade antimicrobiana.
Introducing new chemotherapeutic agents is a great demand in the control of infectious diseases. Brazil is one of the richest countries in biodiversity and the Laboratório de Extração at UNIP has been collecting plants from the Amazon and Atlantic Rain Forests with the aim of screening for new antibacterial and antitumor plant extracts. Previous studies demonstrated that the ethanol fraction obtained from the crude extract of Tabernaemontana angulata stems showed an antibacterial activity against Staphylococcus aureus (ATCC 6538) in the microdilution broth assay. Two alkaloids were the major compounds in the active fraction, verified by thin layer chromatography analysis. In the present study, the total alkaloids were obtained from the crude extract and were fractionated by preparative thin layer chromatography for the isolation of the main components. The isolated compounds were identified by GC/MS and ¹H-NMR as coronaridine and voacangine. The alkaloid fractions obtained from the isolation procedure were tested for antibacterial activity, but no activity was detected.
ABSTRACT
Crude extracts from 17 plant species collected from an Atlantic Forest regionin the State of São Paulo (Brazil) have been screened for antifungal, DNA-damaging and acetylcholinesterase inhibiting activities. Of the 34 extracts obtained from leaves and stems ofplants assayed for antifungal activity with Cladosporium sphaerospermum and C. cladosporioides 26.5% were active. However, only the extract of leaves of Cabralea canjerana showed a stronginhibition of both fungi. The DNA-damaging assay with mutant strains of Saccharomyces cerevisiae resulted in 11.7 % of the extracts being active whereas 100% of them showedselectivity for the DNA-repair mechanism of topoisomerase II. Of the 17 species analysed, 12 showed anticholinesterasic activity in TLC assay. However, only extracts from Tetrastylidium grandifolium (stems) and Sloanea guianensis (leaves and stems) inhibited acetylcholinesterase activity more than 50% in quantitative assay.
Extratos brutos de 17 espécies de plantas coletadas em região de Mata Atlântica no Estado de São Paulo (Brasil)foram avaliadas para as atividades: antifúngica, no reparo do DNA e inibição da acetilcolinesterase. Dos 34 extratos obtidos de folhas e galhos das plantas analisadas para a atividade antifúngicacom Cladosporium sphaerospermum e C. cladosporioides, 26,5% foram ativos. Todavia, apenas o extrato das folhas de Cabralea canjerana inibiu fortemente o crescimento dos dois fungos. No ensaio de reparo do DNA com linhagens mutantes de Saccharomyces cerevisiae, 11,7% dos extratos foram ativos, sendo que, 100% destes foram seletivos para o mecanismo de reparo do DNA envolvendo topoisomerase II. Das 17 espécies analisadas, 12 demonstraram atividade anticolinesterásica no ensaio qualitativo sobre cromatografi a de camada delgada (CCD). No entanto, apenas os extratos de Tetrastylidium grandifolium (galhos) e Sloanea guianensis (folhas e galhos) apresentaram atividade anticolinesterásica maior que 50% no ensaio quantitativo.
ABSTRACT
Chromatographic fractionation of the organic extract from leaves of Ouratea multiflora afforded the flavone dimers heveaflavone, amentoflavone-7'',4''''-dimethyl eter, podocarpusflavone-A and amentoflavone. Their structures were elucidated from spectral data, including 2D-NMR experiments of the natural substances. Biological activities of all isolates were evaluated, using antimicrobial assay against Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis, cytotoxicity assay against mouse lymphoma (L5178) and KB cell lines, TLC screening for acetylcholinesterase inhibitors and antioxidant activity measured by DPPH test.
O fracionamento cromatográfico do extrato orgânico das folhas de Ouratea multiflora forneceu os flavonóides diméricos, heveaflavona, 7'',4''''-dimetilamentoflavona, podocarpusflavona-A e amentoflavona. Suas estruturas foram elucidadas com base nos dados espectrais, incluindo experimentos bidimensionais de RMN, das substâncias naturais. A atividade antibiótica de todos os isolados foi avaliada, usando-se as bacterias Gram-positivas Staphylococcus aureus and Bacillus subtilis. Teste de citotoxicidade nas linhagens de linfoma de ratos (L5178) e KB também foram conduzidos para avaliar os extratos e os flavonóides isolados. a triagem biológica para a avaliação de atividade antioxidante e inibidora de acetil colinesterase foram conduzidas pela técnica da bioautografia com DPPH e teste pelo teste de Ellman respectivamente.
Subject(s)
Biflavonoids/pharmacology , Biflavonoids/isolation & purification , In Vitro Techniques , Ochnaceae , Ochnaceae/chemistryABSTRACT
The bioassay-guided fractionation of stems from Kielmeyera variabilis, traditionally used in Brazilian folk medicine, yielded assiguxanthone-B (1), kielcorin (4), 2,5-dihydroxybenzoic acid (3), and a mixture of xanthones containing assiguxanthone-B (1) and 1,3,5,6-tetrahydroxy-2-prenylxanthone (2) (1:1 w/w). The xanthone mixture inhibited Staphylococcus aureus and Bacillus subtilis at a concentration of 6.25 µg/ml. When tested alone, the minimal inhibitory concentration of assiguxanthone-B was 25 µg/ml against B. subtilis. Kielcorin and 2,5-dihydroxybenzoic acid were inactive against both strains. None of the fractions was active against Escherichia coli or Pseudomonas aeruginosa. Viable cells of S. aureus were reduced by a 1-3 log CFU/ml within 12 h after exposure of one to eight times the MIC of the xanthone mixture. It is not known whether the tetrahydroxy-2-prenylxanthone or other components of the xanthone mixture are responsible for the main antibacterial activity or whether additive or synergistic action is involved
Subject(s)
Anti-Infective Agents , Gram-Negative Bacteria , Gram-Positive Bacteria , Ericales , Xanthenes , Anti-Infective Agents , Bacillus subtilis , Drug Synergism , Escherichia coli , Microbial Sensitivity Tests , Plant Extracts , Pseudomonas aeruginosa , Staphylococcus aureus , Time Factors , XanthenesABSTRACT
O estudo da atividade antimicrobiana de nove semicarbazonas heterociclicas foi efetuado atraves de tres metodos, ineditos para estes compostos nas condicoes em que foram efetuados. No metodo da diluicao seriada em meio liquido utilizaram-se Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans e Aspergillus niger como microorganismos testes, ao passo que no metodo da difusao em meio solido utilizaram-se apenas Staphylococcus aureus, Escherichia coli e Candida albicans. Verificou-se que a atividade dos compostos foi muito baixa quando comparada com a 5-nitro-2-furanocarboxaldeidos semicarbazona, de atividade anteriormente comprovada. Pelo metodo da bioautografia verificou-se que das nove semicarbazonas ensaiadas, seis inibiram o crescimento do Cladosporium sphaerospermum