Antiplasmodial evaluation of Anacardium occidentale and alkyl-phenols

Abstract The ethanol crude extract from cashew (Anacardium occidentale L. Anacardiaceae) displayed significant antiplasmodial activity (IC50 0.577 µg/ml). Liquid chromatography-high resolution Mass spectrometry analysis was performed to identify the main compounds existing in the ethanol extract. The occurrence of anacardic acids, cardols, and 2-methylcardols derivatives was confirmed in the extract. The IC50 obtained, when the main isolated compounds were evaluated in Plasmodium falciparum D6 strain, ranged from 5.39 µM to >100 µM. Tested here for the first time, the data showed that cardol triene 1 (IC50 = 5.69 µM) and 2-methylcardol triene 4 (IC50 = 5.39 µM) demonstrated good antimalarial activity. In conclusion, Anacardium occidentale nuts presented relevant biological potential, and further studies should be considered.

Antibacterial activity of (-)-cubebin isolated from Piper cubeba and its semisynthetic derivatives against microorganisms that cause endodontic infections

Abstract Recent publications have highlighted the numerous biological activities attributed to the lignan (-)-cubebin (1), Piper cubeba L. f., Piperaceae, and ongoing studies have focused on its structural optimization, in order to obtain derivatives with greater pharmacological potential. The aim of this study was the obtainment of (1), its semisynthetic derivatives and evaluation of antibacterial activity. The extract of the seeds of P. cubeba was chromatographed, subjected to recrystallization and was analyzed by HPLC and spectrometric techniques. It was used for the synthesis of: (-)-O-methylcubebin (2), (-)-O-benzylcubebin (3), (-)-O-acetylcubebin (4), (-)-O-(N, N-dimethylamino-ethyl)-cubebin (5), (-)-hinokinin (6) and (-)-6.6'-dinitrohinokinin (7). The evaluation of the antibacterial activity has been done by broth microdilution technique for determination of the minimum inhibitory concentration and the minimum bactericidal concentration against Porphyromonas gingivalis, Prevotella nigrescens, Actinomyces naeslundii, Bacteroides fragilis and Fusobacterium nucleatum. It was possible to make an analysis regarding the relationship between structure and antimicrobial activity of derivatives against microorganisms that cause endodontic infections. The most promising were minimum inhibitory concentration =50 µg/ml against P. gingivalis by (2) and (3), and minimum inhibitory concentration =100 µg/ml against B. fragilis by (6). Cytotoxicity assays demonstrated that (1) and its derivatives do not display toxicity.

Effects of (-)-6,6'-dinitrohinokinin on adult worms of Schistosoma mansoni: a proteomic analyses

Abstract Schistosomiasis, a chronic disease that affects million people worldwide, is caused by trematode flukes of the genus Schistosoma. The lack of an anti-schistosomiasis vaccine and massive monotherapy with praziquantel reinforces the need for search and development of new therapeutic drugs. Recently, we demonstrated that the essential oil of Piper cubeba L., Piperaceae, and their derivative dibenzylbutyrolactolic (-)-6,6'-dinitrohinokinin, presents in vitro and in vivo activities against Schistosoma mansoni. Here, we identified changes in the protein expression after exposure to dibenzylbutyrolactolic (-)-6,6'-dinitrohinokinin. We applied two-dimensional gel electrophoresis (2-DE) to S. mansoni soluble protein extracts and observed at least 38 spots to be affected by dibenzylbutyrolactolic (-)-6,6'-dinitrohinokinin. We further identified 25 differentially expressed proteins by mass spectrometry. Enrichment for biological processes and predictive analyses of protein-protein interactions suggest that dibenzylbutyrolactolic (-)-6,6'-dinitrohinokinin targets proteins involved mainly in metabolic processes, especially carbohydrate metabolism. In summary, this study provides an interesting approach to understand the anti-parasitic activity of semi-synthetic (-)-6,6'-dinitrohinokinin a derivative compound from lignan and for the development of new therapy strategies.

Chemical composition, antischistosomal and cytotoxic effects of the essential oil of Lavandula angustifolia grown in Southeastern Brazil

This paper reports on the chemical composition, the in vitro antischistosomal effects, and the cytotoxicity of the essential oil from the leaves of Lavandula angustifolia Mill., Lamiaceae, grown in the Southeastern Brazil. Borneol (22.4%), epi-α-muurolol (13.4%), α-bisabolol (13.1%), precocene I (13.0%), and eucalyptol (7.9%) were the major essential oil constituents. Incubation with essential oil at 200 μg/ml killed all the adult S. mansoni worms after 24 h (LC50 117.7 and 103.9 μg/ml at 24 and 120 h of incubation, respectively). At a concentration of 50 μg/ ml, the essential oil significantly decreased the motor activity and reduced the percentage of egg development after 120 h. In addition, the essential oil separated all the coupled S. mansoni worm pairs into individual male and female at 25 and 50 μg/ml within 120 and 24 h, respectively. This oil was cytotoxic to GM07492-A cells at only concentrations higher than 200 µg/ml (IC50 243.7 µg/ml). These data indicate that LA-EO exhibits moderate in vitro activity against adult S. mansoni and exerts remarkable effects on eggs development.

Evaluation of antimicrobial activity of extracts of Tibouchina candolleana (melastomataceae), isolated compounds and semi-synthetic derivatives against endodontic bacteria

This work describes the phytochemical study of the extracts from aerial parts of Tibouchina candolleana as well as the evaluation of the antimicrobial activity of extracts, isolated compounds, and semi-synthetic derivatives of ursolic acid against endodontic bacteria. HRGC analysis of the n-hexane extract of T. candolleana allowed identification of b-amyrin, a-amyrin, and b-sitosterol as major constituents. The triterpenes ursolic acid and oleanolic acid were isolated from the methylene chloride extract and identified. In addition, the flavonoids luteolin and genistein were isolated from the ethanol extract and identified. The antimicrobial activity was investigated via determination of the minimum inhibitory concentration (MIC) using the broth microdilution method. Amongst the isolated compounds, ursolic acid was the most effective against the selected endodontic bacteria. As for the semi-synthetic ursolic acid derivatives, only the methyl ester derivative potentiated the activity against Bacteroides fragilis.

In vitro schistosomicidal effects of the essential oil of Tagetes erecta

The in vitro schistosomicidal effects of the essential oil obtained from Tagetes erecta L. Asteraceae, leaves (TE-EO) collected in Brazil against Schistosoma mansoni worms are reported in this paper. The oil caused a significant decrease in the motor activity at 50 µg/mL as minimal concentration after 24 h. This oil also caused death of all the parasites and the separation of coupled pairs into individual male and female at 100 µg/mL after 24 h. The viability of adult worm groups treated with the TE-EO at 100 µg/mL was similar to that of groups treated with praziquantel (positive control). In addition, the oil promoted the inhibition of eggs development at all the tested concentrations. These data indicate that the TE-EO could be considered as a promising source for the development of new schistosomicidal agents.

Antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens / Atividade antimicrobiana de Aegiphila sellowiana Cham., Lamiaceae, contra patógenos orais

The antimicrobial activity of Aegiphila sellowiana Cham., Lamiaceae, against oral pathogens is reported. The Minimal Inhibitory Concentrations (MICs) for inhibiting the microorganisms growth were determined using the broth microdilution method from the CLSI M7-A7 protocol. Chlorhexidine was used as the positive control. The ethanol crude extract of the aerial parts of A. sellowiana exhibited activity against the microorganisms tested in this work; however, the activity decreased after partition with n-hexane, dichloromethane, and ethyl acetate. Among the tested fractions, the n-hexane fraction was found to be the most effective against the evaluated oral pathogens. GC-MS analysis of this latter fraction revealed that fatty acids esters, steroids, and aliphatic sesquiterpene hydrocarbons are its major constituents. These compounds may be responsible for the activity of the n-hexane fraction, but other chemical constituents of the dichloromethane, ethyl acetate, and hydroalcoholic fraction may potentialize their activities in the crude extract.

A atividade antimicrobiana de Aegiphila sellowiana Cham., Lamiaceae, contra patógenos da cavidade bucal foi avaliada empregando-se o método de microdiluição em caldo, segundo o protocolo CLSI M7-A7, utilizando-se clorexidina como controle positivo. O extrato etanólico bruto das partes aéreas de A. sellowiana, obtido por maceração, exibiu atividade contra os microrganismos testados neste trabalho, entretanto, os valores de CIM (concentração inibitória mínima) aumentaram após a partição com n-hexano, diclorometano e acetato de etila. Entre as frações testadas, a fração n-hexânica foi a mais efetiva contra os patógenos bucais avaliados, com valores de CIM entre 140 e 350 µg/mL-1. Dados obtidos por CG-EM revelaram que ésteres de ácidos graxos, esteróides e hidrocarbonetos sesquiterpênicos alifáticos são os constituintes majoritários desta fração. Embora esses compostos possam ser os responsáveis pela atividade da fração n-hexânica, outros constituintes químicos presentes nas frações em diclorometano, acetato de etila e hidroalcoólica podem potencializar suas atividades no extrato bruto.