Genotoxic Effects of Semi-Synthetic Isodillapiole on Oviposition in Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

Abstract INTRODUCTION: Semi-synthetic dillapiole compounds derived from Piper aduncum essential oil are used as alternative insecticides to control insecticide-resistant Aedes aegypti. Thus, we aimed to evaluate the genotoxic effects of semi-synthetic isodillapiole on the nuclei of neuroblasts (larvae) and oocytes (females) and the mean oviposition rates of the females over four generations (G1, G2, G3, and G4) of Ae. aegypti. METHODS: Larvae were captured in the city of Manaus, Amazonas state, Brazil, and exposed to isodillapiole in bioassays (20, 40, and 60 µg/mL) and a negative control (0.05% DMSO in tap water) for 4 h. The cerebral ganglia were extracted from the larvae and oocytes from the adult females to prepare slides for cytogenetic analysis. Breeding pairs were established and eggs counts were quantified taken after the bioassays. RESULTS: The analysis of 20,000 interphase nuclei of neuroblasts and oocytes indicated significant genotoxicity (micronuclei, budding, polynucleated cells, and other malformations) compared to that of the control. Metaphasic and anaphasic nuclei presented chromosomal breaks; however, no significant variation and damage was observed in the negative control. A significant reduction in mean oviposition rates was also recorded following exposure to isodillapiole over the four generations (G1, G2, G3, and G4). CONCLUSIONS: The toxic and genotoxic effects of isodillapiole on Ae. aegypti were caused by reduced oviposition in the females and nuclear abnormalities over the four generations of the trials. Further studies are required, rather than our in vitro assays, to verify the efficacy of exposure to this compound for controlling Ae. aegypti.

First phytochemical description of essential oils from Piper cachimboense (Piperales, Piperaceae) / Primeira descrição fitoquímica de óleos essenciais de Piper cachimboense (Piperales, Piperaceae)

Piper cachimboense is recorded only for the Amazon region of Brazil and Colombia, and the objective of this study was to report the first phytochemical assessment of the composition of the essential oils (EOs) from this species collected in the Amazon rainforest, in Novo Progresso, Pará State, Brazil. Samples of leaves were subjected to hydrodistillation in a Clevenger-type apparatus. The chemical identification was carried out by gas chromatography. The yield of oils was of 11.03 ± 5.94% for fresh leaves, and 1.07 ± 0.27% for dry leaves. The analysis showed 36 volatile compounds from fresh leaves and 49 from dried leaves. Main constituents in EOs of both fresh and dried leaves from P. cachimboense were (E)-caryophyllene, germacrene-D, -amorfene, -cadinene and apiole.

Piper cachimboense é registrada apenas para a região amazônica do Brasil e Colômbia, e o objetivo deste estudo foi relatar, pela primeira vez, a composição fitoquímica dos óleos essenciais (OEs) desta espécie coletada na floresta amazônica, em Novo Progresso/PA, Brasil. Amostras de folhas foram submetidas a hidrodestilação em aparelho tipo Clevenger. A identificação química foi realizada por cromatografia gasosa e o rendimento dos óleos foi de 11,03 ± 5,94% para as folhas frescas e de 1,07 ± 0,27% para as folhas secas. A análise mostrou 36 compostos voláteis para folhas frescas e 49 para folhas secas. Os constituintes principais dos OEs de folhas frescas e secas de P. cachimboense foram (E)-cariofileno, germacreno-D, -amorfeno, -cadineno e apiol.

Piper aduncum against Haemonchus contortus isolates: cross resistance and the research of natural bioactive compounds / Piper aduncum contra isolados de Haemonchus contortus: resistência cruzada e a pesquisa de bioativos naturais

Abstract The anthelminthic activity of the essential oil (EO) of Piper aduncum L. was tested in vitro on eggs and larvae of resistant (Embrapa2010) and susceptible (McMaster) isolates of Haemonchus contortus. The EO was obtained by steam distillation and its components identified by chromatography. EO concentrations of 12.5 to 0.02 mg/mL were used in the egg hatch test (EHT) and concentrations of 3.12 to 0.01 mg/mL in the larval development test (LDT). Inhibition concentrations (IC) were determined by the SAS Probit procedure, and significant differences assessed by ANOVA followed by Tukey’s test. In the EHT, the IC50 for the susceptible isolate was 5.72 mg/mL. In the LDT, the IC50 and IC90 were, respectively, 0.10 mg/mL and 0.34 mg/mL for the susceptible isolate, and 0.22 mg/mL and 0.51 mg/mL for the resistant isolate. The EO (dillapiole 76.2%) was highly efficacious on phase L1. Due to the higher ICs obtained for the resistant isolate, it was raised the hypothesis that dillapiole may have a mechanism of action that resembles those of other anthelmintic compounds. We further review and discuss studies, especially those conducted in Brazil, that quantified the major constituents of P. aduncum-derived EO.

Resumo Este estudo avaliou a atividade anti-helmíntica in vitro do óleo essencial (OE) de Piper aduncum L. sobre ovos e larvas de Haemonchus contortus, verificando se um isolado resistente (Embrapa2010), apresentaria o mesmo comportamento que um sensível (McMaster). O OE foi obtido por arraste a vapor e analisado por cromatografia para identificação dos constituintes. O óleo foi avaliado nas concentrações de 12,5 a 0,02 mg/mL no Teste de eclosão dos ovos (TEO) e nas concentrações de 3,12 a 0,01 mg/mL no Teste de desenvolvimento larvar (TDL). As concentrações inibitórias (CI) foram determinadas pelo procedimento Probit do SAS e as diferenças estatísticas geradas pela ANOVA seguida pelo teste de Tukey. Para o isolado sensível obteve-se CI50 de 5,72 mg/mL no TEO. No TDL o óleo apresentou CI50 e CI90 de 0,10 mg/mL e 0,34 mg/mL para o isolado sensível e 0,22 mg/mL e 0,51 mg/mL para o resistente, respectivamente. Demonstrou-se que o OE (dilapiol 76,2%) teve alta eficácia sobre a fase L1. Devido às elevadas CIs obtidas para o isolado resistente, levantou-se a hipótese de que o dilapiol talvez possua um mecanismo de ação semelhante a algum grupo anti-helmíntico. O artigo faz uma revisão e discute estudos de quantificação dos constituintes majoritários do OE de P. aduncum, destacando os realizados no Brasil.

Antifungal Action of the Dillapiole-rich Oil of Piper aduncum against Dermatomycoses Caused by Filamentous Fungi.

Aims and Study Design: Piper aduncum L. is a Brazilian plant with many biological properties attributed to its dillapiole-rich essential oil. Despite the development of antibiotics, bacterial and fungal infections are still a public health issue in the medical field. This study measured the antimicrobial activity of the dillapiole-rich essential oil of P. aduncum against pathogenic skin microorganisms. Place of Study: Faculty of Pharmacy and Graduate Program in Pharmaceutical Science, Federal University of Pará, Brazil. This work was performed in 2014. Methodology: Gas Chromatography (GC) and Gas Cromatography-Mass spectrometry (GC-MS) have analyzed the oil and its dillapiole-rich fraction. The determination of Minimum Inhibitory Concentration (MIC) and Minimum fungicidal concentration (MFC) values was carried out by microdilution method and counting of formed colonies. Results: For the strains of Trichophyton mentagrophytes (ATCC 9533 and clinical isolate), the oil and its dillapiole-rich fraction exhibited MIC values of 500 μg/ml while the MFC values were 1,500 μg/ml for the oil and 1,000 μg/ml for the fraction rich in dillapiole. For clinical isolates of T. rubrum and Epidermophyton floccosum, MIC values of 500 μg/ml and MFC 1,500 μg/ml were equal for the oil and the dillapiole-rich fraction, respectively. For clinical isolates of Microsporum canis and M. gypseum, the MIC and MFC values were 250 μg/ml and 500 μg/ml, respectively. For strains of Aspergillus fumigatus (ATCC 40152 and clinical isolate), the oil and its dillapiole-rich fraction have shown the same MIC value of 3.9 μg/ml while the MFC values were 7.8 μg/ml for the strain ATCC 40152, and 15.6 μg/ml for the clinical isolate. The oil and dillapiole-rich fraction did not show antibacterial activity against the strain of Staphylococcus aureus ATCC 6538 and its clinical isolate Conclusion: The dillapiole-rich essential oil of P. aduncum and its dillapiole-rich fraction demonstrates significant antifungal activity against dermatophytes, filamentous fungi and potent antifungal activity against non-dermatophyte filamentous fungi.

Antibacterial activity of the Piper aduncum oil and dillapiole, its main constituent, against multidrug-resistant strains / Actividad antibacteriana del aceite de Piper aduncum y dillapiole, su componente principal, frente a cepas resistentes a múltiples fármacos

The study aimed to evaluate the bactericidal activity of oil essential and dillapiole from P. aduncum against standard and multidrug-resistant strains of Staphylococcus spp. The oil showed antimicrobial action against these strains, but better results were obtained for the standards strains of S. epidermidis and S. aureus, with MIC of 250 and 500 ug/mL, respectively. Dillapiolle was less effective than the oil against the same standard and multi-drug resistant strains (MIC =1000 ug/mL). However, when dillapiolle was tested in combination with myristicin, another component of the oil, it increased its bactericidal activity and showed a synergistic action...

El objetivo del estudio fue evaluar la actividad bactericida de los aceites esenciales y dillapiole de P. aduncum contra cepas estándar y multirresistentes de Staphylococcus spp. El aceite mostró acción antimicrobiana frente a estas cepas, pero se obtuvo mejores resultados para las cepas de S. epidermidis y S. aureus, con MIC de 250 y 500 ug/ml, respectivamente. Dillapiolle fue menos eficaz que el aceite contra cepas estándar y multirresistentes (MIC = 1000 ug/ml). Sin embargo, cuando dillapiolle fue probado en combinación con la miristicina, otro componente del aceite, que aumentó su actividad bactericida y mostró una acción sinérgica...

Rendimento e composição do óleo essencial de Piper aduncum L. cultivado em Manaus, AM, em função da densidade de plantas e épocas de corte / Yield and composition of the essential oil from Piper aduncum L, cultivated in Manaus, AM, regarding plant density and cutting period

A pimenta-de-macaco (Piper aduncum L. - Piperaceae) é uma espécie usada na medicina popular em quase todo o Brasil e apresenta alto teor de óleo essencial (2,5 a 4,0%) rico em dilapiol - éter fenílico com ação inseticida. O presente trabalho teve como objetivo contribuir para o sistema de cultivo da espécie P. aduncum nas condições de Manaus - AM. O experimento foi realizado na área experimental da Embrapa Amazônia Ocidental. O delineamento utilizado foi o de blocos casualizados com quatro repetições, cada repetição com quatro plantas na área útil. Sete densidades de plantas (0,5 m x 0,5 m; 1,0 m x 0,5 m; 1,0 m x 1,0 m; 1,5 m x 1,0 m; 1,5 m x 1,5 m; 2,0 m x 1,5 m e 2,0 m x 2,0 m, E1 a E7, respectivamente) e três épocas de corte (C1 - 6 meses após transplantio; C2 - rebroto de C1 aos 6 meses - plantas com idade de 12 meses, no campo; C3 - rebroto de C2 aos 6 meses - plantas com 18 meses, no campo), portanto em esquema fatorial. Foi observado que o segundo corte (C2) apresentou maior produção, no espaçamento E4. Não houve diferença estatística para o teor de óleo essencial em C1, independente da densidade de plantas. Com relação ao rendimento (produção) em óleo essencial, o melhor foi observado com o corte C2, nos espaçamentos E3 e E4, com 76,0 kg/ha e 88 kg/ha, respectivamente, contendo até 85,6% de dilapiol no óleo. Assim, a melhor condição de cultivo nas condições de teste foi observada para o período de corte C2 e espaçamentos de 1,0 m x 1,0 m, e de 1,0 m x 1,5 m.

Pimenta-de-macaco (monkey pepper - Piper aduncum L. - Piperaceae) is a species used in folk medicine throughout Brazil, containing an essential oil (2.5 to 4.0% yield) rich in dillapiole, an arylpropanoid with insecticide action. The objective of this research was to improve the cultivation system of P. aduncum in local conditions of Manaus, AM. The study was conducted in the experimental fields of Embrapa Western Amazon, and used randomized blocks with four replicates, each replicate with four plants in its testing area. Seven plant densities (0.5 m x 0.5 m; 1.0 m x 0.5 m; 1.0 m x 1.0 m; 1.5 m x 1.0 m; 1.5 m x 1.5 m; 1.5 m 2.0 m; 2.0 m x 2.0 m, E1 to E7 respectively) and three cutting periods (C1 - 6 months after transplanting, C2 - regrowth of C1 after 6 months (plants with 12 months in the field) and C3 - regrowth of C2 after 6 months (plants with 18 months in the field), therefore in a factorial scheme. A larger production was observed in the second cutting (C2) in the plant density E4. There were no statistical differences in the essential oil content in C1, regardless of densities. In relation to the essential oil yield, the best result was observed for the cutting period C2 in the E3 and E4 densities, 76.0 kg/ha and 88 kg/ha, respectively, with a dillapiole content of up to 85.6%. Therefore, the best cultivation condition according to the test was observed for the cutting after 12 months of transplantation and plant density of 1.0 m x 1.0 m or 1.5 m x 1.5 m.