Anti-Trypanosoma cruzi and cytotoxic activities of Eugenia uniflora L

Genome-Wide Identification and Analysis of DOF Gene Family in Eugenia uniflora L. (Myrtaceae)

Eugenia uniflora is a Brazilian native plant species with great ecological and economic importance. It is distributed throughout the Atlantic forest, where two distinct populations show local adaptation to the contrasting conditions of restinga and riparian forest. Among various TFs described in plants, the DOF TF family has been reported to affect flowering and vascular development, making them promising candidates for characterization in E. uniflora. In this study, 28 DOF genes were identified by a genome-wide analysis, of which 20 were grouped into 11 MCOGs by Bayesian phylogeny, suggesting a shared functionallity between members. Based on RNA-seq experiments, we have detected eight drought responsive genes, and SNPs identification revealed population unique polymorphisms, implying a role in local adapatation mechanisms. Finally, analysis of conserved motifs through MEME revealed 15 different protein motifs, and a promoter region analysis returned 40 enriched TF binding motifs, both reporting novel biological functions circa the DOF gene family. In general, the DOF family is found to be conserved both in sequence and expression. Furthermore, this study contributes to both DOF literature and the genetic exploration of native species, elucidating their genetic potential and bringing to light new research topics, paving the way to future studies.

EFEITO IN VITRO E IN VIVO DE EXTRATOS DE Eugenia uniflora EM NEMATÓDEOS GASTRINTESTINAIS DE OVINOS

Resumo Este estudo avaliou a ação in vitro e in vivo de extratos de Eugenia uniflora em nematódeos gastrintestinais de ovinos. No teste de inibição da eclodibilidade dos ovos, extratos aquosos e hidroalcoólicos foram testados nas concentrações de 40 a 1,25 mg/mL. O efeito citotóxico foi mensurado através do ensaio de MTT em células VERO nas concentrações de 4000 a 1,95 µg/mL. A composição química foi analisada através da marcha fitoquímica qualitativa. No teste in vivo, foram administrados 100 mg/kg, por via oral, do extrato hidroalcoólico por três dias em ovinos naturalmente infectados e realizada coleta de fezes para estimar a redução de ovos por grama de fezes (OPG). Diferentes extratos de E. uniflora inibiram a eclodibilidade dos ovos, com percentual de inibição variando de 14,56 a 99,75%, sendo os hidroalcoólicos mais promissores que os aquosos. Na marcha fitoquímica, compostos com ação anti-helmíntica comprovada foram observados, como flavonoides, saponinas, taninos e triterpenos. Nas condições testadas, os extratos apresentaram citotoxicidade nula a moderada. In vivo, a redução do OPG foi observada apenas no grupo controle (anti-helmíntico). Os extratos de E. uniflora mostraram-se promissores com ação in vitro, necessitando estudos que avaliem outras concentrações e formas de administração in vivo.

Efficacy of essential oil of Syzygium aromaticum alone and in combination with benznidazole on murine oral infection with Trypanosoma cruzi IV

Chagas disease (CD), caused by Trypanosoma cruzi, remains a serious public health problem. One of the causes of the high morbidity and mortality in patients is the lack of an effective drug therapy. Thus, the aim of this study was to evaluate the efficacy of the essential oil of Syzygium aromaticum alone and in combination with benznidazole (BZ) in mice orally inoculated with strain of T. cruzi IV obtained from oral CD outbreak occurred in Western Brazilian Amazonia. All the animals inoculated with metacyclic trypomastigote forms (AM14 strain, BZ resistant), derived from the insect Rhodnius robustus, became infected and there was no difference in the mortality rate between the experimental groups. When compared with untreated control animals (UTC), the treatment with essential oil of S. aromaticum (EOSA) alone promoted reduction in 1/5 parameters derived from the parasitemia curve, whereas the treatments with BZ alone or in combination (BZ + EOSA) promoted reduction in 4/5 of those parameters, presenting similar profiles of parasitemia curve. The animals treated with BZ and with the combination BZ + EOSA presented lower patency periods in comparison with the animals in EOSA group, and lower positivity of blood cultures when compared with the UTC group. The results of molecular analysis by qPCR in both blood and cardiac tissue did not show differences between the groups. The cure rates obtained with the different treatments presented the following ascending order: EOSA = 12.5% (1/8), BZ = 25.0% (2/8) and BZ + EOSA = 37.5% (3/8). Although there are no significant differences between them, these results claims that the use of this essential oil could be of interest for treatment of Chagas disease.

Anti-Trypanosoma, anti-Leishmania and cytotoxic activities of natural products from Psidium brownianum Mart. ex DC. and Psidium guajava var. Pomifera analysed by LC-MS

Neglected diseases are those that are prevalent in developing countries, even with a rich biodiversity. These diseases still persist because of the lack of scientific studies, government negligence or failures of the public health system. This study aims to identify the composition of extracts and fractions from Psidium brownianum and Psidium guajava through LC-MS, to evaluate its in vitro anti-parasitic and cytotoxic activity against Trypanosoma cruzi, Leishmania brasiliensis and L. infantum epismastigote and promastigote forms, as well as mammalian cells. The results showed the presence of chemical constituents in the two Psidium species as quercetin, myricetin and gallic acid derivatives. The P. brownianum extract and fractions showed low toxicity at all tested concentrations and all samples were effective at the concentration of 1000μg/mL against the parasites, with the extract being the most efficient against the L. infantum promastigote form. The ethanolic extract, and the flavonoid and tannic fractions, from P. guajava showed low toxicity for the fibroblasts. All samples showed effectiveness at the highest concentration tested and the extract was more effective against the promastigote forms tested. The results showed that the species Psidium brownianum and Psidium guajava demonstrated an anti-parasitic activity against the T. cruzi, L. brasiliensis and L. infantum parasite cell lines indicating these species as an alternative therapy given their efficacy in the in vitro assays performed, opening the possibility for new biological studies to further this knowledge through in vivo assays.

Life and death of Trypanosoma cruzi in presence of metals

Trypanosoma cruzi has many molecules that need metallic elements to work, allowing cell invasion and the establishment of infection, causing Chagas disease. Nonetheless, knowledge regarding how the parasites address metals and maintain homeostasis is lacking. To study this relationship, zinc, cadmium and mercury were chosen. Epimastigote, trypomastigote and intracellular forms of T. cruzi were incubated with these metals for different times and at different concentrations. In general, epimastigotes were the most sensitive and trypomastigotes the most resistant to metals. ZnCl₂ induced low toxic effects to all parasite forms. Although the parasites were very sensitive to the toxic effects of CdCl₂ and HgCl₂, pretreatment with ZnCl₂ decreased the death rate. The trypomastigotes pretreated with CdCl₂ were unable to infect the host cells, and the treated intracellular forms were damaged after 2 h of incubation, when the toxic effects were poorly reverted. New insights on metal toxicity mechanisms are provided, helping to understand how metallic ions influence the parasite's biochemical and physiological processes.

Chemical Composition of Four Essential Oils of Eugenia from the Brazilian Amazon and Their Cytotoxic and Antioxidant Activity

Background:Eugenia species are appreciated for their edible fruits and are known as having anticonvulsant, antimicrobial and insecticidal actions. Methods: The plant material was collected in the southeastern Pará state of Brazil and submitted to hydrodistillation. GC-MS analyzed the oils, and their antioxidant and cytotoxic activities were evaluated by the DPPH and MTT assays. Results: The main components identified in the Eugenia oils were 5-hydroxy-cis-calemene, (2E,6E)-farnesol, (2E,6Z)-farnesol, caryophylla-4(12),8(13)-dien-5α-ol-5β-ol, E-γ-bisabolene, β-bisabolene, germacrene D, and ishwarane. The oil of E. egensis showed the most significant antioxidant activity (216.5 ± 11.6 mg TE/mL), followed by the oils of E. flavescens (122.6 ± 6.8 mg TE/mL) and E. patrisii (111.2 ± 12.4 mg TE/mL). Eugenia oils were cytotoxic to HCT-116 (colon cancer) cells by the MTT assay, where the most active was the oil of E. polystachya (10.3 µg/mL), followed by the oils of E. flavescens (13.9 µg/mL) and E. patrisii (16.4 µg/mL). The oils of E. flavescens and E. patrisii showed the highest toxicity for MRC5 (human fibroblast) cells, with values of 14.0 µg/mL and 18.1 µg/mL, respectively. Conclusions: These results suggest that Eugenia oils could be tested in future studies for the treatment of colon cancer and oxidative stress management.

Spectrophotometric Quantification of Flavonoids in Herbal Material, Crude Extract, and Fractions from Leaves of Eugenia uniflora Linn

BACKGROUND

The traditional use of Eugenia uniflora L. ("Pitanga") is reported due to several properties, which have often been related to its flavonoid content.

OBJECTIVE

The aim was to evaluate analytical procedures for quantification of total flavonoids content (TFCs) by ultraviolet-visible (UV-Vis) spectrophotometry in the herbal material (HM), crude extract (CE), and fractions from leaves of E. uniflora.

MATERIALS AND METHODS

The method for quantification of flavonoids after complexation with aluminum chloride (AlCl₃) was evaluated: amount of sample (0.25-1.5 g); solvent (40%-80% ethanol); reaction time and AlCl₃ concentration (2.5%-7.5%). The procedures by direct dilution (DD) and after acid hydrolysis (AH) were used and validated for HM and CE and applied to the aqueous fraction (AqF), hexane fraction, and ethyl acetate fractions (EAF).

RESULTS

The ideal conditions of analysis were ethanol 80% as solvent; 0.5 g of sample; λmax of 408 (DD) and 425 nm (AH); 25 min after addition of AlCl₃ 5%. The procedures validated for standards and samples showed linearity (R² > 0.99) with limit of detection and limit of quantification between 0.01 and 0.17 mg/mL (rutin and quercetin); and 0.03 and 0.09 mg/mL (quercetin), for DD and AH, respectively. The procedures were accurate (detect, practice, and repair < 5% and recovery >90%), and stable under robustness conditions (luminosity, storage, reagents, and equipment). The TFCs in AqF and EAF were 0.65 g% and 17.72 g%, calculated as rutin.

CONCLUSIONS

UV-Vis methods for quantification of TFC in HM, CE, and fractions from leaves of E. uniflora were suitably validated. Regarding the analysis of fractions, the EAF achieved enrichment of about nine times in the content of flavonoids.

SUMMARY

The total flavonoids content (TFCs) of herbal material, crude extract, and fractions from Eugenia uniflora can be quantified by ultraviolet-visibleThe spectrophotometric methods (direct dilution and acid hydrolysis) were reproducible and able to quantify TFC in raw material and derivatives from leaves of E. unifloraHigher flavonoids content was observed in ethyl acetate fractions after enrichment. Abbreviations Used: HM: Herbal material, CE: Crude extract, AqF: Aqueous fraction, HF: Hexanic fraction, EAF: Ethyl acetate fraction, TFC: Total flavonoids content, HCl: Hydrochloric acid, DD: Direct dilution, AH: After hydrolysis, RSD: Relative standard, A.U.: Absorption units.

Wound Healing Activity and Chemical Standardization of Eugenia pruniformis Cambess

Background:

Eugenia pruniformis is an endemic species from Brazil. Eugenia genus has flavonoids as one of the remarkable chemical classes which are related to the improvement of the healing process.

Aims:

To evaluate of wound healing activity of E. pruniformis leaves and to identify and quantify its main flavonoids compounds.

Materials And Methods:

Wound excision model in rats was used to verify the hydroethanolic and ethyl acetate extracts potential. The animals were divided in four groups of six and the samples were evaluated until the 15° day of treatment. Hydroxyproline dosage and histological staining with hematoxilin-eosin and Sirius Red were used to observe the tissue organization and quantify the collagen deposition, respectively. Chemical compounds of the ethyl acetate extract were identified by chromatographic techniques and mass spectrometry analysis and total flavonoids content was determined by spectrophotometric method. The antioxidant activity was determined by oxygen radical absorbing capacity (ORAC) and 2,2-diphenyl-1-picrylhydrazylhydrate radical photometric (DPPH) assays.

Results:

The treated group with the ethyl acetate extract showed collagen deposition increase, higher levels of hidroxyproline, better tissue reorganization and complete remodeling of epidermis. Quercetin, kaempferol and hyperoside were identified as main compounds and flavonoids content value was 43% (w/w). The ORAC value of the ethyl acetate extract was 0.81± 0.05 mmol TE/g whereas the concentration to produce 50% reduction of the DPPH was 7.05± 0.09 μg/mL.

Conclusion:

The data indicate a wound healing and antioxidant activities of E. pruniformis. This study is the first report of flavonoids and wound healing activity of E. pruniformis.

KEY MESSAGES

Eugenia pruniformis extract accelerates wound healing in skin rat model, probably due to its involvement with the collagen deposition increase, higher levels of hidroxyproline, dermal remodelling and potent antioxidant activity. Chemical standardization of the active wound healing extract was done. The total flavonoid content was 43% (w/w) and quercetin, kaempferol and hyperoside were identified as main compounds.

SUMMARY

Wound excision model in rats showed the potential wound healing activity of E. pruniformis by collagen deposition increase, higher levels of hidroxyproline, better tissue reorganization and complete remodeling of epidermis.

Flavonoids are the main compounds of the endemic E. pruniformis and quercetin, kaempferol and hyperoside were identified in ethyl acetate extract by TLC, HPLC-PDA and HRESI-MS analysis.

The ethyl acetate extract of E. pruniformis showed a potent antioxidant activity by ORAC and DPPH assays

Abbreviation used: NC: Negative control, PC: Positive control, CH: Crude hydroethanolic extract, EA: Ethyl acetate extract, TE: Trolox equivalent, mg: Milligram, mM: Millimolar, mL: Milliliter, HPLC-PDA: High performance liquid chromatography with a photodiode array detector, HRESI-MS: High-resolution electrospray ionization mass spectrometry analysis, TLC: Thin layer chromatography, ORAC: Oxygen radical absorbance capacity, w/v: Weight per volume

Chemical Profiling of the Essential Oils of Syzygium aqueum, Syzygium samarangense and Eugenia uniflora and Their Discrimination Using Chemometric Analysis

The essential oil compositions of the leaves of three related Myrtaceae species, namely Syzygium aqueum, Syzygium samarangense and Eugenia uniflora, were investigated using GLC/MS and GLC/FID. Altogether, 125 compounds were identified: α-Selinene (13.85%), β-caryophyllene (12.72%) and β-selinene constitute the most abundant constituents in S. aqueum. Germacrene D (21.62%) represents the major compound in S. samarangense whereas in E. uniflora, spathulenol (15.80%) represents the predominant component. Multivariate chemometric analyses were used to discriminate the essential oils using hierarchical cluster analysis (HCA) and principal component analysis (PCA) based on the chromatographic results. The antimicrobial activity of the popularly used E. uniflora essential oil was assessed using broth microdilution method against six Gram-positive, three Gram-negative bacteria and two fungi. The oil showed moderate antimicrobial activity against Bacillus licheniformis exhibiting MIC and MMC of 0.63 mg/ml. The cytotoxic activity of E. uniflora essential oil was investigated against Trypanosoma brucei brucei (T. b. brucei) and MCF-7 cancer cell line using MTT assay. It showed moderate activity against MCF-7 cells with an IC₅₀ value of 76.40 μg/ml. On the other hand, T. brucei was highly susceptible to E. uniflora essential oil with IC₅₀ of 11.20 μg/ml, and a selectivity index of 6.82.

HPLC-DAD phenolic profile, cytotoxic and anti-kinetoplastidae activity of Melissa officinalis

Context Melissa officinalis subsp. inodora Bornm. (Lamiaceae) has been used since ancient times in folk medicine against various diseases, but it has not been investigated against protozoa. Objective To evaluate the activities of M. officinalis against Leishmania braziliensis, Leishmania infantum and Trypanosoma cruzi as well as its cytotoxicity in fibroblast cell line. Materials and methods The fresh leaves were chopped into 1 cm(2) pieces, washed and macerated with 99.9% of ethanol for 72 h at room temperature. Antiparasitic activity of M. officinalis was accessed by direct counting of cells after serial dilution, while the cytotoxicity of M. officinalis was evaluated in fibroblast cell line (NCTC929) by measuring the reduction of resazurin. The test duration was 24 h. High-performance liquid chromatography (HPLC) was used to characterise the extract. Results The extract at concentrations of 250 and 125 μg/mL inhibited 80.39 and 54.27% of promastigote (LC50  value = 105.78 μg/mL) form of L. infantum, 80.59 and 68.61% of L. brasiliensis (LC50 value  = 110.69 μg/mL) and against epimastigote (LC50 value  = 245.23 μg/mL) forms of T. cruzi with an inhibition of 54.45 and 22.26%, respectively, was observed. The maximum toxicity was noted at 500 μg/mL with 95.41% (LC50  value = 141.01 μg/mL). The HPLC analysis identified caffeic acid and rutin as the major compounds. Discussion The inhibition of the parasites is considered clinically relevant (< 500 μg/mL). Rutin and caffeic acids may be responsible for the antiprotozoal effect of the extract. Conclusion The ethanol extract of M. officinalis can be considered a potential alternative source of natural products with antileishmania and antitrypanosoma activities.

Phytochemical Composition, Antifungal and Antioxidant Activity of Duguetia furfuracea A. St.-Hill

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.

Endophytic fungal compounds active against Cryptococcus neoformans and C. gattii

Infections with Cryptococcus are invasive mycoses associated with significant morbidity and mortality, mainly in immunosuppressed patients. Several drugs have been introduced to combat these opportunistic infections. However, resistance of this organism to antifungal drugs has increased, causing difficulties in the treatment. The goal of this work was to evaluate the antifungal activity of ethanol extracts from endophytic fungi isolated from plants collected from different Brazilian ecosystems and to perform the fractionation of the most promising extract. Four-hundred fungal extracts were investigated by microdilution broth assays against Cryptococcus neoformans and Cryptococcus gattii at a concentration of 500 μg ml(-1). Among them, the extract of Mycosphaerella sp. UFMGCB 2032, an endophytic fungus isolated from the plant Eugenia bimarginata DC. (Myrtaceae) exhibited outstanding antifungal activity against C. neoformans and C. gattii, with MIC values of 31.2 μg ml(-1) and 7.8 μg ml(-1), respectively. The fractionation of this extract using liquid-liquid partitioning and semi-preparative HPLC afforded two eicosanoic acids with antifungal activity, compound 1, (2S,3R,4R)-(E)-2-amino-3,4-dihydroxy-2-(hydroxymethyl)-14-oxoeicos-6,12-dienoic acid with MIC values ranging from 1.3-2.50 μg ml(-1), and compound 2, known as myriocin, with MIC values of 0.5 μg ml(-1) against C. neoformans and C. gattii. These compounds are reported for the first time in the Mycosphaerella genus.

In vitro biological evaluation of eight different essential oils against Trypanosoma cruzi, with emphasis on Cinnamomum verum essential oil

BACKGROUND

Essential oils (EOs) are complex mixtures of secondary metabolites from various plants. It has been shown that several EOs, or their constituents, have inhibitory activity against trypanosomatid protozoa. Thus, we analyzed the biological activity of different EOs on Trypanosoma cruzi, as well as their cytotoxicity on Vero cells.

METHODS

The following EOs were evaluated on T. cruzi epimastigote forms: Cinnamomum verum, Citrus limon, Cymbopogon nardus, Corymbia citriodora, Eucalyptus globulus, Eugenia uniflora, Myrocarpus frondosus, and Rosmarinus officinalis. Inhibitory activity against T. cruzi (IC50/24 h) and cytotoxicity against Vero cells (CC50/24 h) were evaluated by the MTT assay. The EO of C. verum was selected for further evaluation against trypomastigotes and intracellular amastigotes, as well as on parasite metacyclogenesis. Constituents of C. verum EO were identified by GC-MS. One-way ANOVA statistical analysis was performed with GraphPad version 5.01.

RESULTS

Cinnamomum verum EO was the most effective against T. cruzi epimastigotes (IC50/24 h = 24.13 μg/ml), followed by Myrocarpus frondosus (IC50/24 h = 60.87 μg/ml) and Eugenia uniflora (IC50/24 h = 70 μg/ml). The EOs of C. citriodora, E. globulus, and R. officinalis showed no activity at concentrations up to 300 μg/ml. Incubation of T. cruzi metacyclic trypomastigotes and intracellular amastigotes with C. verum EO resulted in IC50/24 h values of 5.05 μg/ml and 20 μg/ml, respectively. Therefore, trypomastigotes are more susceptible than epimastigotes, with selectivity index (SI) about 4.7-fold higher (9.78 and 2.05, respectively). Analysis of C. verum EO by GC-MS showed mainly (E)-cinnamaldehyde (81.52%) and eugenol (16.68%).

CONCLUSIONS

C. verum essential oil is effective against T. cruzi (epimastigotes, trypomastigotes and amastigotes) and interferes with the parasite differentiation process in vitro. Thus, it represents a strong candidate for further studies to improve its activity on pathogenic trypanosomatids.

Anti-Trypanosoma cruzi activity of 10 medicinal plants used in northeast Mexico

The aim of this study was to screen the trypanocidal activity of plants used in traditional Mexican medicine for the treatment of various diseases related to parasitic infections. Cultured Trypanosoma cruzi epimastigotes were incubated for 96h with different concentrations of methanolic extracts obtained from Artemisia mexicana, Castela texana, Cymbopogon citratus, Eryngium heterophyllum, Haematoxylum brasiletto, Lippia graveolens, Marrubium vulgare, Persea americana, Ruta chalepensis and Schinus molle. The inhibitory concentration (IC50) was determined for each extract via a colorimetric method. Among the evaluated species, the methanolic extracts of E. heterophyllum, H. brasiletto, M. vulgare and S. molle exhibited the highest trypanocidal activity, showing percentages of growth inhibition between 88 and 100% at a concentration of 150μg/ml. These medicinal plants may represent a valuable source of new bioactive compounds for the therapeutic treatment of trypanosomiasis.

The therapeutic potential of medicinal foods

Pharmaceutical and nutritional sciences have recently witnessed a bloom in the scientific literature geared towards the use of food plants for their diversified health benefits and potential clinical applications. Health professionals now recognize that a synergism of drug therapy and nutrition might confer optimum outcomes in the fight against diseases. The prophylactic benefits of food plants are being investigated for potential use as novel medicinal remedies due to the presence of pharmacologically active compounds. Although the availability of scientific data is rapidly growing, there is still a paucity of updated compilation of data and concerns about the rationale of these health-foods still persist in the literature. This paper attempts to congregate the nutritional value, phytochemical composition, traditional uses, in vitro and in vivo studies of 10 common medicinal food plants used against chronic noncommunicable and infectious diseases. Food plants included were based on the criteria that they are consumed as a common food in a typical diet as either fruit or vegetable for their nutritive value but have also other parts which are in common use in folk medicine. The potential challenges of incorporating these medicinal foods in the diet which offers prospective opportunities for future drug development are also discussed.

Eugenia uniflora L. Essential Oil as a Potential Anti-Leishmania Agent: Effects on Leishmania amazonensis and Possible Mechanisms of Action

Eugenia uniflora L. is a member of the Myrtaceae family and is commonly known as Brazilian cherry tree. In this study, we evaluated the chemical composition of Eugenia uniflora L. essential oil (EuEO) by using gas chromatography-mass spectrometry (GC-MS) and assessed its anti-Leishmania activity. We also explored the potential mechanisms of action and cytotoxicity of EuEO. Thirty-two compounds were identified, which constituted 92.65% of the total oil composition. The most abundant components were sesquiterpenes (91.92%), with curzerene (47.3%), γ -elemene (14.25%), and trans- β -elemenone (10.4%) being the major constituents. The bioactivity shown by EuEO against promastigotes (IC50, 3.04  μ g·mL(-1)) and amastigotes (IC50, 1.92  μ g·mL(-1)) suggested significant anti-Leishmania activity. In the cytotoxicity determination, EuEO was 20 times more toxic to amastigotes than to macrophages. Hemolytic activity was 63.22% at the highest concentration tested (400  μ g·mL(-1)); however, there appeared to be no toxicity at 50  μ g·mL(-1). While the data show that EuEO activity is not mediated by nitric oxide production, they do suggest that macrophage activation may be involved in EuEO anti-Leishmania activity, as evidenced by increases in both the phagocytic capacity and the lysosomal activity. More studies are needed to determine in vivo activity as well as additional mechanisms of the anti-Leishmania activity.

Identification of microRNAs from Eugenia uniflora by high-throughput sequencing and bioinformatics analysis

Background

microRNAs or miRNAs are small non-coding regulatory RNAs that play important functions in the regulation of gene expression at the post-transcriptional level by targeting mRNAs for degradation or inhibiting protein translation. Eugenia uniflora is a plant native to tropical America with pharmacological and ecological importance, and there have been no previous studies concerning its gene expression and regulation. To date, no miRNAs have been reported in Myrtaceae species.

Results

Small RNA and RNA-seq libraries were constructed to identify miRNAs and pre-miRNAs in Eugenia uniflora. Solexa technology was used to perform high throughput sequencing of the library, and the data obtained were analyzed using bioinformatics tools. From 14,489,131 small RNA clean reads, we obtained 1,852,722 mature miRNA sequences representing 45 conserved families that have been identified in other plant species. Further analysis using contigs assembled from RNA-seq allowed the prediction of secondary structures of 25 known and 17 novel pre-miRNAs. The expression of twenty-seven identified miRNAs was also validated using RT-PCR assays. Potential targets were predicted for the most abundant mature miRNAs in the identified pre-miRNAs based on sequence homology.

Conclusions

This study is the first large scale identification of miRNAs and their potential targets from a species of the Myrtaceae family without genomic sequence resources. Our study provides more information about the evolutionary conservation of the regulatory network of miRNAs in plants and highlights species-specific miRNAs.