Cytotoxic activity of essential oil from Leaves of Myrcia splendens against A549 Lung Cancer cells.

BACKGROUND: Plants of the Myrcia genus have been widely used in folk medicine to treat various diseases, including cancer. Myrcia splendens species has a diverse chemical constitution, but the biological activities of its essential oil have not been well investigated. In this study to out the chemistry characterization of essential oil (EO) from the leaves of the species M. splendens from Brazil and evaluate cytotoxic effect in A549 lung cancer cells. METHODS: M. splendens EO was obtained by hydrodistillation and analyzed by Gas Chromatography-Mass Spectrometry (GC-MS). EO was isolated and evaluated for cellular viability in tumor cell lines by MTT assay. The evaluation of the formation of clones and the migratory capacity of the A549 cells treated with EO was done by the clonogenic assay and the wound healing assay. Morphological changes were observed in A549 cells by fluorescence using Phalloidin/FITC and DAPI. RESULTS: 22 compounds were identified in the chemical analysis of EO, corresponding to 88% of the sample. Major compounds were the sesquiterpenic hydrocarbons bicyclogermacrene (15.4%), germacrene D (8.9%) and E-caryophyllene (10.1%). The biological analysis of the EO showed high cytotoxic activity with an IC50 below 20 µg/ml in the THP-1, A549 and B16-F10 tumor cells. The treatment with EO reduced colony formation and inhibited the migratory capacity of A549 cells. Furthermore, apoptotic morphological changes in the nucleus and cytoplasm of A549 cells was observed after of treatment with EO. CONCLUSION: The findings of this study suggest that the M. splendens EO has cytotoxic compounds for the A549 lung cancer cells. Treatment with the EO decreased the colony formation and reduced the ability of lung cancer cells to migrate. Future studies may be used to isolate compounds from the EO for the study of lung cancer.

Cytogenetic effects of ß-particles in Allium cepa cells used as a biological indicator for radiation damages.

Analysis of cytogenetics effects of ionizing radiation for flora and fauna is essential to determine the impact on these communities and may produce an efficient warning system to avoid harm to human health. Onion (Allium cepa) is a well-established in vivo standard model, and it is widely used in cytogenetics studies for different environmental pollutants. In this work, onion roots were exposed to 0.04-1.44 Gy of ß-particles from a 90Sr/90Y source. We investigated the capacity of brief external exposures to ß-particles on inducing cytogenetic damages in root meristematic cells of onion aiming to verify if onion can be used as a radiation-sensitive cytogenetic bioindicator. A nonlinear increase in the frequencies of chromosomal aberrations and cells with micronuclei was observed. Onion roots exposed to doses 0.13 Gy or higher of ß-particles showed a significant difference (p<0.05) in these frequencies when compared to the unirradiated group. The frequencies of these endpoints showed to be suitable to assess the difference in the dose of beta radiation received from 0.36 Gy. Our research shows the potential of using cytogenetic effects in Allium cepa cells as a biological indicator for a first screening of genotoxic damages induced by brief external exposures to ß-particles.

Ethanolic extract of Croton blanchetianus Ball induces mitochondrial defects in Leishmania amazonensis promastigotes.

Leishmaniasis is a neglected disease caused by Leishmania. Chemotherapy remains the mainstay for leishmaniasis control; however, available drugs fail to provide a parasitological cure, and are associated with high toxicity. Natural products are promising leads for the development of novel chemotherapeutics against leishmaniasis. This work investigated the leishmanicidal properties of ethanolic extract of Croton blanchetianus (EECb) on Leishmania infantum and Leishmania amazonensis, and found that EECb, rich in terpenic compounds, was active against promastigote and amastigote forms of both Leishmania species. Leishmania infantum promastigotes and amastigotes presented IC50 values of 208.6 and 8.8 µg/mL, respectively, whereas Leishmania amazonensis promastigotes and amastigotes presented IC50 values of 73.6 and 3.1 µg/mL, respectively. Promastigotes exposed to EECb (100 µg/mL) had their body cellular volume reduced and altered to a round shape, and the flagellum was duplicated, suggesting that EECb may interfere with the process of cytokinesis, which could be the cause of the decline in the parasite multiplication rate. Regarding possible EECb targets, a marked depolarization of the mitochondrial membrane potential was observed. No cytotoxic effects of EECb were observed in murine macrophages at concentrations below 60 µg/mL, and the CC50 obtained was 83.8 µg/mL. Thus, the present results indicated that EECb had effective and selective effects against Leishmania infantum and Leishmania amazonensis, and that these effects appeared to be mediated by mitochondrial dysfunction.

Amebicidal activity of the essential oils of Lippia spp. (Verbenaceae) against Acanthamoeba polyphaga trophozoites.

Amoebic keratitis and granulomatous amoebic encephalitis are caused by some strains of free-living amoebae of the genus Acanthamoeba. In the case of keratitis, one of the greatest problems is the disease recurrence due to the resistance of parasites, especially the cystic forms, to the drugs that are currently used. Some essential oils of plants have been used as potential active agents against this protist. Thus, the aim of this study was to determine the amebicidal activity of essential oils from plants of the genus Lippia against Acanthamoeba polyphaga trophozoites. To that end, 8 × 10(4) trophozoites were exposed for 24 h to increasing concentrations of essential oils from Lippia sidoides, Lippia gracilis, Lippia alba, and Lippia pedunculosa and to their major compounds rotundifolone, carvone, and carvacrol. Nearly all concentrations of oils and compounds showed amebicidal activity. The IC50 values for L. sidoides, L. gracilis L. alba, and L. pedunculosa were found to be 18.19, 10.08, 31.79, and 71.47 µg/mL, respectively. Rotundifolone, carvacrol, and carvone were determined as the major compounds showing IC50 of 18.98, 24.74, and 43.62 µg/mL, respectively. With the exception of oil from L. alba, the other oils evaluated showed low cytotoxicity in the NCI-H292 cell line. Given these results, the oils investigated here are promising sources of compounds for the development of complementary therapy against amoebic keratitis and granulomatous amoebic encephalitis and can also be incorporated into cleaning solutions to increase their amebicidal efficiency.

Antidermatophytic and antileishmanial activities of essential oils from Lippia gracilis Schauer genotypes.

Lippia gracilis, popularly known in Brazil as 'alecrim-de-tabuleiro', is used for many purposes, especially antimicrobial and antiseptic activities. The leaves of three L. gracilis genotypes, including LGRA-106, LGRA-109 and LGRA-110 were collected from the Active Germplasm Bank located in the "Campus Rural da UFS" research farm at the São Cristóvão country, Sergipe State, Brazil. The essential oils were obtained from leaves of L. gracilis plants by hydrodistillation. Chemical analysis of the essential oils was performed by gas chromatography-mass spectrometry (GC-MS). The susceptibility of Trichophyton rubrum strains, MYA3108 and TruMDR2, to the two L. gracilis genotypes (LGRA-106 and LGRA-109) essential oils was determined by the serial microdilution method. Leishmanicidal activity of essential oil from LGRA-106 and LGRA-110 was assayed by tetrazolium-dye (MTT) colorimetric method. The oxygenated monoterpene thymol was the main component of the essential oil from genotype LGRA-106, while Carvacrol was more abundant in LGRA-109 and LGRA-110. The concentrations of LGRA-106 and LGRA-109 essential oils that completely eliminate the fungi were determined and these concentrations were similar to those observed for fluconazole, a common antifungal drug. Among the genotype tested, LGRA-106 essential oil exhibited the best fungicidal activity at 46.87µgmL(-1). Regarding to leishmanicidal activity, the IC50, for LGRA-106 and LGRA-110, was 86.32 and 77.26µgmL(-1), respectively. The results showed that L. gracilis essential oil, rich in thymol and thymol itself presented best antidermatophytic activity, while the best leishmanicidal activity was obtained with essential oil from genotype rich in Carvacrol and Carvacrol itself.

Investigation of protective effects of Erythrina velutina extract against MMS induced damages in the root meristem cells of Allium cepa

Erythrina velutina Willd., Fabaceae, is a medicinal plant that can be found in the tropics and subtropics, including in the semi-arid northeastern Brazil. It is commonly used in folk medicine to treat anxiety, agitation and insomnia. E. velutina has been known to present analgesic, anti-inflammatory and antibacterial activities, however, it is unknown if this plant present a protective effect on DNA. We assessed the antigenotoxic effect of E. velutina against the genotoxic effects induced by MMS in the root meristem cells of Allium cepa. Three concentrations of the aqueous extract (100, 200 and 400 mg/L) of this medicinal plant were used in three different types of treatment (pre-, post- and simultaneous). The effects of the extracts on the root meristem cells of A. cepa were analyzed at both macroscopic and microscopic levels. Protective effects were observed at higher concentrations in pre-treatment and in simultaneous treatment. The results suggest that E. velutina may present antigenotoxic properties and demonstrate its chemopreventive potential.

Leishmanicidal activity of carvacrol-rich essential oil from Lippia sidoides Cham.

Leishamaniasis is a disease that affects more than 2 million people worldwide, whose causative agent is Leishmania spp. The current therapy for leishmaniasis is far from satisfactory. All available drugs, including pentavalent antimony, require parenteral administration and are potentially toxic. Moreover, an increase in clinical resistance to these drugs has been reported. In this scenario, plant essential oils used traditionally in folk medicine are emerging as alternative sources for chemotherapeutic compounds. In this study, in vitro leishmanicidal effects of a thymol- and a carvacrol-rich essential oil from leaves of Lippia sidoides Cham. were investigated. The essential oils were extracted and their constituents were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Both essential oils showed significant activity against promastigote forms of Leishmania chagasi. However, we found that carvacrol-rich essential oil was more effective, with IC50/72 h of 54.8 µg/mL compared to 74.1 µg/mL for thymol-rich oil. Carvacrol also showed lower IC50 than thymol. Our data suggest that L. sidoides essential oils are indeed promising sources of leishmanicidal compounds.

Leishmanicidal activity of carvacrol-rich essential oil from Lippia sidoides Cham

Leishamaniasis is a disease that affects more than 2 million people worldwide, whose causative agent is Leishmania spp. The current therapy for leishmaniasis is far from satisfactory. All available drugs, including pentavalent antimony, require parenteral administration and are potentially toxic. Moreover, an increase in clinical resistance to these drugs has been reported. In this scenario, plant essential oils used traditionally in folk medicine are emerging as alternative sources for chemotherapeutic compounds. In this study, in vitro leishmanicidal effects of a thymol- and a carvacrol-rich essential oil from leaves of Lippia sidoides Cham. were investigated. The essential oils were extracted and their constituents were characterized by gas chromatography coupled to mass spectrometry (GC/MS). Both essential oils showed significant activity against promastigote forms of Leishmania chagasi. However, we found that carvacrol-rich essential oil was more effective, with IC50/72 h of 54.8 μg/mL compared to 74.1 μg/mL for thymol-rich oil. Carvacrol also showed lower IC50 than thymol. Our data suggest that L. sidoides essential oils are indeed promising sources of leishmanicidal compounds.

Genotoxicity and cytotoxicity of Erythrina velutina Willd., Fabaceae, on the root meristem cells of Allium cepa

The effects of the decoction of Erythrina velutina Willd., Fabaceae, were investigated using the root meristem cells of Allium cepa L., Amaryllidaceae. Ten concentrations of the aqueous extract (0.125 to 1.25 percent) of this medicinal plant were analyzed at both macroscopic and microscopic levels. All concentrations showed root growth inhibition after 96 h treatment. Although there were no significant differences between the mitotic indexes of any concentration and the control, there were changes in the frequencies of cell stages at three different concentrations. Additionally, the presence of five different cells abnormalities was recorded: chromosome bridging, lagging chromosomes, chromosome fragments, disturbed metaphase and disturbed anaphase. These results suggest inhibitory and genotoxic activity of the decoction of E. velutina on Allium cepa.