Sidney Gonçalo de Lima

In vitro antileishmanial activity and cytotoxicity of essential oil from Lippia sidoides Cham.

Leishmaniasis is a widespread tropical infection caused by different species of Leishmania protozoa. There is no vaccine available for Leishmania infections and conventional treatments are very toxic to the patients. Therefore, antileishmanial drugs are urgently needed. In this study we have analyzed the effects of essential oils from Lippia sidoides (LSEO) and its major compound thymol on the growth, viability and ultrastructure of Leishmania amazonensis. The essential oil and thymol showed significant activity against promastigote forms of L. amazonensis, with IC(50)/48 h of 44.38 and 19.47 μg/mL respectively. However, thymol showed toxicity against peritoneal macrophages and low selectivity against the promastigotes when compared with the crude LSEO. On the other hand, no cytotoxic effect was observed in macrophages treated with the crude essential oil. Incubation of L. amazonensis-infected macrophages with LSEO showed a marked reduction in amastigote survival within the macrophages. Significant morphological alterations as accumulation of large lipid droplets in the cytoplasm, disrupted membrane and wrinkled cells were usually seen in treated parasites. The LSEOs activity against both promastigote and the amstigote forms of L. amazonensis, together with its low toxicity to mammalian cells, point to LSEO as a promising agent for the treatment of cutaneous leishmaniasis.

Composition and Biological Activity of Essential Oils from Lippia origanoides H.B.K.

Abstract Analyses of the leaf oils from three colletions of Lippia origanoides H.B.K. by GC/MS and 1H- and 13C-NMR showed a similar chemical composition. Carvacrol (33.5–42.9%) was identified as the major component together with γ-terpinene (8.0–10.5%), thymol (5.1–8.4%), methyl thymol (6.1–8.7%) and p-cymene (11.9–15.8%). In vitro evaluation of the oils showed significant antimicrobial activity against Escherichia coli, Staphylococus aureus, Staphylococus aureus MRSA, Candida albicans and Candida tropicalis.

Chemical composition and resistance-modifying effect of the essential oil of Lantana camara Linn.

In this work, the chemical constituents, antibacterial and modulatory activities of the essential oil of Lantana camara Linn were studied. The essential oil was extracted from the leaves of L. camara by hydrodistillation method using Clevengers apparatus and its chemical constituents were separated and identified by GC-MS, and the relative content of each constituent was determined by area normalization. Among the 25 identified components, bicyclogermacrene (19.42%), isocaryophyllene (16.70%), valecene (12.94%) and germacrene D (12.34%) were the main constituents. The oil was examined to antibacterial and modulatory activities against the multiresistant strains of Escherichia coli and Staphylococcus aureus by microdilution test. The results show an inhibitory activity to E. coli (MIC 512 μg/ml) and S. aureus (MIC 256 μg/ml). The synergism of the essential oil and aminoglycosides was verified too, with significant reduction of MICs (7 ×, 1250-5 μg/ml) against E. coli. It is suggested that the essential oil of Lantana camara Linn could be used as a source of plant-derived natural products with resistance-modifying activity.

Composição química e avaliação das atividades antibacteriana e de toxicidade dos óleos essenciais de Lantana camara L. e Lantana sp.

The essential oils from Lantana camara L. and Lantana sp. Verbenaceae, were obtained by hydrodistillation and analyzed by GC/MS. This GC/MS analysis revealed the sesquiterpenoids bicyclogermacrene (19.42%), isocaryophyllene (16.70%), valencene (12.94%) and germacrene D (12.34%) as majoritaries in the essential oil of L. camara, and bicyclogermacrene (13.93%), germacrene D (27.54 and β-caryophyllene (31.50%) in the essential oil from Lantana sp. The two essential oils were evaluated to antibacterial activity and toxicity using Artemia salina. The results revealed considerable antibacterial activity for essential oil from L. camara, meanly for Proteus vulgaris (ATCC 13315) and Escherichia coli (ATCC 25922). The essential oil of Lantana sp. showed major activity for Sthaphylococcus aureus (ATCC 10390). The evaluation of toxicity CL50 revealed results with minor values to limit pattern of 1000 μg/mL.

Chemical Composition, Antibacterial and Fungicidal Activities of Leaf Oil of Plectranthus amboinicus (Lour.) Spreng.

Abstract Essential oil was isolated from the leaves of Plectranthus amboinicus by hydrodistillation and analyzed using both gas chromatography (GC) and gas chromatography/mass spectrometry (GC/MS). Ten components were characterized representing 94.0% of the total components detected. The major constituents were: thymol (64.3%), p-cymene (10.3%), γ-terpinene (9.9%) and β-caryophyllene (2.8%). The leaf oil demonstrated antibacterial activity against Staphylococcus aureus, Proteus vulgaris and Aeromonas caviae as well as moderate fungicidal activity against Aspergillus niger.

Lantana montevidensis Briq improves the aminoglycoside activity against multiresistant Escherichia coli and Staphylococcus aureus

Objective: In this work, we report the antibacterial and modulatory activity of Lantana montevidensis Briq. Materials and Methods: The antibacterial activities of leaf (LELm) and root (RELm) extracts alone or in association with aminoglycosides were determined by a microdilution test. Multiresistant strains of Escherichia coli (Ec 27) and Staphylococcus aureus (Sa 358) were used. Results: The results show the inhibitory activity of LELm against E. coli (minimal inhibitory concentration [MIC] 16 μg/mL) and S. aureus (MIC 128 μg/mL). The synergistic effect of the extracts and aminoglycosides was verified too. The maximum effects were obtained with RELm with gentamicin against E. coli with MIC reduction (312 to 2 μL). Conclusion: The data from this study are indicative of the activity antibacterial of extracts of L. montevidensis and its potential in modifying the resistance of aminoglycosides.

Chemical composition and synergistic interaction between aminoglycosides antibiotics and essential oil of Lantana montevidensis Briq.

The chemical composition of the essential oil from Lantana montevidensis Briq. and its antibiotic resistance modifying activity were investigated by gas chromatography/mass spectrometry (GC/MS) and microdilution assay, respectively. β-Caryophyllene (31.50%), germacrene D (27.50%) and bicyclogermacrene (13.93%) were the main constituents. The essential oil was examined for antibiotic activity alone in association with aminoglycosides against Escherichia coli Ec27 and Staphylococcus aureus Sa358. The results showed antibacterial activities of the oil and synergistic effects combined with aminoglycosides. The most expressive effect was the potentiating of amikacin on E. coli with minimal inhibitory concentration decrease (512–5 µg mL−1). The data obtained are indicative of the antibacterial activity of the essential oil of L. montevidensis and its potential in modifying the resistance of aminoglycosides analysed.

MONOTERPENES, SESQUITERPENES AND FATTY ACIDS FROM JULOCROTON TRIQUETER (EUPHORBIACEAE) FROM CEARA - BRAZIL

ABSTRACT In this study the volatile constituents from leaves and fruits of Julocroton triqueter (Lam.) Didr. (Euphorbiaceae), a medicinal plant from northwest Brazil, were investigated by GC/MS. Twenty one compounds, which represent about 96% of the total constituents of the essential oil, were identified. Caryophyllene oxide, humulene epoxide II, trans -caryophyllene, occidentalol, α-humulene in the fruit and cis -carvyl acetate, spathulenol, cis -carveol, trans -caryophyllene, trans -carvyl acetate and α-humulene in the leaves were the principal components. From one fraction of the hexane extract of the fruits a mixture of fatty acids were identified as: dodecanoic, tetradecanoic, hexadecanoic, 9-octadecenoic, eicosanoic, trieicosanoic and tetracosanoic acids. The partial analysis of the non-volatile constituents (hexanic fraction) from fruit allowed the isolation and characterization of tetracosan-1-ol (identify by 1 H and 13 C NMR, FTIR). Keywords : Julocroton triqueter , volatile constituents, Euphorbiaceae, fatty acid

Effects of the essential oil from fruits of Schinus terebinthifolius Raddi (Anacardiaceae) on reproductive functions in male rats

The essential oil of Schinus terebinthifolius (Anacardiaceae) was analyzed by GC and GC-MS. α-Fenchene, limonene, β-pinene, α-phellandrene, and β-isosylvestrene represent about 80% of the oil composition. The reproductive toxicity of the essential oil in Wistar male rats was evaluated. No changes were observed in the mass of the reproductive organs, number and morphology of spermatozoa, reproductive rates, and the body mass of offspring of male rats after treatment with the essential oil of S. terebinthifolius.

Preparação e caracterização do complexo de inclusão do óleo essencial de Croton zehntneri com β-ciclodextrina

Croton zehntneri, a plant native to northeastern Brazil, is widely used in folk medicine to treat gastrointestinal problems and has rich essential oil content. The essential oil of C. Zehntneri was analyzed by GC-MS, and its inclusion complex with β-cyclodextrin (β-CD) was characterized by both vibrational spectroscopy and differential scanning calorimetry (DSC). Estragol was the major component identified in the essential oil by the study. IR spectra indicated an interaction of β-CD with essential oil from C. zehntneri, a finding corroborated by the stability constant and scanning calorimetry. Microencapsulation within β-CD has the potential to mask sensory attributes and increase aqueous solubility of oils, thereby improving their applicability as drugs.