GC-MS Chemical Characterization and In Vitro Evaluation of Antioxidant and Toxic Effects Using Drosophila melanogaster Model of the Essential Oil of Lantana montevidensis (Spreng) Briq.

Background and objectives: Natural products such as essential oils with antioxidant potential can reduce the level of oxidative stress and prevent the oxidation of biomolecules. In the present study, we investigated the antioxidant potential of Lantana montevidensis leaf essential oil (EOLM) in chemical and biological models using Drosophila melanogaster. Materials and methods: in addition, the chemical components of the oil were identified and quantified by gas chromatography coupled to mass spectrometry (GC-MS), and the percentage compositions were obtained from electronic integration measurements using flame ionization detection (FID). Results: our results demonstrated that EOLM is rich in terpenes with Germacrene-D (31.27%) and ß-caryophyllene (28.15%) as the major components. EOLM (0.12-0.48 g/mL) was ineffective in scavenging DPPH radical, and chelating Fe(II), but showed reducing activity at 0.24 g/mL and 0.48 g/mL. In in vivo studies, exposure of D. melanogaster to EOLM (0.12-0.48 g/mL) for 5 h resulted in 10% mortality; no change in oxidative stress parameters such as total thiol, non-protein thiol, and malondialdehyde contents, in comparison to control (p > 0.05). Conclusions: taken together, our results indicate EOLM may not be toxic at the concentrations tested, and thus may not be suitable for the development of new botanical insecticides, such as fumigants or spray-type control agents against Drosophila melanogaster.

Chemical composition, antibacterial and modulatory action of the essential oil of Croton rhamnifolioides leaves Pax and Hoffman / Composição química, ação antibacteriana e moduladora do óleo essencial das folhas de Croton rhamnifolioides Pax and Hoffman

The species Croton rhamnifolioides is a shrub popularly known as "quebra faca", utilized in teas or infusions for the treatment of gastrointestinal disorders as ulcers, gastric discomfort, vomiting and hemorrhagic diarrhea. This work has as its main objective to evaluate the chemical composition of the essential oil of the Croton rhamnifolioides leaves (EOC), antibacterial activity and modulatory activity of antibiotic resistance, against bacterial strains of Escherichia coli, Staphylococcus aureus and Pseudomonas aeruginosa and, and antifungal activity against Candida albicans, Candida krusei and Candida tropicalis. The chemical composition was determined through chromatography with a gas phase coupled with mass spectrometry (CG/MS), whereas antimicrobial activity and modulation were determined by microdilution assay. The chemical composition of the oil revealed 21 compounds, with the major compounds being spathulenol (22.46%) and 1,8-cineol (18.32%). The antimicrobial activity was not significant with MIC>1024 µg/mL, however, was observed a synergistic interference when essential oil associated with the antibiotics aminoglycoside and -lactam, and the antifungal polyene.

Croton rhamnifolioides is é um arbusto conhecido popularmente como "quebra-faca" e utilizado como chá ou infusão para o tratamento de problemas gastro-intestinais como úlceras, desconforto gástrico, vômitos e diarréias hemorrágicas. O objetivo deste trabalho foi avaliar a composição química do óleo essencial das folhas de Croton rhamnifolioides (OEC), atividade antibacteriana, moduladora da resistência bacteriana, contra linhagens bacterianas de Escherichia coli, Staphylococcus aureus e Pseudomonas aeruginosa e, atividade antifúngica contra Candida albicans, C. krusei e C. tropicalis. A composição química foi determinada através de Espectroscopia de Massas acoplada a Cromatografia Gasosa (EM/CG), enquanto as atividades antimicrobianas e moduladoras foram determinadas pelo método de microdiluição. A composição química do OEC revelou a presença de 21 compostos, sendo os principais o Espatulenol (22,46%) e 1,8-cineol (18,32%). A atividade antimicrobiana não foi considerada significativa apresentando MIC > 1024 µg/mL, contudo, foi observado um sinergismo quando o óleo essencial foi associado com aminoglicosídios, -lactâmicos e antifúngicos poliênicos.