ABSTRACT
Essential oil from fresh aerial parts of Achyrocline ramosissima Britton ex Rusby (Asteraceae) collected in the Venezuelan Andes was obtained by hydrodistillation and analyzed by GC/MS. A yield of 0.10 percent w/v was afforded, and thirty seven components were identified by comparison of their retention indices (RI) and mass spectra with the Wiley GC-MS Library Data. The major components identified were rosifoliol (31.69 percent), beta-caryophyllene (8.61 percent), guaiol (3.95 percent), beta-eudesmol (3.33 percent) and selina-3,7 (11)-diene (2.99 percent). Antimicrobial activity of A. ramosissima essential oil was also evaluated against Gram positive, Gram negative bacterial strains and Candida albicans yeast. The results showed that, this oil is effective against Gram positive bacteria Staphylococcus aureus ATCC 6538 with MIC values ranging from 50 to 100 μg/mL and MBC values > 200 μg/mL as well as Bacillus subtilis CECT 39 with MIC values of 50 μg/mL and MBC of 100 μg/mL, however a low activity was observed against Gram negative bacterial strains, Pseudomonas aeruginosa AK 958, Escherichia coli CECT 99 and C. albicans yeast performing MIC and MBC values > 200 μg/mL. Cytotoxic activity was also determined against HeLa (cervix carcinoma), A-459 (lung carcinoma), MCF-7 (breast adenocarcinoma) human cancer cell lines and against normal Vero cells (African green monkey kidney), exhibiting antiproliferative effects with IC50 values of 28.2 μg/mL (HeLa cells). This is the first report regarding the chemical composition, antibacterial and cytotoxic activities of the essential oil from this species.
El aceite esencial de las partes aéreas frescas de Achyrocline ramosissima Britton ex Rusby (Asteraceae) recolectada en los Andes venezolanos fue extraído por hidrodestilación y analizado por CG/EM. Se obtuvo un rendimiento de 0,10 por ciento m/v, treinta y siete componentes fueron identificados por comparación de los índices de retención (IR) y sus espectros de masas con los datos de la biblioteca Wiley GC-MS. Los principales componentes identificados fueron rosifoliol (31,69 por ciento), beta-cariofileno (8,61 por ciento), guaiol (3,95 por ciento), beta-eudesmol (3,33 por ciento) y selina-3,7 (11)-dieno (2,99 por ciento). La actividad antimicrobiana del aceite esencial de A. ramosissima fue evaluada contra cepas bacterianas Gram positivas, Gram negativas y la levadura Candida albicans. Los resultados mostraron que el aceite esencial fue activo contra las bacterias Gram positivas Staphylococcus aureus ATCC 6538 con una CIM entre 50-100 μg/mL y CBM de valores > 200 μg/mL y Bacillus subtilis CECT 39 con CIM de 50 μg/mL y CBM de 100 μg/mL, sin embargo se observó una baja actividad contra las cepas bacterianas Gram negativas Pseudomonas aeruginosa AK 958, Escherichia coli CECT 99 y la levadura C. albicans cuyos valores de CIM y CBM fueron > 200 μg/mL. La actividad citotóxica fue determinada frente a las líneas celulares cancerígenas HeLa (carcinoma de cuello uterino), A-459 (carcinoma de pulmón), MCF-7 (adenocarcinoma de mama) y frente a las células normales Vero (células renales de mono verde), mostrando efectos antiproliferativos con valores de CI50 28.2 μg/mL frente a las células HeLa. Este es el primer reporte sobre la composición química, actividad antibacteriana y citotóxica del aceite esencial de esta especie.
Subject(s)
Achyrocline/chemistry , Anti-Bacterial Agents/pharmacology , Bacteria , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Anti-Bacterial Agents/chemistry , Gas Chromatography-Mass Spectrometry , Microbial Sensitivity Tests , Terpenes/isolation & purificationABSTRACT
The aim of this study was to verify the trypanocidal effectiveness of aqueous, methanolic, and ethanolic extracts of Achyrocline satureioides against Trypanosoma evansi in vitro. A. satureioides extracts, known as macela, were used on trypomastigotes at different concentrations (1, 5, 10, 50, 100, 500, and 1,000 microg/ml) and exposure times (0, 1, 3, 6, and 9 hr). A dose-dependent effect was observed when the 3 extracts were tested. The concentrations of 1, 5, and 10 microg/ml were not able to kill trypomastigotes until 3 hr after exposure, and the highest concentrations (500 and 1,000 microg/ml) were able to kill all trypomastigotes after 1 hr. When the time of exposure was increased up to 9 hr, the concentrations at 50 and 100 microg/ml were 100% effective to 3 extracts. The chemical analysis of the extracts revealed the presence of flavonoids, a trypanocidal compound already described. Based on the results, we can conclude that the A. satureioides extracts exhibit trypanocidal effects.