RESUMO
ABSTRACT Casearia genus (Salicaceae) is found in sub-tropical and tropical regions of the world and comprises about 160-200 species. It is a medicinal plant used in South America, also known as "guaçatonga", "erva-de-tiú", "cafezinho-do-mato". In Brazil, there are about 48 species and 12 are registered in the State of Rio de Janeiro, including Casearia sylvestris Sw. There are many studies related to the chemical profile and cytotoxic activities of extracts from these plants, although few studies about the antifungal potential of the essential oil have been reported. In this work, we have studied the antifungal properties of the essential oil of C. sylvestris leaves, as well as of their fractions, against four yeasts (Saccharomyces cerevisae, Candida albicans, C. glabrata and C. krusei) for the first time. The chemical analysis of the essential oil revealed a very diversified (n = 21 compounds) volatile fraction composed mainly of non-oxygenated sesquiterpenes (72.1%). These sesquiterpenes included α-humulene (17.8%) and α-copaene (8.5%) and the oxygenated sesquiterpene spathulenol (11.8%) were also identified. Monoterpenes were not identified. The fractions are mainly composed of oxygenated sesquiterpenes, and the most active fraction is rich in the sesquiterpene 14-hydroxy -9-epi-β-caryophyllene. This fraction was the most effective in inhibiting the growth of three yeast strains.
Assuntos
Sesquiterpenos/química , Candida albicans/efeitos dos fármacos , Extratos Vegetais/farmacologia , Folhas de Planta/química , Casearia/química , Antifúngicos/farmacologia , Plantas Medicinais , Brasil , Óleos Voláteis/farmacologia , Sesquiterpenos PolicíclicosRESUMO
Extracts from leaves of C. sylvestris have cytotoxic effect in different tumor cell lines, possibly due to clerodane type diterpenes (casearins). On the other hand, there are few studies related to the antitumor activity of the essential oils from this species. This work evaluated for the first time the cytotoxicity effects of the pure essential oil and its nanoemulsion against A549 tumor cell line (human lung carcinoma). The essential oil was obtained from fresh leaves by hydrodistillation in a Clevenger-type apparatus and analyzed by GC/MS and GC/FID. Cytotoxicity evaluation was performed using the WST-1 test. The chemical analysis of the essential oil revealed a volatile fraction composed mainly of non-oxygenated sesquiterpenes (72.1%). The essential oil and its nanoemulsion exhibited cytotoxic activity against A549 tumor cells with EC50 of 4.0 µg/mL and EC50 of 1.0 µg/mL, respectively. Both samples displayed a dose dependent pattern (r = -0.79, p = 0.03) as determined by linear regression test.
Los extractos de las hojas de Casearia sylvestris tienen efectos citotoÌxicos en diferentes liÌneas celulares tumorales, posiblemente debido a los diterpenos tipo clerodane (casearinas). Por otra parte, hay muy pocos estudios relacionados con la actividad antitumoral del aceite esencial de estas especies. Este trabajo evaluÌa por primera vez el efecto citotoÌxico del aceite esencial puro y su nanoemulsioÌn contra la liÌnea de ceÌlulas tumorales A549 (carcinoma humano de pulmoÌn). El aceite esencial fue obtenido de hojas frescas por hidrodestilacioÌn en un aparato tipo Clevenger y analizado por GC/MS y GC/FID. La evaluacioÌn de citotoxicidad fue realizada usando la prueba WST-1. El anaÌlisis quiÌmico del aceite esencial reveloÌ una fraccioÌn volaÌtil compuesta principalmente por sesquiterpenos no oxigenados (72,1%). El aceite esencial y su nanoemulsioÌnexhibioÌ actividad citotoÌxica contra las ceÌlulas tumorales A549 con una EC50 de 4,0 µg/mL y una EC50 de 1,0 µg/mL, respectivamente. Ambas muestras exhibieron un patroÌn dosis-dependiente (r = -0,79, p = 0,03) determinado por anaÌlisis de regresioÌn lineal.