ABSTRACT
In the present study, we have evaluated the cytotoxic activity of 282 extracts from 72 native plant species of the Brazilian Atlantic Forest biome. As a result, Casearia arborea and Sorocea hilarii leaves extracts showed cytotoxic activity against three tumour cell lines tested (B16F10, SW480 and Jurkat). After bioassay-guided fractionation, the bioactive fractions were submitted to the dereplication study via High-performance Liquid Chromatography, connected to High-resolution Mass Spectrometry (HPLC-ESI-QTOF/MS) analysis, combined with a Global Natural Products Social Molecular Networking (GNPS) tool. A combination of bioactivity-guided and dereplication approaches resulted in the putative annotation of 27 clerodane diterpenes and 9 flavonoids as main compounds present in the cytotoxic fractions of C. arborea. Regarding the active fraction of S. hilarii, 10 megastigmans, 17 spirostane steroids derivatives and 2 lignans were putatively identified. In conclusion, Casearia arborea and Sorocea hilarii are potential sources of antitumor compounds.
ABSTRACT
The genus Casearia (Salicaceae) is found in sub-tropical and tropical regions of the world and comprises about 200 species. In Brazil, there are about 48 species and 12 are registered in the State of Rio de Janeiro; including Casearia arborea (Rich.) Urb. Essential oil was obtained from the fresh leaves by hydrodistillation and analyzed by GC-MS and GC-FID. The cytotoxic effect was determined by WST-1 assay. Chemical analysis of the essential oil revealed a very diversified (n = 37 compounds) volatile fraction composed mainly of non-oxygenated sesquiterpenes (90.2%). These sesquiterpenes included byciclogermacrene (18.7%), germacrene D (12.1%) and α-humulene (11.5%). In addition, the essential oil demonstrated cytotoxic effects against A549 tumor cells in the concentration of 4 µg/mL (EC50) (p < 0.05).
El género Casearia (Salicáceas) se encuentra en las regiones tropicales y sub-tropicales del planeta y comprende alrededor de 200 especies. En Brasil existen 48 especies, 12 de las cuales fueron registradas en el Estado de Río de Janeiro incluyendo Casearia arborea (Rich.) Urb. El aceite esencial fue extraído de hojas frescas por hidrodestilación y analizado por GC-MS y GC-FID. El efecto citotóxico fue determinado por ensayo WST-1. Las cavidades secretorias fueron ocasionalmente encontradas tanto en la lámina foliar como en el pecíolo. El análisis químico del aceite esencial reveló una muy diversa fracción volátil (n = 37 compuestos) formada principalmente por sesquiterpenos no oxigenados (90,2%). Estos sesquiterpenos incluyen biciclogermacreno (18,7%), germacreno D (12,1%) y α-humuleno (11,5%). Además, el aceite esencial demostró efectos citotóxicos contra las células tumorales A549 en una concentración de 4µg/mL (EC50) (p < 0.05).
Subject(s)
Casearia/chemistry , Cytotoxins/pharmacology , Oils, Volatile/chemistry , Oils, Volatile/pharmacology , Plant Leaves/chemistry , Antineoplastic Agents, Phytogenic/pharmacology , Chromatography, Gas/methods , Salicaceae/chemistry , Sesquiterpenes/analysisABSTRACT
Bioactivity-guided fractionation of antileishmanial active extract from leaves of Casearia arborea led to isolation of three metabolites: tricin (1), 1',6'-di-O-ß-d-vanilloyl glucopyranoside (2) and vanillic acid (3). Compound 1 demonstrated the highest activity against the intracellular amastigotes of Leishmania infantum, with an IC50 value of 56 µm. Tricin (1) demonstrated selectivity in mammalian cells (SI > 7) and elicited immunomodulatory effect on host cells. The present work suggests that tricin modulated the respiratory burst of macrophages to a leishmanicidal state, contributing to the parasite elimination. Therefore, the natural compound tricin could be further explored in drug design studies for leishmaniasis treatment.
