RESUMO
Casearia sylvestris Swartz (Salicaceae) is a plant commonly widespread in the Americas. It has oxygenated tricyclic bioactive clerodane diterpenes with antimicrobial, antiulcer, larvicidal, chemopreventive, anti-inflammatory, antioxidant and antiproliferative properties. Due to this requirement for the developing of new anticancer drugs, it was initially evaluated the cytotoxic activity of a fraction with Casearins (FC) and its clerodane diterpenes Casearin B (Cas B), D (Cas D), X (Cas X) and Caseargrewiin F (Cas F) isolated from C.sylvestris leaves against 7 tumor cell lines, Sarcoma 180 cells (S180) and on normal peripheral blood mononuclear cells (PBMC). All substances tested showed cytotoxic potential. Cas F and X were the most active compounds. Cell death analyzes with Cas F (0.5 and 1µM) and Cas X (0.7 and 1.5µM) using the HL-60 leukemia line as experimental model showed DNA synthesis and membrane integrity reduction, DNA fragmentation and mitochondrial depolarization, specially after 24h exposure, cell cycle arrest in G0/G1 phase caused by Cas X, activation of the initiator -8/-9 and effector -3/-7 caspases and phosphatidylserine externalization, all biochemical features of apoptosis corroborated by chromatinic condensation, karyorrhexis, cytoplasmic vacuolation and rarefaction and cellular shrinkage, morphological findings specially observed after 12 and 24h of incubation. Therefore, Cas X and F were the most functional molecules with more pronounced lethal and discriminating effects on tumor cells and antiproliferative action predominantly mediated by apoptosis, highlighting clerodane dipertenes as promising lead antineoplastic compounds.
Assuntos
Antineoplásicos Fitogênicos/farmacologia , Diterpenos Clerodânicos/farmacologia , Animais , Antineoplásicos Fitogênicos/química , Apoptose/efeitos dos fármacos , Casearia/química , Caspases/metabolismo , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Membrana Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Fragmentação do DNA , Diterpenos/farmacologia , Diterpenos Clerodânicos/química , Feminino , Células HL-60 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Fosfatidilserinas/metabolismo , Folhas de Planta/química , Espécies Reativas de Oxigênio/metabolismo , Sarcoma 180RESUMO
The total phenol and flavonoid content, in addition to the antioxidant and cytotoxic activities, of extracts and fractions of Piptadenia moniliformis was determined. This honey plant species is commonly known as "catanduba" or "angico de bezerro". The aqueous fraction derived from the peels of the fruits exhibited the highest antioxidant activity, remaining comparable to the standard value, and there was a general correlation between this activity and the phenol and flavonoid content. The antioxidant potential of this species provides a basis for future developments in herbal medicines and cosmetics. Only the hydro alcoholic extract, the dichloromethane fractions and the ethyl acetate fractions showed moderate cytotoxicity.
Foram determinados o teor de fenóis e flavonoides, as atividades antioxidante e citotóxica dos extratos e frações de Piptadenia moniliformis. Essa é uma espécie melitófila comumente conhecida como "catanduba" ou "angico de bezerro". Das frações testadas, a fração aquosa das cascas dos frutos apresentou a maior atividade antioxidante, com valor comparável ao padrão, e no geral houve correlação do teor de fenóis e flavonoides com essa atividade. Os resultados do potencial antioxidante para essa espécie fornecem subsídios para futuros trabalhos que visem o desenvolvimento de fitoterápicos e cosméticos. Quanto à atividade citotóxica apenas o extrato hidroalcoólico e as frações diclorometano e acetato de etila demonstraram moderada citotoxicidade.
