ABSTRACT
Cytotoxic activity of eight plant extracts, native from the Mid-West of Brazil comprising Cerrado, Pantanal and semideciduous forest, was evaluated for MDA-MB-435, SF-295, and HCT-8 cancer cell strains. A single 100 µg.mL-1 dose of each extract was employed with 72 h of incubation for all tests. Doxorubicin (1 µg.mL-1) was used as the positive control and the MTT method was used to detect the activity. Cytotoxicity of distinct polarities was observed in thirty extracts (46 percent), from different parts of the following species: Tabebuia heptaphylla (Vell.) Toledo, Bignoniaceae, Tapirira guianensis Aubl., Anacardiaceae, Myracrodruon urundeuva Allemão, Anacardiaceae, Schinus terebinthifolius Raddi, Anacardiaceae, Gomphrena elegans Mart., Amaranthaceae, Attalea phalerata Mart. ex Spreng., Arecaceae, Eugenia uniflora L., Myrtaceae, and Annona dioica A. St.-Hil., Annonaceae. Extracts of at least two tested cell strains were considered to be highly active since their inhibition rate was over 75 percent.
ABSTRACT
The cytotoxic potential of stem organic extracts from Calotropis procera (Asclepiadaceae) was firstly evaluated against cancer cell lines by MTT assay. Subsequently, samples considered cytotoxic were tested for antimitotic activity on sea urchin egg development and for in vivo antiproliferative activity in mice bearing Sarcoma 180 tumor. Among the five extracts (hexane, dichloromethane, ethyl acetate, acetone and methanol), ethyl acetate and acetone extracts displayed higher cytotoxic potential against tumor cells, with IC50 ranging from 0.8 to 4.4 μg/mL, while methanolic extract was weakly cytotoxic. Cytotoxic extracts also exhibited cell division inhibition capacity by antimitotic assay, revealing IC50 values lower than 5 μg/mL. In the in vivo antitumor assessments, ethyl acetate- and acetone-treated animals showed tumor growth inhibition ratios of 64.3 and 53.1 percent, respectively, with reversible toxic effects on liver and kidneys. Further studies are in progress in order to identify C. procera cytotoxic compound(s) and to understand the mechanism of action responsible for this tumor-decreasing potential.
O potencial citotóxico de extratos orgânicos do caule de Calotropis procera (Asclepiadaceae) foi primeiramente avaliado frente a linhagens de células tumorais através do ensaio de MTT. Aquelas amostras consideradas citotóxicas foram sub-sequentemente testadas para atividade antimitótica sobre o desenvolvimento de ovos de ouriço-do-mar e para atividade antiproliferativa in vivo em camundongos transplantados com tumor Sarcoma 180. Dentre os cinco extratos estudados (hexano, diclorometano, acetato de etila, acetona e metanol), os extratos acetato de etila e acetona mostraram maior potencial citotóxico contra células tumorais, com CI50 variando de 0,8 to 4,4 μg/mL, enquanto o extrato metanólico revelou ser fracamente citotóxico. s extratos citotóxicos também exibiram capacidade de inibição da divisão celular com valores de CI50 menores que 5 μg/mL. Nas avaliações antitumorais in vivo, os animais tratados com os extratos acetato de etila e acetona mostraram taxas de inibição do crescimento tumoral de 64,3 e 53,1 por cento, respectivamente, com efeitos tóxicos reversíveis sobre o fígado e os rins.
Subject(s)
Animals , Mice , Antineoplastic Agents, Phytogenic/pharmacology , Calotropis/chemistry , Cell Proliferation/drug effects , Plant Extracts/pharmacology , Cell Line, Tumor , Drug Screening Assays, Antitumor , Sea UrchinsABSTRACT
Phytochemical investigation of heartwood of Auxemma glazioviana (Boraginaceae) has led to the isolation of three benzoquinones, one hydroquinone identified as: oncocalyxone A (1), oncocalyxone C (2), glazioviana A (3), glaziovianol (4) besides allantoin (5) á-bisabolol (6) and á-cadinol (7). Their structures were determined based on spectral analysis, including 2D NMR experiments. Essential oil obtained from heartwood by hydrodistillation was analyzed by GC/MS. The major constituents were identified as á-bisabolol and á-cadinol. The oil was active against larvae of dengue (Aedes aegypti ) with DL50 2.98 ppm.