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
Objective To investigate the antitumor effects of total glycoside of Cimicifuga dahurica (TGCD) in vivo and in vitro, and further explore its mechanisms. Methods The anti-tumor activity in vitro was determined by MTT assay and the anti-tumor activity in vivo was evaluated using experimental mouse tumor (S180) model and human tumor (A549) xenografts in nude mice. After treatment, A549 cell apoptosis and morphologic change were evaluated by Annexin V/PI flow cytometry and HE staining. Results Inhibitory concentration 50% (IC50) of TGCD on A549, HepG2, HL60, Eca-109 and MDA-MB231 cells were 20.3, 27.1, 21.2, 23.4 and 32.7 ?g/mL respectively. Administration of TGCD (100 or 200 mg/kg) inhibited S180 solid tumor development in mice, the inhibition rates were 42.8% and 54.6% respectively. Administration of TGCD (100 or 200 mg/kg) inhibited A549 tumor growth with a T/C (mean value of treated group/mean value of control group) value of 58.1% and 52.2% respectively. In addition, increased percentage of apoptotic cells induced by TGCD in human A549 nude mice xenografts and the histopathological changes including cell shrinkage and condensation of chromosomes were observed. Conclusion TGCD has demonstrated antitumor bioactivity both in vitro and in vivo, which may be related to its effects of inducing apoptosis activity.