In vitro and in vivo antitumor activity of Macrothelypteris torresiana and its acute/subacute oral toxicity

The aim of this study was to evaluate the antitumor potential of Macrothelypteris torresiana by studying in vitro antitumor activity of the protoapigenone, as well as in vivo antitumor activity and acute/subacute oral toxicity of the total flavonoid fraction from the roots of M. torresiana. Considering that the protoapigenone is a main constituent of the total flavonoid fraction and it might play a key role in the antitumor activity of M. torresiana, the MIT assay was used to investigate the in vitro antitumor activity of the protoapigenone. Our study revealed that the protoapigenone of M. torresiana showed significant antitumor activity towards Hep G2, Tca-8113, MCF-7, M5 and K562 with IC50 values of 2.3, 0.6, 0.8, 0.3 and 0.9 mu g/ml, respectively. The antitumor potential of the total flavonoid fraction was evaluated using preparations 1, 2 and 3, which were prepared by total flavonoid fraction directly diluted with sterile saline, dissolved using sodium carboxymethyl cellulose (CMC-Na) and included by hydroxypropyl-beta-cyclodextrin, respectively. These were investigated in vivo using mouse sarcoma S-180 in BALB/c mice after completing tumor inoculation for 24 h. Pronounced antitumor activity was observed in the treated groups for preparations 2 and 3, and the high and medium doses in particular showed very high inhibition ratio of tumor growth (>50%). No significant difference was observed when compared to the positive control group (5-fluorouracil). The acute/subacute oral toxicity test was performed, and the results of acute oral toxicity showed that the LD50 values of preparations 2 and 3 were 2.76 and 0.87 g/kg body wt., respectively. According to the results of the subacute oral toxicity study, the total flavonoid fraction had low toxicity. The overall results of this study suggest that the total flavonoid fraction from the roots of M. torresiana shows significant antitumor activity and represents a potential source of medicine for the treatment of cancer. (C) 2010 Elsevier GmbH. All rights reserved.