Selenium-enriched polysaccharides from pyracantha fortuneana (Se-PFPs) augment docetaxel-induced tumor suppression in human ovarian cancer

Pyracantha fortuneana (Maxim.) contains many healthy ingredients, including selenium-enriched polysaccharides. Selenium-enriched polysaccharides from P. fortuneana (Se-PFPs) have anti-mutation and anti-oxidation activities, along with anti-tumor activity in ovarian cancer and breast cancer cells. Docetaxel (DTX) is widely applied in therapeutic treatment for ovarian cancer. However, its use in clinics is restricted due to its unfavorable side-effects. Thus there is a need to improve the therapeutic efficacy of Docetaxel (DTX). This study aimed to determine whether Se-PFPs and DTX can be used together to generate additive and/or synergistic effect in therapeutic treatment for ovarian cancer. In vitro and in vivo experiments were conducted to compare the anti-proliferative and apoptosis-inducing effects of the combined use of both drugs with that of each one used alone. Two ovarian carcinoma cell lines, SKOV3 and A2780 cells, were used and divided into four groups: 1) Saline control (vehicle); 2) Se-PFPs only; 3) DTX only; and 4) Se-PFPs+DTX. The apoptotic rate of group treated with a combination of Se-PFPs and DTX was found to be significantly higher than those of groups treated with either agent alone. This finding was confirmed by increased TdT-mediated dUTP nick end labeling (TUNEL)-positive rate, rate of apoptotic cells, enhanced cleavage of caspase-3 and PARP, and reduced cell viability and Ki-67 expression. The combined drugs did not significantly increase the toxicity HOSE cells, the human ovarian surface epithelial cells immortalized with hTERT. Similar results were obtained in the in vivo experiments by measuring tumor weight and volume. Thus, Se-PFPs can augment DTX tumor inhibitory effect. The combination of Se-PFPs and DTX can be a promising therapeutic strategy for ovarian cancer. Key words: Selenium-enriched Pyracantha fortuneana (Maxim.) Li polysaccharides, docetaxel, tumor suppression, ovarian cancer.