Efeito in vitro da suplementação do guaraná (Paullinia cupana) na atividade de quimioterápicos usados no tratamento do câncer de mama

Abstract

Cancer related fatigue (CRF) is a common phenomenon in patients undergoing chemotherapy and radiotherapy representing a negative impact on functional status and quality of life. Some plants present tonic and antifatiguing properties, as guaraná (Paullinia cupana) and a previous study described positive effect on CRF of breast cancer patients submitted to chemotherapy. Despite the positive results indicating that guaraná improve CRF, this fruit present bioactive molecule as caffeine and catechin which can to influence the effect of antitumor drugs. Therefore, the aim of this study was to evaluate if guaraná changes the viability and antiproliferative effect of seven chemotherapic agents currently used in the breast cancer treatment using as in vitro experimental model MCF-7 breast cancer cell line. The cells were exposed at 1, 5 and 10 μg/mL guaraná concentrations with and without chemotherapics. The main results showed an antiproliferative effect of guaraná at 5 10 μg/mL. The guaraná influence on chemotherapic effects was drug-dependent. The guaraná effect on MCF-7 cells viability was heterogeneous and drug dependent. Different of the results found after 24 hours exposition, the guaraná plus all chemotherapic drugs showed a strong antiproliferative effect ( > 40% of cell inhibition) on MCF-7 cells after 72 hours of exposition of 10 uM gemcitabine, vinorelbine and methotrexate, 2 uM 5-fluoracil, 50 uM paclitaxel, 200 nM doxorubicin, and 5mM cyclophosphamide. Because chemotherapic drugs were affected by guaraná addition most improve the antiproliferative activity, the therapeutic use of guaraná against CRF seems did not affect negatively the chemotherapy. However, in vitro protocols present methodological limitations that need to be considered and complementary in vitro and in vivo investigations need to be performed to evaluate whether chemotherapic plus guaraná administration is safe to breast cancer patients.