Quercus spp. extract as a promising preventive or therapeutic strategy for cancer: A systematic review

Acorns have traditionally been used in the human diet and for the treatment of specific diseases. Therefore, the present study performed a systematic review of studies which investigated the effects of Quercus spp. extracts in cancer prevention and treatment. A systematic literature search was performed for original records which addressed the anticancer effects of Quercus spp. extract in in vitro and in vivo cancer models. Body composition, food consumption, tumor development and/or toxicity were evaluated in in vivo studies, while cytotoxicity was evaluated in in vitro studies. Few studies and low sample sizes presented a challenge in the drawing of solid conclusions. Overall, the results suggested a positive impact of Quercus spp. extract, by reducing cancer development. Therefore, more studies with different cancer cell lines and animal models to address the efficacy of the acorn extracts in several types of cancer are required. Furthermore, the effects of acorn flour, incorporated in the diet, in an animal model of mammary cancer should be evaluated.