Antitumor potential of whole plant functional foods in breast cancer

Whole plant foods are a rich source of a wide range of bioactive functional substances - phytochemicals, with extensive additive and/or synergistic effects within the process of carcinogenesis. Thanks to the growing body of evidence from preclinical studies on their effectiveness and relatively safe toxicological profile, they can be considered a suitable strategy in the prevention or adjuvant therapy of cancer diseases. Our study aimed to compare the antitumor capacity of various mixtures of phytochemicals contained in whole plant functional foods, namely in salvia (Salvia officinalis L.), aronia (Aronia melanocarpa L.), and sea buckthorn (Hippophae rhamnoides L.), in a chemopreventive model of breast cancer in female rats.

Phytopharmaceuticals were administered to animals through the diet in three independent experiments using two concentrations: 1) a lower of 0.1% or 0.3% (Groups 0.1 or 0.3), and 2) a 10-fold higher of 1% or 3% (Groups 1 or 3). In the third group, serving as a control (CONT), no phytopharmaceuticals were administered to the animals. After completing each experiment, an analysis of the basic parameters of experimental mammary carcinogenesis and a comprehensive evaluation of well-validated prognostic, predictive, and diagnostic biomarkers used in oncological practice and preclinical research were performed. CS/LC-MS or LC-DAD/MS analysis of phytopharmaceuticals was performed to detect the presence of dominant phytochemicals.

A comprehensive analysis of the mechanism of action of plant-based functional foods confirmed their significant antitumor effects in our experimental breast cancer model, which were, however, specific to the phytopharmaceutical used. Phytopharmaceuticals significantly improved parameters of mammary carcinogenesis in vivo - incidence, frequency, latency of tumors, and/or ratio of HG/LG carcinomas. They statistically significantly improved the expression of markers of apoptosis, proliferation, angiogenesis, cancer stem cells, and oncogenic/tumor-suppressor miRNAs. In addition, chemoprevention led to significant modulation of histone chemical modifications and a decrease in methylation of promoter regions of tumor-suppressor genes.

By comparing the efficacy of phytopharmaceuticals, we concluded that the presence of specific dominant plant metabolites may favorably influence the prognosis of mammary carcinogenesis. However, further preclinical and clinical research is necessary to confirm these findings, including assessing the potential of these agents as adjuvant therapy alongside standard oncological treatment.