The Genistein Supply and Elemental Composition of Rat Kidneys in an Induced Breast Cancer Model

Background: Many natural phytochemicals support the work of the kidneys. The health effects of genistein have been confirmed in many kidney diseases (inflammation and acute kidney injury, cancer or menopausal or senile changes). Genistein through various mechanisms can affect kidney conditions. Objectives: The purpose of this work was to analyze the supply of various forms of genistein at a low dose (0.2 mg/kg b.w.) on the renal mineral composition of rats under conditions of mammary gland tumorigenesis (induced with DMBA). Methods: Sprague rats at the age of 40 days were divided into four research groups, i.e., a control group receiving only standard feed and four groups receiving feed supplemented with genistein in the form of nanoparticles (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.) (size: 92 ± 41 nm), genistein in microparticle form (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.) (size: 587 ± 83 nm) and genistein in macroparticle form (normal, classical) (0.1 mg/mL, i.e., 0.2 mg/kg.i.d.). Mammary gland cancer was induced using DMBA (7,12-dimethyl-1,2-benz(a)anthracene). The experiment lasted 100 days. The concentrations of Ca, Zn, Fe, Cu, As, Se, Rb, Sr, Mo, B, and Mn were measured using the ICP-MS method, while the levels of K, Mg, and Na were measured using the FAAS method. Results: It was shown that, depending on the degree of miniaturization of genistein, its administration affected changes in kidney mineral composition, primarily resulting in a strongly reduced calcium content in the group of rats receiving nanogenistein. We found a negative impact of nanogenistein administration on the amount of calcium and iron, indicating an increased distribution or excretion of these elements from the body, as well as an increase in the number of elements, especially magnesium, sodium, zinc, boron, and copper concentrations, compared to the non-supplemented group. Conclusions: This study confirms the need for thorough clinical analyses in the future, with regard to the effects of genistein, especially its nanoforms on the body.