Impact of dietary practices on DNA adduct formation by aristolochic acid I in mice: drinking alkaline water as a risk mitigation strategy

Balkan endemic nephropathy (BEN) is a chronic kidney disease associated with the consumption of aristolochic acids (AAs) through contaminated food sources. AAs are known to form DNA adducts that are implicated in tumorigenesis and kidney fibrosis. Given the sensitivity of DNA adduct formation to dietary factors, this study aimed to investigate the impact of various dietary practices on AA-DNA adduct formation, thereby assessing the risk of developing BEN. We quantified AA-DNA adducts in DNA extracted from the kidneys and livers of mice subjected to high-fat, high-protein, high-sucrose, and high-salt diets, utilizing a highly sensitive liquid chromatography–tandem mass spectrometry method combined with stable isotope dilution. Our results demonstrated that unbalanced diets significantly elevated the formation of DNA adducts from AAs. Notably, mice fed high-fat diets exhibited increases in adduct levels of 71 and 114% for diets containing 17 and 25% fat, respectively. Mice on a 20% sucrose diet showed an 80% increase in adduct levels compared to those on a standard diet. Further investigations using gut sacs from the small intestines of these mice revealed that the increased level of DNA adduct formation was primarily attributed to enhanced intestinal absorption. Additionally, we observed that drinking alkaline water reduced adduct levels by 30% compared to tap water, likely by decreasing AA absorption. In contrast, commonly used dietary supplements, such as vitamin C and cysteine, significantly increased AA-DNA adduct levels by enhancing the activity of enzymes involved in the metabolic activation of AAs. These findings highlight the critical role of a balanced diet in mitigating the risk of BEN and suggest that alkaline water consumption may serve as a protective strategy for individuals living in AA-contaminated regions.