Oxidative stress, DNA damage and apoptosis levels in those who use borderline high level fluoride content drinking water

Abstract

Aim: Fluoride is necessary for tooth and bone development, but when exposed to excessive levels can cause oxidative stress, DNA damage, apoptosis, fluorosis and cancer. The aim of this study is to reveal the underlying mechanism of fluoride toxicity and to clarify, in part, the uncertainty of the fluoride level in the reference value ranges of drinking water. Material and Methods: Two groups were included in the study as exposure and control groups. Serum Total Oxidant Status and Total Antioxidant Status were measured with colorimetric; Urine 8-OHdG (8-hydroxy-2-deoxyguanosine) (CUSABIO) levels as DNA damage biomarkers and serum M30 and M65 levels (PEVIVA) as apoptosis biomarkers were studied by ELISA method. In addition, all participants underwent a dental examination by the dentist. Results: Serum total antioxidant status (TAS) were lower in the exposure group compared to the control group (p <0.001); serum total oxidant status (TOS) (p <0.001), OSI (p <0.001), M30 (p <0.001) and M65 (p <0.001) levels and urine 8-OHdG (p = 0.011) levels were high. However, the M30 / M60 ratio was not statistically different between the two groups (p = 0.371). Dental fluorosis was detected in all participants in the exposure group. Conclusion: This study showed increased levels of oxidative stress, DNA damage and apoptosis biomarkers in drinking water users with borderline high level fluoride. Therefore, instead of the World Health Organization's reference value range (0.5-1.5 mg/L) for fluoride levels in drinking water, the US Public Health Service’s (0.7 mg/L) reference value range seems to be more appropriate to the precaution.