Protective effect of selenium on fluoride-induced renal impairments in rats / 中国地方病学杂志

ABSTRACT

Objective To explore the protective effect of selenium, an antioxidant, on fluoride-induced renal injury in rats and find out the optimal level of selenium against fluoride toxicity and its valid molecular target.Methods All 80 male weanling SD rats were randomly divided into 8 groups by body weight as follows normal control group(drinking tap water), fluoride exposed group (drinking water containing 50 mg/L of NaF), low, middle,high selenium exposed groups(drinking water containing 0.375, 0.750, 1.500 mg/L of Na2SeO3) and low, middle,high Se-fluoride groups (drinking water containing both 50 mg/L NaF and three doses of Na2SeO3 as abovementioned, respectively). After 6 months, the rats were killed then the oxidation level and nuclear factor κB(NF-κB)expression level in kidney were measured. Results The weight of the fluoride exposed group[(695.95 ± 55.89 )g]was significantly deceased than the controls[(782.69 ± 56.12)g, P ＜ 0.01]. Glutathione peroxidase(GSH-Px)activity of fluoride exposed group[(55.86 ± 5.09)U/mgprot] was not significantly different but decreased. Tatal antioxidant capacity (T-AOC) activity in fluoride exposed group [(7.54 ± 1.35)U/mgprot] significantly decreased than the controls[(9.03 ± 0.37 )U/mgprot, P ＜ 0.05]. In addition, a significant increase of malondialdehyde ( MDA )in fluoride exposed group[(3.86 ± 0.31 )mnol/mgprot, P ＜ 0.05] was observed than the controls[(3.14 ± 0.32)nmol/mgprot, P ＜ 0.05]. GSH-Px activity of high Se-fluoride group[(74.99 ± 8.41 )U/mgprot] was significantly higher than the fluoride exposed group[(55.86 ± 5.09)U/mgprot, P ＜ 0.05] and its MDA level[(3.17 ± 0.20)nmol/mgprot] was lower than the fluoride exposed group[(3.86 ± 0.31 ) nmol/mgprot, P ＜ 0.05]. NF-κB expression levels of fluoride group, high selenium group and low Se-fluoride group(0.360 ± 0.015,0.367 ± 0.007,0.376 ± 0.006,respecyively) were obviously increased compared with the controls(0.312 ± 0.022, P ＜ 0.05); it was significantly lower in high Se-fluoride group(0.312 ± 0.005) than in fluoride exposed group(0.360 ± 0.015, P ＜ 0.05). Conclusions Na2SeO3 of 1.5 mg/L is the optimal dose against chronic fluorosis on kidney injury under this experimental condition.NF-κB is likely to be a target molecule of the selenium as an antagonist on fluorosis.