Fluoride-induced oxidative stress in rat's brain and its amelioration by buffalo (Bubalus bubalis) pineal proteins and melatonin.

Fluoride (F) becomes toxic at higher doses and induces some adverse effects on various organs, including brain. The mechanisms underlying the neurotoxicity caused by excess fluoride still remain unknown. The aims of this study were to examine F-induced oxidative stress (OS) and role of melatonin (MEL) and buffalo pineal proteins (PP) against possible F-induced OS in brain of rats. The 24 rats were taken in present study and were divided into four groups: control, F, F + PP, and F + MEL. The F group was given 150 mg/L orally for 28 days. Combined 150 ppm F and 100 microg/kg BW (i.p.) PP and F (150 ppm) + MEL (10 mg/kg BW, i.p.) were also administered. The activities of enzymatic, viz., superoxide dismutase (SOD), glutathione peroxidase (GPx), catalase (CAT), glutathione reductase (GR), and non-enzymatic, viz., reduced glutathione (GSH) concentration, and the levels of malondialdehyde (MDA) in the brain tissue were measured to assess the OS. Fluoride administration significantly increased brain MDA compared with control group, while GSH levels were decreased in fluoride-treated groups, accompanied by the markedly reduced SOD, GPx, GR, and SOD activity. Buffalo PP and MEL administration caused brain MDA to decrease but caused SOD, GPx, GR, GSH, and CAT activities to increase to significant levels in F-treated animals. Together, our data provide direct evidence that buffalo PP and MEL may protect fluoride-induced OS in brain of rats through mechanisms involving enhancement of enzymatic and non-enzymatic antioxidant defense system. Therefore, this study suggested that PP and MEL can be useful in control of neurotoxicity induced by fluoride.