Indian Journal of Experimental Biology Vol. 51, March 2013, pp. 249-255 Effects of fluoride and ethanol administration on lipid peroxidation systems in rat brain Shailender Singh Chauhan, Sudarshan Ojha & Akhtar Mahmood* 1 Department of Biochemistry, Panjab University, Chandigarh, 160 014, India Received 6 June 2012; revised 21 September 2012 Exposure to fluoride and excessive ethanol consumption has been identified as a serious public health problem in many parts of the world, including India. Thus, the effect of co-exposure to fluoride and ethanol for 3-6 weeks was studied on lipid peroxidation (LPO) and oxidative stress related parameters in the rat brain. After 3 weeks, co-treated animals showed 95% increase in LPO levels compared to control. However, the levels of reduced glutathione, total and protein thiols were decreased. These changes were accompanied by a decrease in the activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase. Rats exposed to fluoride together with ethanol for 6 weeks resulted in 130% increase in LPO and decrease in the reduced glutathione levels. The activities of superoxide dismutase, catalase, glutathione peroxidase, glutathione reductase and glutathione-S-transferase were reduced under these conditions. Brain histology revealed excessive lymphocytes, edema and spongeosis in the cortical region after six weeks of fluoride and ethanol treatment. These results suggest that exposure to fluoride together with ethanol enhances lipid peroxidation by affecting antioxidant defence systems in the rat brain. Keywords: Co-exposure, Ethanol, Fluoride, Lipid peroxidation, Rat brain Fluorosis, as a consequence of exposure to high amounts of the fluoride 1 is a serious public health problem in many parts of the world. Human exposure to fluoride occurs mainly through drinking water and World Health Organization has established 1.5 mg fluoride/L drinking water as the safe limit 2 . However, in many parts of the world, as in India, fluoride concentration in the groundwater is as high as 27 mg/day 2 . The detrimental effects of fluoride on skeletal tissues are characterized by dental mottling, crippling deformities, osteoporosis and osteosclerosis 1 . Exposure to fluoride also affects various soft tissues including brain 3 . Fluoride can pass through blood brain barrier 4 and its accumulation in brain may facilitate the formation of reactive oxygen species (ROS) which are capable of inducing oxidative damage to vital cell components 5 . In healthy subjects, oxidative damage is largely prevented by a very complex antioxidant system, consisting of several enzymatic and non-enzymatic components, which act cooperatively to provide better protection against free radical attack. The extent to which fluoride can cause oxidative damage is influenced by a number of factors, such as duration of exposure, age, sex, nutrition and simultaneous exposures to other xenobiotics. Recently, increased attention has been paid to interactions of fluoride with other xenobiotics 6 . However, there are negligible scientific reports about fluoride and ethanol interactions following their combined exposures. Interactions between fluoride and ethanol are important, since both pose a risk to human and animal health. Combined exposures to these toxicants may be commonly noticed in alcoholics who happen to be the inhabitants of high fluoride endemic areas 7 . Inkielewicz et al. 8 have reported the induction of lipid peroxidation in liver, kidney, brain and serum of male rats following co-exposures to fluoride and ethanol for four weeks. A marked elevation in intestinal lipid peroxidation status in rats exposed to fluoride together with ethanol has been reported 9 . This communication reports the combined effects of fluoride and ethanol administration on lipid peroxidation and oxidative stress related parameters in rat brain. Materials and Methods Animals―Six month old female Sprague Dawley rats weighing 190-200 g were procured from the Central Animals House of Panjab University, Chandigarh, India. They were housed in propylene cages and maintained at 22 ± 3 °C, on a 12:12 h light dark cycle and a minimum 40% RH. Standard pellet diet (Ashirwad Industries, India) and water were given ad libitum. The animals ________ *Correspondent author Telephone 91-0172-2534136 Fax: 91-0172-2541409 E-mail: akhtarmah@yahoo.com