Indian Journal of Biocbemistry :::. Biophysics Vol. 36, February 1999, pp. 51-54 Effect of high arsenic content in drinking water on rat brain Aditi Nag Chaudhurio, Srabanti Basu, Sukumar Chattopadhyay' and S Das Gupta° *Department of Chemistry, Lady Brabourne College, P 1/2, Surawardy 'Avenue, Calcutta 700017; tsiotechnology and Life Science Centre, Jadavpur University, Raja S C Mullick Road, Calcutta 700032; and cIndian Science Congress Association, 14, Biresh Guha Street, Calcutta 700017, India Received 17 February 1998; revised 8 September 1998 The permissible limit of arsenic content in drinking water is 0.05 ppm, whereas, in many parts of West Bengal the arsenic level in drinking water is 0.1 ppm, frequently 0.3 ppm and even 3.0 ppm, though rarely. In order to assess possible risk to brain function by drinking such water, rats were given arsenic mixed in drinking water afthe.above four concentrations for 40 days. There was increased lipid peroxidation at all doses of arsenic, includmg the 'permissible limit', decrease in glutathione level, superoxide dismutase and glutathione reductase activities, indicating the free-radical-mediated degeneration of brain. Arsenic (As) is a naturally occurring element and is used as poison I. Ingestion of As is known to cause skin cancer and inhalation causes lung cancer. Recently it has been reported that ingested As also causes cancer of the bladder, kidney, lung and li ver3. Ramos et al. 4 . have shown that As decreased glutathione (GSH) level and increased lipid peroxidation (LPO) in liver, kidney and heart. This effect was higher at 18.2 mg/ kg dose (a.dose within the-95% confidence limit for LD IOO ) than that.at 14.8 mg/ kg dose (a dose within the 95% confidence limit . 5 for LDo) It has been reported that when GSH is low As toxicity was enhanced. Therefore it is expected that a relationship between As toxicity, lipid peroxidation and GSH level exists. LPO has been implicated in the pathology of various degenerative disorders of the central nervous system (CNS). _ Brain is thought to be particularly vulnerable to damage because of its high rate of oxygen consumption; the high levels ' of polyunsaturated fatty acids, low levels of peroxisomal catalase and glutathione peroxidase (GSG-Px) activities, low levels of mitochondrial' superoxide dismutase and catalase activities, dependence of neurons on glial cells for synthesis of Cys from Cys- Cys and non regenerative nature of neuron. Lipid peroxidation in brain differs from liver system and uses either NADPH or NADH as the reducing source and only Fe 2 + ion, whereas liver lipid peroxidation uses only NADPH as reducing source and both Fe 2 + and Fe 3 + ion 6 • We had earlier reported that As at the • Author for correspondence level known as "permissible limit" is harmful to brain 7 ,8. Arsenic contamination of drinking water in West Bengal has been noted 9 as a serious health hazard as people suffer from melanosis, leukomelanosis, keratosis, hyperkeratosis, gangrene, skin cancer and other types of cancer. According to the report by' Mondal et al. lO , more than 200,000 people of 520 villages covering 34,000 sq.km. area suffer from As related diseases. They have analysed 25,000 tube wells and found average As concentration to be approximately 0.3 mg/l . and in some places the concentration reaches to 3.0 mg/l, whereas, 0.05 mg/l of As is the permissible limit of As in drinking water. People drinking As contaminated water have high As concentration in their hair, nails and urine lO . But there are no information on the effect of that high concentration of As in brain. Therefore, in the present study an attempt was made to evaluate the effect of As in the brain of mammals at dose levels that were found contaminating the ground water and also at the "permissible limit" level laid by WHO. The parameters studied were GSH depletion, LPO and the activities of SOD, catalase, GSH-Px and GSH-red. Materials and Methods Sprague ' Dawley male rats (four weeks old; average body wt. 110 g) were divided into five groups. The first group (control) was given distilled water; while the second, third, fourth and fifth groups were given water containing As, 0.05 ppm (the c\permissible limit"), 0.10 ppm, 0.30 ppm (the average concentration found in affected areas of West