title: Calcium and zinc supplementation protects lead (Pb)-induced perturbations in antioxidant enzymes and lipid peroxidation in developing mouse brain.
abstract: Several studies have implicated oxidative stress as one of the important mechanisms of toxic effects of lead (Pb). In the present study we tested the beneficial effects of calcium (Ca2+) and zinc (Zn2+) in protecting the Pb-induced oxidative stress in the brains of developing and adult mice. Mice were lactationally exposed to 0.2% Pb and supplemented with either calcium (Ca2+) or zinc (Zn2+) and the mitochondrial antioxidant enzymes [superoxide dismutase (SOD), xanthine oxidase (XO) and catalase (CAT)] and lipid peroxidation (LP) were analyzed in cortex, hippocampus, cerebellum and medulla of brains excised on postnatal day (PND) 14, 21, 28 and 3 months. The levels of free radicals were measured using direct Electron Paramagnetic Resonance (EPR) spectroscopy. Exposure to Pb resulted a significant decrease in the activities of SOD, XO and CAT while the LP levels were significantly increased in different brain regions. Evaluation of EPR signals and g-values showed abundant accumulation of free radicals in different regions of the brain following Pb exposure. Interestingly the supplementation with Ca2+ or Zn2+ reversed the Pb-induced effects on antioxidant enzymes, LP and free radical formation; however Zn2+ supplementation appeared to be more protective. These findings strongly support that zinc and calcium supplementation significantly protect the Pb-induced oxidative stress, a major contributing factor to neurotoxicity.
authors.affiliation: Department of Pharmacology, Physiology and Therapeutics, University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58203, USA.
authors.forename: R P Jaya
authors.initials: RP
authors.lastname: Prasanthi
authors.forename: C Bhuvaneswari
authors.initials: CB
authors.lastname: Devi
authors.forename: D Chand
authors.initials: DC
authors.lastname: Basha
authors.forename: N Saya
authors.initials: NS
authors.lastname: Reddy
authors.forename: G Rajarami
authors.initials: GR
authors.lastname: Reddy
mesh_terms: D000284:Administration, Oral; D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001921:Brain / Q000187:drug effects / Q000503:physiopathology*; D002118:Calcium / Q000008:administration & dosage*; D019587:Dietary Supplements; D004798:Enzymes / Q000378:metabolism*; D007855:Lead Poisoning / Q000188:drug therapy / Q000378:metabolism*; D015227:Lipid Peroxidation / Q000187:drug effects*; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects; D015032:Zinc / Q000008:administration & dosage*
chemical_list: D000975:Antioxidants; D004798:Enzymes; D015032:Zinc; D002118:Calcium