Objectives: Oxidative stress is considered as a possible molecular mechanism involved in lead (Pb(2+)) neurotoxicity. Very few studies have been investigated on the occurrence of oxidative stress in developing animals due to Pb(2+) exposure. Considering the vulnerability of the developing brain to Pb(2+), this study was carried out to investigate the effects of Pb(2+) exposure in brain regions especially on antioxidant enzyme activities along with ameliorative effects of ethylenediaminetetraacetic acid (EDTA) and clinoptilolite.
Methods: Three-week old developing Swiss mice Mus musculus were intraperitoneally administered with Pb(2+) acetate in water (w/v) (100 mg/kg body weight/day) for 21 days and control group was given distilled water. Further Pb(2+)-toxicated mice were made into two subgroups and separately supplemented with EDTA and clinoptilolite (100 mg/kg body weight) for 2 weeks.
Results: In Pb(2+)-exposed mice, in addition to increased lipid peroxidation, the activity levels of catalase, superoxide dismutase (SOD), glutathione peroxidase (GPx), and glutathione (GSH) found to decrease in all regions of brain indicating, existence of severe oxidative stress due to decreased antioxidant function. Treatment of Pb(2+)-exposed mice with EDTA and clinoptilolite lowered the lipid peroxidation (LPO) levels revealing their antioxidant potential to prevent oxidative stress. Similarly their administration led to recover the level of catalase, SOD, and GPx enzymes affected during Pb(2+) toxicity in different regions of brain.
Conclusions: The protection of brain tissue against Pb(2+)-induced toxicity by clinoptilolite and EDTA in the present experiment might be due to their ability to react faster with peroxyl radicals there by reducing the severity of biochemical variable indicative of oxidative damage. Thus, the results of present study indicate the neuroprotective potential of clinoptilolite and EDTA against Pb(2+) toxicity.
Keywords: Clinoptilolite; EDTA; lead neurotoxicity; oxidative stress.