ABSTRACT
<p><b>OBJECTIVE</b>Toxic metal ions have been implicated in the generation of reactive oxygen species (ROS) and nitric oxide (NO). Metallothionines (MT) and plant flavonoids have been reported in the intervention against oxidative damage. We investigated the effect of zinc induced MT and green tea polyphenol (GTP) in reducing the oxidative responses induced by nickel and platinum.</p><p><b>METHODS</b>Zinc (10 mg/kg b. wt, sc) was administered to rats twice at a gap of 24 hrs and GTP (10 mg/100 mL in drinking water) was fed ad libitum for 8 days. Nickel chloride (150 umol/kgb.wt, ip) and cisplatin (50 mumol/kg b.wt, sc) was administered to rats 24 h after Zn or GTP pre-treatment. Animals of all the groups were sacrificed 16 hrs after treatment and biochemical markers for toxicity were monitored.</p><p><b>RESULTS</b>Zinc or GTP pre-treatment caused significant protection against nickel or cisplatin enhanced mortality in rats, and reduction in lipid peroxidation and NO.</p><p><b>CONCLUSION</b>It is proposed that inhibition of ROS and NO by GTP and zinc may prove useful as a selective pharmacological agent in the amelioration of metal toxicity.</p>
Subject(s)
Animals , Rats , Antioxidants , Pharmacology , Biomarkers , Cisplatin , Toxicity , Flavonoids , Pharmacology , Free Radical Scavengers , Pharmacology , Lipid Peroxidation , Metallothionein , Metabolism , Mortality , Nickel , Toxicity , Nitric Oxide , Metabolism , Phenols , Pharmacology , Polyphenols , Tea , Chemistry , Time Factors , Zinc , PharmacologyABSTRACT
<p><b>OBJECTIVE</b>To investigate the effect of Lead (Pb) acetate exposure on Semliki forest virus (SFV) pathogenesis in mice.</p><p><b>METHODS</b>Different doses (62.5, 125, 250 and 500 mg/Kg body weight) of Pb dissolved in normal saline were given to mice by oral intubation in a sub-acute (28 days) and sub-chronic (90 days) regimen followed by SFV infection. Morbidity, mortality, clinical symptoms, mean survival time (MST), changes in body and organ weight, accumulation of lead in soft tissues, virus titre in brain and histopathological alterations were compared between lead exposed and infected groups.</p><p><b>RESULTS</b>Early appearance of virus symptoms, increased mortality, decreased MST, enhanced SFV titre and greater tissue damage were observed in lead exposed-SFV-infected mice.</p><p><b>CONCLUSION</b>Pre-exposure to lead increases the susceptibility of mice towards SFV infection. Further studies are suggested in view of the persistence of lead in the environment and the possibility of infection by microbial pathogens.</p>