Effect of Different Concentrations of Lead Nitrate on Biochemical Parameters of Alfalfa

Corresponding author: Reihaneh Sabbaghzadeh Tel: +985144012521 Email: r.sabbaghzadeh@hsu.ac.ir Address: Department of Biology, Faculty of Sciences, Hakim Sabzevari University, Sabzevar, Iran ABSTRACT Background and objectives: Polyphenols can exert free radical scavenging effects by naturalizing dangerous reactive oxidants. Formation of reactive oxygen species can cause oxidative damage to human cells, leading to various diseases such as cancer, cardiovascular disease, osteoporosis and degenerative diseases. In this study, we investigated effect of treatment with various concentrations of lead (II) nitrate, a toxic and an oxidizing agent, on growth and biochemical parameters of alfalfa (Medicago sativa L). Methods: Total phenol content was estimated by the Folin-Ciocalteu method. The 1,1diphenyl-2-picrylhydrazyl (DPPH) stable free radical was used for assessment of free radicalscavenging activity. Changes in the activity of catalase and peroxidase as well as in the level of proteins, phenol content and malondialdehyde (as marker of lipid peroxidation) were investigated following treatment with different concentrations (0, 8, 12 and 16 mg/l) of lead nitrate for 21 days. All experiments were done in triplicate. Butylated hydroxytoluene and quercetin were used as standard controls. Results: Treatment with lead significantly altered the level of total phenolic content, proteins, malondialdehyde and the activity of catalase and peroxidase (P<0.05). Conclusion: Our results indicate that lead-contaminated soil can significantly alter biochemical and growth parameters of alfalfa.