Author(s): Abdel-Moneim AMH, Meki AR, Gabr AMAS, Mobasher AA, Lutfi MF
Background: Previous reports claimed that lead enhances oxidative stress and induces renal dysfunction. Antioxidant and free radicals scavenger properties of green tea extract (GTE) can play a protective role against harmful effects of lead on the kidneys.
Objectives: (1) to assess the effects of lead on renal function and oxidative stress, (2) to investigate the effects of GTE on oxidative stress and lead-induced renal dysfunction.
Methods: 60 male Sprague-Dawley rats were divided into four equal groups (N= 15 rat for each); control group (received distilled water), GTE–group (received GTE as 1.5% w/v), Pb–group (received 0.4% lead acetate in distilled water), Pb + GTE-group (received both Pb and GTE). Lead concentration in kidney tissue was measured by atomic absorption spectrometer. Serum levels of total proteins, lipid peroxides (LPO), glutathione (GSH), glutathione S-transferase (GST), were measured using colorimetric methods and compared between different study groups.
Results: Sprague-Dawley rats treated with lead and GTE (GTE + Pb group) showed significantly increased total protein (6.9 ± 0.4 vs 4.5 ± 0.3 g/dL, P < 0.01) and improved renal functions as indicated by lower levels of urea (35.9 ± 3.0 mg/dL) and creatinine (0.4 ± 0.03 mg/dL) compared to the Pb-control group (48.6 ± 2.6 mg/dL and 0.7 ± 0.05 mg/dL respectively, P < 0.01). GTE + Pb group also showed decreased levels of lead (1.9 ± 0.1 ppm) and LPO (1.3 ± 0.1 nmol/mg protein) compared to the Pb- group (2.5 ± 0.1 ppm, P < 0.001 and 1.7 ± 0.2 nmol/mg protein, P < 0.05 respectively). Alternatively, GSH was significantly increased in GTE + Pb group (13.4 ± 0.8 nmol/mg protein) compared to the Pb-group (8.3 ± 0.7 nmol/mg protein, P < 0.001).
Conclusion: Lead can compromise renal function by interfering with redox state in the renal tissues. The treatment with GTE can attenuate oxidative stress and lead burden on renal function.