Abstract: Objective: The effects of grape seed proanthocyanidins (GSPAs) on renal function in iron-overload rats were investigated by observing the iron content, oxidative stress status, creatinine and urea nitrogen levels, pathological sections and expression of Fas and Bax genes. Methods: Forty male SD rats were randomly divided into normal control group (NC), iron overload model group (model, injected with 100 mg/kg mb of iron dextran every other day), GSPAs group (gavaged at 100 mg/kg mb on a daily basis) and GSPA + iron overload group. Red blood cell (RBC) count and hemoglobin (Hb) levels were measured by an automatic blood biochemical analyzer, and iron content in kidney tissue was determined by inductively coupled plasma mass spectrometry (ICP-MS). Serum total iron binding capacity (TIBC), glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity, malondialdehyde (MDA) concentration, total antioxidant capacity (T-AOC), creatinine (CR) and urea nitrogen (BUN) levels were measured by commercial kits. Kidney sections were examined histologically by hematoxylin-eosin (HE) staining. Reverse transcription real-time polymerase chain reaction was used to determine the expression of Fas and Bax genes in kidney tissues. Results: Compared with the NC group, the RBC count, Hb level, renal Fe content, MDA content, CR and BUN level, Fas and Bax gene expression in the model group were significantly increased (P < 0.05 or P < 0.01), while TIBC, GSH-Px activity and SOD activity were significantly decreased (P < 0.05 or P < 0.01). There was no significant difference in T-AOC between the two groups (P > 0.05). The Hb content and T-AOC in the GSPAs group were increased significantly, while the expression of the Fas gene was downregulated significantly (P < 0.05 or P < 0.01). Compared with the model group, the RBC number, Hb content, MDA content, CR and BUN levels, and Fas and Bax gene expression in the GSPA + iron overload group were significantly decreased (P < 0.05 or P < 0.01), while TIBC, GSH-Px activity, SOD activity and T-AOC were significantly increased (P < 0.05 or P < 0.01). Conclusion: Grape seed proanthocyanidins can protect kidney tissues from iron accumulation, oxidative damage, renal physiological dysfunction and apoptosis induced by iron overload in rats.

Key words: grape seed proanthocyandins, iron overload, kidney, oxidative stress, apoptosis