Nephroprotective role of bromelain against oxidative injury induced by aluminium in rats

The present study was designed to investigate the nephroprotective effect of bromelain against oxidative stress stimulated by aluminium chloride in rats. Rats were grouped as follows; group one was used as control while groups 2, 3 and 4 were treated orally with bromelain (250 mg/kg, daily), aluminium chloride (AlCl₃; 34 mg/kg BW, every other day) and bromelain plus AlCl₃ for 30 days, respectively. Administration of AlCl₃ caused a significant reduction in rats' body and kidney weights, and increased Al accumulation in kidney tissue. Also, AlCl₃ treatment elevated thiobarbituric acid reactive substances, hydrogen peroxide, kidney functions biomarkers levels and lactate dehydrogenase activity. While enzymatic (SOD, CAT, GPx, GR, GST) and non-enzymatic (GSH) antioxidants, protein content, and alkaline phosphatase activity were significantly decreased. In addition, significant alterations in lipid and protein profiles were detected. Furthermore, histopathological and immunohistochemical variations were seen in kidney sections supporting the obtained biochemical changes. Otherwise, rats supplemented with bromelain singly declined lipid peroxidation and improved most of the studied parameters. Moreover, rats pretreated with bromelain followed by AlCl₃ intoxication showed significant alleviation in lipid peroxidation, antioxidant status and biochemical indices with respect to AlCl₃ treated group. Conclusively, bromelain has beneficial protective effects and has the capability to counteract the toxic influence of AlCl₃. So, bromelain might represent a novel approach in the therapy of metal toxicity because of its antioxidant and chelating properties.