Silymarin administration protects against cisplatin-induced nephrotoxicity in adult male albino rats. [histological and immunohistochemical study]

ABSTRACT

Cisplatin is one of the most commonly used chemotherapeutics for cancer treatment, but its use is limited because of its nephrotoxicity Several evidences suggested that cisplatin-induced nephrotoxicity is partially mediated by reactive oxygen species. The purpose of the present study is to investigate whether silymarin administration as an antioxidant before cisplatin could afford protection against cisplatin-induced nephrotoxicity. This study was performed on 30 adult male albino rats that were divided into 5 groups. Group 1 served as control group. Animals of other groups received a single intraperitoneal [IP] injection of the following treatments Group II received 0.1ml of normal saline+1% w/v methylcellulose, Group III received silymarin [50 mg/kg BW], Group IV Received cisplatin [7.5 mg/kg BW] and Group V Received silymarin 6 h before cisplatin injection. Kidneys were excised 5 days after the end of the experiment biopsies were processed for light microscopic studies. Immunohistoehemical expression of Bak protein was investigated. Renal cortex of group IV showed extensive renal tubularnecrosis, intratubular casts, desquamated renal tubular cells, cytoplasmic degeneration and mononuclear cellular infiltration. The cells of proximal convoluted tubules [PCT] were severely affected. Also, there was a decrease in the PAS +ve material at brush borders of the PCT and a positive cytoplasmic reaction of Bak protein in renal tubular cells. There were statistical significant differences regarding these changes when compared to the other groups. In group V, the renal cortex of examined animals appeared similar to control group. Silymarin pretreatment prevented the histopathological changes caused by cisplatin. Therefore, silymarin can be used as an effective protecting agent against cisplatin-induced nephrotoxicity