Does silybin protect against toxicity induced by polymyxin E in rat kidney?

Aims: Although once a common antibiotic, polymyxin E fell out of favor after reports of its nephrotoxicity. However, recent concerns with gram-negative bacteria, which are resistant to multiple antibiotics, have resulted in increased interest in polymyxin E. Silybin is a known antihepatotoxic drug and may have potential for protecting the kidney from polymyxin E. Therefore, the aim of the current study was to evaluate whether silybin affected the damages produced by polymyxin E on the rat kidney. Methods: Four groups of rats with 10 rats per group were included in the study: control (no treatment, group I), vehicle (control vehicle treatment, group II), polymyxin E treatment (group III), and polymyxin E and silybin treatment (group IV). Groups II-IV received intravenous treatment twice a day for 7 days. All rats were euthanized after 7 days. Histological, ultrastructural, and morphometric analyses were performed on the rats’ kidney tissues. Results: Analysis of tissues from group III showed differences from groups I and II, such as glomerular and tubular affection and changes in morphometric measures. Results for group IV were more similar to those of groups I and II than those of group III. Conclusions: Our results suggested that administering silybin with polymyxin E alleviated polymyxin E-induced nephrotoxicity in the rat kidney. Future biochemical studies should investigate whether silybin could ameliorate the nephrotoxicity caused by polymyxin E in rats and whether concomitant administration of silybin could be an effective clinical pharmacological strategy to protect against polymyxin E-induced insult in human kidneys.