Protective effect of propolis on methotrexate-induced kidney injury in the rat

Objectives Propolis is a potent antioxidant and a free radical scavenger. Pharmacological induction of heat shock proteins (HSPs) has been investigated for restoring normal cellular function following an injury. In this study, effect of propolis on HSP-70 expression in methotrexate-induced nephrotoxicity and direct preventive effect of propolis in this toxicity were investigated. Material and methods A total of 40 male Wistar albino rats were divided into four groups: Group 1 was the untreated control. On the eighth day of the experiment, groups 2 and 3 received single intraperitoneal injections of methotrexate (MTX) at 20 mg/kg. Groups 3 and 4 received 100 mg/kg/day propolis (by oral gavage) for 15 d by the first day of the experimental protocol. Then the rats were decapitated under ketamine esthesia and their kidney tissues were removed. HSP-70 expression, apoptosis, and histopathological damage scores were then compared. Results MTX caused epithelial desquamation into the lumen of the tubules, dilatation, and congestion of the peritubular vessels and renal corpuscles with obscure Bowman's space. The number of apoptotic cells (p = 0.000) and HSP-70 (p = 0.002) expression were increased in group 2. Propolis prevented the rise in number of apoptotic cells (p = 0.017), HSP-70 (p = 0.000) expression, and improved kidney morphology. Conclusions It was found that methotrexate gives rise to serious damage in the kidney and propolis is a potent antioxidant agent in preventing kidney injury.