Protective effects of icariin on cisplatin-induced acute renal injury in mice

Abstract

Cisplatin chemotherapy often causes acute kidney injury in cancer patients. Icariin is a bioactive flavonoid, which has renal protection and anti-inflammation effects. This study investigated the mechanism underlying the attenuation of cisplatin-induced renal injury by icariin. BALB/c mice were treated with cisplatin (15 mg/kg) with or without treatment with icariin (30 or 60 mg/kg for 5 days). Renal function, histological changes, degree of oxidative stress and tubular apoptosis were examined. The effects of icariin on cisplatin-induced expression of renal TNF-α, NF-κB, cleaved caspase-3 and Bcl-2 family proteins were evaluated. Treatment of mice with cisplatin resulted in renal damage, showing an increase in blood urea nitrogen and creatinine levels, tubular damage, oxidative stress and apoptosis. These renal changes could be significantly improved by icariin treatment, especially in high dose of icariin group. Examination of molecules involving inflammation and apoptosis of the kidney revealed that treatment of icariin reduced expression of TNF-α, NF-κB, cleaved caspase-3, and Bax, increased the expression of BCL-2. These results indicate that icariin ameliorates the cisplatin-mediated nephrotoxicity via improving renal oxidant status, consequent NF-κB activation and inflammation cascade and apoptosis, and the following disturbed expression of apoptosis related proteins.

Keywords: Acute kidney injury; apoptosis; cisplatin; icariin; inflammation.

Figure 1

Effect of icariin on renal function after cisplatin treatment. Acute kidney injury was induced by cisplatin administration. Mice were treated with icariin or control buffer once a day for six consecutive days and on the 3rd day followed by intraperitoneal cisplatin injection. Blood samples were collected 72 h after cisplatin treatment and BUN (A) and creatinine (B) levels were measured. Data are expressed as mean ± SD (n=10 mice per group). #p<0.01 vs. Control; *p<0.01 vs. Cisplatin.

Figure 2

Effect of icariin on MDA level GSH content SOD and catalase activities in cisplatin-induced acute kidney injury. Tissue GSH content (A) MDA level (B) catalase (C) and SOD (D) activities were measured in the whole kidney lysate. Data are expressed as mean ± SD. #p<0.01 vs. Control; *p<0.01 vs. Cisplatin.

Figure 3

Effect of icariin on cisplatin-induced renal tubular damage. Histologic sections of kidney at 72 h after treatment with control buffer (A) cisplatin (B) and cisplatin plus icariin (C and D) (400×). Histopathological scoring of tubular injury was concomitant with histologic analysis (n=10 for each experimental group). Data are expressed as mean ± SD. #p<0.05 vs. Control; *p<0.05 vs. Cisplatin.

Figure 4

DNA fragmentation was visualized in situ by the TUNEL procedure and by electrophoresis. Fluorescence microscopy of TUNEL staining in control (A) cisplatin (B) and cisplatin plus icariin (C and D).

Figure 5

Effect of icariin on cisplatin-induced TNF-α NF-κB cleaved caspase-3 and BCL-2 protein expressions. Kidneys from mice treated with control buffer cisplatin and cisplatin plus icariin were evaluated for protein expressions by western blot analysis (A). Densitometric analyses are presented as the relative ratio of each protein to β-actin (B). Data are expressed as mean ± SD of three independent experiments. #p<0.01 vs. control; *p<0.01 vs. Cisplatin.

Figure 6

Effect of Icariin on immunohistochemical stain of cleaved caspase 3 and Bax in cisplatin-induced mice. The brown area was the positive expression area (400×).