Combine colorants of tartrazine and erythrosine induce kidney injury: involvement of TNF-α gene, caspase-9 and KIM-1 gene expression and kidney functions indices.

Twenty-five male Wistar rats (140-170 g) were partitioned into 5 groups (n = 5). 2.5 mg/kg, 5 mg/kg, 10 mg/kg and 20 mg/kg of combine Tartrazine and Erythrosine (T+E; 50:50) were administered for 23 days. Serum urea and creatinine, gene expression and profiling of pro-inflammatory cytokine (Tumor Necrosis Factor- α gene), Caspase-9 and Kidney injury molecule-1 (KIM-1) and histomorphological examination of the kidney were investigated. The fold change of relative gene expression of TNF-α gene showed significantly (p < 0.05) up-regulation in all the treated rats except for the 10 mg/kg T+E treated rats when compared to control rats. Casp-9 and KIM-1 genes were significantly (p < 0.05) up-regulated in low dose treatment (2.5 mg/kg T+E and 5 mg/kg T+E) and down-regulated in high dose treatment (10 mg/kg T+E and 20 mg/kg T+E). However, there was significant (p < 0.05) increase in serum urea concentration in the rats treated with 5 mg/kg T+E and 20 mg/kg T+E while the rats treated with 10 mg/kg T+E indicated a significant (p < 0.05) decrease. Conversely, serum creatinine concentration indicated significant (p < 0.05) increase in10mg/kg T+E and 20 mg/kg T+E treated rats versus the control. From the histomorphological examination of the kidney, there was hypertrophy of the glomeruli in relation to the size of Bowman's capsule in the 10 mg/kg T+E and 20 mg/kg T+E treated rats. Kidney function was impaired as evident in up-regulation of TNF-α gene, KIM-1 gene, and serum urea and creatinine concentration with down-regulation of Casp-9 gene. The combined treatment also tampers with the architecture of the kidney.