Intervention effect and mechanism of curcumin in chronic urinary tract infection in rats

ABSTRACT

Objective To analyze the invention effect of curcumin on chronic urinary tract infection in rats and explore its possible mechanism of action. Methods The experimental animals were randomly divided into three groups, normal, model and curcumin group. Chronic urinary tract infection models were built for model group and curcumin group by injecting coliform fluid into the cavity of bladder. From the first day of modeling, rats in the curcumin group were injected with 150 mg/kg curcumin, while rats in normal group and model group were given no other treatment. The treatment lasted for 14 d. The white blood cell counts in blood and urine, bacterial colony count in urine and renal tubular functional indexes of rats in all groups at day 1, 7, and 14 after treatment were detected. Urine β2-microglobulin (β2-MG), urinary N-acetyl-β-D glucosaminidase (NAG) levels were used to detected the inflammatory cytokines in serum after treatment including the contents of IL-6, IL-8, IL-10 and monocyte chemoattractant protein-1 (MCP-1), and real-time PCR was employed to determine the expression of mRNA of toll-like receptor 2 (TLR-2) and TLR-4 in renal tissues and bladder tissues of all groups after treatment. Results The white blood cell counts at day 1 and 7 after treatment in rats of model group and curcumin group were significantly higher than those of normal group at the same time points, while the white blood cell counts of the curcumin group were significantly lower than those of model group (P < 0.05). The urine white blood cell counts in rats of model group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points; those in the curcumin group were significantly lower than those of the model group at day 1, 7 and 14 at the same time points (P < 0.05). The bacterial colony counts of urine in rats of model group and curcumin group at day 1, 7 and 14 were all significantly higher than those of normal group at the same time points, while the counts of curcumin group were significantly lower than those of model group at the same time points (P < 0.05). Levels of urine β2-MG, NAG, IL-6, IL-8, IL-10, MCP-1 and expression of TLR2 mRNA and TLR4 mRNA in renal and bladder tissues in rats of model group were significantly higher than those of the normal group, while these variables of the curcumin group were significantly higher than those of the normal group but lower than those of model group (P < 0.05). Conclusions Curcumin can significantly improve the symptoms of chronic urinary tract infections, protect renal tubular function, and also decline inflammatory responses by influencing the expressions of TLR2 mRNA and TLR4 mRNA so as to exert its curative effect on chronic urinary tract infections.