Abstract:

 To investigate the inhibitory effects of tannic acid(TA) on the expressions of renal inflammatory factors in streptozotocin(STZ)-induced diabetic rats and explore their mechanisms. Methods Seventy male Wistar rats were randomly divided into control group,diabetic model group (DM),aminoguanidine (AG) group,low dose TA group(TA20) and high dose TA group(TA30). After the rats were treated for 10 weeks,24　h urinary protein excretion and the renal function parameters including serum creatinine(Cre) and blood urea nitrogen(BUN) were measured. The morphological changes of kidney tissues were observed using PAS staining. The expressions of ICAM-1 and TNF-α proteins in the kidney tissues were examined by immunohistochemistry. The ICAM-1 mRNA expression in the kidney tissues was detected by RT-PCR. Results Compared with DM group,the serum Cre,BUN and the 24 h urinary protein excretion in TA groups were reduced(P<0.05 or P<0.01);the PAS-positive substance in mesangial area was reduced;the expressions of ICAM-1 and TNF-α proteins and ICAM-1 mRNA in kidney tissues were significantly decreased(P<0.05). Conclusion TA plays a protective role in diabetic kidney and inhibits the expressions of inflammatory factor ICAM-1 and TNF-α in kidney tissues.

Key words: tannic acid;diabetic nephropathy;intercellular adhesion molecule 1;tumor necrosis factor-α