الفهرس 
AcknowledgmentOnly 14 pages are availabe for public view
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Abstract
Diabetic nephropathy (DN) is responsible for the occurrence of 30–47% of the incident cases of end-stage renal disease (ESRD) worldwide. DN is a chronic inflammatory disorder, which results from hyperglycemia-induced alterations and leads to renal fibrosis and ESRD. Toll like receptor-4 (TLR-4) participates in regulation of inflammatory response through controlling of innate immune system. P-coumaric acid (P-CA) is a natural hydroxycinnamic acid derivative and Syringic acid (SA) is a derivative of benzoic acid. Both of them are widely present in vegetables, fruits, mushrooms and cereals. This study aimed to explore the renoprotective effects of separate administration of P-CA and SA, as anti-inflammatory and antioxidant natural compounds, against experimental DN. DN was induced by single intraperitoneal injection of streptozotocin (45mg/kg) in rats. In kidney homogenate, levels of TLR-4, interleukin-6 (IL-6) and transforming growth factor β1 (TGFβ1) were measured using ELISA technique. Also, kidney collagen content was determined colorimetrically. Separate oral administration of P-CA (100mg/kg) and SA (50 mg/kg) for 8 weeks significantly alleviated the DN. They significantly reduced serum concentrations of glucose, creatinine, blood urea nitrogen (BUN) and reduced protein content in urine. Also, they significantly increased superoxide dismutase (SOD) activity and significantly reduced kidney contents of malondialdehyde (MDA), TLR-4, IL-6, TGFβ1 and collagen when compared with DN group. Moreover, P-CA and SA significantly improved DN-induced histopathological abnormalities. P-CA confers protection against the progression of DN. This renoprotective effect can be attributed to their ability to decrease the generation of inflammatory and fibrotic cytokines in addition to restoring oxidant/antioxidant balance through its ability to down-regulate TLR-4 activation.