Protective effect of a potent antioxidant, pomegranate juice, in the kidney of rats with nephrolithiasis induced by ethylene glycol.

PURPOSE: We aimed to study the protective effects of pomegranate juice (PJ) on ethylene glycol (EG)-induced crystal deposition in renal tubules, renal toxicity, and inducible nitric oxide synthase (iNOS) and nuclear factor-kappaB activities in rat kidneys. MATERIALS AND METHODS: Fifty-six rats were divided into four equal groups: Control, EG, EG + 50 microL PJ/d (PJ50), and EG + 100 microL PJ/d (PJ100). Rats were sacrified on days 10 and 45. Tissue sections were evaluated under light and polarized microscopy for the presence and degree of crystal deposition and toxicity in the kidneys. Crude extracts of the cortex were used to determine reduced gluthatione (GSH), nitric oxide (NO), and malondialdehyde (MDA) levels. RESULTS: In the EG group, crystal depositions were more evident and mild crystalization was observed in proximal tubules on day 10; severe crystalization and granulovacuolar epithelial cell degeneration were observed on day 45. There was limited or no crystal formation in the EG + PJ-given groups. There were completely normal renal and tubular structures in the control group. There was no significant difference between the four groups in serum levels of sodium, potassium, blood urea nitrogen, and creatinine in any sampling time. Hyperoxaluria, a marked increase in MDA and NO levels, and decrease of GSH were observed in the EG-given groups compared with the others. There were marked iNOS and p65 expressions in only the EG-given rats compared with control and PJ groups, immunohistochemically. CONCLUSION: This experiment shows the protective effect of PJ in the EG-induced crystal depositions in renal tubules.

Pyrolidium dithiocarbamate prevents shockwave lithotripsy-induced renal injury through inhibition of nuclear factor-kappa B and inducible nitric oxide synthase activity in rats.

PURPOSE: Extracorporeal shockwave lithotripsy (SWL) is commonly used for treatment of renal stones. Free oxygen radicals are involved in the pathophysiology of renal injury due to SWL. We investigated the protective effect of pyrolidium dithiocarbamate (PDTC), an antioxidant and nuclear factor kappa-B (NFkappa-B) inhibitor, against renal injury. MATERIALS AND METHODS: Forty-eight rats were divided into three groups: group 1, controls; group 2, SWL (15 kW, 1500 pulses); and group 3, SWL + pyrolidium dithiocarbamate (PDTC) (100 mg/kg/day given intraperitoneally 1 day before and 5 days after SWL). The rats were sacrificed and their kidneys were removed on days 7 and 35 after SWL. Samples were fixed in formaldehyde solution, and renal tissues were examined for proximal tubular injury under light microscopy. iNOS activity and active subunit of NFkappa-B, p65, were evaluated immunohistochemically using rat monoclonal antibodies interpreting results semiquantitatively. RESULTS: There were significant differences between SWL and control groups on days 7 and 35, considering histological changes under light microscope (p < 0.02). There was significant decrease in necrosis and fibrosis in PDTC group compared to SWL group. Expression of inducible nitric oxide synthase (iNOS) and p65 on days 7 and 35 were at basal levels as seen with immunohistochemical staining. There were high concentrations of iNOS and p65 in the SWL group (P < 0.02). No significant difference in concentrations was seen between the control and the PDTC groups (P > 0.02). CONCLUSION: We found that curcumin decreased the expression of iNOS, p65, and serum nitric oxide levels, and helped prevent interstitial, glomerular, tubular epithelial, and endothelial cellular injury. We believe that PDTC could be used, particularly in high-risk patients, as a protective agent against renal injury due to SWL.