Pomegranate extract ameliorates renal ischemia/reperfusion injury in rats via suppressing NF-κB pathway.

Inflammation and oxidative stress are the major pathways involved in ischemia-reperfusion (I/R)-induced renal injury. This study was designed to evaluate the potential effect of pomegranate against I/R-induced renal injury. I/R injury was induced in nephrectomized rats by unilateral occlusion of the left renal pedicle for 45 min followed by 24 h of perfusion. Pomegranate succeeded to decrease serum levels of creatinine, potassium, and urea nitrogen, along with increasing creatinine clearance. Pomegranate also decreased I/R-induced changes in histopathological examination. Pomegranate attenuated the renal inflammatory response reflected by the suppression of nuclear factor κB p65 DNA binding activity, the upregulation of inhibitory protein kappa B-alpha mRNA expression, the downregulation of mRNA and protein expression of tumor necrosis factor α, in addition to the reduced myeloperoxidase activity and mRNA expression. Additionally, pomegranate attenuated oxidative stress likely through the modulation of lipid peroxidation and antioxidant levels reflected by the decreased MDA content and the increased glutathione level and superoxide dismutase activity. Results confirm the potential protective effect of pomegranate against I/R-induced renal injury through its anti-inflammatory and anti-oxidant effects mediated through the upregulation of inhibitory protein kappa B-alpha, the inhibition of NF-κB activity, and the associated TNF-α release, neutrophil infiltration, and oxidative stress.

Pomegranate protects liver against cecal ligation and puncture-induced oxidative stress and inflammation in rats through TLR4/NF-κB pathway inhibition.

Acute liver injury secondary to sepsis is a major challenge in intensive care unit. This study was designed to investigate potential protective effects of pomegranate against sepsis-induced acute liver injury in rats and possible underlying mechanisms. Pomegranate was orally given (800mg/kg/day) for two weeks before sepsis induction by cecal ligation and puncture (CLP). Pomegranate improved survival and attenuated liver inflammatory response, likely related to downregulation of mRNA expression of toll like recptor-4, reduced nuclear translocation and DNA binding activity of proinflammatory transcription factor NF-κB subunit p65, decreased mRNA and protein expression of tumor necrosis factor-alpha and reduction in myeloperoxidase activity and mRNA expression. Pomegranate also decreased CLP-induced oxidative stress as reflected by decreased malondialdehyde content, and increased reduced glutathione level and superoxide dismutase activity. These results confirm the antiinflammatory and antioxidant effects of pomegranate in CLP-induced acute liver injury mediated through inhibiting TLR4/NF-κB pathway, lipid peroxidation and neutrophil infiltration.

Cytoprotective potential of tiron and methyl palmitate against acetaminophen-induced acute liver injury.

Acute liver injury is a debilitating disorder associated with loss of synthetic and detoxifying functions of the liver. This investigation was designed to assess cytoprotective efficacy of daily oral tiron (300 mg/kg) and daily oral methyl palmitate (300 mg/kg) against acetaminophen-induced acute liver injury. Rats were orally pretreated with either tiron or methyl palmitate at doses (300 mg/kg) for 7 days prior to oral acetaminophen (3 g/kg). Biochemical assay of markers of hepatotoxicity indices and oxidative stress was undertaken. Expression of inflammatory cytokine IL-6 was also evaluated. Histopathological examination of liver specimens was carried out as well. Both methyl palmitate and tiron significantly reversed the acetaminophen-induced elevation of biochemical markers (ALT, AST, and ALP) with restoration of SOD levels. Serum albumin levels and GSH liver contents increased, but in a nonsignificant manner. Moreover, methyl palmitate and tiron significantly decreased the level of serum LDH and serum IL-6 levels. Histopathology revealed that tiron markedly reduced the extent of acetaminophen-induced necrosis and methyl palmitate moderately decreased the necrosis in liver tissue. Methyl palmitate (300 mg/kg) and tiron (300 mg/kg) demonstrated promising hepatoprotective effects against acetaminophen-induced acute liver injury via modulation of inflammatory response and alleviation of the oxidative stress, allowing the preservation of hepatic functions.

Modulation of thioacetamide-induced liver fibrosis/cirrhosis by sildenafil treatment.

Sildenafil citrate is a phosphodiesterase-5 inhibitor, approved for the treatment of erectile dysfunction. It enhances nitric-oxide-induced vasodilatation and it promotes angiogenesis. A relationship between angiogenesis and hepatic fibrosis has long been speculated, where the 2 are believed to progress together. In this study, the ability of sildenafil (10 mg·(kg body mass)(-1), orally, once daily) to prevent and also reverse liver fibrosis/cirrhosis experimentally induced by thioacetamide injection (200 mg·kg(-1), intraperitoneal (i.p.), 3 times·week(-1)) in male Sprague-Dawley rats has been investigated. Sildenafil administration, either to prevent or to reverse liver fibrosis/cirrhosis significantly improved the estimated hepatic functions, reduced hepatic hydroxyproline and, in turn, hepatic collagen content, as well as reducing serum levels of the pro-fibrogenic mediator transforming growth factor ß1. In co-ordination with such improvement, fibrosis grades declined and fibrosis retracted. Herein, the observed results provide evidence for the potential therapeutic efficacy of sildenafil as an antifibrotic agent.

Tranilast ameliorates impaired hepatic functions in Schistosoma mansoni-infected mice.

The ability of tranilast, a mast cell stabilizer and anti-transforming growth factor(ß) (TGF(ß)) to improve impaired hepatic functions in Schistosoma mansoni (S. mansoni)-infected mice, was investigated, providing the first evidence on the ability of tranilast to improve hepatic impairment due to schistosomal infection. Tranilast had significant beneficial effects against progression of hepatic fibrosis in S. mansoni-infected mice treated with praziquantel and those untreated. Different aspects of drug activity were investigated. Its effect on serum liver functions was evaluated by estimating: alanine aminotransferase, aspartate aminotransferase, total bilirubin, alkaline phosphatase and albumin. Its effect on the extent of liver fibrosis, through estimation of hepatic hydroxyproline and hepatic collagen content in liver hydrolysates, was also evaluated. Also, the expression of profibrogenic mediators, such as serum TGF(ß1), was estimated. Finally, the effect on S. mansoni infection itself was studied, via histopathological examination of liver specimens stained with both hematoxylin-eosin and Masson's trichome stains. Tranilast ameliorated the harmful effects of S. mansoni infection on the liver. Such action was manifested in its significant ability to improve impaired hepatic functions, reduce histopathological changes, lower hepatic collagen content and finally reduce serum TGF(ß1) levels. The beneficial effect of tranilast may be in part due to its ability to reduce the production of profibrogenic mediators in the infected animals by improving the host immune response or by interfering with critical steps in the fibrogenic cascade.

Mediation of the schistosomicidal effect of praziquantel through nitric oxide.

The effect of praziquantel (CAS 55268-74-1) on serum nitrate/nitrite level (a marker for nitric oxide (NO) synthesis) in S. mansoni infected mice was studied. The effects of the NO precursor (L-arginine) and NO-synthase inhibitor (NG-nitro-L-arginine methyl ester, L-NAME) on the effect of praziquantel on nitrate/nitrite level as well as on its antischistosomal activity were also evaluated. Praziquantel increased nitrate/nitrite level in serum of infected mice in a dose dependent manner. An oral dose of 75 mg/kg praziquantel produces a significant (p < 0.05) increase in serum nitrate/nitrite level by about 3.5 fold. Administration of L-arginine (200 mg/kg orally) induced a significant (p < 0.05) increase in nitrate/nitrite level (to about 5 fold) compared to praziquantel 75 mg/kg alone. Praziquantel-induced increase in nitrate/nitrite level was significantly reduced by administration of L-NAME 100 mg/kg. The antischistosomal activity of praziquantel was evaluated using two models: hepatic shift model and reduction of worm burden. In the hepatic shift model, praziquantel increased the percentage of worms in the liver (from 5% in control to 60%). Praziquantel-induced hepatic shift was not significantly affected by concurrent L-arginine or L-NAME administration. In the second model, praziquantel induced a significant decrease of the worm burden (p < 0.05) and the action of praziquantel was significantly increased by L-arginine and reduced by L-NAME administration. In conclusion, NO is possibly involved in the antibilharzial effect of praziquantel and administration of L-arginine with praziquantel produces beneficial antibilharzial effect.