Role of oxygen free radical scavengers in acute renal failure complicating obstructive jaundice

Anemonin inhibits sepsis-induced acute kidney injury via mitigating inflammation and oxidative stress

Elevated inflammation and oxidative stress (OS) are the main pathologic features of acute kidney injury (AKI)-caused by sepsis. Here, we made an investigation into the protective effects of the natural compound Anemonin (ANE) on sepsis-induced AKI both in vitro and in vivo. Lipopolysaccharide (LPS) was applied to construct an in vitro AKI model in renal tubular epithelial cells, and the septic C57BL/6J mouse model was constructed via cecal ligation and puncture (CLP). Cell viability and apoptosis were detected. The levels of p53, Bax, Bcl2, Caspase3, Caspase8, Caspase9, AMP-activated protein kinase (AMPK), Sirt-1, and forkhead box O3 were determined by Western Blot or RT-PCR. The reactive oxygen species level and OS markers were measured. Furthermore, the pathological changes of kidneys were evaluated by hematoxylin-eosin staining and immunohistochemistry. As per the information presented, ANE improved LPS-elicited apoptosis, inflammatory response, and OS in a dose-dependent pattern in renal tubular epithelial cells. Besides, ANE activated the AMPK/Sirt-1 pathway, and the AMPK inhibitor (Compound C) and Sirt-1 inhibitor (EX-527) significantly attenuated ANE-mediated protection on renal tubular epithelial cells. In vivo, ANE mitigated the levels of serum creatinine and urea nitrogen in the CLP-induced mouse sepsis model, reduced the renal tissue injury score, and attenuated OS, inflammation, and apoptosis levels in the kidney. Taken together, this study suggested that ANE has protective effects in sepsis-triggered AKI through repressing inflammation, OS, and cell apoptosis by activating the AMPK/Sirt-1 pathway.

The pathogenesis of renal injury in obstructive jaundice: A review of underlying mechanisms, inducible agents and therapeutic strategies

Kidney injury is one of the main complications of obstructive jaundice (OJ) and its pathogenesis has not been clarified. As an independent risk factor for OJ associated with significant morbidity and mortality, it can be mainly divided into two types of morphological injury and functional injury. We called these dysfunctions caused by OJ-induced kidney injury as OJKI. However, the etiology of OJKI is still not fully clear, and research studies on how OJKI becomes a facilitated factor of OJ are limited. This article reviews the underlying pathological mechanism from five aspects, including metabolisms of bile acids, hemodynamic disturbances, oxidative stress, inflammation and the organic transporter system. Some nephrotoxic drugs and measures that can enhance or reduce the renal function with potential intervention in perioperative periods to alleviate the incidence of OJKI were also described. Furthermore, a more in-depth study on the pathogenesis of OJKI from multiple aspects for exploring more targeted treatment measures were further put forward, which may provide new methods for the prevention and treatment of clinical OJKI and improve the prognosis.

Preventing oxygen free radical damage by proanthocyanidin in obstructive jaundice

OBJECTIVE

Tissue damage and endotoxemia in obstructive jaundice are attributed to the increase in oxygen free-radicals. We aimed at evaluating the possible protective effect of grape seed proanthocyanidin extract (GSPE), which is a potent exogenous free-radical scavenger and antioxidant.

MATERIAL AND METHODS

The study was performed at the Necmettin Erbakan University Meram School of Medicine Research and Application Center for Experimental Medicine Laboratory with ethical approval. 30 Wistar-Albino rats were used and were divided into 3 groups. The common bile duct was identified and only dissected in the first group (sham). Following dissection of the common bile duct it was ligated with 4/0 silk just above the pancreas in the second group (control). After ligation of the common bile duct, 100mg/kg/day GSPE was administered via orogastric lavage for 10 days in the third group.

RESULTS

Biochemical values revealed a statistically significant difference between Group I and the others. There was no difference between Group II and III regarding biochemical values. There was a statistically significant difference, however, between Group II and III with regards to nitric oxide levels. There was a statistically significant difference between Group I and the other groups concerning hepatic and pulmonary tissue damage on histopathologic evaluation. There was no difference among the groups with regards to renal tubular damage.

CONCLUSION

Proanthocyanidin is an effective natural antioxidant in decreasing the level of tissue damage caused by oxygen free-radicals.

EFFECTS OF SALVIA MILTIORRHIZAE ON THE KIDNEY OF RATS WITH SEVERE ACUTE PANCREATITIS AND OBSTRUTIVE JAUNDICE

Background:

Severe acute pancreatitis (SAP) and obstructive jaundice (OJ) are frequent recurring diseases that bring about huge threat to human health. Some reports have demonstrated that Salviae miltiorrhizae can protect multiple organs of SAP and OJ model animals or patients, but their related mechanisms were not clear. In this study, we observed the effects of Salvia miltiorrhizae injection on apoptosis and NF-κB expression in kidney and explored the protective effect and mechanism of Salvia miltiorrhizae on the kidney of SAP or OJ rats. The results obtained will provide a theoretical basis for clinical application of Salvia miltiorrhizae.

Material and Methods:

A total of 288 rats were used for SAP -and OJ-associated experiments. The mortality rates of rats, the contents of serum BUN and CREA, the expression levels of Bax, NF-κB proteins and the apoptosis index were observed, respectively.

Results:

The pathological changes in the kidney of SAP or OJ rats in treated group were mitigated to varying degrees. At 6 and 12 hours after operation in SAP rats or on 21 and 28 days after operation in OJ rats, the contents of serum CREA in treated group were significantly lower than those in model control group; At 3 and 6 hours after operation, the staining intensity of Bax protein of kidney in treated group was significantly lower than that in model control group; on 14 days after operation, the apoptosis index in the kidney of OJ rats in treated group was significantly lower than that in model control group.

Conclusion:

Salvia miltiorrhizae can exert protective effects on the kidney of SAP and OJ rats.

Oxidative stress influence on renal dysfunction in patients with obstructive jaundice: A case and control prospective study

Background: Obstructive Jaundice (OJ) is associated with a significant risk of developing acute renal failure (ARF). The involvement of oxidative stress in the development of cholestasis has been demonstrated in different experimental models. However, its role in the morbidity of human cholestasis is far to be elucidated. The aim of the study was the evaluation of oxidative stress markers in blood from patients with OJ and its relation to complications and benign/malignant evolution of cholestasis. Methods: A prospective cross-sectional study of 105 patients with OJ and 34 control subjects were included. Several markers of liver function and oxidative stress, such as lipoperoxides (LPO), as well as reduced glutathione (GSH), catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities were assessed. Results: The patients with OJ showed a marked increase in plasma levels of LPO, SOD and GSH, while GSH-Px levels were decreased. The increase in lipid peroxidation products and the depletion of SOD activity in blood were also related to renal dysfunction. The highest level of LPO was associated with malignant etiology of the disease. The logistic regression analysis showed that the age of the patient and the levels of LPO in blood were predictors of renal dysfunction in OJ patients. Conclusions: This study demonstrates a correlation between oxidative stress and renal dysfunction patients with OJ.

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Obstructive jaundice was associated to a decreased glomerular filtration rate.

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Renal impairment was more frequent in jaundiced patients than in healthy subjects.

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LPO levels were higher in jaundiced patients than in healhy subjects, with highest levels related to malignant ethiology.

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Renal function was affected by the intensity of the biliary obstruction, and the balance between LPO and antioxidant defenses

Protective effects of intravenous anesthetics on kidney tissue in obstructive jaundice

AIM: To evaluate the protective effects on kidney tissue of frequently used intravenous anesthetics (ketamine, propofol, thiopental, and fentanyl) in rats with obstructive jaundice.

METHODS: There is an increased incidence of postoperative acute renal failure in patients with obstructive jaundice. Thirty-two Wistar-albino rats were randomly divided into four equal groups. Laparatomy was performed on each animal in the four groups and common bile ducts were ligated and severed on day 0. After 7 d, laparotomy was again performed using ketamine, propofol, thiopental, or fentanyl anesthesia whose antioxidative properties are well known in oxidative stress in a rat liver model of obstructive jaundice. After 2 h, the rats were sacrificed. Renal tissue specimens were analyzed for catalase, superoxide dismutase and malondialdehyde enzymes activities. All values are expressed as the mean ± SD. P values less than 0.05 were considered statistically significant.

RESULTS: All animals survived without complications until the end of the study. Enlargement in the bile duct and obstructive jaundice were observed in all rats. Catalase was found to be significantly lower in the fentanyl group than in the ketamine (P = 0.039), propofol (P = 0.012), and thiopental (P = 0.001) groups. Superoxide dismutase activities were similar in all groups (P > 0.05). Malondialdehyde was found to be significantly lower in the ketamine group than in the propofol (P = 0.028), thiopental (P = 0.002) and fentanyl (P = 0.005) groups. Malondialdehyde was also lower in the fentanyl group than in the thiopental group (P = 0.001). The results showed that obstructive jaundice sensitizes renal tissue to damage under the different anesthetics.

CONCLUSION: Among the agents tested, ketamine and propofol generated the least amount of oxidative stres on renal tissues in this rat model of obstructive jaundice created by common bile duct ligation. The importance of free radical injury in renal tissue in obstructive jaundice under different intravenous anesthetics during hepatobiliary and liver transplant surgery should be considered for prevention of postoperative acute renal failure.

A review on renal toxicity profile of common abusive drugs

Drug abuse has become a major social problem of the modern world and majority of these abusive drugs or their metabolites are excreted through the kidneys and, thus, the renal complications of these drugs are very common. Morphine, heroin, cocaine, nicotine and alcohol are the most commonly abused drugs, and their use is associated with various types of renal toxicity. The renal complications include a wide range of glomerular, interstitial and vascular diseases leading to acute or chronic renal failure. The present review discusses the renal toxicity profile and possible mechanisms of commonly abused drugs including morphine, heroin, cocaine, nicotine, caffeine and alcohol.

Human adrenomedullin and its binding protein ameliorate sepsis-induced organ injury and mortality in jaundiced rats

Sepsis is a serious complication for patients with obstructive jaundice. Although administration of adrenomedullin (AM) in combination with its binding protein (AMBP-1) is protective after injury, it remains unknown whether AM/AMBP-1 ameliorates sepsis-induced organ injury and mortality in the setting of biliary obstruction. The aim of this study is, therefore, to test the efficacy of human AM/AMBP-1 in a rat model of obstructive jaundice and polymicrobial sepsis. To study this, obstructive jaundice was induced in male adult rats (275-325g) by common bile duct ligation (BDL). One week after BDL, the rats were subjected to sepsis by cecal ligation and puncture (CLP). Plasma levels of AM and AMBP-1 were measured at 20h after CLP. In additional groups of BDL+CLP rats, human AM/AMBP-1 (24/80microg/kg body weight (BW)) or vehicle (i.e., human albumin) was administered intravenously at 5h after CLP. Blood and tissue samples were collected at 20h after CLP for various measurements. To determine the long-term effect of human AM/AMBP-1 after BDL+CLP, the gangrenous cecum was removed at 20h after CLP and 7-day survival was recorded. Our results showed that plasma levels of AM were significantly increased while AMBP-1 levels were markedly decreased after BDL+CLP (n=8, P<0.05). Administration of human AM/AMBP-1 attenuated tissue injury and inflammatory responses after BDL+CLP. Moreover, human AM/AMBP-1 significantly increased the survival rate from 21% (n=14) to 53% (n=15). Thus, human AM/AMBP-1 ameliorates sepsis-induced organ injury and mortality in jaundiced rats. Human AM/AMBP-1 can be further developed as a novel treatment for sepsis in jaundiced patients.

Ursodeoxycholic acid and artesunate in the treatment of severe falciparum malaria patients with jaundice

BACKGROUND AND AIMS

Plasmodium falciparum (PF) infection can lead to severe complications. Ursodeoxycholic acid (UDCA) is increasingly used for the treatment of cholestatic liver diseases. The present study aims to determine the effects of combined UDCA and artesunate compared to placebo and artesunate on the improvement of liver tests in severe PF jaundiced patients.

METHODS

All severe PF jaundiced patients, aged > or = 15 years and diagnosed as having severe malaria according to WHO 2000 criteria, were enrolled. Patients with evidence of biliary obstruction, other cholestatic liver diseases and those who were pregnant were excluded. Patients were randomized to receive either oral UDCA or placebo for 2 weeks in additional to artesunate. All patients were admitted for at least 14 days to monitor the result of the treatment.

RESULTS

Seventy-four severe PF malaria patients with jaundice were enrolled. Both groups had similar demographic and laboratory tests, with the exception being more males in the UDCA group than in the placebo group (P = 0.04). The median of percentage change of total bilirubin and aminotransferase levels at the end of weeks 1, 2, 3 and 4 showed no difference between the two groups. Only the median of percentage change of alkaline phosphatase at the end of week one compared with the baseline values showed less increment in the UDCA group than in the placebo group (P = 0.04). No serious adverse events were seen during the 4 weeks of follow up.

CONCLUSIONS

In severe PF malaria patients with jaundice, combined therapy with UDCA and artesunate is safe, but does not significantly improve liver tests compared to placebo and artesunate.

Bile duct ligation in rats: A reliable model of hepatorenal syndrome?

The two most widely used experimental models of advanced liver disease are the administration of carbon tetrachloride, and common bile duct ligation (BDL), however, neither has been systematically evaluated as a model of hepatorenal syndrome (HRS). The BDL model in rats, studied at diverse time points, induced a progressive renal dysfunction without structural changes in the kidney. The authors concluded that BDL is a good model for further studies of HRS and its treatment. However, the renal impairment observed at the acute phase of the BDL model is based on a different pathophysiology than that of HRS. Specifically, in acute obstructive jaundice, cholemia predominates over parenchymal liver disease (reversible at this stage without portal hypertension or cirrhosis) and independently induces negative inotropic and chronotropic effects on the heart, impaired sympathetic vasoconstriction response and profound natriuresis and diuresis that might lead to volume depletion. In addition, systemic endotoxemia contributes to the prerenal etiology of renal impairment and promotes direct nephrotoxicity and acute tubular necrosis. On the other hand, the renal failure observed in the chronic BDL model (with development of biliary cirrhosis, portal hypertension and ascites) shares pathophysiological similarities with HRS, but the accordance of the chronic BDL model to the diagnostic criteria of HRS (e.g. absence of spontaneous bacterial peritonitis, no renal function improvement after plasma volume expansion) should have been confirmed. In conclusion, we think that the BDL model is not suitable for the study of the natural history of HRS, but the chronic BDL model might be valid for the study of established HRS and its potential therapies.

Increased renal cell apoptosis and its mechanism in rats with biliary cirrhosis

AIM: To investigate the renal pathological changes, cell apoptosis and expression of Bcl-2 and Bax proteins in rats with hepatic cirrhosis induced by common bile duct ligation (CBDL).

METHODS: Hepatic cirrhosis was induced by CBDL in SD rats. Thirty rats were randomized to 3 groups: sham operation group, 2-wk CBDL group and 5-wk CBDL. Hepatic and renal tissues were collected for pathohistological observation under microscope; the creatinine clearance rate (Ccr) and renal malonaldehyde (MDA) content were measured by biochemical method and spectrophotometric method, respectively; the apoptosis of renal cells was detected by TUNEL method; finally, the levels of Bcl-2 and Bax protein expression were examined by immunohistochemistry.

RESULTS: Hepatic histological examination showed that hepatic fibrosis occurred in 2-wk CBDL group and biliary cirrhosis in 5-wk CBDL. In the 5-wk CBDL group, desquamation and necrosis of renal tubule epithelia were found by HE staining, and irregular thickening of glomerular basement membrane, mesangial expansion and fusion of epithelial foot processes were observed by electron microscopy. The Ccr significantly decreased (1.10 ± 0.03 vs 1.40 ± 0.03, 1.80 ± 0.02; P < 0.05 or 0.01) while MDA content increased (4.07 ± 0.51 vs 2.32 ± 0.85, 0.79 ± 0.37, both P < 0.01) in the 5-wk CBDL group in comparison with that in the 2-wk CBDL group or sham operation group. The apoptotic rate of renal cells was significantly higher in the 5-wk CBDL group than that in the 2-wk CBDL group or sham operation group (68.36% ± 8.71% vs 24.08% ± 2.59%, 11.43% ± 2.77%; both P < 0.01). Bcl-2 protein decreased while Bax protein increased by turns in sham operation group, 2-wk CBDL group and 5-wk CBDL group (P < 0.05).

CONCLUSION: There are renal histopathological changes and cell apoptosis in rats with CBDL-induced hepatic cirrhosis, and low expression of Bcl-2 protein and high expression of Bax protein play important roles in the renal injury induced by CBDL cirrhosis.

Change of renal aquaporin 3 expression in rats after release of obstructive jaundice and its significance

AIM: To study the change of renal aquaporin 3 (AQP3) expression in rats after release of obstructive jaundice in biliary tract and its significance.

METHODS: Fifty Wistar rats were divided into control group (n = 10) and experimental group (n = 40). A model of experimental obstructive jaundice was established. Seven days after release of obstructive jaundice, serum biochemical parameters were detected. Rats in the experimental group were randomly divided into five subgroups: OJ 0 h, OJ 24 h, OJ 72 h, OJ 1 wk and non-operated control (NC). Biochemical parameters in venous blood were detected and the expression level of renal AQP3 was determined by Western blot.

RESULTS: The TBIL and ALT gradually decreased after release of obstructive jaundice in biliary tract (TBIL: 93.26 ± 1.32 vs 63.31 ± 1.85, 30.78 ± 1.40, 5.04 ± 0.24, P < 0.05; ALT: 70.95 ± 1.22 vs 69.96 ± 0.82, 30.74 ± 1.52, 11.84 ± 1.12, P < 0.05). There was no significant difference in levels of BUN and Cr between the OJ 0 h and NC subgroups, but the expression level of AQP3 was lower in the OJ 0 h subgroup than in the NC subgroup. Both BUN and Cr were significantly decreased 24 h after operation and the expression of AQP3 was further decreased. The levels of BUN and Cr did not markedly change between the OJ 24 h and OJ 72 h subgroups. The expression level of AQP3 was slightly higher, but still lower in the OJ 24 h subgroup than in the NC subgroup (P < 0.05). The expression levels of BUN, Cr and AQP3 were not significantly different between the two groups 7 days after operation.

CONCLUSION: The renal function is further damaged after release of obstructive jaundice in biliary tract. The expression level of AQP3 becomes higher when renal function improves. The sensitivity and specificity of AQP3 are higher than those of BUN and Cr.

Antioxidant activity of a novel extract from bamboo grass (AHSS) against ischemia-reperfusion injury in rat small intestine

Production of free radical species in cells and body tissues is known to cause many pathological disorders. Therefore, free radical scavengers play an important role in the prevention of various human diseases. Bamboo grass, Sasa senanensis, is a native Japanese plant. Sasa has been used for medicine in Japan for many centuries. In this study, we investigated the antioxidative activity of Absolutely Hemicellulose Senanensis (AHSS), a novel extract from Sasa. In the first part of this study, we found that AHSS has antioxidant activities by the assay using superoxide anion-2-methyl-6-methoxyphenylethynylimidazopyrazynone (MPEC) reaction kit. We then confirmed its antioxidative activity using a rat ischemia and subsequent reperfusion (I/R) injury model. Breakdown of the intestinal wall caused by intestinal I/R was attenuated by pretreatment with AHSS. Moreover, AHSS inhibited the production of lipid peroxide by intestinal I/R. AHSS could be an important source of ingredients for use in functional foods and other applications.