Prostacyclin inhibition by indomethacin aggravates hepatic damage and encephalopathy in rats with thioacetamide-induced fulminant hepatic failure

Effect of Berberine against Cognitive Deficits in Rat Model of Thioacetamide-Induced Liver Cirrhosis and Hepatic Encephalopathy (Behavioral, Biochemical, Molecular and Histological Evaluations)

BACKGROUND

Liver cirrhosis (LC) is one of the chronic liver diseases with high disability and mortality accompanying hepatic encephalopathy (HE) followed by cognitive dysfunctions. In this work, the effect of berberine (Ber) on spatial cognition was studied in a rat model of LC induced by thioacetamide (TAA).

MATERIALS AND METHODS

Male Wistar rats (200-250 g) were divided into six groups: (1) control; (2) TAA, 200 mg/kg/day, i.p.; (3-5) TAA + Ber; received Ber (10, 30, and 60 mg/kg, i.p., daily after last TAA injection); (6) Dizocilpine (MK-801) + TAA, received MK-801 (2 mg/kg/day, i.p.) 30 m before TAA injection. The spatial memory, BBB permeability, brain edema, liver enzymes, urea, serum and brain total bilirubin, oxidative stress and cytokine markers in the hippocampus were measured. Furthermore, a histological examination of the hippocampus was carried out.

RESULTS

The BBB permeability, brain edema, liver enzymes, urea, total bilirubin levels in serum and hippocampal MDA and TNF-α increased significantly after TAA injection (p < 0.001); the spatial memory was impaired (p < 0.001), and hippocampal IL-10 decreased (p < 0.001). Ber reversed all the above parameters significantly (p < 0.05, p < 0.01 and p < 0.001). MK-801 prevented the development of LC via TAA (p < 0.001).

CONCLUSION

Results showed that Ber improves spatial learning and memory in TAA-induced LC by improving the BBB function, oxidative stress and neuroinflammation. Ber might be a promising therapeutic agent for cognitive improvement in LC.

Naringenin mitigates thioacetamide-induced hepatic encephalopathy in rats: targeting the JNK/Bax/caspase-8 apoptotic pathway

Hepatic encephalopathy (HE) is a serious neurological disorder which is related to liver dysfunction. HE was induced by thioacetamide (TAA) injection (350 mg kg^-1, i.p.) for 3 consecutive days. This study was performed to investigate the prophylactic impact of naringenin against TAA-induced HE. Naringenin (100 mg kg^-1) was orally administered for 7 days starting 4 days prior to TAA injection. Naringenin effectively mitigated TAA-induced behavioural, structural and functional alterations. Naringenin ameliorated TAA-induced cognitive impairment as evidenced by the increase in the fall-off time in the rotarod test, decrease in the escape latency in the Morris water maze test and increase in the time spent in the center and in the number of rearing in the open field test. Additionally, naringenin significantly decreased the serum levels of transaminases, alkaline phosphatase, gamma-glutamyl transferase, bile and ammonia. Moreover, naringenin succeeded in reducing the levels of hepatic and cerebral c-Jun N-terminal kinases (JNK) as well as hepatic SORT1 levels. In addition, naringenin successfully elevated the levels of hepatic and cerebral pro-brain-derived neurotrophic factor (pro-BDNF) and BDNF in addition to the cerebral SORT1 level. Finally, naringenin markedly decreased the expression of Bax and caspase-8 as presented by the immunohistochemical results. Collectively, the ameliorative effect of naringenin on the development of HE might be attributed to the modulation of the JNK/Bax/caspase-8 apoptotic pathway.

Hepatoprotective and cognitive-enhancing effects of hesperidin against thioacetamide-induced hepatic encephalopathy in rats

Hepatic encephalopathy (HE) is a serious neurological disorder which might occur in both acute and chronic liver injury.

AIMS

This study was carried out to explore the protective effects of hesperidin against experimentally induced HE.

MAIN METHODS

Rats were sorted into four groups each of six; Normal group, TAA group: rats were administered 350 mg/kg of TAA i.p. from day 5 to day 7. TAA+ Hesp 100 group: rats were administered hesperidin 100 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. TAA+ Hesp 200 group: rats were administered hesperidin 200 mg/kg/day orally for 7 days along with i.p TAA injection 350 mg/kg from day 5 to 7. Liver function, oxidative stress biomarkers, behavioral tests in addition to histopathological examination were assessed.

KEY FINDINGS

Hesperidin efficiently mitigated TAA-induced HE as evidenced by significant reduction in liver enzymes, bile and ammonia levels in serum. Moreover, hesperidin restored oxidant/antioxidant balance as manifested by reduction in MDA content in both cerebral and hepatic tissues. Additionally, hesperidin improved motor and cognitive abilities besides tissues' architecture as demonstrated by behavioral tests and histopathology results, respectively. Hesperidin also decreased levels of NLRP3 and increased levels of Sirt1 and FOXO in both cerebral and hepatic tissues. Finally, hesperidin markedly decreased the expression of IL-1β and caspase-1 as shown by immunohistochemical results.

SIGNIFICANCE

Taken together, the hepatoprotective impact of hesperidin and its ameliorative effect on the progression of HE appear to be mediated by its modulatory influence on NLRP3/Sirt1/FOXO signaling.

Drug-induced-acute liver failure: A critical appraisal of the thioacetamide model for the study of hepatic encephalopathy

Hepatic encephalopathy (HE) following acute and chronic liver failure is defined as a complex of neuropsychiatric abnormalities, such as discrete personal changes, sleep disorder, forgetfulness, confusion, and decreasing the level of consciousness to coma. The use and design of suitable animal models that represent clinical features and pathological changes of HE are valuable to map the molecular mechanisms that result in HE. Among different types of animal models, thioacetamide (TAA) has been used extensively for the induction of acute liver injury and HE. This agent is not directly hepatotoxic but its metabolites induce liver injury through the induction of oxidative stress and produce systemic inflammation similar to that seen in acute HE patients. In this short review article, we shortly review the most important pathological findings in animal models of acute HE following the administration of TAA.

ACTION OF VITAMIN E ON EXPERIMENTAL SEVERE ACUTE LIVER FAILURE

BACKGROUND

Severe Acute Liver Failure (ALF) is a life-threatening clinical syndrome characterized by hepatocyte necrosis, loss of hepatic architecture, and impairment of liver functions. One of the main causes of ALF is hepatotoxicity from chemical agents, which damage hepatocytes and result in increase of reactive oxygen species. The vitamin E isoform is the one with the strongest biological antioxidant activity.

OBJECTIVE

To evaluate the antioxidant effect of vitamin E in this ALF model.

METHODS

We used 56 rats (mean weight of 300 g) divided into eight groups, four groups assessed at 24 hours and 4 assessed at 48 hours after induction: control group (CO); Vitamin E (Vit. E); Thioacetamide (TAA) and Thioacetamide + Vitamina E (TAA+Vit.E). Rats were submitted to injections of thioacetamide (400 mg/kg i.p.) at baseline and 8 hours later. Vitamin E (100 mg/kg ip) was administered 30 minutes after the second dose of thioacetamide. The 48-hour group rats received two additional doses of vitamin E (24h and 36h). At 24h or 48 hours after the administration of the first dose of TAA, rats were weighed and anesthetized and their blood sampled for evaluation of liver integrity through enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Liver tissue was sampled for assessment of lipid peroxidation (LPO) by the technique TBARS, antioxidant enzymes SOD, CAT, GPx and GST activity, levels of the NO 2 /NO 3 and histology by H&E in two times. The results were expressed as mean ± standard deviation and statistically analyzed by ANOVA followed by Student-Newman-Keuls, with P <0.05 considered as significant.

RESULTS

After treatment with vitamin E, we observed a reduction in liver enzymes AST (U/L) (101.32±19.45 in 24 hours and 97.85±29.65 in 48 hours) related to the TAA group (469.56± 0.69 in 24 hours and 598.23±55.45 in 48 hours) and ALT (U/L) (76.59±8.56 in 24 hours and 68.47±6.49 in 48 hours) compared to the TAA group (312.21±10.23 in 24 hours and 359.15±17.58 in 48 hours). There was a reduction of LPO (nmol/mg Prot) in the TAA+Vit.E group (0.77±0.07 in 24 hours and 0.95±0.08 in 48 hours) compared to the TAA group (1.50±0.07 in 24 hours e 1.65±0.16 in 48 hours). SOD decreased in the TAA+Vit.E group (49.48±9.47 in 24 hours and 62.45±18, 47 in 48 hours), related to the TAA group (98.46±15.48 in 24 hours and 154.13±21.46 in 48 hours), as well as GST (nmol/min/mg Prot) in the TAA+Vit.E group (350.57±36.93 in 24 hours and 453.29±13.84 in 48 hours) compared to the TAA group (561.57±64.56 in 24 hours and 673.43±38.13 in 48 hours). There was an increase in CAT (pmol/min/mg Prot) in the TAA+Vit.E group (3.40±0.44 in 24 hours and 3.0±0.35 in 48 hours) compared to the TAA group (1.65±0.21 in 24 hours and 1.86±0.42 in 48 hours). The GPx (nmol/min/mg Prot) increased in 24 hours in the TAA+Vit.E group (1.01±0.16) compared to the TAA group (0.41±0.04) and decreased in 48 hours (1.19±0.17) compared to the TAA group (1.76±0.21). There was a reduction in NO2/NO3 (mmol/L) levels in the TAA+Vit.E group (31.47±4.26 in 24 hours and 38.93±5.20 in 48 hours) compared to the TAA group (49.37±5.12 in 24 hours and 53.53±5.97 in 48 hours). The histopathological evaluation showed a decrease in liver injury (necrosis and inflammation) in both studied times.

CONCLUSION

These results suggest that vitamin E was able to protect the liver from lesions caused by thioacetamide.

Potential targeted therapies for the inflammatory pathogenesis of hepatic encephalopathy

Hepatic encephalopathy (HE) is a severe neuropsychiatric complication of acute and chronic liver dysfunction, and is characterized by a spectrum that ranges from mild neuropsychological disturbances to coma. Although ammonia plays a critical role in the pathogenesis of HE, the plasma concentrations of ammonia and manifest symptoms of HE are not always consistent in patients with HE. Recently, a substantial body of evidence has indicated that inflammation acts in concert with ammonia in the pathogenesis of HE. Meanwhile, emerging novel and potential therapeutic strategies, including N-acetylcysteine, hypothermia, minocycline, non-steroidal anti-inflammatory drugs, tumour necrosis factor-alpha antagonists and p38 inhibitors, have been reported to ameliorate systemic inflammation and neuroinflammation, improve or reverse neuropsychiatric manifestations, and prevent the onset and progression of HE in patients and/or animal models of acute or chronic liver failure. These results point to the possible therapeutic utility of decreasing inflammation in the treatment of HE, and translation of these experimental results to the clinic may provide novel and promising therapeutic approaches for patients with HE secondary to acute or chronic liver failure. This review will provide an overview of these potential targeted therapies in the prophylaxis and treatment of HE.

Cost-comparison of laparoscopic and open surgery for mid or low rectal cancer after preoperative chemoradiotherapy: data from a randomized controlled trial

BACKGROUND

The purpose of the present study was to compare the direct costs of laparoscopic surgery (LS) and open surgery (OS) in the treatment of mid or low rectal cancer after preoperative chemoradiotherapy in patients in Korea.

METHODS AND RESULTS

The records of 130 LS patients and 125 OS patients were reviewed. Hospital stay after surgery and overall complication rates within three months of surgery were not significantly different. The LS group had significantly higher median costs than the OS group ($7,467.30 vs. $5,667.00; P < 0.001). The median hospital costs during hospitalization for surgery were higher in the LS group ($7,436.60 vs. $5,626.60; P < 0.001), but hospital costs for management of early postoperative complications were similar. The higher direct costs of LS were mainly due to the more expensive consumables and equipment needed for LS.

CONCLUSIONS

Further study is needed to determine whether the higher direct costs of LS for rectal cancer are balanced by advantages of LS over OS, such as better short-term outcomes and cosmetic effect.

Ibuprofen hepatic encephalopathy, hepatomegaly, gastric lesion and gastric pentadecapeptide BPC 157 in rats

Chronic ibuprofen (0.4 g/kg intraperitoneally, once daily for 4 weeks) evidenced a series of pathologies, not previously reported in ibuprofen-dosed rats, namely hepatic encephalopathy, gastric lesions, hepatomegaly, increased AST and ALT serum values with prolonged sedation/unconsciousness, and weight loss. In particular, ibuprofen toxicity was brain edema, particularly in the cerebellum, with the white matter being more affected than in gray matter. In addition, damaged and red neurons, in the absence of anti-inflammatory reaction was observed, particularly in the cerebral cortex and cerebellar nuclei, but was also present although to a lesser extent in the hippocampus, dentate nucleus and Purkinje cells. An anti-ulcer peptide shown to have no toxicity, the stable gastric pentadecapeptide BPC 157 (GEPPPGKPADDAGLV, MW 1419, 10 μg, 10 ng/kg) inhibited the pathology seen with ibuprofen (i) when given intraperitoneally, immediately after ibuprofen daily or (ii) when given in drinking water (0.16 μg, 0.16 ng/ml). Counteracted were all adverse effects, such as hepatic encephalopathy, the gastric lesions, hepatomegaly, increased liver serum values. In addition, BPC 157 treated rats showed no behavioral disturbances and maintained normal weight gain. Thus, apart from efficacy in inflammatory bowel disease and various wound treatments, BPC 157 was also effective when given after ibuprofen.

In vitro and in vivo anti-inflammatory effects of ethanol extract from Acer tegmentosum

AIM OF STUDY

Acer tegmentosum has been traditionally used for folk medicine to treat hepatic disorders such as hepatitis, hepatic cancer, and hepatic cirrhosis. In this study, we demonstrate the ethno-pharmacological activity of Acer tegmentosum in in vitro and in vivo inflammatory conditions.

RESULTS

The 70% ethanol extract (At-EE) of Acer tegmentosum dose-dependently diminished the production of nitric oxide (NO), tumour necrosis factor (TNF)-alpha, and prostaglandin (PG)E(2), in lipopolysaccharide (LPS)-activated RAW264.7 cells and peritoneal macrophages, by a transcriptional mechanism. At-EE also suppressed the activation of nuclear factor (NF)-kappaB, activator protein (AP)-1, and cAMP-responsive element binding (CREB), and simultaneously blocked their upstream inflammatory signalling cascades, including Akt, p38, and JNK. Furthermore, At-EE protected against LPS-induced cell death induced by reactive oxygen species (ROS) and reactive nitrogen species (RNS) and neutralized reactive species generation. In agreement with the in vitro results, orally administered At-EE strongly ameliorated ear oedema formation induced by arachidonic acid.

CONCLUSION

At-EE displays strong anti-inflammatory activities in vitro and in vivo, contributing to its major ethno-pharmacological role such as anti-hepatitis remedy and may be applicable to novel anti-inflammatory therapeutics.

An overview of animal models for investigating the pathogenesis and therapeutic strategies in acute hepatic failure

Acute hepatic failure (AHF) is a severe liver injury accompanied by hepatic encephalopathy which causes multiorgan failure with an extremely high mortality rate, even if intensive care is provided. Management of severe AHF continues to be one of the most challenging problems in clinical medicine. Liver transplantation has been shown to be the most effective therapy, but the procedure is limited by shortage of donor organs. Although a number of clinical trials testing different liver assist devices are under way, these systems alone have no significant effect on patient survival and are only regarded as a useful approach to bridge patients with AHF to liver transplantation. As a result, reproducible experimental animal models resembling the clinical conditions are still needed. The three main approaches used to create an animal model for AHF are: surgical procedures, toxic liver injury and infective procedures. Most common models are based on surgical techniques (total/partial hepatectomy, complete/transient devascularization) or the use of hepatotoxic drugs (acetaminophen, galactosamine, thioacetamide, and others), and very few satisfactory viral models are available. We have recently developed a viral model of AHF by means of the inoculation of rabbits with the virus of rabbit hemorrhagic disease. This model displays biochemical and histological characteristics, and clinical features that resemble those in human AHF. In the present article an overview is given of the most widely used animal models of AHF, and their main advantages and disadvantages are reviewed.

Indomethacin improves locomotor deficit and reduces brain concentrations of neuroinhibitory steroids in rats following portacaval anastomosis

Hepatic encephalopathy (HE) is a neuropsychiatric complication of both acute and chronic liver failure characterized by progressive neuronal inhibition. Some neurosteroids are potent positive allosteric modulators of the gamma-aminobutyric acid (GABA)-A receptor complex, and 'increased GABAergic tone' has been proposed to explain the neuroinhibition characteristics of HE. Brain levels of the neurosteroids pregnenolone, allopregnanolone and tetrahydrodesoxycorticosterone (THDOC) and the functional status of the GABA-A receptor complex were assessed in rats following portacaval anastomosis (PCA). Effects of indomethacin, an inhibitor of the 3alpha-hydroxysteroid dehydrogenase enzyme involved in neurosteroid synthesis, on PCA rat locomotor activity and brain neurosteroid levels were also assessed. Significant increases of the neurosteroid pregnenolone (2.6-fold), allopregnanolone (1.7-fold) and THDOC (4.7-fold) were observed in brains of PCA rats. Brain levels of these neurosteroids were in the nanomolar range, sufficient to exert positive allosteric modulatory effects at the GABA-A receptor. Indomethacin (0.1-5 mg kg(-1)) ameliorated dose-dependently the locomotor deficit of PCA rats and concomitantly normalized brain levels of allopregnanolone and THDOC. Increased brain levels of neurosteroids with positive allosteric modulatory actions at the neuronal GABA-A receptor offer a cogent explanation for the notion of 'increased GABAergic tone' in HE. Pharmacological approaches using agents that either reduce neurosteroid synthesis or modulate the neurosteroid site on GABA-A receptor could offer new therapeutic tools for the management and treatment of HE.

Pathogenesis of hepatic encephalopathy: the tumour necrosis factor-alpha theory

Hepatic encephalopathy (HE) is a major complication for acute and chronic liver failure. Despite several decades of intensive clinical and basic research, the pathogenesis of HE is still incompletely understood, and the precise mechanisms causing brain dysfunction in liver failure are still not fully established. Several theories concerning the pathogenesis of HE have been previously suggested, including the ammonia theory, which received the most attention. These theories are not mutually exclusive and the validity of none of them has been definitely proved experimentally. In this review article, an attractive theory concerning the pathogenesis of HE, the tumour necrosis factor-alpha (TNF) theory, is presented and comprehensively discussed after accumulation of sufficient data which indicate that the pro-inflammatory cytokine, TNF, is strongly involved in the pathogenesis of HE associated with both acute and chronic liver failure. This theory seems to be superior to all other previous theories in the pathogenesis of HE, and may induce development of other beneficial therapeutical modalities for HE directed towards inhibition of TNF production and/or action, and towards enhancement of its degradation.

Lack of detrimental or therapeutic effects of cyclooxygenase inhibition in bile duct-ligated rats with hepatic encephalopathy

BACKGROUND

The pathogenetic mechanisms of hepatic encephalopathy (HE) are not fully understood. Cerebral blood flow regulated by cyclooxygenase (COX) may be involved in the development of HE. There are no comprehensive data concerning the effects of COX inhibition on HE in chronic liver disease.

METHODS

Male Sprague-Dawley rats weighing 240-270 g at the time of surgery were selected for experiments. Secondary biliary cirrhosis was induced by bile duct ligation (BDL). Those rats were then divided into two groups to receive i.p. injection of indomethacin (5 mg/kg per day) or distilled water for 7 days from day 36 to day 42 after BDL. The control group consisted of rats receiving a sham operation. Severity of encephalopathy was assessed by counts of motor activity. Plasma levels of tumor necrosis factor (TNF)-alpha and 6-keto-prostaglandin F(1alpha) (6-keto-PGF(1alpha)), and liver biochemistry tests were determined after treatment.

RESULTS

The motor activity in both groups of BDL rats were significantly lower than that of the control group (P < 0.001). As compared with the BDL rats treated with distilled water, BDL rats treated with indomethacin had significant lower levels of 6-keto-PGF(1alpha), but the motor activity, TNF-alpha levels and serum biochemistry tests were not significantly different between both BDL groups.

CONCLUSIONS

Chronic indomethacin administration did not have significantly detrimental or therapeutic effects on the severity of encephalopathy in BDL rats.