Ameliorative effects of rutin on hepatic encephalopathy-induced by thioacetamide or gamma irradiation

Neuromodulatory role of L-arginine: nitric oxide precursor against thioacetamide-induced-hepatic encephalopathy in rats via downregulation of NF-κB-mediated apoptosis

The aim of the present study was to investigate the impact of arginine (ARG), a nitric oxide (NO) precursor, on thioacetamide (TAA)-induced hepatic encephalopathy (HE) in rats by injection of TAA (100 mg/kg, i.p) three times per week for six consecutive weeks. TAA-injected rats were administered ARG (100 mg/kg; p.o.) concurrently with TAA for the six consecutive weeks. Blood samples were withdrawn, and rats were sacrificed; liver and brain tissues were isolated. Results of the present study demonstrated that ARG administration to TAA-injected rats revealed a restoration in the serum and brain ammonia levels as well as serum aspartate transaminase, alanine transaminase, and alkaline phosphatase and total bilirubin levels as well as behavioral alterations evidenced by restoration in locomotor activity, motor skill performance, and memory impairment. ARG showed also improvement in the hepatic and neuro-biochemical values, pro-inflammatory cytokines, and oxidative stress biomarkers. All these results were confirmed by histopathological evaluation as well as ultrastructural imaging of the cerebellum using a transmission electron microscope. Furthermore, treatment with ARG could ameliorate the immunological reactivity of nuclear factor erythroid-2-related factor 2 (Nrf2) and cleaved caspase-3 proteins in the cerebellum and hepatic tissues. From all the previous results, it can be fulfilled that ARG showed a beneficial role in modulating the adverse complications associated with TAA-induced HE in rats via reducing hyperammonemia and downregulating nuclear factor kappa B (NF-κB)-mediated apoptosis.

Ameliorative Effect of Chitosan Oligosaccharides on Hepatic Encephalopathy by Reshaping Gut Microbiota and Gut-Liver Axis

This study investigated the influence of chitosan oligosaccharides (COSs) on a thioacetamide-induced hepatic encephalopathy (HE) Wistar rat model. COS treatment statistically reduced the false neurotransmitters and blood ammonia in HE rats, along with the suppression of oxidative stress and inflammation. The disbalanced gut microbiota was detected in HE rats by 16S rDNA sequencing, but the abundance alterations of some intestinal bacteria at either the phylum or genus level were at least partly restored by COS treatment. According to metabolomics analysis of rat feces, six metabolism pathways with the greatest response to HE were screened, several of which were remarkably reversed by COS. The altered metabolites might serve as a bridge for the alleviated HE rats treated with COS and the enhanced intestinal bacterial structure. This study provides novel guidance to develop novel food or dietary supplements to improve HE diseases due to the potential beneficial effect of COS on gut-liver axis.

SB332235, a CXCR2 antagonist, ameliorates thioacetamide-induced hepatic encephalopathy through modulation of the PI3K/AKT pathways in rats

RATIONALE

Hepatic encephalopathy (HE) is a neuropsychiatric disorder that results from either acute or chronic liver failure. CXCR2 plays an essential role in the pathophysiology of liver and brain diseases. In the present study, the potential beneficial effects of SB332235, a selective inhibitor of CXCR2, against HE were evaluated.

METHODS

HE was induced in male rats by thioacetamide injection (200 mg/kg, i.p.) at three alternative days. SB332235 was injected in rats 1 h before TAA at a dose of 1 and 3 mg/kg i.p.

RESULTS

SB332235 alleviated oxidative stress as shown by the decreased serum NO and reduced MDA, elevated GSH and SOD levels, and reduced TNF-α and NF-κB levels in both brain and liver tissues of rats. Additionally, SB332235 suppressed brain ASK-1, JNK, IL-8, and caspase-3 expression, and activated PI3K/AKT expression in brain tissues. Markers of brain dysfunction, such as ammonia, and markers of hepatic injury, such as LDH, albumin, bilirubin, γGT, AST, ALT, and ALP, were significantly ameliorated. Also, the protective effect of SB332235 was confirmed by histological examination of both brain and liver tissues.

CONCLUSIONS

Both doses (1 and 3 mg/kg) of SB332235 revealed significant hepatic/neuroprotective effects due to their anti-inflammatory, antioxidant, and antiapoptotic activities via activation of the PI3K/AKT pathway. Between the two, the 1 mg/kg dose provided significantly improved outcomes.

Effect of Low-Dose Gamma Radiation and Lipoic Acid on High- Radiation-Dose Induced Rat Brain Injuries

Aim

This work aims to investigate the possible radio-adaptive mechanisms induced by low-dose (LD) whole-body γ-irradiation alone or combined with alpha-lipoic acid (ALA) administration in modulating high-dose (HD) head irradiation–induced brain injury in rats.

Materials and Methods

Rats were irradiated with LD (.25 Gy) 24 hours prior HD (20 Gy), and subjected to ALA (100 mg/kg/day) 5 minutes after HD and continued for 10 days. At the end of the experiment, animals were sacrificed and brain samples were dissected for biochemical and histopathological examinations.

Results

HD irradiation-induced brain injury as manifested by elevation of oxidative stress, DNA damage, apoptotic, and inflammatory markers in brain tissue. Histological examination of brain sections showed marked alterations. However, LD alone or combined with ALA ameliorated the changes induced by HD.

Conclusion

Under the present experimental conditions, LD whole-body irradiation exhibited neuroprotective activity against detrimental effects of a subsequent HD head irradiation. This effect might be due to the adaptive response induced by LD that activated the anti-oxidative, anti-apoptotic, and anti-inflammatory mechanisms in the affected animals making them able to cope with the subsequent high-dose exposure. However, the combined LD exposure and ALA supplementation produced a further modulating effect in the HD-irradiated rats.

Ashwagandha (Withania somnifera) root extract attenuates hepatic and cognitive deficits in thioacetamide-induced rat model of hepatic encephalopathy via induction of Nrf2/HO-1 and mitigation of NF-κB/MAPK signaling pathways

ETHNOPHARMACOLOGICAL RELEVANCE

Ashwagandha (ASH) is one of the medicinal plants used in traditional Indian, Ayurvedic, and Unani medicines for their broad range of pharmacological activities including, tonic, aphrodisiac, energy stimulant, and counteracting chronic fatigue. Besides, it is used in the treatment of nervous exhaustion, memory-related conditions, insomnia, as well as improving learning ability and memory capacity. ASH is preclinically proven to be efficient in hepatoprotection and improving cognitive impairment, however, its beneficial effects against hepatic encephalopathy (HE) is still unclear. Therefore, this study aimed at investigating the protective effects of ASH root extract against thioacetamide (TAA)-induced HE and delineate the underlying behavioral and pharmacological mechanisms.

MATERIALS AND METHODS

ASH metabolites were identified using UPLC-HRMS. Rats were pretreated with ASH (200 and 400 mg/kg) for 29 days and administrated TAA (i.p, 350 mg/kg) in a single dose. Then, behavioral (open field test, Y-maze, modified elevated plus maze and novel object recognition test), and biochemical (ammonia and hepatic toxicity indices) assessments, as well as oxidative stress markers (MDA and GSH) were evaluated. The hepatic and brain levels of glutamine synthetase (GS), nuclear factor erythroid 2-related factor 2 (Nrf2), heme-oxygenase (HO)-1, inducible nitric oxide synthase (iNOS) were detected by enzyme-linked immunosorbent assay (ELISA). The mRNA expressions of p38/ERK½ were determined using real-time polymerase chain reaction (PCR). Moreover, histopathological investigations and immunohistochemical (NF-κB and TNF-α immunohistochemical expressions) examinations were performed.

RESULTS

Metabolite profiling of ASH revealed more than 45 identified metabolites including phenolic acids, flavonoids and steroidal lactone triterpenoids. Compared to the TAA-intoxicated group, ASH improved the locomotor and cognitive deficits, serum hepatotoxicity indices and ammonia levels, as well as brain and hepatic histopathological alterations. ASH reduced hepatic and brain levels of MDA, GS, and iNOS, and increased their GSH, Nrf2, and HO-1 levels. Also, ASH downregulated p38 and ERK½ mRNA expressions, and NF-κB and TNF-α immunohistochemical expressions in brain and hepatic tissues.

CONCLUSIONS

Our results provided insights into the promising hepato- and neuroprotective effects of ASH, with superiority to 400 mg/kg ASH, to ameliorate HE with its sequential hyperammonemia and liver/brain injuries. This could be attributed to the recorded increase in the spontaneous alternation % and recognition index, antioxidant and anti-inflammatory activities, as well as upregulation of Nrf2 and downregualtion of MAPK signaling pathways.

Effect of Uncaria rhynchophylla against Thioacetamide-Induced Acute Liver Injury in Rat

Both oxidative stress (OS) and inflammation are two fundamental pathological processes of acute liver injury (ALI). The current work is to investigate the effect and possible mechanism of Uncaria rhynchophylla (UR) on thioacetamide- (TAA-) induced ALI in rats. UR (100 and 200 mg/kg) was orally administrated with TAA (200 mg/kg of bodyweight, intraperitoneal injection) for 3 consecutive days. ALI was confirmed using histological examination and the factors associated with OS and liver function activity measured in serum. Moreover, expressions of inflammation and collagen-related proteins were measured by the Western blot analysis. Myeloperoxidase (MPO), which mediates OS in the ALI control group, was manifested by a significant rise compared with the normal group. UR significantly reduced AST, ALT, and ammonia levels in serum. The nuclear factor-κB (NF-κB) activation induced by TAA led to increase both inflammatory mediators and cytokines. Whereas, UR administration remarkably suppressed such an overexpression. UR supplementation improved matrix metalloproteinases (MMPs) such as MMP-1, -2, and -8. In contrast, tissue inhibitors of metalloproteinases- (TIMP-) 1 level increased significantly by UR treatment. In addition, the histopathological analysis showed that the liver tissue lesions were improved obviously by UR treatment. UR may ameliorate the effects of TAA-induced ALI in rats by suppressing both OS through MPO activation and proinflammatory factors through NF-κB activation. In conclusion, UR exhibited a potent hepatoprotective effect on ALI through the suppression of OS.

Protective role of rutin against combined exposure to lipopolysaccharide and D-galactosamine-induced dysfunctions in liver, kidney, and brain: Hematological, biochemical, and histological evidences

Protective efficacy of rutin over liver, kidney, and brain dysfunctions was evaluated in this investigation. Rutin (5, 10, and 20 mg/kg) was administered continuously for 6 days followed by single dose of D-galactosamine (300 mg/kg I.P.) and lipopolysaccharide (50 µg/kg I.P.) on the 6th day. Hematological, serological, biochemical, and histological aspects were considered for this study. One-way ANOVA (p ≤ .05) followed by Tukey's HSD post hoc test determined the statistical significance. Serum AST, ALT, ALP, urea, uric acid, and creatinine were increased significantly, whereas albumin and glucose were significantly decreased after combined exposure to LPS and D-GalN. Glutathione level and activity of SOD and catalase were decreased, whereas lipid peroxidation, triglycerides, and cholesterol were increased in tissue samples due to LPS- and D-GalN-induced toxicity. Prophylactic treatment of rutin maintained studied variables toward control claiming the protective role of rutin. PRACTICAL APPLICATION: Rutin is plenteous in a variety of commonly ingested foods such as onion, wine, grape, citrus fruits, tea, and buckwheat. Rutin supplement is recommended for the treatment of various diseases such as varicose veins, internal bleeding, or hemorrhoids. Rutin is better than well-known antithrombic agent, Juniferdin, or Bacitracin. In the present study, rutin showed protective effects against LPS- and D-GalN-induced multiorgan dysfunctions due to its anti-inflammatory and antioxidant properties. Therefore, rutin may be developed and practiced as a food supplement to cope with acute organ dysfunctions caused by inflammatory and oxidative damage.

Flavonoids from Barnebydendron riedelii leaf extract mitigate thioacetamide-induced hepatic encephalopathy in rats: The interplay of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways

Phytochemical investigation of the butanol fraction (BUF) derived from the 70% aqueous methanolic leaf extract of Barnebydendron riedelii led to the isolation of three flavonoid glycosides; kaempferol-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside, quercetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-galactopyranoside and quercetin-3-O-α-l-rhamnopyranosyl-(1 → 6)-β-d-glucopyranoside. Docking studies were fulfilled to validate the possible bio-properties of BUF toward nuclear factorkappa B (NF-κB) and nuclear factor erythroid 2-related factor 2 (Nrf2). The protective role of BUF against behavioral, biochemical, molecular, histopathological and immunohistochemical alterations in thioacetamide (TAA)-induced hepatic encephalopathy in rats was investigated. The toxicological studies indicated that BUF was safe up to 2000 mg/kg bw. Prior to TAA intoxication, rats were orally treated with either BUF at multiple doses (70, 140 and 280 mg/kg bw) or lactulose (8 mL/kg bw) for 14 consecutive days. On the 13th and the 14th day, TAA (200 mg/kg bw/day) was intraperitoneally injected. The BUF significantly improved motor impairment, ameliorated cognitive deficits and attenuated TAA-induced hepatotoxicity. Moreover, BUF controlled the inflammatory processes by suppressing the hepatic inflammatory cytokine; interleukin-6 (IL-6) as well as its pro-inflammatory mediator; NF-κB supporting the molecular docking assessment. The brain neurotransmitters; dopamine, serotonin and noradrenaline, as well as ammonia levels were improved in BUF-treated TAA-intoxicated animals in a dose-dependent manner. Furthermore, BUF administration to TAA-intoxicated rats modulated the Nrf2 and heme oxygenase 1 (HO-1) genes expression in liver and brain tissues. The histological evaluation showed that pretreatment of TAA-intoxicated rats with BUF ameliorated the degenerative effects of TAA on liver and brain tissues as well as reduced the activation of cellular apoptotic marker; caspase-3 and glial fibrillary acidic protein (GFAP⁺) astrocytes. In conclusion, the observed hepato-neuroprotective effect of BUF is attributed to its flavonoidal content through its modulatory effects on of NF-κB/IL-6 and Nrf2/HO-1 signaling pathways.

Synergistic effect of aminoguanidine and l-carnosine against thioacetamide-induced hepatic encephalopathy in rats: behavioral, biochemical, and ultrastructural evidence

Hepatic encephalopathy depicts the cluster of neurological alterations that occur during acute or chronic hepatic injury. Hyperammonemia, inflammatory injury, and oxidative stress are the main predisposing factors for the direct and indirect changes in cerebral metabolism causing encephalopathy. The aim of this study was to evaluate the possible synergistic effect between aminoguanidine (AG; 100 mg/kg, p.o.) and l-carnosine (CAR; 200 mg/kg, p.o.) on hepatic encephalopathy that was induced by thioacetamide (TAA; 100 mg/kg, i.p.) administered three times weekly for six weeks. Behavioral changes, biochemical parameters, histopathological analysis, and immunohistochemical and ultrastructural studies were conducted 24 h after the last treatment. Combining AG with CAR improved TAA-induced locomotor impairment and motor incoordination evidenced by reduced locomotor activity and decline in motor skill performance, as well as ameliorated cognitive deficits. Moreover, both drugs restored the levels of serum hepatic enzymes and serum and brain levels of ammonia. In addition, the combination significantly modulated hepatic and brain oxidative stress biomarkers, inflammatory cytokines, and cleaved caspase-3 expression. Furthermore, they succeeded in activating nuclear erythroid 2-related factor 2 (Nrf2) expression and heme oxygenase-1 (HO-1) activity and ameliorating markers of hepatic encephalopathy, including hepatic necrosis and brain astrocyte swelling. This study shows that combining AG with CAR exerted a new intervention for hepatic and brain damage in hepatic encephalopathy due to their complementary antioxidant, anti-inflammatory effects and hypoammonemic effects via Nrf2/HO-1 activation and NO inhibition.

Pro-inflammatory cytokines serve as communicating molecules between the liver and brain for hepatic encephalopathy pathogenesis and Lycium barbarum polysaccharides protection

ETHNOPHARMACOLOGICAL RELEVANCE

Gogi berry is a traditional food supplement and medical herbal which has been widely used in Eastern Asian countries. Lycium barbarum polysaccharides (LBP) are the major active components of Gogi berry and have been proved to possess a lot of biological activities.

AIM OF THE STUDY

We aimed to delineate the protective effect and mechanism of LBP on hepatic encephalopathy (HE).

MATERIALS AND METHODS

We investigated the protective mechanism of LBP in a thioacetamide (TAA, intraperitoneally injected, 400 mg/kg) induced acute HE mice model. Key phenotypes of clinical HE were phenocopied in the mice model, including high mortality, severe hepatic histology injury, increased hepatic oxidative stress, apoptosis, enhanced circulating levels of pro-inflammatory cytokines and ammonia, suppressed tryptophan hydroxylase activity, and deficits in locomotor activity.

RESULTS

The pathological alterations were effectively ameliorated by the oral administration with LBP (5 mg/kg, oral gavage, everyday), which were mediated by regulating MAPK pathways in both the liver and brain. Knockout of pro-inflammatory cytokines TNF-α or IL-6 effectively ameliorated impaired mice locomotor activity and MAPK activation in the brain. In an in vitro TNF-α-, IL-6-, or ammonia-induced microglia damaged cell model, cell injuries were evidently protected by the co-administration with LBP (50 μg/ml).

CONCLUSION

LBP ameliorated the hepatic/brain injuries and impaired locomotor activities in a HE mice model. Pro-inflammatory cytokines may serve as communicating molecules linking the liver and brain for the HE pathogenesis, partly through MAPK regulation.

Role of Natural Phenolics in Hepatoprotection: A Mechanistic Review and Analysis of Regulatory Network of Associated Genes

The liver is not only involved in metabolism and detoxification, but also participate in innate immune function and thus exposed to frequent target Thus, they are the frequent target of physical injury. Interestingly, liver has the unique ability to regenerate and completely recoup from most acute, non-iterative situation. However, multiple conditions, including viral hepatitis, non-alcoholic fatty liver disease, long term alcohol abuse and chronic use of medications can cause persistent injury in which regenerative capacity eventually becomes dysfunctional resulting in hepatic scaring and cirrhosis. Despite the recent therapeutic advances and significant development of modern medicine, hepatic diseases remain a health problem worldwide. Thus, the search for the new therapeutic agents to treat liver disease is still in demand. Many synthetic drugs have been demonstrated to be strong radical scavengers, but they are also carcinogenic and cause liver damage. Present day various hepatic problems are encountered with number of synthetic and plant based drugs. Nexavar (sorafenib) is a chemotherapeutic medication used to treat advanced renal cell carcinoma associated with several side effects. There are a few effective varieties of herbal preparation like Liv-52, silymarin and Stronger neomin phages (SNMC) against hepatic complications. Plants are the huge repository of bioactive secondary metabolites viz; phenol, flavonoid, alkaloid etc. In this review we will try to present exclusive study on phenolics with its mode of action mitigating liver associated complications. And also its future prospects as new drug lead.

Crocin mitigates γ-rays-induced hepatic toxicity in rats

Crocin (C₄₄H₆₄O₂₄) is an isolated bioactive molecule of saffron extract. It has different pharmacological effects such as antioxidant and anti-inflammatory activities. In the present study, radioprotective property of crocin was investigated in the rat liver. Thirty-two rats were equally divided into four groups: (1) control (normal saline), (2) crocin (200 mg/kg), (3) γ-rays (6Gy), and (4) crocin plus γ-rays-treated groups. The liver histopathology, serum transaminases (ALT and AST), alkaline phosphatase (ALP), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and hepatic lipid peroxidation, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) have been assessed. The histopathological result of hepatic tissue in group 3 showed hydropic degeneration and this progressed to focal or spotty necrosis through the lobule. Moreover, some sinusoids are distended with blood or with leukocytic infiltrations. Other cases in group 3 showed periportal leukocytic infiltrations and necrosis extended out from the portal tract to involve hepatic lobules with fibrinous necrosis in portal vessels, while the examination of hepatic tissues of group 4 showed reduced deformities, irregular arrangement, congested hepatic vessels, and necrosis in hepatocytes. The results also showed significant decreased level of liver function activities, inflammatory markers, lipid peroxidation, and increased levels of liver antioxidants enzymes in group 4. Crocin showed moderate protective effect against γ-rays-induced liver toxicity. The antioxidant effect of crocin may be a major reason for its positive impact on liver parameters. Graphical abstract .

Radiation-Induced Reactions in The Liver - Modulation of Radiation Effects by Lifestyle-Related Factors

Radiation has a wide variety of effects on the liver. Fibrosis is a concern in medical fields as one of the acute effects of high-dose irradiation, such as with cancer radiotherapies. Cancer is also an important concern following exposure to radiation. The liver has an active metabolism and reacts to radiations. In addition, effects are modulated by many environmental factors, such as high-calorie foods or alcohol beverages. Adaptations to other environmental conditions could also influence the effects of radiation. Reactions to radiation may not be optimally regulated under conditions modulated by the environment, possibly leading to dysregulation, disease or cancer. Here, we introduce some reactions to ionizing radiation in the liver, as demonstrated primarily in animal experiments. In addition, modulation of radiation-induced effects in the liver due to factors such as obesity, alcohol drinking, or supplements derived from foods are reviewed. Perspectives on medical applications by modulations of radiation effects are also discussed.

Immunomodulatory effect of new quinolone derivative against cisplatin/gamma radiation-induced renal and brain toxicity in mice

Treatment of cancer often requires exposure to radiation, which has several limitations involving non-specific toxicity toward normal cells, reducing the efficacy of treatment. Recent studies synthesize new quinolone derivatives to satisfy other purposes such as treatment of inflammatory and malignant diseases. The main purpose of the present study is to evaluate the effect of a new quinolone derivative; 2-(1-Ethyl-4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-2-oxoacetic acid (EHQA) and its possible mechanism against gamma radiation (IRR) and cisplatin (Cis) induced nephrotoxicity and neurotoxicity in mice. The structure of the newly synthesized quinolone derivative was elucidated by microanalytical and spectral data, which were found consistent with the assigned structures. Exposure to Cis and IRR significantly induced renal damage manifested by a significant increase in levels of urea and creatinine. Moreover, the exposure to both Cis and IRR significantly decreased the levels of anti-apoptotic protein; Bcl-2 in both renal and brain tissue homogenate accompanied by activation of an inflammatory marker; IL-17. Immunophenoting results showed an activation of T- lymphocytes marker; CD3 and B-lymphocytes marker; CD19. Interperitonial administration of EHQA significantly ameliorated the above-mentioned parameters. Overall, the present results indicated that EHQA is a promising anti-inflammatory and anti-apoptotic agent. From the obtained results it can be concluded that EHQA could be a candidate as immunomodulatory agents. Further studies are required to establish its molecular mechanism.