CCl4-induced Acute Hepatotoxicity Research Articles

AMPK-mTOR-ULK1-mediated autophagy protects carbon tetrachloride-induced acute hepatic failure by inhibiting p21 in rats

Autophagy is a lysosomal-dependent degradation pathway in eukaryotic cells. Recent studies have reported that autophagy can facilitate the activation of hepatic stellate cells (HSCs) and fibrogenesis of the liver during long-term carbon tetrachloride (CCl4) exposure. However, little is known about the role of autophagy in CCl4-induced acute hepatic failure (AHF). This study aimed to identify whether modulation of autophagy can affect CCl4-induced AHF and evaluate the upstream signaling pathways mediated by CCl4-induced autophagy in rats. The accumulation of specific punctate distribution of endogenous LC3-II, increased expression of LC3-II, Atg5, and Atg7 genes/proteins, and decreased expression of p62 gene were observed after acute liver injury was induced by CCl4 in rats, indicating that CCl4 resulted in a high level of autophagy. Moreover, loss of autophagic function by using chloroquine (CQ, an autophagic inhibitor) aggravated liver function, leading to increased expression of p21 (a cyclin-dependent kinase inhibitor) in CCl4-treated rats. Furthermore, the AMPK-mTORC1-ULK1 axis was found to serve a function in CCl4-induced autophagy. These results reveal that AMPK-mTORC1-ULK1 signaling-induced autophagy has a protective role in CCl4-induced hepatotoxicity by inhibiting the p21 pathway. This study suggests a useful strategy aimed at ameliorating CCl4-induced acute hepatotoxicity by autophagy.

Artichoke edible parts are hepatoprotective as commercial leaf preparation

Chemical profile analyses of artichoke (Cynara scolymus L., Asteraceae) edible parts (fleshy receptacle, inner bracts) as well as roots are compared with the commercially usable leaf extract using HPLC-DAD-ESI-MS via chlorogenicacid as a marker. Overall polyphenolic constituents demonstrated by means of LC/MS profiling. The nutritional values and inulin contents of different assessed parts were investigated. The present study was designed to determine the effect of artichoke: leaves, bracts, receptacles and roots alcoholic extracts against CCl4-induced acute hepatotoxicity and hyperlipidemia in rats by means of histopathological and biochemical parameters. Serum liver enzymes levels of aspartate amino transferase, alanine amino transferase, alkaline phosphatase and lipid peroxidase content (malondialdehyde MDA) were estimated. Blood glutathione, total cholesterol, triacylglycerides and high density lipid level were estimated in plasma. The ethanol extract of roots, leaves, bracts and receptacles were standardized to (0.82±0.02, 1.6±0.06, 2.02±0.16 and 2.4±0.27mg chlorogenic acid/100mg extract), respectively. The receptacle showed the highest content of polyphenols and exhibits the highest antioxidant activity. HPLC analysis of inulin in the receptacles of globe artichoke revealed high content of inulin (41.47mg/g) dry extract. All artichoke parts contain comparable vitamins and minerals. Artichokes receptacles extract when taken in dose of (500mg/kg/day) reduce the lesion caused by CCl4 alone more than groups receiving silymarin. Bracts and leaves extract exert nearly the same effect.

Protective effect of Combretum Hypopilinum diels: Root bark extract against CCl4-Induced hepatotoxicity in wistar rats

Background: Combretum hypopilinum is used in Togolese traditional medicine to alleviate various ailments including hepatic disorders. Objective: This study evaluates the hepatoprotective activities of crude ethanolic extract of C. hypopilinum root bark (CECH) and its possible mechanism(s) of action in Wistar rats. Materials and methods: In vitro antioxidant potential was evaluated using DPPH, Ferric-reducing power and hydroxyl radical scavenging assays. Hepatoprotective activity was assessed using CCl4-induced acute hepatotoxicity in rats. Animals were pretreated orally with different doses of CECH (200 and 400 mg/kg) once daily for 7 consecutive days and were subjected to intraperitoneal single injection of CCl4 (1 mL/kg). Serum markers of hepatic damage, hepatic endogenous antioxidants, NO, TNF-α and lipid peroxidation contents were measured out. Results: The pretreatment with CECH significantly decreased levels of hepatic enzymes (p < 0.05, p < 0.01, p < 0.001) and MDA in pretreated rats (p < 0.05, p < 0.01). CECH restored the decreased levels of hepatic antioxidants including SOD (p < 0.01), CAT (p < 0.05 at 400 mg/kg) and GSH (p < 0.05 at 400 mg/kg) and significantly inhibited hepatic production of NO (p < 0.05, p < 0.01).as well as the level of TNF-α (p < 0.001) in pretreated rats. Protective effects of CECH were confirmed by histopathological examinations. CECH exhibited antioxidant in vitro and contains also total phenol and flavonoid. Conclusion: This study suggests that CECH protected the liver from CCl4-induced hepatic damage possibly via antioxidant and anti-inflammatory mechanisms. Abbreviations Used: CECH: Crude ethanolic extract of combretum hypopilinum root bark, CCl4: Carbon tetrachloride, DPPH: 2,2-Diphenyl-1-picrylhydrazyl, AlCl3: Aluminum chloride, ALT: Alanine aminotransferase, AST: Aspartate aminotransferase, LDH: Lactate dehydrogenase, ALP: Alkaline phosphatase, TC: Total cholesterol, TG: Triglycerides, TB: Total bilirubin, TP: Total protein, MDA: Malondialdehyde, SOD: Superoxide dismutase, CAT: Catalase, GSH: Glutathione, NO: Nitric oxide.

Hepatoprotective and antioxidant effects of single clove garlic against CCl4-induced hepatic damage in rabbits

BackgroundThe increase in demand and consumption of single clove garlic or ‘Solo garlic’ (Allium sativum) has resulted in an increase in research on its therapeutic properties. The present study aims to evaluate the antioxidant activities, oxidant-scavenging efficiency and preventive effects of SCG (single clove garlic) and MCG (multi clove garlic) on CCl4-induced acute hepatotoxicity in male rabbits.MethodsFor this purpose, rabbits were orally administered with 3 ml of CCl4 /kg of body weight, followed by 0.8 g of MCG or SCG/kg twice a week for three successive weeks. Oxidative hepatotoxicity was then assessed.ResultsSCG extracts exhibited higher antioxidant capacity than the MCG extract. Scavenging ability of SCG showed significant (p < 0.05) elevation against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and superoxide radicals in comparison to MCG. In addition, total phenolic content of SCG was significantly elevated (p < 0.001), thereby suggesting that the composition of garlic storage constituents varies with the number of cloves present. CCl4-induced hepatotoxicity demonstrated histological changes including severe damage in the structure of liver tissues which correlated well to oxidative stress levels. Simultaneously, administration of SCG resulted in a significant reduction of serum alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), and total bilirubin (TB) levels in addition to improvement in some histological parameters. Low levels of lipid peroxidation (malondialdehyde, MDA) (p < 0.001), along with a huge reduction in peroxidase (POx) (p < 0.001) revealed protection against oxidative toxicity in the liver homogenate. Higher levels of catalase (CAT) (p < 0.001) and superoxide dismutase (SOD) (p < 0.05) when compared to the MCG test (TM) group indicates that removal of H2O2 is based on CAT activity in SCG test (TS) group rather than the POx activity demonstrated in the former group.ConclusionThe present study indicates that SCG possesses more protective ability than MCG against CCl4-induced liver injury and might be an effective alternative medicine against acute oxidative liver toxicity.

Protective effect of geraniin against carbon tetrachloride induced acute hepatotoxicity in Swiss albino mice

Geraniin is a hydrolysable tannin, widely present in many plant species, specifically used in traditional medicines. It has been shown to exhibit strong antioxidant activity in vitro. This study was performed to investigate hepatoprotective activity of geraniin against carbon tetrachloride (CCl4) induced damage in Swiss albino mice. Mice were treated with 30 and 60 mg/kg geraniin for 10 days followed by CCl4 administration for 24 h. Increase in Serum biochemical marker enzymes and histological deteriorative changes of liver tissue after CCl4 administration were attenuated by geraniin. Geraniin significantly reduced CCl4 induced lipid peroxidation, increase in amount of glutathione, glutathione reductase and Heme oxygenase-1 (HO-1). On the other hand it inhibited significant reduction in catalase activity and expression caused by CCl4 administration. Pre-treatment with geraniin reduced phosphorylation of translation initiation factor eIF2α, at serine 51, caused by CCl4 exposure and reduced elevated expression of its upstream kinase, Heme-regulated Inhibitor (HRI). These results clearly demonstrate hepatoprotective activity of geraniin against CCl4-induced acute hepatotoxicity via its free radical scavenging and antioxidant activities.

Hepatoprotective activity of chrysin is mediated through TNF-α in chemically-induced acute liver damage: An in vivo study and molecular modeling.

Chrysin (5,7-dihydroxyflavone) is a naturally occurring flavonoid present at high levels in honey, propolis and numerous plant extracts. Chrysin is known to have hepatoprotective activity, however, the mechanisms by which it exerts this effect remain unclear. In the present study, the effects of chrysin in carbon tetrachloride (CCl4)-induced acute liver damage were investigated and the results used to infer a possible mechanism behind chrysin's hepatoprotective activity. Prior to an intraperitoneal injection of CCl4 (1 ml/kg) to induce acute liver damage, chrysin (50 mg/kg) was administered orally to mice for 7 days. The positive control group was given 50 mg/kg standardized silymarin, a well-studied hepatoprotective flavonoid. Twenty-four h following CCl4 administration, an increase in the activity levels of serum aspartate-amino-transferase and alanine-amino-transferase was found. This was accompanied by extended centrilobular necrosis, steatosis and an altered hepatocyte ultrastructure. In addition, CCl4-induced acute hepatotoxicity was associated with an increase in hepatic tumor necrosis factor-α (TNF-α) and α-smooth muscle actin (α-SMA) protein expression, which was significantly decreased in the livers of mice pre-treated with chrysin (P<0.001), similar to the results of the silymarin pre-treated group (P<0.001). Treatment with chrysin prior to CCl4 exposure significantly reduced the activity of enzymes used as biochemical markers of poor liver function compared with the group which did not receive pre-treatment (P<0.001). In addition, the results of histopathological and electron microscopy liver examination showed chrysin pre-treatment reduced the effects of CCl4 treatment. Molecular modeling results demonstrated that the hepatoprotective activity of chrysin is mediated through TNF-α, as it reduces soluble TNF-α generation via blocking TNF-α-converting enzyme activity. In conclusion, the results of the present study suggest that inflammatory pathways are activated in CCl4-induced acute liver damage, which are ameliorated by chrysin pre-treatment. This indicates that chrysin is a potent hepatoprotective agent, similarly to silymarin at the same dose, which has the potential to be a viable alternative to conventional hepatoprotective treatments.

Preliminary Characterization of Phenolic Acid Composition and Hepatoprotective Effect ofStachys pumila

The present study aimed to investigate phenolic acid composition, antioxidant activity and hepatoprotective potential of Stachys pumila extract (SPE) against CCl4-induced acute hepatotoxicity. Pretreatment of rats with SPE significantly (P < 0.01) ameliorated both the increased levels of ALT, AST, OSI, MDA and the decreased activities of SOD and CAT, as compared to CCl4-control group. Histological and biochemical examinations revealed that SPE was more potent than reference drug silymarin in protecting the liver from toxic injury of CCl4 and preserving the hepatocyte ultrastructure. The phenolic acid profile of the methanol extract was determined quantitatively by HPLC/DAD. Ferulic acid was found as the predominant phenolic acid among the analyzed phenolic acids. SPE exerted high antioxidant effect according to in vitro antioxidant activity tests. Taken together, these results suggest that SPE could be a candidate as promising therapeutic agent for treating oxidative stress-related hepatic injury and other diseases. Practical Applications Recently, there has been a tremendous surge of interest in medicinal plants because of their high efficacy, safety and cost effectiveness. Among the identified medicinal plants, only a small percentage has been phytochemically investigated and submitted to pharmacological screening. Thus, more research is needed to discover the bioactive chemical components that are responsible for the claimed medicinal effects of the herbs. As a prominent local medicinal plant, Stachys pumila has been widely used against gastrointestinal disorders even though there is no scientific proof of its effectiveness. This study is the first to reveal the hepatoprotective activity of S. pumila against hepatotoxicity and to identify its phytochemicals. The results of the present study show that S. pumila extract protects the liver better than the reference drug silymarin against CCl4 induced hepatic injury. S. pumila could offer a novel alternative to the limited therapeutic options that exist for the treatment of liver diseases.

Role of the sympathetic nervous system in carbon tetrachloride-induced hepatotoxicity and systemic inflammation.

Carbon tetrachloride (CCl4) is widely used as an animal model of hepatotoxicity and the mechanisms have been arduously studied, however, the contribution of the sympathetic nervous system (SNS) in CCl4-induced acute hepatotoxicity remains controversial. It is also known that either CCl4 or SNS can affect systemic inflammatory responses. The aim of this study was to establish the effect of chemical sympathectomy with 6-hydroxydopamine (6-OHDA) in a mouse model of CCl4-induced acute hepatotoxicity and systemic inflammatory response. Mice exposed to CCl4 or vehicle were pretreated with 6-OHDA or saline. The serum levels of aminotransferases and alkaline phosphatase in the CCl4-poisoning mice with sympathetic denervation were significantly lower than those without sympathetic denervation. With sympathetic denervation, hepatocellular necrosis and fat infiltration induced by CCl4 were greatly decreased. Sympathetic denervation significantly attenuated CCl4-induced lipid peroxidation in liver and serum. Acute CCl4 intoxication showed increased expression of inflammatory cytokines/chemokines [eotaxin-2/CCL24, Fas ligand, interleukin (IL)-1α, IL-6, IL-12p40p70, monocyte chemoattractant protein-1 (MCP-1/CCL2), and tumor necrosis factor-α (TNF-α)], as well as decreased expression of granulocyte colony-stimulating factor and keratinocyte-derived chemokine. The overexpressed levels of IL-1α, IL-6, IL-12p40p70, MCP-1/CCL2, and TNF-α were attenuated by sympathetic denervation. Pretreatment with dexamethasone significantly reduced CCl4-induced hepatic injury. Collectively, this study demonstrates that the SNS plays an important role in CCl4-induced acute hepatotoxicity and systemic inflammation and the effect may be connected with chemical- or drug-induced hepatotoxicity and circulating immune response.

Hepatoprotective effect of ethanol extract from Berchemia lineate against CCl4-induced acute hepatotoxicity in mice

Context: The roots of Berchemia lineate (L.) DC. (Rhamnaceae) have been long used as a remedy for the treatment of some diseases in Guangxi Province, China.Objective: The present study investigates the hepatoprotective effect of Berchemia lineate ethanol extract (BELE) on CCl4-induced acute liver damage in mice.Materials and methods: Effect of BELE administrated for 7 consecutive days was evaluated in mice by the serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin (TBIL), albulin (ALB), globulin (GLB), and total protein (TP) levels, as well as liver superoxide dismutase (SOD) activity and malondialdehyde (MDA) level. Moreover, histopathological examinations were also taken.Results: Compared with the model group, administration of 400 mg/kg BELE for 7 d in mice significantly decreased the serum ALT (56.25 U/L), AST (297.67 U/L), ALP (188.20 U/L), and TBIL (17.90 mol/L), along with the elevation of TP (64.67 g/L). In addition, BELE (100, 200, and 400 mg/kg, i.g.) treated mice recorded a dose-dependent increment of SOD (291.17, 310.32, and 325.67 U/mg prot) and reduction of MDA (7.27, 6.77, and 5.33 nmol/mg prot) levels. Histopathological examinations also confirmed that BELE can ameliorate CCl4-induced liver injuries, characterized by extensive hepatocellular degeneration/necrosis, inflammatory cell infiltration, congestion, and sinusoidal dilatation.Discussion and conclusion: The results indicated that BELE possessed remarkable protective effect against acute hepatotoxicity and oxidative injuries induced by CCl4, and that the hepatoprotective effects of BELE may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity.

BIOCHEMICAL EFFECT OF SOME MEDICINAL HERBS ON INDUCED HEPATOTOXICITY IN RAT

This study was planned to clarify the biochemical effects of the ginger on CCl4-induced acute hepatotoxicity and its comparison with garlic and combination between ginger and garlic through the determination of the following parameters in the blood and liver tissues of albino rats liver function test. The effect of ginger and garlic against CCL4 was estimated by using white albino rats (150-200 g), which divided into 5 groups of 15 rats. The result showed that CCl4 increase GGT, AST and ALT enzymatic activities, while rats received ginger and / or garlic, their liver function parameters were restored to normal levels and the best result was that group received ginger and garlic after CCL4 injection.

Sparassis crispaAttenuates Carbon Tetrachloride-Induced Hepatic Injury in Rats

Sparassis crispa is an edible mushroom with various medicinal properties. Here we demonstrate the effect of Sparassis crispa on carbon tetrachloride (CCl₄)-induced hepatotoxicity and the underlying mechanism. To evaluate the hepatoprotective effects of Sparassis crispa ethanol extract (SCE), 50 male Sprague-Dawley rats were equally divided into 5 groups. Group I is the normal control rats with an intraperitoneal (i.p.) 0.5% carboxy methyl cellulose (CMC) pretreatment and olive oil treatment. Group II is the model group with an i.p. 0.5% CMC and 0.5 mL/kg CCl₄ treatment. Group III and IV is the CCl₄-administered rats pretreated with an i.p. 100 and 200 mg/kg SCE, respectively. Group V includes the silymarin group with an i.p. 50 mg/kg silymarin and CCl₄ treatment. At 16 h after the CCl₄ treatment, the levels of serum aminotransferases, TNF-α, and lipid peroxidation were substantially increased, whereas the activity of hepatic antioxidative enzymes, such as superoxide dismutase and catalase, was decreased. These changes were attenuated by SCE. The histological studies also showed that SCE inhibited the CCl4-induced liver injury. Furthermore, the contents of hepatic nitrite, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were elevated after CCl₄ treatment, while the cytochrome P450 2E1 (CYP2E1) expression was suppressed. SCE treatment inhibited the formation of liver nitrite, reduced the overexpression of iNOS and COX-2 proteins, but restored the liver CYP2E1 content compared with the CCl₄-treated model group. The present data elucidate that SCE protects the liver against CCl₄-induced acute hepatotoxicity, which might be due to its ability to restore the CYP2E1 function and suppress the inflammatory responses, in combination with its capacity to reduce oxidative stress.

Protective effect of Spirulina platensis enriched in phenolic compounds against hepatotoxicity induced by CCl4

Phenolic compounds make up the major secondary metabolites with high pharmaceutical potential. Microalgae were reported to contain low amounts of phenolic compounds. The present study aimed to investigate the hepatoprotective potential of biomass of Spirulina platensis enriched in phenolic compounds. The protective effects of the biomass of S. platensis with low amounts of phenolics (SP1) and with high amounts of phenolics (SP2) against CCl4-induced acute hepatotoxicity were evaluated in rats. The increased levels of ALT, AST and MDA along with decreased activities of SOD and CAT were significantly (p<0.01) ameliorated by SP2. Histological examinations revealed that SP2 was more potent than SP1 in protecting the liver from toxic injury of CCl4 and preserving the hepatocyte ultrastructure. The lesions including necrosis, lymphocyte infiltration, ballooning degeneration and hepatocyte injury as irregular lamellar organisation, dilations in endoplasmic reticulums and the presence of great number of cytoplasmic vacuolization were healed by SP2.

Evaluation of protective effect of Sapindus mukorossi saponin fraction on CCl4-induced acute hepatotoxicity in rats

AimThis investigation aimed to assess the hepatoprotective effect of saponin fraction isolated from the fruit pericarp of Sapindus mukorossi on carbon tetrachloride (CCl4)-induced hepatotoxicity.MethodsFruit of S. mukorossi was collected and authenticated, and dried pericarp powder subjected to extraction with cold ethanol (70%) by maceration followed by isolation of total saponin fraction. Hepatoprotective activity was demonstrated in the CCl4-damaged primary monolayer culture. In in vivo studies, pretreatment with total saponin fraction (50,100 and 150 mg/kg per os once a day for 4 days before CCl4 introduction and continued afterward for 3 days) attenuated the CCl4-induced acute increase in serum glutamic pyruvic transaminase, serum glutamic oxaloacetic transaminase, and alkaline phosphatase activities and considerably reduced histopathological alterations. Further, saponin fraction reduced thiopentone-induced (4 mg/kg, intraperitoneal) sleeping time in rats.ResultsSaponin fraction pretreatment improves bromsulphalein clearance and also increases cellular viability. Saponin administration replenished depleted hepatic glutathione and superoxide dismutase by improving the antioxidant status of the liver and liver function enzymes. These effects substantiate protection of cellular phospholipids from peroxidative damage induced by highly reactive toxic intermediate radicals formed during biotransformation of CCl4.ConclusionThe above findings lead to the conclusion that the saponin fraction of S. mukorossi has a protective capability both in vitro on primary hepatocyte cultures and in vivo in a rat model of CCl4-mediated liver injury. Hence, we suggest that the inclusion of this S. mukorossi fruit pericarp in the management of liver disorders is justified.

Hepatoprotection of different water extracts from Acer tegmentosum M. on CCl4-induced acute hepatotoxicity in mice: comparative efficacies between the extracts of boughs, twigs, and leaves

While Acer tegmentosum M. (AT) has been widely used as a popular folk remedy to prevent or treat liver diseases in Korea, the scientific evidences for the usage of AT against liver disease are poorly documented. To address this issue, we compared hepatoprotection of hot water extract (WEAT) from three parts of AT, boughs (E1), twigs (E2), and leaves (E3), on CCl4-induced acute hepatic injury in mice by way of morphometric and biochemical examination: liver function test, antioxidant enzymes activity of liver, histopathological and ultrastructural examination of liver, and antioxidant capacity (DPPH assay) of WEAT. We found that only oral intake group of WEAT-boughs showed significant differences in aspartate transaminase (AST), alanine transaminase (ALT) levels and glutathione peroxidase (GPx) activities as compared to CCl4 control group, whereas the glutathione levels were significantly low in all WEAT-pretreated groups. Consistently, histopathological and ultrastructural findings displayed hepatoprotection in the order of WEAT-boughs >WEAT-twigs>WEAT-leaves. Collectively, these results indicate that of three WEAT, WEAT-bough extract has the highest hepatoprotection against CCl4-induced acute hepatic injury in mice via the possible regulation of antioxidant enzyme activities in liver.

S-allylmercaptocysteine reduces carbon tetrachloride-induced hepatic oxidative stress and necroinflammation via nuclear factor kappa B-dependent pathways in mice

PurposeTo study the protective effects and underlying molecular mechanisms of SAMC on carbon tetrachloride (CCl4)-induced acute hepatotoxicity in the mouse model.MethodsMice were intraperitoneally injected with CCl4 (50 μl/kg; single dose) to induce acute hepatotoxicity with or without a 2-h pre-treatment of SAMC intraperitoneal injection (200 mg/kg; single dose). After 8 h, the blood serum and liver samples of mice were collected and subjected to measurements of histological and molecular parameters of hepatotoxicity.ResultsSAMC reduced CCl4-triggered cellular necrosis and inflammation in the liver under histological analysis. Since co-treatment of SAMC and CCl4 enhanced the expressions of antioxidant enzymes, reduced the nitric oxide (NO)-dependent oxidative stress, and inhibited lipid peroxidation induced by CCl4. SAMC played an essential antioxidative role during CCl4-induced hepatotoxicity. Administration of SAMC also ameliorated hepatic inflammation induced by CCl4 via inhibiting the activity of NF-κB subunits p50 and p65, thus reducing the expressions of pro-inflammatory cytokines, mediators, and chemokines, as well as promoting pro-regenerative factors at both transcriptional and translational levels.ConclusionsOur results indicate that SAMC mitigates cellular damage, oxidative stress, and inflammation in CCl4-induced acute hepatotoxicity mouse model through regulation of NF-κB. Garlic or garlic derivatives may therefore be a potential food supplement in the prevention of liver damage.

Protective Effect of Cornuside against Carbon Tetrachloride-Induced Acute Hepatic Injury

This study elucidated the effects of cornuside on carbon tetrachloride (CCl₄)-induced hepatotoxicity. Rats were treated intraperitoneally with 0.5 mL/kg of CCl₄. Sixteen h after CCl₄ treatment, the levels of serum aminotransferases, tumor necrosis factor-α (TNF-α), and lipid peroxidation were significantly elevated, whereas the hepatic antioxidative enzyme activities were decreased. These changes were attenuated by cornuside. Histological studies also indicated that cornuside inhibited CCl₄-induced liver damage. Furthermore, the contents of hepatic nitrite, inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2) were elevated after CCl₄ treatment, while cytochrome P450 2E1 (CYP2E1) expression was suppressed. Cornuside treatment inhibited the formation of liver nitrite, and reduced the overexpression of iNOS and COX-2 proteins, but restored the liver CYP2E1 content as compared with the CCl₄-treated rats. Our data indicate that cornuside protects the liver from CCl₄-induced acute hepatotoxicity, perhaps due to its ability to restore the CYP2E1 function and suppress inflammatory responses, in combination with its capacity to reduce oxidative stress.

Antioxidant and protective effects of spinach (Spinacia oleraceaL.) leaves against carbon tetrachloride-induced liver injury

Spinach, (Spinacia oleracea L.) is a popular vegetable. The hepatoprotective activity of the ethanolic extract of the leaves of spinach (EESO) was studied against carbon tetrachloride (CCl4)-induced oxidative stress (OS) and liver injury in rats. Pretreatment of rats with EESO, at 250 and 500 mg/kg body weight for 21 consecutive days significantly prevented the CCl4-induced hepatic damage as indicated by the serum marker enzymes (SGOT, SGPT, ALP and GGT) and bilirubin levels. Parallel to these changes, the leaves extract also prevented CCl4-induced OS in rat liver by inhibiting lipid peroxidation (LPO) and restoring the levels of antioxidant non-enzymatic biomarker, such as total protein (TP) and non-protein sulfhydryl (NP-SH) in liver tissue. The biochemical changes were consistent with the histological findings of the liver tissue suggesting marked hepatoprotective effect of the leaves extract in a dose-dependent manner, besides, a significant reduction was also observed in pentobarbital-induced sleeping time in mice. The results of spinach extract were comparable to that of silymarin. The protective effect of the EESO against CCl4-induced acute hepatotoxicity could be attributed to the potent antioxidant constituents of the spinach.

Hepatoprotective effect of the root extract of Decalepis hamiltonii against carbon tetrachloride-induced oxidative stress in rats

Decalepis hamiltonii, a climbing shrub, grows in the forests of peninsular India and is consumed for its health promoting properties. The hepatoprotective activity of the aqueous extract of the roots of D. hamiltonii with known antioxidant constituents was studied against carbon tetrachloride (CCl4)-induced oxidative stress and liver injury in rats. Pretreatment of rats with aqueous extract of the roots of D. hamiltonii, single (50, 100 and 200 mg/kg b.w.) and multiple doses (50 and 100 mg/kg b.w. for 7 days) significantly prevented the CCl4 (1 ml/kg b.w.) induced hepatic damage as indicated by the serum marker enzymes (AST, ALT, ALP, and LDH). Parallel to these changes, the root extract also prevented CCl4-induced oxidative stress in the rat liver by inhibiting lipid peroxidation and protein carbonylation, and restoring the levels of antioxidant enzymes (SOD, CAT, GPx, GR, and GST) and glutathione. The biochemical changes were consistent with histopathological observations suggesting marked hepatoprotective effect of the root extract in a dose dependent manner. Protective effect of the aqueous extract of the roots of D. hamiltonii against CCl4-induced acute hepatotoxicity could be attributed to the antioxidant constituents.

Hepatoprotection of tea seed oil ( Camellia oleifera Abel.) against CCl 4-induced oxidative damage in rats

The oil of tea seed ( Camellia oleifera Abel.) is used extensively in China for cooking. This study was designed to evaluate the effects of tea seed oil on CCl 4-induced acute hepatotoxicity in rats. Male SD rats (200 ± 10 g) were pre-treated with tea seed oil (50, 100, and 150 g/kg diet) for six weeks before treatment with a single dose of CCl 4 (50% CCl 4, 2 mL/kg of bw, intraperitoneally), the rats were sacrificed 24 h later, and blood samples were collected for assaying serum biochemical parameters. The livers were excised for evaluating peroxidation products and antioxidant substances, as well as the activities of antioxidant enzymes. Pathological histology was also performed. The results showed that a tea seed oil diet significantly ( p < 0.05) lowered the serum levels of hepatic enzyme markers (alanine aminotransferase, aspartate aminotransferase, and lactate dehydrogenase), inhibited fatty degeneration, reduced the content of the peroxidation product malondialdehyde, and elevated the content of GSH. Pre-treatment of animals with tea seed oil (150 g/kg diet) could increase the activities of glutathione peroxidase, glutathione reductase and glutathione S transferase in liver when compared with CCl 4-treated group ( p < 0.05). Therefore, the results of this study show that a tea seed oil diet can be proposed to protect the liver against CCl 4-induced oxidative damage in rats, and the hepatoprotective effect might be correlated with its antioxidant and free radical scavenger effects.

MRI study of the inhibitory effect of new spin traps on in vivo CCl 4-induced hepatotoxicity in rats

Acute CCl 4 hepatotoxicity is thought to occur as a result of free generated from the metabolism of CCl 4 in the liver. With the use of MRI it is possible to detect in vivo a CCl 4-induced edematous region surrounding the major branch of the hepatic portal vein in the right lobe. Inhibition of the CCl 4-induced response has been obtained by pretreatment with the spin trap, PBN, 30 min prior to CCl 4 exposure. The inhibitory effect of two new traps, M 3PO or methyl-DMPO, and PhM 2PO or phenyl-DMPO, on in vivo CCl 4-induced acute hepatotoxicity was investigated. Both PhM 2PO and M 3PO were found to inhibit the CCl 4-induced response at lower concentrations (0.35 M/kg body weight) than PBN (0.70 M/kg body weight). However, both M 3PO and PhM 2PO were also found to induce and edematous response at the same concentrations used for the PBN studies (0.70 M/kg body weight). PhM 2PO, at a concentration of 0.35 M/kg body weight, was 93% as efficient as PBN, at a concentration of 0.70 M/kg body weight; whereas M 3PO, at a concentration of 0.35 M/kg, was 89% as efficient as PBN at 0.70 M/kg body weight. Electron micrographs were obtained from small liver sections taken in proximity to the major branch of the hepatic portal veins of all treatment groups. The electron microscopy investigations support the MRI findings.