Functional and biochemical correlates of chlordecone exposure and its enhancement of CCl4 hepatotoxicity

Animals pretreated with chlordecone exhibit a greatly increased hepatotoxic response to CCl₄ challenge. Possible mechanisms underlying this interaction were examined. A single p.o. administration of chlordecone (5 mg/kg) was followed by CCl₄ (200 μl/kg) administered i.p. 48 h later. Twenty-four hours later, animals treated with chlordecone + CCl₄ had decreased hepatic excretory function (20% of controls) and elevated plasma transaminase activities and bilirubin. Hepatic mixed function oxidase activity was assessed as pentobarbital sleeping time and was not affected by chlordecone pretreatment. Irreversible binding of label from ¹⁴CCl₄ to hepatic protein or lipid was not different in the chlordecone group compared to vehicle controls. Hepatic and renal glutathione concentrations were not affected by chlordecone alone (at 6 h, 1, 2, 3, 5 and 7 days) or by a combination of chlordecone (48 h) and CCl₄ (24 h). CCl₄-induced lipid peroxidation of liver tissue, measured in vitro or in vivo, was not increased by chlordecone treatment. Thus, while the mechanism for the enhanced toxicity remains to be elucidated, these results suggest that the interaction between chlordecone and CCl₄ is a subtle one, not causally involving increased covalent binding of the toxin, increased susceptibility of tissue lipids to peroxidative damage or decreased hepatic GSH.     

Ameliorative effect of methanol extract of Rumex vesicarius on CCl4-induced liver damage in Wistar albino rats

Abstract

Context: Rumex vesicarius L. (Polygonaceae), an edible plant, is reported to have many bioactive phytochemicals, especially flavonoids and anthraquinones with antioxidant and detoxifying properties.

Objective: This study evaluated the methanolic extract of R. vasicarius (MERV) for hepatoprotective activity in rats against CCl₄-induced liver damage.

Materials and methods: The whole plant extract was prepared and investigated for its hepatoprotective activity. Rats were pretreated with MERV (100 and 200?mg/kg, p.o.) for 7?d prior to the induction of liver damage by CCl₄. Animals were then sacrificed 24?h after CCl₄ administration for the biochemical (AST, ALT, and ALP activity in serum; lipid peroxidation (LPO) and glutathione (GSH) levels in liver tissue) and histological analyses.

Results: CCl₄-induced hepatotoxicity was confirmed by an increase (p?<?0.05) in serum AST (4.55-fold), ALT (3.51-fold), and ALP (1.82-fold) activities. CCl₄-induced hepatotoxicity was also manifested by an increase (p?<?0.05) in LPO (3.88-fold) and depletion of reduced glutathione (3.14-fold) activity in liver tissue. The multiple dose MERV administration at 200?mg/kg showed promising hepatoprotective activity as evident from significant decrease levels of serum AST (230.01?±?13.21), serum ALT (82.15?±?5.01), serum ALP (504.75?±?19.72), hepatic LPO (3.38?±?0.33), and increased levels of hepatic glutathione (0.34?±?0.04) towards near normal. Further, biochemical results were confirmed by histopathological changes as compared with CCl₄-intoxicated rats.

Discussion and conclusion: The results obtained from this study indicate hepatoprotective activity of Rumex plant against CCl₄-induced liver toxicity; hence, it can be used as a hepatoprotective agent.     

Effect of Aerva lanata against hepatotoxicity of carbon tetrachloride in rats

The partially purified petroleum ether extractable fraction of the whole plant Aerva lanata (PF) was evaluated for the protective effect against liver damage induced by carbon tetra chloride (CCl₄) in Sprague Dawley rats. Rats were orally administered with PF (50 and 100 mg/kg body weight) for 14 days before CCl₄ challenge and 100 mg of PF alone for toxicity analysis without CCl₄ administration. The results showed that CCl₄ administration significantly damaged the liver as evident from histopathology and very high activity of serum and liver marker enzymes. It also reduced the antioxidant enzyme status of the animals. PF administration significantly reversed the histopathological changes and restored the elevated activities of liver marker enzymes and also enhanced the antioxidant enzyme activities. The extract also reduced hepatic lipid peroxidation and increased the serum total protein and albumin/globulin (A/G) ratio. Preliminary phytochemical analysis of PF showed the presence of alkaloids. These observations clearly indicate that PF contains antioxidant alkaloids capable of ameliorating the CCl₄-induced hepatic injury by virtue of its antioxidant activity.     

The antioxidant activity of chondroitin-4-sulphate, in carbon tetrachloride-induced acute hepatitis in mice, involves NF-kappaB and caspase activation

Background and purpose:

Reactive oxygen species (ROC) are the main causes of carbon tetrachloride (CCl₄)-induced acute liver injury. Chondroitin-4-sulphate (C4S) is known to inhibit lipid peroxidation through antioxidant mechanisms. Activation of nuclear factor (NF)-κB and caspases may strongly intensify inflammation and cell damage, in addition to that directly exerted by ROS. We investigated whether treatment with C4S, besides exerting antioxidant activity, was able to modulate NF-κB and apoptosis activation in CCl₄-induced liver injury in mice.

Experimental approach:

Acute hepatitis was induced in mice by an i.p. injection of CCl₄. Varying doses of C4S were administered i.p. 1 h before, 6 and 12 h after CCl₄ injection. 24 h after CCl₄ injection, the mice were killed for biochemical and histological analysis.

Key results:

CCl₄ injection produced: marked elevation of alanine aminotransferase and aspartate aminotransferase; hepatic membrane lipid peroxidation, assayed by 8-isoprostane levels; and depletion of reduced glutathione and superoxide dismutase. CCl₄ also decreased NF-κB translocation and IkBα, and increased gene expression of mRNA and protein of metalloproteases (MMP)-2 and -9, and of pro- and cleaved forms of caspases-3 and -7. There was also increased liver polymorphonuclear infiltration, evaluated by elastase assay, and hepatic cell disruption.C4S treatment inhibited lipid peroxidation; blocked NF-κB activation and IkBα protein loss; decreased mRNA and proteins for MMPs and caspases; restored endogenous antioxidants; limited hepatic polymorphonuclear accumulation and tissue damage.

Conclusions and implications:

As antioxidants may inhibit NF-κB and caspase activation, we hypothesize that treatment with C4S was able to inhibit NF-κB and apoptosis activation in hepatic injury.     

Hepatoprotective activity of Stereospermum suaveolens against CCl4-induced liver damage in albino rats

The present study aims to evaluate the hepatoprotective activity of Stereospermum suaveolens DC (Bignoniaceae). Hepatoprotective activity is studied by carbon tetrachloride (CCl₄)-induced liver damage in albino rats. The degree of protection in this activity has been measured by using biochemical parameters such as serum glutamate oxaloacetate transaminase (SGOT), serum glutamate pyruvate transaminase (SGPT), alkaline phosphatase (ALP), total bilirubin, LDL-cholesterol and SOD, CAT, GSH, total thiols, NO, and lipid peroxidation in liver tissue homogenate. The results suggest that the methanol stem bark extract of Stereospermum suaveolens at the doses 125, 250, and 500?mg/kg and reference standard Liv-52 treated group produced significant (p <0.001) hepatoprotection against CCl₄-induced liver damage by decreasing the activities of serum enzymes, bilirubin and lipid peroxidation. The extract significantly (p <0.001) increased levels of SOD, CAT, GSH and total thiols, as compared to control group. Histopathological studies further substantiate the protective effect of the extract. It was concluded that methanol stem bark extract of Stereospermum suaveolens showed effective hepatoprotective activity.     

Sulforaphane protects against acetaminophen-induced hepatotoxicity

Oxidative stress is closely associated with acetaminophen (APAP)-induced toxicity. Heme oxygenase-1 (HO-1), an antioxidant defense enzyme, has been shown to protect against oxidant-induced tissue injury. This study investigated whether sulforaphane (SFN), as a HO-1 inducer, plays a protective role against APAP hepatotoxicity in vitro and in vivo. Pretreatment of primary hepatocyte with SFN induced nuclear factor E2-factor related factor (Nrf2) target gene expression, especially HO-1 mRNA and protein expression, and suppressed APAP-induced glutathione (GSH) depletion and lipid peroxidation, which eventually leads to hepatocyte cell death. A comparable effect was observed in mice treated with APAP. Mice were treated with 300 mg/kg APAP 30 min after SFN (5 mg/kg) administration and were then sacrificed after 6 h. APAP alone caused severe liver injuries as characterized by increased plasma AST and ALT levels, GSH depletion, apoptosis, and 4-hydroxynonenal (4-HNE) formations. This APAP-induced liver damage was significantly attenuated by pretreatment with SFN. Furthermore, while hepatic reactive oxygen species (ROS) levels were increased by APAP exposure, pretreatment with SFN completely blocked ROS formation. These results suggest that SFN plays a protective role against APAP-mediated hepatotoxicity through antioxidant effects mediated by HO-1 induction. SFN has preventive action in oxidative stress-mediated liver injury.     

Late preventive effects of quinacrine on carbon tetrachloride induced liver necrosis

We have previously reported that treatments stimulating phospholipid (PL) synthesis or preventing PL degradation were late preventive agents against CCl₄-induced liver necrosis. Later studies by others postulated that stimulation of phospholipase A₂ (PLA₂) plays a role in PL degradative processes responsible for CCl₄ damage. Quinacrine (QUIN) is a well known inhibitor of PLA₂. In this work we report that QUIN (150 mg/kg i.p.) partially prevents CCl₄-induced liver necrosis at 24 h when given 30 min before or 6 or 10 h after CCl₄ (2.5 ml/kg p.o.) QUIN administration does not modify at 1 or 3 h after poisoning CCl₄ levels reaching the liver, covalent binding of CCl₄ reactive metabolites to proteins or lipids, CCl₄-induced lipid peroxidation process, CCl₄-induced decreases in body temperature, or glutathione levels in liver. QUIN concentrations in liver at times from 1 to 24 h are well over those required to inhibit PLA₂ activity. Results are compatible with the hypothesis that CCl₄ activation of PLA₂ at late stages of poisoning plays a role in CCl₄-induced liver necrosis.A. González Padrón was partially supported by a research fellowship from the Autonomic Government of the Canary Islands (Spain).     

Mushroom insoluble polysaccharides prevent carbon tetrachloride-induced hepatotoxicity in rat

The aim of the present study was to investigate the effect of mushroom insoluble non-starch polysaccharides (MINSP) on the carbon tetrachloride (CCl₄)-induced hepatic damage in rat. MINSP (100 and 200 mg/kg) administered daily orally for 15 days before CCl₄ (1.5 ml/kg). The effect of MINSP treatment was also examined in normal rats. Normal groups treated with MINSP showed significant decrease in serum activities of the liver enzymes, lipid peroxides and nitric oxide (NO) in the liver. Reduced glutathione (GSH) and total proteins (TP) contents in liver homogenate also increased after treatment with only MINSP for 15 days. In CCl₄-treated rats, significant elevation in serum liver enzymes, increased lipid peroxides and NO in the liver, and depletion of hepatic-GSH level were observed. Pre-treatment with MINSP significantly ameliorated the tested parameters when compared with CCl₄-treated group. It improved the antioxidant activity of the liver in a dose-dependent manner. Histopathological examination of hepatic tissue revealed that MINSP administration alone protected hepatocytes from the damage induced by CCl₄. Conclusion: MINSP are safe; it could be used as fat replacer in processing low fat diet. MINSP represents a good functional food and liver supporter for patient suffering from various liver diseases.     

Antioxidative and hepatoprotective effects of magnolol on acetaminophen-induced liver damage in rats

Acute liver failure (ALF), an often fatal condition characterized by massive hepatocyte necrosis, is frequently caused by drug poisoning, particularly with acetaminophen (N-acetyl-p-aminophenol/APAP). Hepatocyte necrosis is consecutive to glutathione (GSH) depletion and mitochondrial damage caused by reactive oxygen species (ROS) overproduction. Magnolol, one major phenolic constituent of Magnolia officinalis, have been known to exhibit potent antioxidative activity. In this study, the anti-hepatotoxic activity of magnolol on APAP-induced toxicity in the Sprague-Dawley rat liver was examined. After evaluating the changes of several biochemical parameters in serum, the levels of aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) were elevated by APAP (500 mg/kg) intraperitoneal administration (8 and 24 h) and reduced by treatment with magnolol (0.5 h after APAP administration; 0.01, 0.1, and 1 μg/kg). Histological changes around the hepatic central vein, lipid peroxidation (thiobarbituric acid-reactive substance/TBARS), and GSH depletion in liver tissue induced by APAP were also recovered by magnolol treatment. The data show that oxidative stress followed by lipid peroxidation may play a very important role in the pathogenesis of APAP-induced hepatic injury; treatment with lipid-soluble antioxidant, magnolol, exerts anti-hepatotoxic activity. Our study points out the potential interest of magnolol in the treatment of toxic ALF. Yen-Yi Ho and Ming-Tsung Lai contributed equally to this work.     

The novel role of β-aescin in attenuating CCl4-induced hepatotoxicity in rats

Context: β-Aescin has anti-inflammatory, anti-oxidant and antiedematous properties.

Objective: The present study investigated the hepatoprotective effect and underlying mechanisms of β-aescin in CCl₄-induced liver damage.

Materials and methods: Thirty-five Wistar rats were divided into six groups: normal control, CCl₄ control, silymarin (50?mg/kg, p.o) and β-aescin (0.9, 1.8 and 3.6?mg/kg, i.p.) treatment for 14 d. CCl₄ (1?mL/kg, i.p. for 3 d) was administered to produce hepatic damage. Ponderal changes and liver marker enzymes were estimated. Hepatic oxidative and nitrosative stress was estimated by levels of thiobarbituric acid reactive substances (TBARS), glutathione (GSH) and nitrite/nitrate. Serum TGF-β1 and TNF-α were estimated by ELISA technique. Hepatic collagen and histopathological studies were carried out.

Results: β-Aescin (3.6?mg/kg) markedly decreased CCl₄-induced increased levels of ALT, AST, ALP (71.77 versus 206.7, 71.39 versus 171.82, 121.20 versus 259?IU/L, respectively), total bilirubin (0.41 versus 1.35?mg/dL), TBARS (2.0 versus 8.83?nmol MDA/mg protein), nitrite/nitrate (352.50 versus 745.15?μg/mL) and increased CCl₄-induced decreased GSH levels (0.095 versus 0.048?μmol/mg protein). β-Aescin (3.6?mg/kg) induced focal regenerative changes in liver and markedly decreased TBARS (2.0 versus 8.83?nmol MDA/mg protein), nitrite/nitrate (352.50 versus 745.15?μg/mL), TGF-β1 (92.28 versus 152.1?pg/mL), collagen content (110.75 versus 301.74?μmol/100?mg tissue) and TNF-α (92.82 versus 170.56?pg/mL) when compared with CCl₄ control.

Discussion and conclusion: The findings suggest that β-aescin has a protective effect on CCl₄-induced liver injury, exhibited via its anti-inflammatory, antioxidative, antinitrosative and antifibrotic properties inducing repair regeneration of liver. Hence, it can be used as a promising hepatoprotective agent.     

Studies on the role of protein synthesis in cell injury by toxic agents: I. Effect of cycloheximide administration on several factors modulating carbon tetrachloride-induced liver necrosis

Cycloheximide pretreatment (1 mg/kg, ip) slightly attenuated the hepatic necrosis 24 hr after CCl₄ administration and this attenuation was more obvious at 72 hr. A dose of cycloheximide, 2 mg/kg, evoked a marked protective effect even at 24 hr. Cycloheximide administration (1 mg/kg) significantly reduced the body temperature in CCl₄-treated rats but did not change the CCl₄ concentrations in the liver. Prior treatment of the rats with cycloheximide decreased the amount of binding of ¹⁴CCl₄ to liver microsomal lipids and reduced CCl₄-induced lipid peroxidation at 1 hr but not at 6 hr after administration of the hepatotoxin. Cycloheximide did not alter the pentobarbital sleeping time of the rats nor did it interact with microsomes to give spectral changes. Cycloheximide did not alter microsomal cytochrome P-450 reductase activity. Administration of cycloheximide prior to CCl₄ did not prevent the CCl₄-induced decrease in cytochrome P-450 or glucose 6-phosphatase activity caused by the hepatotoxin. However it did prevent the CCl₄-induced polysome breakdown and it did attenuate the severity of the lesions caused by CCl₄ at the ultrastructural level.     

Resveratrol ameliorates carbon tetrachloride-induced acute liver injury in mice

Present investigation aimed to evaluate the hepatoprotective potential of resveratrol (30 mg/kg, po) in mice following two different routes (po and sc) of exposure to carbon tetrachloride (CCl₄, 1.0 ml/kg). Administration of CCl₄ caused significant increase in the release of transaminases, alkaline phosphatase, lactate dehydrogenase, γ-glutamyl transpeptidase, creatinine kinase, total bilirubin, urea and uric acid in serum. Significantly enhanced hepatic lipid peroxidation and oxidized glutathione with marked depletion in reduced glutathione were observed after CCl₄ intoxication. It was also found that CCl₄ administration caused severe alterations in liver histology. Hepatic injury was more severe in those animals who received CCl₄ by oral route than those who exposed to CCl₄ subcutaneously. Resveratrol treatment was able to mitigate hepatic damage induced by acute intoxication of CCl₄ and showed pronounced curative effect against lipid peroxidation and deviated serum enzymatic variables as well as maintained glutathione status toward control. Treatment of resveratrol lessened CCl₄ induced damage in liver. The results of the present study suggest that resveratrol has potential to exert curative effects against liver injury.     

Pequi (Caryocar brasiliense Camb.) almond oil attenuates carbon tetrachloride-induced acute hepatic injury in rats: Antioxidant and anti-inflammatory effects

Carbon tetrachloride (CCl₄) is a potent hepatotoxin, capable of generating free radicals that lead to oxidative stress and the inflammation process. Pequi almond oil (PAO) has been reported to possess unsaturated fatty acid and antioxidant compounds related to beneficial effects on oxidation and inflammatory conditions. The present study was undertaken to evaluate the hepatoprotective effects of handmade and coldpressed PAO on CCl₄-induced acute liver injury. The possible mechanisms underlying the effect on liver injury enzymes, histopathological parameters, lipid profile, lipid peroxidation, and antioxidant and detoxification defense systems, as well as inflammatory parameters, were determined. Rats treated with PAO (3 or 6 mL/kg) for 21 days before CCl₄ induction (3 mL/kg, 70%) showed significantly decreased levels of alanine aminotransferase and aspartate aminotransferase, milder hepatic lesions and higher levels of serum high-density lipoprotein compared to CCl₄ group. Moreover, PAO enhanced antioxidant capacity by increasing hepatic glutathione peroxidase and glutathione reductase enzyme activities, as well as reducing circulating concentrations of leptin and inflammatory mediators such as interleukin-6, leukotrienes -4 and -5 and the tumor necrosis factor receptor. In summary, PAO, especially cold-pressed oil, attenuated the CCl₄-induced alterations in serum and hepatic tissue in rats due to its antioxidant and anti-inflammatory properties.     

Carbon tetrachloride-induced hepatotoxicity in rat is reversed by treatment with riboflavin

Liver is a vital organ for the detoxification of toxic substances present in the body and hepatic injury is associated with excessive exposure to toxicants. The present study was designed to evaluate the possible hepatoprotective effects of riboflavin against carbon tetrachloride (CCl₄) induced hepatic injury in rats. Rats were divided into six groups. Hepatotoxicity was induced by the administration of a single intraperitoneal dose of CCl₄ in experimental rats. Riboflavin was administered at 30 and 100 mg/kg by oral gavage to test its protective effect on hepatic injury biochemically and histopathologically in the blood/liver and liver respectively. The administration of CCl₄ resulted in marked alteration in serum hepatic enzymes (like AST, ALT and ALP), oxidant parameters (like GSH and MDA) and pro-inflammatory cytokine TNF-α release from blood leukocytes indicative of hepatic injury. Changes in serum hepatic enzymes, oxidant parameters and TNF-α production induced by CCl₄ were reversed by riboflavin treatment in a dose dependent manner. Treatment with standard drug, silymarin also reversed CCl₄ induced changes in biomarkers of liver function, oxidant parameters and inflammation. The biochemical observations were paralleled by histopathological findings in rat liver both in the case of CCl₄ and treatment groups. In conclusion, riboflavin produced a protective effect against CCl₄-induced liver damage. Our study suggests that riboflavin may be used as a hepato-protective agent against toxic effects caused by CCl₄ and other chemical agents in the liver.     

Hepatoprotective effects of kaempferol 3-O-rutinoside and kaempferol 3-O-glucoside from Carthamus tinctorius L. on CCl4-induced oxidative liver injury in mice

Safflower (Carthamus tinctorius L.) is a traditional medicinal and edible herb with a long history of use in China. In this study, a model of hepatotoxicity induced by carbon tetrachloride (CCl₄) in mice was used to investigate the hepatoprotective effects of kaempferol 3-O-rutinoside (K-3-R) and kaempferol 3-O-glucoside (K-3-G), two kaempferol glycosides isolated from C. tinctorius L. K-3-R and K-3-G, at doses of 200 mg/kg and 400 mg/kg, were given orally to male mice once/d for 7 days before they received CCl₄ intraperitoneally. Our results showed that K-3-R and K-3-G treatment increased the level of total protein (TP) and prevented the CCl₄-induced increases in serum aspartate aminotransferase (AST), serum alkaline phosphatase (ALP), and hepatic malondialdehyde (MDA) levels. Additionally, mice treated with K-3-R and K-3-G had significantly restored glutathione (GSH) levels and showed normal catalase (CAT) and superoxide dismutase (SOD) activities, compared to CCl₄-treated mice. K-3-R and K-3-G also mitigated the CCl₄-induced liver histological alteration, as indicated by histopathological evaluation. These findings demonstrate that K-3-R and K-3-G have protective effects against acute CCl₄-induced oxidative liver damage.     

Effects of rosmarinic acid on acetaminophen-induced hepatotoxicity in male Wistar rats

Context: Drug-induced liver injury is a significant worldwide clinical problem. Rosmarinic acid (RA), a natural phenol, has antioxidant effects.

Objective: The effects of RA against acetaminophen (N-acetyl-p-amino-phenol (APAP))-induced oxidative damage and hepatotoxicity in rats were investigated.

Materials and methods: Male Wistar rats were pretreated with RA (10, 50 and 100?mg/kg, i.g.) for one week. On day 7, rats received APAP (500?mg/kg, i.p.). Then aspartate aminotransferase (AST), alanine aminotransferase (ALT), albumin, total protein, malondialdehyde (MDA), glutathione (GSH), total antioxidant capacity (TAC), glutathione S-transferase (GST), cytochrome CYP450 and histopathological changes were determined.

Results: APAP-induced oxidative stress in liver by a significant increase in the level of MDA (7.6?±?0.21?nmol/mg) as well as a decrease in the contents of TAC (1.75?±?0.14?μmol/g), GSH (1.9?±?0.22?μmol/g) and GST) 3.2?±?0.28?U/mg). RA treatment decreased MDA (4.32?±?0.35?nmol/mg) but increased the contents of TAC (3.51?±?0.34?μmol/g), GSH (3.42?±?0.16?μmol/g) and GST (5.71?±?0.71?μmol/g) in APAP group. RA 100?mg/kg decreased ALT (91.5?±?1.5?U/L), AST (169?±?8.8?U/L) and CYP450 (3?±?0.2?nmol/min/mg) in APAP group. Histologically RA attenuated hepatic damage by decreasing necrosis, inflammation, and haemorrhage in liver sections of APAP group.

Discussion and conclusions: This is the first report that oral administration of RA dose-dependently elicited significant hepatoprotective effects in rats through inhibition of hepatic CYP2E1 activity and lipid peroxidation. RA-protected hepatic GSH and GST reserves and total tissue antioxidant capacity.     

Mulberry water extracts (MWEs) ameliorated carbon tetrachloride-induced liver damages in rat

Mulberry extracts are antidiabetic and antihyperlipidemic, as well as preventive of cardiovascular disease. The current study investigates the protective mechanisms of mulberry water extracts (MWEs) in carbon tetrachloride (CCl₄)-induced hepatic injury. Oral administration of MWEs significantly reduced the lipid peroxidation triggered by CCl₄, as shown by the reduced production of thiobarituric acid-reactive substance (TBARS). The levels of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and alkaline phosphatase (ALP) were also reduced via cotreatment with MWEs compared with CCl₄ treatment alone. Cotreatment with MWE evidently reduced CCl₄-induced liver weight and inhibited lipid deposition and fibrogenesis. In a similar manner, cotreatment with silymarin, a well-known liver protective agent, also reversed the CCl₄-induced effects, such as reduced TBARS formation, decreased serum AST, ALT, and ALP levels, blocked lipid accumulation, and liver fibrosis. Furthermore, MWEs attenuated the proinflammatory genes such as cyclooxygenase 2, nuclear factor kappa B, and inducible nitric oxide synthase expression. The current findings suggest that MWEs such as silymarin exhibit protective and curative effects against CCl₄-induced liver damage and fibrosis via decreased lipid peroxidation and inhibited proinflammatory gene expression.     

Protective effects of Dunaliella salina – A carotenoids-rich alga,against carbon tetrachloride-induced hepatotoxicity in mice

The protective effects of Dunaliella salina (D. salina) on liver damage were evaluated by carbon tetrachloride (CCl₄)-induced hepatotoxicity in mice. Male ICR mice were orally treated with D. salina or silymairn daily with administration of CCl₄ twice a week for 8 weeks. CCl₄ induced liver damage and significantly (p < 0.05) increased the activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) in serum and decreased the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), and GSH content in liver whereas increased hepatic malondialdehyde (MDA) content as compared with control group. Treatment with D. salina or silymarin could significantly (p < 0.05) decrease the ALT, AST, and ALP levels in serum and increase the activities of SOD, catalase, GSH-Px, glutathione reductase, and GSH content and decrease the MDA content in liver when compared with CCl₄-treated group. Liver histopathology also showed that D. salina reduced the incidence of liver lesions induced by CCl₄. The results suggest that D. salina exhibits potent hepatoprotective effects on CCl₄-induced liver damages in mice, and that the hepatoprotective effects of D. salina may be due to both the increase of antioxidant enzymes activities and inhibition of lipid peroxidation.     

Amelioration effects against N-nitrosodiethylamine and CCl(4)-induced hepatocarcinogenesis in Swiss albino rats by whole plant extract of Achyranthes aspera

Objective:

The prevalence of oxidative stress may be implicated in the etiology of many pathological conditions. Protective antioxidant action imparted by many plant extracts and plant products make them a promising therapeutic drug for free-radical-induced pathologies. In this study, we assessed the antioxidant potential and suppressive effects of Achyranthes aspera by evaluating the hepatic diagnostic markers on chemical-induced hepatocarcinogenesis.

Materials and Methods:

The in vivo model of hepatocarcinogenesis was studied in Swiss albino rats. Experimental rats were divided into five groups: control, positive control (NDEA and CCl₄), A. aspera treated (100, 200, and 400 mg/kg b.w.). At 20 weeks after the administration of NDEA and CCl₄, treated rats received A. aspera extract (AAE) at a dose of 100, 200, and 400 mg/kg once daily route. At the end of 24 weeks, the liver and relative liver weight and body weight were estimated. Lipid peroxidation (LPO), superoxide dismutase (SOD), catalase (CAT), glutathione peroxidase (GPx), glutathione-S-transferase (GST), and reduced glutathione (GSH) were assayed. The hepatic diagnostic markers namely serum glutamic oxaloacetic transminase (AST), serum glutamic pyruvate transminase (ALT), serum alkaline phosphatase (ALP), gamma glutamyl transpeptidase (GGT), and bilirubin (BL) were also assayed, and the histopathological studies were investigated in control, positive control, and experimental groups.

Results:

The extract did not show acute toxicity and the per se effect of the extract showed decrease in LPO, demonstrating antioxidant potential and furthermore no change in the hepatic diagnosis markers was observed. Administration of AAE suppressed hepatic diagnostic and oxidative stress markers as revealed by decrease in NDEA and CCl₄ -induced elevated levels of SGPT, SGOT, SALP, GGT, bilirubin, and LPO. There was also a significant elevation in the levels of SOD, CAT, GPx, GST, and GSH as observed after AAE treatment. The liver and relative liver weight were decreased after treatment with AAE in comparison to positive control group. The architecture of hepatic tissue was normalized upon treatment with extract at different dose graded at 100, 200, and 400 mg/kg. b.w. in comparison to positive control group.

Conclusion:

These results suggest that A. aspera significantly alleviate hepatic diagnostic and oxidative stress markers which signify its protective effect against NDEA and CCl⁴-induced two-stage hepatocarcinogenesis.     

Effect of fasting,diethyl maleate,and alcohols on carbon tetrachloride-induced hepatotoxicity

The effect of fasting, diethyl maleate treatment, and methanol, ethanol, iso-propanol, or tert-butanol treatment on carbon tetrachloride (CCl₄)-induced hepatotoxicity in male Sprague-Dawley rats was studied. A 24-hr fast and the administration of diethyl maleate were found to be equipotent and not additive in potentiating CCl₄-induced hepatotoxicity; this potentiation appeared to be due to a depletion of hepatic glutathione (GSH) levels. Concomitant diurnal variations in hepatic GSH content and in CCl₄-induced hepatotoxicity also suggested hepatic GSH involvement in CCl₄-induced hepatic damage. Whereas ethanol has been reported to potentiate CCl₄-induced hepatotoxicity and to lower hepatic GSH levels, the present study suggested that these effects are due to an ethanol-induced loss of body weight. Methanol, iso-propanol, and tert-butanol, on the other hand, show the same maximal potentiation of CCl₄-induced hepatotoxicity and do so without inducing a depletion of hepatic GSH content or producing a loss of body weight. In contrast to a previous report, however, methanol was found to be markedly less effective on an equimolar basis than either iso-propanol or tert-butanol in potentiating CCl₄-induced hepatotoxicity. The study suggests that GSH is an important modulator of CCl₄-induced hepatotoxicity and also suggests that methanol, iso-propanol, and tert-butanol, but not ethanol, potentiate CCl₄-induced hepatotoxicity by a mechanism that does not involve altered hepatic GSH levels.