Du-Zhong (Eucommia ulmoides Oliv.) leaves inhibits CCl4-induced hepatic damage in rats.

The protective effects of water extract of Du-Zhong (Eucommia ulmoides Oliv.) leaves (WEDZ) and its active compound (protocatechuic acid; PCA) on liver damage were evaluated by carbon tetrachloride (CCl4)-induced chronic hepatotoxicity in rats. Wistar rats were orally treated with WEDZ (0.1, 0.5, and 1.0 g/kg bw) or PCA (0.1 g/kg bw) with administration of CCl4 (0.5 ml/rat, 20% CCl4 in olive oil) for 28 consecutive days. It showed that CCl4-treated rats increased the relative organ weights of liver and kidney. CCl4-induced rats liver damage and significantly (p<0.05) increased the GOT, GPT, LDH and ALP levels in serum as compared with the control group. Treatment with WEDZ or PCA could decrease the GOT, GPT, LDH and ALP levels in serum when compared with CCl4-treated group. CCl4-treated rats also significantly (p<0.05) decreased the GSH content in liver and trolox equivalent antioxidant capacity (TEAC) in serum whereas increased (p<0.05) MDA content in liver as compared with the control group. Treatment with WEDZ or PCA also significantly (p<0.05) increased the GSH content and significantly (p<0.05) decreased the MDA content in liver. Administration of WEDZ or PCA could increase the activities of GPx, GRd and GST in liver. Liver histopathology showed that WEDZ or PCA reduced the incidence of liver lesions including hepatic cells cloudy swelling, lymphocytes infiltration, cytoplasmic vacuolization, hepatic necrosis and fibrous connective tissue proliferated induced by CCl4 in rats. The data suggest that oral administration with WEDZ for 28 consecutive days significantly decrease the intensity of hepatic damage induced by CCl4 in rats.     

Function of reticuloendothelial system on CCl4 induced liver injury in mice

Phagocytic activity as a function of the reticuloendothelial system (RES) has been studied in CCl4-induced liver injury by using the carbon clearance test. Liver damage in mice was induced by administration of 20% CCl4 in olive oil (p.o.). After a single administration of CCl4, significant increases in liver/body weight ratio, serum GOT and GPT levels, alpha, beta and gamma-globulins and BSP retention, and decreases in serum albumin, an activity of the hepaplastintest and the correct phagocytic activity, alpha value, were found. After 15 administrations of CCl4 (3 times a week), mild increases in serum GPT level and BSP retention and decreases in the activity of the hepaplastintest and both phagocytic indices, K and alpha values, were observed. However, zymosan treatment 3 days before sacrifice induced an increase in K value depressed by multiple administrations of CCl4. The depression of carbon uptake by Kupffer cells can be seen by light microscopy after multiple administrations of CCl4 compared with that of saline and olive oil. These findings indicate that the RES phagocytosis is suppressed more strongly in chronic liver injury by 15 CCl4 administrations than in acute injury by a single one, although the biochemical parameters indicating liver injury are shown to have an opposite tendency. A clear correlation between the alteration of RES activity and the degree of liver injury was not noted.     

Antioxidant and hepatoprotective actions of the medicinal herb Artemisia campestris from the Okinawa Islands

The antioxidant action of Artemisia campestris was examined in vitro and in vivo. A water extract of A. campestris showed a strong scavenging action of 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl and superoxide anion radicals. When the extract was given intraperitoneally to mice prior to carbon tetrachloride (CCl4) treatment, CCl4-induced liver toxicity, as seen by an elevation of serum aspartate aminotransferase and alanine aminotransferase activities, was significantly reduced. Depression of the elevation of serum enzyme levels after CCl4-treatment was also observed by oral administration of the extract. In that case, CCl4-derived lipid peroxidation in the liver was decreased by the extract treatment. These results suggest that the extract of A. campestris scavenges radicals formed by CCl4 treatment resulting in protection against CCl4-induced liver toxicity.     

The effects of fucoidan extracts on CCl<Subscript>4</Subscript>-induced liver injury

The aim of this study was to elucidate the antioxidant properties of fucoidan extracts (FE) against CCl(4)-induced oxidative stress by monitoring the levels of glutamate oxaloacetate transaminase (GOT), glutamate pyruvate transaminase (GPT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx). Female, Sparague-Dowley rats were administered with FE (100 mg/kg daily) for 14 days and CCl(4) on the 15'th day, 12 h before they were sacrificed. The levels of GOT, GPT, ALP and LDH in serum of rats, as well as the levels of MDA, SOD, CAT and GPx in total liver homogenate were analyzed. CCl(4)-treatment was found to increase the levels of GOT, GPT, ALP, LDH and MDA, as well as decrease levels of SOD, CAT and GPx significantly. The pre-treatment of rats with FE, however, suppressed the increment of levels of GOT, GPT, ALP, LDH and MDA, as well as recovered the levels of SOD, CAT and GPx in CCl(4)-treated rats. Moreover there was a significant decrease in incidences of necrosis and cirrhosis in the liver tissue of FE-treated rats. These results implied that FE possessed antioxidant properties against CCl(4)-induced oxidative stress.     

Effects of acute and continuous pentobarbital administration on the gamma-aminobutyric acid system

Effects of acute anesthetic doses and chronic administration of pentobarbital on γ-aminobutyric acid (GABA) and glutamic acid levels in mouse brain have been investigated. Acute administration of pentobarbital caused an increase in the brain level of GABA which was associated with pentobarbital-induced narcosis. This was further substantiated by the finding that pentobarbital-induced sleeping time was prolonged when brain GABA level was elevated by the administration of either amino-oxyacetic acid (AOAA), an inhibitor of GABA-2-oxoglutarate aminotransferase (GABA-T), or glutamate, the precursor of GABA. In addition, the activity of l-glutamate-1-carboxylase (GAD) measured during pentobarbital-induced narcosis was higher than that of the control group. On the other hand, chronic administration of pentobarbital resulted in a decrease of both GABA and glutamate levels. There was a concomitant 30 per cent decrease in the activity of GAD. This was confirmed by the finding that the rate of brain GABA accumulation induced by AOAA administration in tolerant mice was slower than that of the non-tolerant animals. Brain GABA remained at significantly lower levels after an abrupt withdrawal from pentobarbital; however, brain glutamate levels showed no significant difference as compared to the control group. It appears that the GABA system in the central nervous system may be involved in barbiturate narcosis and further linked with the development of tolerance to barbiturate.     

Sho-saiko-to and Saiko-keisi-to, the traditional Chinese and Japanese herbal medicines, altered hepatic drug-metabolizing enzymes in mice and rats when administered orally for a long time

As the consumption of herbal remedies has increased, the opportunity that such herbal medicines are co-administered with other drugs has also risen gradually and we are, therefore, very much concerned about herb-drug interactions. We examined the effects of pre-administration of Kampo medicines (Sho-saiko-to, Saiko-keishi-to, Shigyaku-san and Dai-saiko-to) on the pentobarbital-induced sleeping time in mice and rats, to clarify the possibility that they could affect the drug-metabolizing enzymes. The administration of Sho-saiko-to and Saiko-keishi-to for 4 weeks significantly shortened the pentobarbital-induced sleeping time in mice and the administration of Sho-saiko-to for 2 weeks significantly reduced the sleeping time in rats. Furthermore, we tried to identify the molecular species of rat cytochrome P450s (CYPs) affected by Sho-saiko-to and Saiko-keishi-to by competitive RT-PCR. The oral administration of Sho-saiko-to for 2 weeks upregulated the mRNA expression of CYP2B, CYP3A1, CYP2E1 and CYP4A1 in rats. The treatment with Saiko-keishi-to for 2 weeks also up-regulated the mRNA expression of CYP2B, CYP3A1 and CYP4A1. Sho-saiko-to and Saiko-keishi-to may potentially influence the drug-metabolizing enzymes in man, and would thus require much attention when used in the clinical situation.     

The role of opiate receptors in the potentiation of pentobarbital sleeping time by the acute and chronic administration of opiates

Male rats injected with pentobarbital (50.0 mg/kg i.p.) showed increased sleeping time after the acute administration of morphine (5.0 or 10.0 mg/kg s.c.). This effect was antagonized by naltrexone (2.0 mg/kg s.c.). The enhancement displayed stereoselectivity as levorphanol greatly lengthened the sleeping time induced by pentobarbital while dextrophan only produced a slight increase. Rats implanted for 3 days with pellets of morphine base (75.0 mg) were tolerant to the analgesic effects of morphine (2.5 mg/kg s.c.) but showed an even greater increase in pentobarbital-induced sleeping time than rats treated acutely. No potentiation was observed in subjects that were also implanted with a pellet of naltrexone (30.0 mg). It is concluded that the potentiation of pentobarbital-induced sleeping time produced by opiates is mediated by opiate receptors, but fails to show the development of tolerance.     

Sanjoinine A isolated from Zizyphi Spinosi Semen augments pentobarbital-induced sleeping behaviors through the modification of GABA-ergic systems

Zizyphi Spinosi Semen (ZSS) has been widely used for the treatment of insomnia in oriental countries. This experiment was performed to investigate whether sanjoinine A, one of major alkaloid compounds of ZSS, has hypnotic effects and/or enhances pentobarbital-induced sleeping behaviors through the gamma-aminobutyric acid (GABA)-ergic systems. Sanjoinine A itself did not induce sleeping at the higher dose used in this experiment. However, sanjoinine A prolonged sleeping time and reduced the sleeping latency induced by pentobarbital in a dose-dependent manner similar to muscimol, a GABA(A) receptor agonist. Sanjoinine A also increased sleeping rate and sleeping time when administered combined with pentobarbital at a sub-hypnotic dosage and showed synergistic effects with muscimol in potentiating sleeping onset and enhancing sleeping time induced by pentobarbital. In addition, both sanjoinine A and pentobarbital increased chloride influx in primary cultured cerebellar granule cells. Sanjoinine A also showed similar effects with muscimol in potentiating chloride influx inducing effects of low dose pentobarbital. Sanjoinine A decreased GABA(A) receptor alpha-subunit expression and increased gamma-subunit expression, and had no effects on the abundance of beta-subunits in primary cultured cerebellar granule cells, showing different subunit expression from pentobarbital. In addition, we found that sanjoinine A also enhanced expression of glutamic acid decarboxylase (GAD), but pentobarbital did not. In conclusion, sanjoinine A itself does not induce sleeping, but it augments pentobarbital-induced sleeping behaviors through the modification of GABA-ergic systems.     

Effect of carbon tetrachloride on blood coagulation and fibrinolytic activities in rats

Blood coagulation and fibrinolytic activities were studied in rats with hepatic injury induced by carbon tetrachloride (CCl4). Acute hepatic injury was induced by single oral administration of 0.5, 1.0, 2.0 and 3.0 ml/kg of CCl4. Experiments were performed on the parameters of blood coagulation activities (TEG, HPT, TT, PRCT, PT, PTT, fibrinogen, factor XIII and AT III) and those of fibrinolytic activities (PLG, alpha 2PI) and plasma total protein, GOT, GPT, Ht, L/B ratio. All determinations were measured at 24 hr after administration of CCl4. Blood coagulation and fibrinolytic activities in rats were weakened in accordance with the dosage of CCl4 administration. Below CCl4 administration of 1.0 ml/kg, the GOT and GPT values increased in accordance with the dosage. However, with CCl4 administration of above 1.0 ml/kg, these values stayed at almost the same level. On the other hand, the relationship between the dosage of CCl4 and logarithmic values of HPT, PT, PTT, factor XIII and PLG all showed a good straight line.     

Protective mechanism of salvia miltiorrhiza on carbon tetrachloride-induced acute hepatotoxicity in rats

The purpose of this study was to investigate the possible mechanisms of Salvia miltiorrhiza (Sm) in carbon tetrachloride (CCl(4))-induced acute hepatotoxicity in rats. Male Wistar rats received a single dose of CCl(4) (2 ml/kg in corn oil, intraperitoneally). Three hours after CCl(4) intoxication, rats received either Sm (100 mg/kg) or silymarin (100 mg/kg) by gastrogavage twice a day for 2 consecutive days. CCl(4)-induced liver damage was shown by significant elevation of serum aminotransferase levels. Additionally, a significant decrease was observed in hepatic microsomal P450 2E1 protein content and hepatic concentrations of antioxidant enzymes. In contrast, rats given both Sm and silymarin supplement had less elevation of serum aminotransferase concentrations associated with less severe lobular damage of hepatocytes than rats receiving CCl(4) alone. Sm administration restored the reduction of hepatic microsomal P450 2E1 protein content as well as inducing an increase in hepatic glutathione concentration. On the other hand, administration of silymarin resulted in an elevation of hepatic superoxide dismutase levels. Moreover, both Sm and silymarin treatment inhibited the elevation of hepatic inducible nitric oxide (iNOS) protein content and nitrite concentration in liver homogenate 24 h after CCl(4) intoxication. We concluded that administration of Sm is effective in amelioration of CCl(4)-induced hepatotoxicity. This effect may be due to its ability to decrease the metabolic activation of CCl(4) by an increase in P450 2E1 protein content and its antioxidant activity associated with less increase in hepatic iNOS protein content.     

Sulfasalazine prevents the increase in TGF-β, COX-2, nuclear NFκB translocation and fibrosis in CCl4-induced liver cirrhosis in the rat

It has been demonstrated that this sulfasalazine (SF) inhibits the nuclear factor κB (NFκB) pathway, which regulates important genes during inflammation and immune answer. The aim of this work was to evaluate the effects of SF on carbon tetrachloride (CCl(4))-induced liver fibrosis. We formed the following experimental groups of rats: controls, damage induced by chronic CCl(4) (0.4?g/kg, intraperitoneally, three times a week for 8 weeks) administration and CCl(4)?+?SF (100?mg/kg/day, postoperatively for 8 weeks) administration. We determined the activities of alanine aminotransferase (ALT), γ-glutamyl transpeptidase (γ-GTP), cyclooxygenase (COX)-1 and COX-2, lipid peroxidation, glutathione levels, collagen content, expression of transforming growth factor-β (TGF-β) and nuclear translocation of NFκB. SF was capable to inhibit the ALT and γ-GTP elevated levels induced with the CCl(4) administration. SF had antioxidant properties, prevented the lipid peroxidation and the imbalance of reduced and oxidized glutathione produced by CCl(4). Importantly, SF blocked the accumulation of collagen in the liver, the expression of TGF-β, the nuclear translocation of NFκB and the activity of COX-2, all induced with the administration of CCl(4) in the rat. These results show that SF has strong antifibrotic properties because of its antioxidant properties and its ability to prevent nuclear translocation of NFκB and consequently the expression of TGF-β and the activity of COX-2.     

Protective effects of luteolin-7-glucoside against liver injury caused by carbon tetrachloride in rats

Ixeris chinensis (Thunb.) Nakai has been used as a Chinese folk medicine; the information on the physiological and biochemical functions of the compounds extracted from I. chinensis is still scanty. We investigated the effects of luteolin -7-glucoside (LUTG) isolated from I. chinensis against liver injury caused by carbon tetrachloride (CCl4). CCl4 significantly increased the enzyme activities of glutamic pyruvic transaminase (GPT) and glutamic oxaloacetic transaminase (GOT) in blood serum, as well as the level of malondialdehyde (MDA) and 8-hydroxydeoxyguanosine (8-OHdG) in liver tissue, and decreased the levels of reduced glutathione (GSH). Pretreatment with LUTG was not only able to suppress the elevation of GPT, GOT, MDA and 8-OHdG, and inhibit the reduction of GSH in a dose-dependent manner in vivo, but also reduce the damage of hepatocytes in vitro. On the other hand, we also found LUTG has strong antioxidant activity against reactive oxygen species (ROS) in vitro in a concentration-dependent manner. The hepatoprotective activity of LUTG was possibly due to its antioxidant properties, acting as scavengers of ROS. These results obtained in vivo and in vitro suggest that LUTG had protective effects against hepatic oxidative injury induced by chemicals. Further studies on the pharmaceutical functions and immunological responses of LUTG may help in the development of a clinical application.     

Protective effects of Pycnogenol on carbon tetrachloride-induced hepatotoxicity in Sprague-Dawley rats.

Oxidative damage is implicated in the pathogenesis of various liver injuries. In the present study the ability of Pycnogenol (PYC) as an antioxidant to protect against CCl4-induced oxidative stress and hepatotoxicity in rats was investigated. Four experimental groups of six rats each were constructed: a vehicle control group received the respective vehicles (distilled water and corn oil) only; a CCl4 group received a 14-day repeated intraperitoneal (i.p.) dose of distilled water and then a single oral dose of CCl4 at 1.25 ml/kg; and the CCl4&PYC 10 and CCl4&PYC 20 groups received a 14-day repeated i.p. dose of PYC 10 and 20 mg/kg, respectively, and then a single oral dose of CCl4 at 1.25 ml/kg. Hepatotoxicity was assessed 24 h after the CCl4 treatment by measurement of serum aminotransferase (AST) and alanine aminotransferase (ALT) activities, hepatic malondialdehyde (MDA) and glutathione (GSH) concentrations, and catalase, superoxide dismutase (SOD), and glutathione-S-transferase (GST) activities. The results were confirmed histopathologically. The single oral dose of CCl4 produced significantly elevated levels of serum AST and ALT activities. Histopathological examinations showed extensive liver injuries, characterized by extensive hepatocellular degeneration/necrosis, fatty changes, inflammatory cell infiltration, congestion, and sinusoidal dilatation. In addition, an increased MDA concentration and decreased GSH, catalase, SOD, and GST were observed in the hepatic tissues. On the contrary, PYC treatment prior to the administration of CCl4 significantly prevented the CCl4-induced hepatotoxicity, including the elevation of serum AST and ALT activities and histopathological hepatic lesions, in a dose-dependent manner. Moreover, MDA and GSH levels and catalase, SOD, and GST activities in hepatic tissues were not affected by administration of CCl4, indicating that the pretreatment of PYC efficiently protects against CCl4-induced oxidative damage in rats. The results indicate that PYC has a protective effect against acute hepatotoxicity induced by the administration of CCl4 in rats, and that the hepatoprotective effects of PYC may be due to both the inhibition of lipid peroxidation and the increase of antioxidant activity.     

Hepatocurative and antioxidant profile of HP-1, a polyherbal phytomedicine

HP-1 a herbal formulation comprising of Phyllanthus niruri and extracts of Terminalia belerica, Terminalia chebula, Phyllanthus emblica and Tinospora cordifolia has been evaluated for hepatoprotective activity against carbon tetrachloride (CCl4) induced toxicity. Results show that HP-1 reversed the leakage of lactate dehydrogenase (LDH) and glutamate pyruvate transaminase (GPT) and prevented the depletion of glutathione (GSH) levels in a primary monolayer culture of rat hepatocytes (in vitro). HP-1 attenuated the serum toxicity as manifested in elevated levels of transaminases (glutamate oxaloacetate transaminase (GOT), and GPT) The antioxidative enzymes in liver (catalase and superoxide dismutase (SOD)) were restored to normal values after the oral administration of HP-1. HP-1 suppressed the formation of the superoxide anion radical and reduced CCl4 mediated lipid peroxidation (LPO). Silymarin and antioxidants (ascorbic acid, beta-carotene and alpha-tocopherol) were used for comparison. The present study showed that HP-1 is a potential hepatoprotective formulation with an additional attribute of being anti-peroxidative.     

A comparative study of Laennec by intravenous or subcutaneous injection on CCl4-induced acute or chronic liver injury in rats

The effect of Laennec (human placenta hydrolysate) on CCl4-induced acute or chronic liver injury in rats was examined. In the acute liver injury induced by CCl4, 0.5 ml/kg for 4 days, intravenous injection of Laennec increased total protein and decreased nonesterified fatty acid in the liver. Subcutaneous injection of Laennec inhibited the decrease of liver phospholipid by CCl4 administration. Both intravenous and subcutaneous injections of Laennec inhibited the increases of serum transaminase (GOT, GPT) levels caused by CCl4. Furthermore, intravenous Laennec inhibited the increase of serum alkaline phosphatase level. Pathological examinations of the liver indicated that both intravenous and subcutaneous injections of Laennec inhibited the loss of cytoplasma and nuclei, vacuolation, swelling and necrosis in the centrizonal hepatocytes caused by CCl4. Intravenous and subcutaneous injection of Laennec also inhibited the increases of GOT and GPT levels in rats with chronic liver injury caused by CCl4, 0.5 ml/kg for 7 weeks. Both intravenous and subcutaneous injections of Laennec minimized the pathological changes of the liver by CCl4 such as vacuolation, necrosis and swelling of nuclei, but did not inhibit the formation of pseudolobules. Thus, no therapeutic difference was noted between intravenous and subcutaneous injections of Laennec.     

Effects of cianidanol on chronic liver injury induced by carbon tetrachloride and on liver regeneration after partial hepatectomy in rats

Effects of cianidanol on chronic liver injury induced by prolonged administration of carbon tetrachloride (CCl4) and on liver regeneration after partial hepatectomy of normal liver and CCl4 chronically injured liver were investigated by the measurement of plasma and liver biochemical parameters. Cianidanol increased the total plasma protein and 14C-Leu incorporation into plasma protein, while it reduced the contents of liver cholesterol and triglycerides. In rats with chronically injured liver or regenerating liver after partial hepatectomy of chronically injured liver, cianidanol improved the retention rate of BSP and the content of liver sugar. In rats with chronically injured liver, plasma GPT and GOT activities were reduced with the administration of cianidanol. Cianidanol had no effect on the regeneration rate after partial hepatectomy of normal liver, but it increased the regeneration rate after partial hepatectomy of chronically injured liver. These results suggest that cianidanol has the effect of improving the function of liver cells damaged by CCl4 treatment and of promoting the recovery of cell function to a normal level.     

Pachymic Acid Enhances Pentobarbital-Induced Sleeping Behaviors via GABAA-ergic Systems in Mice

This study was investigated to know whether pachymic acid (PA), one of the predominant triterpenoids in Poria cocos (Hoelen) has the sedative-hypnotic effects, and underlying mechanisms are mediated via γ-aminobutyric acid (GABA)-ergic systems. Oral administration of PA markedly suppressed locomotion activity in mice. This compound also prolonged sleeping time, and reduced sleep latency showing synergic effects with muscimol (0.2 mg/kg) in shortening sleep onset and enhancing sleep time induced by pentobarbital, both at the hypnotic (40 mg/kg) and sub-hypnotic (28 mg/kg) doses. Additionally, PA elevated intracellular chloride levels in hypothalamic primary cultured neuronal cells of rats. Moreover, Western blotting quantitative results showed that PA increased the amount of protein level expression of GAD_65/67 over a broader range of doses. PA increased α- and β-subunits protein levels, but decreased γ-subunit protein levels in GABA_A receptors. The present experiment provides evidence for the hypnotic effects as PA enhanced pentobarbital-induced sleeping behaviors via GABA_A-ergic mechanisms in rodents. Taken together, it is proposed that PA may be useful for the treatment of sleep disturbed subjects with insomnia.     

Anti-oxidant activities of<Emphasis Type="Italic">acanthopanax senticosus</Emphasis> stems and their lignan components

The antioxidant activities of Acanthopanax senticosus stems were evaluated in CCl4-intoxicated rats. The n-butanol fraction from the water extract of the stems, when pretreated orally at 200 mg/kg/day for 7 consecutive days in rats, was demonstrated to exhibit significant increases in antioxidant enzyme activities such as hepatic cytosolic superoxide dismutase, catalase and glutathione peroxidase by 30.31, 19.82 and 155%, respectively. The n-butanol fraction whereas showed a significant inhibition of serum GPT activity (65.79% inhibition) elevated with hepatic damage induced by CCl4-intoxication. Eleutheroside B, a lignan component, isolated from the n-butanol fraction was found to cause a moderate free radical scavenging effect on DPPH, its scavenging potency as indicated in IC50 value, being 58.5 microM. These results suggested that the stems of A. senticosus possess not only antioxidant but also hepatoprotective activities.     

银杏叶提取物对小鼠急性肝损伤保护作用的实验研究

目的：研究银杏叶提取物对四氯化碳致小鼠急性肝损伤的保护作用。方法：随机分为正常对照组、四氯化碳（CCl4）致肝损伤模型组和银杏叶提取物给药组,采用灌胃方式给药,观察银杏叶提取物对血清GPT、肝组织MDA和SOD活性的影响。结果：银杏叶提取物能够明显降低CCl4致急性肝损伤小鼠血清GPT、肝组织MDA含量（P〈0．01）,提高SOD活性（P〈0．05）。结论：银杏叶提取物对肝损伤具有保护作用。