Mechanism of the stationary canalicular excretion of tributylmethyl ammonium in rats with a CCl4-induced acute hepatic injury

The in vivo canalicular excretion clearance of tributylmethyl ammonium (TBuMA), a P-glycoprotein (P-gp) substrate, was previously reported to be unaffected by the induction of an experimental hepatic injury (EHI) by CCl(4) despite the increased expression of P-gp in the EHI liver. The objective of this study, therefore, was to elucidate the mechanism for the unchanged canalicular excretion clearance of TBuMA in EHI rats. TBuMA uptake was increased in cLPM vesicles from EHI rats compared with that from control rats. The total bile salt concentration in EHI liver was significantly reduced compared with that in a control liver. Because, in our previous studies, the uptake of TBuMA by cLPM vesicles was found to be significantly enhanced in the presence of bile salts, the reduction in bile salt levels in the EHI liver may be related to the unaltered TBuMA clearance. Despite the fact that the uptake of TBuMA by cLPM vesicles was increased by the addition of an EHI liver extract, the extent of the increase was comparatively less compared to the addition of a control liver extract. The in vivo excretion clearance of TBuMA was increased in a taurodeoxycholate dose-dependent manner in EHI rats. These observations suggest, therefore, that despite the induction of P-gp expression by the EHI, the in vivo canalicular excretion clearance of TBuMA remains unaltered as the result of an offset by reduced levels of bile salt(s).     

Protective effect of diphenylmethyl selenocyanate against CCl4-induced hepatic injury

Organoselenocyanates represent an important class of chemopreventive agent, which possess antioxidative, antimutagenic as well as cancer chemopreventive properties. The present study is an attempt to evaluate the protective effect of diphenylmethyl selenocyanate -- a synthetic organoselenocyanate against carbon tetrachloride (CCl(4))-induced hepatic damage in Swiss albino mice in vivo.Mice were pretreated with the Se-compound orally in a duration dependent manner (7 and 15 days) to observe its protective action against an acute toxic dose (24 h) of CCl(4) (single injection at a dose of 20 microl and 50 microl kg(-1) b.w.) that induced hepatic necrosis and caused DNA damage (strand breaks) in the hepatocytes.This study revealed that pretreatment with the Se-compound reduced the extent of massive hepatic necrosis in a duration dependent manner, but it had no modulatory effect on hepatocellular apoptosis caused by acute toxic doses of CCl(4). It was also found that the Se-compound could significantly (P < 0.01) prevent the CCl(4)-induced elevation of DNA damage in hepatocytes measured by comet assay in a duration dependent manner.So these findings will further strengthen the view that organoselenocyanate is an effective chemopreventive agent against acute hepatic damage, caused by halogenated alkanes such as CCl(4).     

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.     

丹参粉针剂对四氯化碳致大鼠慢性肝纤维化的保护作用

目的:探讨丹参粉针剂对四氯化碳(CCl_4)致大鼠慢性肝纤维化的保护作用。方法:SD大鼠随机分为正常组、模型组、阳性对照组(葡醛内酯注射液26．5 mg·kg~(-1))和丹参粉针剂低、中、高剂量组(100,250, 500 mg·kg~(-1)),除正常组外的其余各组动物先在饮水中加入350 mg·L~(-1)的苯巴比妥诱导2周,然后腹腔注射CCl_4 0．04 mL·kg~(-1)建立慢性肝纤维化模型,每周1次,共注射8周。于注射CCl_4第5周时,各组分别腹腔注射生理氯化钠溶液或相应剂量的药物,在给药2,4,6周后测定血清中谷丙转氨酶(ALT)、谷草转氨酶(AST)活性和前胶原肽(PIIIP)、层黏连蛋白(LN)、透明质酸(HA)的含量。结果:丹参粉针剂低、中、高剂量组和阳性对照组大鼠血清中ALT,AST活性和PIIIP,LN,HA含量均比模型组明显降低(P＜0．01～P＜0．05)。结论:丹参粉针剂对CCl_4致大鼠慢性肝纤维化具有保护作用。     

Protective effect of Indigofera aspalathoides against CCl4-induced hepatic damage in rats

The alcoholic extract of stem of Indigofera aspalathoides was evaluated for its antihepatotoxic activity against CCl(4)-induced hepatic damage in rats. The activity was evaluated by using biochemical parameters, such as serum glutamate pyruvate transaminase (SGPT), serum glutamate oxaloacetate transaminase (SGOT), alkaline phosphatase (ALP), total bilirubin and gama glutamate transpeptidase (GGTP). The histopathological changes of liver sample were compared with respective control. The extract showed remarkable hepatoprotective effect.     

Agaricus blazei Murill extract abrogates CCl4-induced liver injury in rats

Agaricus blazei Murill (ABM) is enriched with polysaccharides, lipids, vitamins, fibers and minerals. Many studies have shown that ABM possesses immune-enhancing and anti-tumor effects. However, little is known about its protective effects on liver function. We employed carbon tetrachloride (CCl(4)) to induce hepatic fibrosis in a rat model to examine the protective effects of ABM on the liver in this study. The experiments included non-treatment control, CCl(4)-only control, and treatment with 200 mg and 2,000 mg of ABM extracts (per kilogram rat weight). All groups other than the non-treatment control were treated with intraperitoneal injections of CCl(4) twice a week. Experimental and control rats were tube-fed with experimental ABM extracts or double-distilled water, respectively, on the remaining four days each week. The whole experimental protocol lasted 8 weeks; blood and liver samples were collected for biochemical and tissue histochemical analysis. Plasma alanine aminotransferase and aspartate aminotransferase, and the activities of the anti-oxidative enzymes glutathione peroxidase, superoxide dismutase and catalase in the liver were measured. We found that high-dose ABM treatment reduced hepatic necrosis and fibrosis caused by CCl(4) in comparison with the CCl(4) control group. ALT and AST activities in the sera collected from ABM-treated rats were lower than those in the CCl(4) control rats. These results suggested that ABM extract was capable of either enhancing liver recovering from CCl(4) damage or attenuating CCl(4) toxicity. Results of anti-oxidative enzyme activity analysis showed no apparent differences among ABM-treated groups and CCl(4) control groups, indicating that removal of free radicals does not explain the protective/recovery effects observed in this study.     

Prophylactic effect of tritoqualine (TRQ) on the CCl4-induced chronic liver injury model in rats

Tritoqualine (TRQ) administered at doses of 100 or 200 mg/kg, perorally, had a preventive effect on the liver injury in rats induced by the treatment with CCl4 for 12 weeks consecutively. Rats subjected to this chronic treatment with CCl4 showed a decrease in body weight gain and changes in several serum parameters that are indicators of hepatic function were observed: the increase of transaminases, as a parameter of hepatocyte breakdown; the increase of alkaline phosphatase, as a parameter of biliary system abnormalities, the reduction of prothrombin time, as a marker of protein biosynthesis in the liver; and the change of lipids concentrations, reflecting liver injury. After the administration of TRQ perorally, there was a notable suppression of the increment in leaked enzymes in the serum and a marked improvement of the parameters concerning protein biosynthesis and lipid metabolism in comparison with CCl4 control rats. Marked fibrosis in the liver was observed after CCl4 treatment for 12 weeks, and the collagen content in the liver was 5 times higher than that of control rats. TRQ suppressed the increment in collagen formation and also showed improvement of the decrease of the liver function with regards to protein biosynthesis in CCl4-treated rats. Judging from these results, it was concluded that TRQ had a remarkable protecting action on the liver injury chronically induced by CCl4 treatment and was a effective compound for restoring liver function.     

Ameliorative action of cyanobacterial phycoerythrin on CCl(4)-induced toxicity in rats

Carbon tetrachloride (CCl₄) is largely used as solvent in chemical industries. Carbon tetrachloride is also well known for hepatic and renal toxic actions. The in vivo metabolism of carbon tetrachloride to trichloromethyl (CCl₃) and peroxy trichloromethyl (OOCCl₃) radicals has been extensively reported to cause acute liver damage like cirrhosis, steatosis and necrosis. We have evaluated protective action of purified cyanobacterial phycoerythrin (C-PE) on carbon tetrachloride-induced hepatic and renal toxicity in male rats. Rats were orally treated with 25 and 50 mg/kg BW of C-PE along with CCl₄ (50% CCl₄, 0.5 ml/kg BW, intraperitoneally) for 28 consecutive days. Results demonstrated that C-PE dose-responsively ameliorates CCl₄-toxicity by significantly decreasing (P < 0.05) organs weight, aminotransferases, alkaline phosphatase, glucose, lipid profile, creatinine, uric acid and malondialdehyde (MDA) concentrations with rise in body weight, food intake, hemoglobin, protein, bilirubin and FRAP values. Neither C-PE nor CCl₄ influenced on serum minerals. Hepatic and renal tissues showed significant decline (P < 0.05) in malondialdehyde, lipid hydroperoxides and conjugated dienes with rise in SOD, catalase, GPx, GSH, vitamin-E and vitamin-C levels. Presently observed pharmacological effect on CCl₄ toxicity were from tetrapyrrole molecule and to some extent bilirubin biotransformations, as well as metabolic (dietary protein) actions of C-PE.     

夏枯草硫酸多糖对四氯化碳致大鼠肝纤维化的干预作用

摘要： 目的 探讨夏枯草硫酸多糖 （PVSP） 对四氯化碳 （CCl4 ） 致大鼠纤维化的干预作用。方法 采用 CCl4-橄榄油腹腔注射诱导建立 SD 大鼠肝纤维化模型, 将造模成功的大鼠随机分成 3 组, 每组 10 只, 分别为模型组 （Model 组）、 PVSP 高剂量组 （PVSP-H 组： 400 mg/kg） 和 PVSP 低剂量组 （PVSP-L 组： 100 mg/kg）。并设空白对照组 （Blank 组） 和溶剂对照组 （Solvent 组）。采用全自动生化分析仪测定血清丙氨酸转氨酶 （ALT） 和天冬氨酸转氨酶 （AST） 的含量, HE 和天狼猩红染色比较炎症及肝纤维化程度; 采用 qRT-PCR 和免疫组织化学分析肝组织中Ⅰ型胶原 （Col- Ⅰ）、 平滑肌肌动蛋白 （α-SMA） mRNA 和蛋白的表达量。结果 Solvent 组大鼠血清中 ALT、 AST 及肝组织中 Col-Ⅰ、 α-SMA mRNA 和蛋白与 Blank 组相比差异均无统计学意义; 与 Model 组相比, PVSP 能显著降低血清 ALT 和 AST （P＜0.05）; HE 和天狼猩红染色结果显示 PVSP 能减轻炎症及纤维化程度; qRT-PCR 和免疫组织化学结果显示 PVSP 明显降低大鼠肝脏内 Col-Ⅰ、 α-SMA mRNA 和蛋白表达 （P＜0.05）。结论 PVSP 具有减轻大鼠肝纤维化作用, 其机制可能与抑制Col-Ⅰ、 α-SMA 表达, 减少细胞外基质的生成并促进细胞外基质的降解有关。     

Hepatoprotective effect of Arazyme on CCl4-induced acute hepatic injury in SMP30 knock-out mice

Arazyme is a novel protease produced by the HY-3 strain of Aranicola proteolyticus, which is a Gram-negative aerobic bacterium that has been isolated from the intestine of the spider Nephila clavata. This study focused on the hepatoprotective effect of Arazyme on carbon tetrachloride (CCl4)-induced acute hepatic injury in senescence marker protein 30 (SMP30) knock-out (KO) mice and SMP30 wild-type (WT) mice. WT mice and SMP30 KO mice were divided into eight groups as follows: (i) two negative control groups (G1, G5) which were treated with a single intraperitoneal (i.p.) olive oil injection. (ii) Two positive control groups (G2, G6) which received a single i.p. CCl4 (0.4mL/kg) injection. (iii) Two vitamin C-treated groups (G3, G7) which received a single oral administration of vitamin C (100mg/kg) and were injected with a single i.p. CCl4 (0.4mL/kg). (iv) Two Arazyme-treated groups (G4, G8) which received a single oral administration of Arazyme (500mg/kg) and were injected with a single i.p. CCl4 (0.4mL/kg). Through present study, we could find that Arazyme-treated groups showed decreased degree of liver injury, increased expression of SMP30, decreased expression of phospho-Smad3 (p-Smad3), elevated expression of antioxidant proteins including sorbitol dehydrogenase, dihydropteridine reductase (DHPR), dehydrofolate reductase (DHFR), NADH dehydrogenase, glutathione S-transferase kappa 1 (GSTK1) and phospholipid hydroperoxide glutathione peroxidase (PHGPx) compared with non-Arazyme-treated groups. Therefore, it is concluded that Arazyme plays a significant role in protecting injured hepatocytes by increasing the expression of SMP30, inhibiting the transforming growth factor-beta (TGF-beta)/Smad pathway and elevating the expression of antioxidant proteins.     

Hepatoprotection by Elephantopus scaber Linn. in CCl4-induced liver injury

The efficacy of the medicinal plant Elephantopus scaber Linn. (Asteraceae), to prevent carbon teterachloride (CCI4)-induced chronic liver dysfunction in the rats was examined by determining different biochemical markers in serum and tissues. In serum, liver function marker enzymes like aspartate aminotrasferase (AST), alanine aminotrasferase (ALT), alkaline phosphatase (ALP) and also protein were evaluated. The concentrations of total lipid, cholesterol and phospholipids were studied in serum and the different tissues. The concentration of serum triglycerides was also studied. The biochemical changes induced by CCI4 in different tissues particularly in the liver tissue improved following treatment with E. scaber Linn. The results suggest the hepatoprotective effect of this medicinal plant.     

Effect of dried fruits of Solanum nigrum LINN against CCl4-induced hepatic damage in rats

Ethanol extract of Solanum nigrum LINN was investigated for its hepatoprotective activity against CCl4-induced hepatic damage in rats. The ethanol extract showed remarkable hepatoprotective activity. The activity was evaluated using biochemical parameters such as serum aspartate amino transferase (AST), alanine amino transferase (ALT), alkaline phosphatase (ALP) and total bilirubin. The histopathological changes of liver sample in treated animals were compared with respect to control.     

Use of canalicular membrane vesicles (CMVs) from rats, dogs, monkeys and humans to assess drug transport across the canalicular membrane

INTRODUCTION: A novel application of a Ultrafree filter cartridge/centrifugation method was evaluated to determine uptake in canalicular membrane vesicles (CMVs) from SD rats, beagle dogs, cynomolgus monkeys (common safety species in the pharmaceutical industry) and humans to assess biliary transport. METHODS: CMVs prepared from fresh livers of rats, dogs, monkeys and humans (four donors) were characterized for enrichment, basolateral and Golgi contamination and orientation. The presence of MRP2 and p-glycoprotein (P-gp) were confirmed by Western blots. Uptake of [3H]-leukotriene C4 (LTC4) and [3H]-estradiol-17beta-d-glucuronide (E2-Gluc) was determined at a low substrate concentration and/or by kinetic measurements (K(m) and V(max)). Correlation of in vitro data with in vivo findings was achieved by determining the biliary clearance of E2-Gluc in rats after a single i.v. dose and with literature in vivo data for LTC4. RESULTS:CMVs were highly enriched and minimally contaminated based on marker enzyme activities. Uptake clearance among different species varied by approximately ten-fold (rat > dog = human > monkey) for LTC4 and less than two-fold for E2-Gluc. The lower uptake of LTC4 by human than rat CMVs may be attributed to a higher Km value for human than rat CMVs. Uptake of LTC4 or E2-Gluc by human CMVs showed little inter-subject variability (2-5-fold). Differences in in vitro uptake clearance (10-fold) between LTC4 and E2-Gluc in rat CMVs seemed to correlate with differences in their biliary clearance (4-fold) in rats, consistent with LTC4 and E2-Gluc being a high and a low clearance substrate, respectively. DISCUSSION: A novel application of a Ultrafree filter cartridge/centrifugation method was developed to determine uptake in CMVs from different preclinical animal safety species and humans, and may represent a useful approach to study the mechanism of biliary excretion during drug discovery and development.     

Methyl palmitate prevents CCl(4)-induced liver fibrosis

Liver fibrosis is characterized by an excess of collagen fiber deposition, and it is known that Kupffer cells play an important role by immunomodulation of the toxic response. Methyl palmitate (MP) is an effective Kupffer cell inhibitor. The aim of this work was to evaluate the effect of MP on experimental liver fibrosis. Four groups were formed: the control group, which received the vehicles only; CCl(4) group (0.4 g kg(-1), i.p., three times a week, for eight weeks); CCl(4) plus MP (300 mg kg(-1), i.p., daily); and MP alone. Alanine aminotransferase was increased by CCl(4), and MP did not prevent this increase. Lipid peroxidation was increased markedly by CCl(4); again, MP was not able to prevent this effect. Fibrosis increased nearly 6-fold (measured as liver hydroxyproline content) in the CCl(4) group; MP preserved the normal content of collagen. These results were corroborated by histopathology. To elucidate the antifibrogenic mechanism of MP, we measured the production of TGF-beta; CCl(4) increased this cytokine several-fold, and MP abolished this increase. Collectively the present results indicate that MP possesses a strong antifibrogenic effect at least in the CCl(4) model of fibrosis. The antifibrotic effect of MP is probably associated with its ability to reduce TGF-beta content, maybe by immunomodulation of Kupffer cells functioning.     

An epoxysuccinic acid derivative(loxistatin)-induced hepatic injury in rats and hamsters

Loxistatin is a possible therapeutic agent of muscular dystrophy. A single oral administration of loxistatin to male rats caused focal necrosis of the liver with inflammatory cell infiltration. The severity of the lesions was dose-dependent up to 200 mg/kg and also manifest by an increase in serum alanine aminotransferase and aspartate aminotransferase activities. Hepatic glutathione (GSH) levels decreased with a maximum 20% depletion within 5 hr after the oral administration of loxistatin. Pretreatment with diethyl maleate did not potentiate the loxistatin-induced hepatic injury. On the other hand, the hepatoprotective effect of cysteamine was observed when cysteamine was administered 24 hr before loxistatin dosing, but the effect was not observed when the antidote was administered concomitantly with loxistatin. Pretreatment of rats with phenobarbital or trans-stilbene oxide provided partial protection against the hepatotoxic effect of loxistatin. Pretreatment with SKF-525A resulted in increased hepatic injury, while pretreatment with piperonyl butoxide, cimetidine, or 3-methylcholanthrene had no effect on hepatic damage by loxistatin. Five hours after [14C]loxistatin administration to rats, the covalent binding of the radioactivity to proteins was greatest in the liver, followed by the kidney, then muscle and blood to a lesser extent. [14C]Loxistatin acid, the pharmacologically active form of loxistatin, irreversibly bound to rat liver microsomal proteins; more binding occurred when the NADPH-generating system was omitted and when the microsomes were boiled first. GSH did not alter the extent of irreversible binding, whereas N-ethylmaleimide decreased the binding of [14C]loxistatin acid to rat liver microsomal proteins by 75%. Unlike the rat, administration of loxistatin to hamsters caused neither hepatic injury nor hepatic GSH depletion even at a high dose (500 mg/kg). Both the distribution and covalent binding of radioactivity in the hamster liver were one-third of those in rats following [14C]loxistatin dosing. These results suggest that loxistatin causes species-specific hepatotoxicity and that, at least in part, some of the toxic effects of loxistatin are mediated by the nonenzymatic covalent binding of loxistatin acid to thiol residues on cellular macromolecules.     

软肝片抗肝纤维化作用的实验研究

目的探讨软肝片对四氯化碳中毒性肝纤维化的防治作用。方法用四氯化碳皮下注射造成大鼠肝纤维化模型 ,以联苯双酯作为阳性对照 ,测定血清丙氨酸氨基转移酶 (ALT)、天冬氨酸氨基转移酶 (AST)、玻璃酸(HA)、唾液酸及肝组织羟脯氨酸 (Hyp)、丙二醛 (MDA)、超氧化物歧化酶 (SOD)含量 ,以反映肝细胞损伤及肝纤维化程度。结果软肝片可明显降低肝纤维化大鼠血清ALT、AST、HA、唾液酸水平及肝组织Hyp和MDA水平 ,提高肝组织中SOD活力。结论软肝片具有一定的抗肝纤维化及抗脂质过氧化作用。     

Drinking of Salvia officinalis tea increases CCl(4)-induced hepatotoxicity in mice.

In a previous study, the drinking of a Salvia officinalis tea (prepared as an infusion) for 14 days improved liver antioxidant status in mice and rats where, among other factors, an enhancement of glutathione-S-transferase (GST) activity was observed. Taking in consideration these effects, in the present study the potential protective effects of sage tea drinking against a situation of hepatotoxicity due to free radical formation, such as that caused by carbon tetrachloride (CCl(4)), were evaluated in mice of both genders. Contrary to what was expected, sage tea drinking significantly increased the CCl(4)-induced liver injury, as seen by increased plasma transaminase levels and histology liver damage. In accordance with the previous study, sage tea drinking enhanced significantly GST activity. Additionally, glutathione peroxidase was also significantly increased by sage tea drinking. Since CCl(4) toxicity results from its bioactivation mainly by cytochrome P450 (CYP) 2E1, the expression level of this protein was measured by Western Blot. An increase in CYP 2E1 protein was observed which may explain, at least in part, the potentiation of CCl(4)-induced hepatotoxicity conferred by sage tea drinking. The CCl(4)-induced hepatotoxicity was higher in females than males. In conclusion, our results indicate that, although sage tea did not have toxic effects of its own, herb-drug interactions are possible and may affect the efficacy and safety of concurrent medical therapy with drugs that are metabolized by phase I enzymes.     

Antioxidant and hepatoprotective effects of Solanum xanthocarpum leaf extracts against CCl4-induced liver injury in rats

Context: Solanum xanthocarpum Schard. and Wendl. (Solanaceae) has been used in traditional Indian medicines for its antioxidant, anti-inflammatory, and antiasthmatic properties.

Objective: The present study demonstrates the antioxidant and hepatoprotective effects of S. xanthocarpum. On the basis of in vitro antioxidant properties, the active fraction from column chromatography of the methanol extract of S. xanthocarpum leaves (SXAF) was chosen as the potent fraction and used for hepatoprotective studies in rats.

Materials and methods: The antioxidant activity was evaluated by 2,2′-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS), 2,2-diphenyl-1-picrylhydrazyl (DPPH), and reducing power assays. Rats were pre-treated with 100 and 200?mg/kg b.w. of SXAF for 14?d with a single dose of CCl₄ in the last day. Hepatoprotective properties were determined by serum biochemical enzymes, aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP), lactate dehydrogenase (LDH), antioxidant enzymes (SOD, CAT, GSH, and GST), and histopathology studies.

Results: SXAF exhibited significant antioxidant activity in scavenging free radicals with IC₅₀ values of 11.72?µg (DPPH) and 17.99?µg (ABTS). Rats pre-treated with SXAF demonstrated significantly reduced levels of serum LDH (1.7-fold), ALP (1.6-fold), and AST (1.8-fold). Similarly, multiple dose SXAF administration at 200?mg/kg b.w. demonstrated significantly enhanced levels of SOD (1.78?±?0.13), CAT (34.63?±?1.98), GST (231.64?±?14.28), and GSH (8.23?±?0.48) in liver homogenates. Histopathological examination showed lowered liver damage in SXAF-treated groups.

Discussion and conclusion: These results demonstrate that SXAF possesses potent antioxidant properties as well as hepatoprotective effects against CCl₄-induced hepatotoxicity.     

Prevention by silymarin of membrane alterations in acute CCl4 liver damage

The effect of silymarin on liver lipid peroxidation and membrane lipid alterations induced by an acute dose of CCl4 was studied. Four groups of animals were treated with CCl4, CCl4 + silymarin, silymarin and its vehicles. CCl4 was given orally (0.4 g 100 g-1 body wt.) and silymarin was administered i.p. All animals were sacrificed 24 h after the treatments. Liver lipid peroxidation was measured and plasma membranes were isolated. Alkaline phosphatase (AP) and gamma-glutamyl transpeptidase (GGTP) were measured in plasma membranes. Membrane lipids were extracted and then analysed by thin-layer chromatography by measuring the phosphorus of the phospholipids in each spot. Liver lipid peroxidation was increased about three times in the group receiving CCl4 only. Silymarin cotreatment prevented this increase. Phosphatidylethanolamine (PEA) decreased, while phosphatidylinositol (PI) increased in the plasma membranes isolated from the CCl4-treated group. Animals that received CCl4 + silymarin showed no decrease in PEA content. A partial prevention of the decrease in phosphatidylinositol content was also observed in plasma membranes of animals treated with silymarin in addition to CCl4. CCl4 decreased gamma-glutamyl transpeptidase (GGTP) and alkaline phosphatase (AP) membrane activities. Silymarin cotreatment prevented the AP (completely) and the GGTP (partially) falls caused by CCl4. Silymarin by itself increased AP membrane activity. A significant relationship between the membrane content of phosphatidylethanolamine (PEA) and the AP activity was observed in plasma membranes of treated animals and in normal liver membranes enriched with PEA. These results indicate that silymarin can protect against the alterations induced by CCl4 on the liver plasma membrane through its antioxidant properties by modifying the plasma membrane phospholipid content.