藏红花对CCl_4致小鼠急性肝损伤的保护作用

目的探索藏红花对四氯化碳致小鼠肝损伤的保护作用。方法取昆明小鼠50只,雌雄各半,均分为五组。分别灌高剂量藏红花(50 mg/mL,30 mL/kg),低剂量藏红花(50 mg/mL,10 mL/kg),肝泰乐(20 mL/kg),生理盐水(20 mL/kg,四氯化碳组与空白对照组均灌生理盐水)1周,于最后1次给药1 h后,除空白对照组外其余各组均以0.1%CCl4花生油20 mL/kg灌胃。对5组小鼠血清ALT、AST、MDA和病理切片进行比较。结果藏红花能降低四氯化碳引起的ALT升高(P<0.05)、AST升高(P<0.05)、MDA升高(P<0.05);高剂量藏红花组、低剂量藏红花组、肝泰乐组及四氯化碳组在肝组织学改变上有明显差异。结论藏红花对四氯化碳所致肝损伤有一定的保护作用。

Protective Effect of Ascorbate-Lysine on Carbon Tetrachloride and Alcohol-Induced Liver Injury in Mice

As an essential amino acid, lysine boosts protein synthesis (Nestor et al1997). Yao et al demonstrated that, lysine also exerts protective effect against the isch-emiclesion of brain. Meanwhile, vitamin C is a natural antioxidant, which has undisputable protectiveaction against free radical damages. In order to ascertain whether their combination could affordbetter effect, we have investigated the prophylactic effect of the couplant ascorbate-lysine inliver injuries.

Hepatoprotective effect of manual acupuncture at acupoint GB34 against CCl_4-induced chronic liver damage in rats

AIM： To investigate the hepatoprotective effect of manual acupuncture at Yanglingquan （GB34） on CCl4-induced chronic liver damage in rats. METHODS： Rats were injected intraperitoneally with CCh （1 mL/kg） and treated with manual acupuncture using reinforcing manipulation techniques at left GB34 （Yanglingquan） 3 times a week for 10 wk. A nonacupoint in left gluteal area was selected as a sham point. To estimate the hepatoprotective effect of manual acupuncture at GB34, measurement of liver index, biochemical assays including serum ALT, AST, ALP and total cholesterol, histological analysis and blood cell counts were conducted. RESULTS： Manual acupuncture at GB34 reduced the liver index, serum ALT, AST, ALP and total cholesterol levels as compared with the control group and the sham acupuncture group. It also increased and normalized the populations of WBC and lymphocytes. CONCLUSION： Manual acupuncture with reinforcing manipulation techniques at left GB34 reduces liver toxicity, protects liver function and liver tissue, and normalizes immune activity in CCh-intoxicated rats.

Protective effect of estradiol on hepatocytic oxidative damage

AIM: To examine the protective effect of estradiol on the cultured hepatocytes under oxidative stress. METHODS: Hepatocytes of rat were isolated by using perfusion method, and oxidative stress was induced by a serum-free medium and FeNTA. MDA level was determined with TBA method. Cell damage was assessed by LDH assay. Apoptosis of hepatocytes was assessed with cytoflowmetric analysis. Expression of Bcl-xl in cultured hepatocytes was detected by Western blot. The radical-scavenging activity of estradiol was valued by its ability to scavenge the stable free radical of DDPH. RESULTS: Oxidative stress increased LDH from 168 +/- 25 x 10(-6)IU.cell(-1) to 780 +/- 62 x 10(-6)IU.cell(-1) and MDA(from 0.28 +/- 0.07 x 10(-6)nmol.cell(-1) to 1.35 +/- 0.12 x 10(-6)nmol.cell(-1)) levels in cultured hepatocyte, and estradiol inhibited both LDH and MDA production in a dose dependent manner. In the presence of estradiol 10(-6)mol.L(-1), 10( -7 )mol.L(-1) and 10(-8)mol.L(-1),the LDH levels are 410 +/- 53 x 10(-6)IU.cell(-1) (P【0.01 vs oxidative group), 530 +/- 37 X 10(-6)IU.cell(-1 ) (P【0.01 vs oxidative group), 687+/-42 x 10(-6)IU.cell(-1) (P【0.05 vs oxidative group) respectively, and the MDA level are 0.71+/-0.12 x 10(-6)nmol.cell(-1) (P【0.01 vs oxidative group),0.97+/-0.11 x 10(-6)nmol.cell(-1 )(P【0.01 vs oxidative group) and 1.27+/-0.19 x 10(-6)nmol.cell(-1) respectively. Estradiol suppressed apoptosis of hepatocytes induced by oxidative stress, administration of estradiol(10(-6)mol/L)decreased the apoptotic rate of hepatocytes under oxidative stress from 18.6 +/- 1.2% to 6.5 +/-2.5%, P【0.01. Bcl-xl expression was related to the degree of liver cell damage due to oxidative stress, and estradiol showed a protective action. CONCLUSION: Estradiol protects hepatocytes from oxidative damage by means of its antioxidant activity.

Protective effect of curcumin against liver warm ischemia/reperfusion injury in rat model is associated with regulation of heat shock protein and antioxidant enzymes

AIM： To investigate the hypothesis that the protective effects of curcumin in hepatic warm ischemia/reperfusion （I/R） injury are associated with increasing heat shock protein 70 （Hsp70） expression and antioxidant enzyme activity. METHODS： Sixty Sprague-Dawley male rats were randomly divided into sham, I/R, C ＋ I/R groups. The model of reduced-size liver warm ischemia and reperfusion was used. Curcumin （50 mg/kg） was administered by injection through a branch of superior mesenteric vein at 30 min before ischemia in C ＋ I/R group. Five rats were used to investigate the survival during 1 wk after operation in each group. Blood samples and liver tissues were obtained in the remaining animals after 3, 12, and 24 h of reperfusion to assess serum alanine aminotransferase （ALT）, aspartate aminotransferase （AST）, liver tissue NO2- ＋ NO3-, malondialdehyde （MDA） content, superoxide dismutase （SOD）, catalase （CAT）, nitricoxide synthase （NOS） and myeloperoxidase （MPO） activity, HspT0 expression and apoptosis ratio. RESULTS： Compared with I/R group, curcumin pretreatment group showed less ischemia/reperfusioninduced injury. CAT and SOD activity and Hsp70 expression increased significantly. A higher rate of apoptosis was observed in I/R group than in C ＋ I/R group, and a significant increase of MDA, NO2^- ＋ NO3^- and MPO level in liver tissues and serum transaminase concentration was also observed in I/R group compared to C ＋ I/R group. Curcumin also decreased the activity of inducible NO synthase （iNOS） in liver after reperfusion,but had no effect on the level of endothelial NO synthase （eNOS） after reperfusion in liver. The 7 d survival rate was significantly higher in C ＋ I/R group than in I/R group. CONCLUSION： Curcumin has protective effects against hepatic I/R injury. Its mechanism might be related to the overexpression of Hsp70 and antioxidant enzymes.

Protective effect of tea polyphenols against paracetamol-induced hepatotoxicity in mice is significanly correlated with cytochrome P450 suppression

AIM： To investigate the hepatoprotective activity of tea polyphenols （TP） and its relation with cytochrome P450 （CYP450） expression in mice. METHODS： Hepatic CYP450 and CYPbs levels were measured by UV-spectrophotometry in mice 2 d after intraperitoneal TP （25, 50 and 100 mg/kg per day）. Then the mice were intragastricly pre-treated with TP （100, 200 and 400 mg/kg per day） for six days before paracetamol （1000 mg/kg） was given. Their acute mortality was compared with that of control mice. The mice were pre-treated with TP （100, 200, and 400 mg/kg per day） for five days before paracetamol （500 mg/kg） was given. Hepatic CYP2E1 and CYPIA2 protein and mRNA expression levels were evaluated by Western blotting, immunohistochemical staining and transcriptase-polymerase chain reaction. RESULTS： The hepatic CYP450 and CYPb5 levels in mice of TP-treated groups （100, 200 and 400 mg/kg per day） were decreased in a dose-dependent manner compared with those in the negative control mice.TP significantly attenuated the paracetamol-induced hepatic injury and dramatically reduced the mortality of paracetamol-treated mice. Furthermore, TP reduced CYP2E1 and CYPIA2 expression at both protein and mRNA levels in a dose-dependent manner. CONCLUSION： TP possess potential hepatoprotective properties and can suppress CYP450 expression.

Protective Effects of Oyster Extract Against Hepatic Tissue Injury in Alcoholic Liver Diseases

Oyster extract is an effective bioactivity component. It has abundant nutritional value and antiviral, antitumor and im- mune defense fimctions. The role of oyster extract in treating liver injury has been paid more attention. We use Wistar rats to make alcoholic liver disease model through injecting alcohol into rats＇ stomachs. These rats were randomly divided into five groups： model group, control group, low-dose, middle-dose and high-dose experimental group with a dose of 0.12gkg-1, 0.40gkg-1, and 1.20gkg-1 alcoholic. After nine weeks, serum biomarkers （ALT, AST, TG and TCHO）, malondialdehyde （MDA）, glutathione （GSH）, C3a, CSa, IL-17, TNF-a, anti-MAA-HAS IgC~ CD3＋, CD4＋, CDS＋, NK cell activation and zinc content were assessed. The results showed that the serum biomarkers（ALT, AST, TG and TCHO）, MDA content, anti-MAA-HSA IgG, serum C3a, CSa IL-17 and TNF-a levels of oyster extract treatment groups were significantly decreased in comparison with model group. On the contrary, GSH showed ad- verse trend. Serum CD3＋, CD4＋ and NK cell activation were significantly increased in middle-dose group and high-dose group compared with model group, and there was decrease of CD8＋ activity in high-dose group. Plasma Zn level was decreased in model group compared with that in control group. Meanwhile, Mean plasma Zn levels increased dramatically following the dose increase of a given oyster extract.

Protective effects of 2,4-dihydroxybenzophenone against acetaminophen-induced hepatotoxicity in mice

AIM:To examine the effects of 2,4-dihydroxybenzophenone(BP-1),a benzophenone derivative used as an ultraviolet light absorbent,on acetaminophen(APAP)induced hepatotoxicity in C57BL/6J mice.METHODS:Mice were administered orally with BP-1 at doses of 200,400 and 800 mg/kg body weight respectively every morning for 4 d before a hepatotoxic dose of APAP(350 mg/kg body weight) was given subcutaneously.Twenty four hours after APAP intoxication,the serum enzyme including serum alaine aminotransferase(ALT),aspartate aminotransferase(AST),lactate dehydrogenase(LDH) were measured and liver histopathologic changes were examined.RESULTS:BP-1 administration dramatically reduced serum ALT,AST and LDH levels.Liver histopathological examination showed that BP-1 administration antagonized APAP-induced liver pathological damage in a dose-dependent manner.Further tests showed that APAP-induced hepatic lipid peroxidation was reduced significantly by BP-1 pretreatment,and glutathione depletion was ameliorated obviously.CONCLUSION:BP-1 can effectively protect C57BL/6J mice from APAP-induced hepatotoxicity,and reduction of oxidative stress might be part of the protection mechanism.

Protective effects of C-phycocyanin on alcohol-induced acute liver injury in mice

Excessive alcohol consumption leads to liver disease. Extensive evidence suggests that C-phycocyanin(C-PC), a chromophore phycocyanobilin derived from Spirulina platensis, exerts protective eff ects against chemical-induced organ damage. In this study, we investigated whether C-PC could protect against ethanol-induced acute liver injury. Serum alanine aminotransferase(ALT), aspartate aminotransferase(AST), triglyceride(TG), total cholesterol(CHOL), low-density lipoprotein(LDL), liver homogenate malondialdehyde(MDA), superoxide dismutase(SOD) content were measured, and pathological examination of liver sections were examined. C-PC showed obvious inhibitory eff ects on serum ALT, AST, TG, CHOL, LDL and MDA, and SOD content significantly increased in the liver. The structure of hepatic lobules was clear, liver sinus returned to normal, and liver cell cords were arranged in neat rows. Cloudiness, swelling, inflammatory cell infiltration and spotty necrosis of liver cells were significantly reduced. Therefore, C-PC can significantly protect against ethanol-induced acute liver injury.

Protective effect of ischemic preconditioning on liver

Objective:: To study the protective effect of ischemic preconditioning (IPC) on the hepatic ischemia-reperfusion injury. Methods: The model of rat liver subjected to ischemia/reperfusion (I/R) injury was made. All 24 mice were divided randomly into 3 groups and anesthetized by 2% sodium pentobarbital (30-40 mg/kg). The enzyme activity of AST, ALT, LDH, SOD and the content of LPO were assayed respectively. Specimens were observed under transmission electron microscope. Results: IPC prevented the increase of ALT, AST and LDH in the blood and that of LPO in the tissues (P< 0.05 ), and maintained high level of SOD in the tissues (P< 0.05 ). Conclusions: IPC has protective effect on the liver function.