Expression of epoxygenases belonging to CYP2 family in rat myocardial ischemia/reperfusion injury in vivo

To elucidate the expression of epoxygenases belonging to cytochrome P-450 mono-oxygenases [CYP2] family in rat ischemic myocardium at varying reperfusion periods, and the effect of epoxygenase inhibition on the post-ischemic heart. The current study was conducted in the Department of Pharmacology, Medical College of Wuhan University, China, between September 2004 and June 2005. Rats were subjected to 40 minutes of myocardial ischemia, followed by 0, 15, 60, and 180 minutes of reperfusion. Superoxide generation was assayed by confocal microscopy, CYP2B1/2, 2C6, 2E1, 2J3 gene expressions were determined by reverse transcriptase polymerase chain reaction. Fourteen, 15-dihydroxyeicosatrienoic acid [DHET] concentration was measured by enzyme-linked immunosorbent assay. The effects of the CYP epoxygenase inhibitor N-methylsulphonyl-6-[2-propargyloxyphenyl] hexanamide [MS-PPOH] on myocardial damage and superoxide generation caused by 60 minutes of reperfusion were also evaluated. During myocardial ischemia/reperfusion, CYP2C6 and 2J3 mRNA expression were up-regulated with the peak level at 15 minutes of reperfusion; CYP2E1 gene expression decreased in a time dependent manner and reached the minimum level at 180 minutes of post-ischemia. Meanwhile, no obvious variations of CYP2B1/2 gene expression were detected during different reperfusion periods. Fourteen, 15-DHET significantly increased during reperfusion in ischemic hearts. The MS-PPOH pretreatment [15 mg/kg] effectively reduced myocardial damage and superoxide production. There are changes in gene expression of individual isozymes and an elevation of CYP epoxygenase activity involved in myocardial reperfusion injury in vivo. Epoxygenase inhibition plays a protective role in cardiac post-ischemic damage

Fast evaluation of oxidative DNA damage by liquid chromatography-electrospray tandem mass spectrometry coupled with precision-cut rat liver slices / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To establish a fast and sensitive method for the detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in precision-cut rat liver slices by HPLC-MS/MS and to investigate isoniazid (INH) -induced oxidative DNA damage.</p><p><b>METHODS</b>Precision-cut liver slices (300 microm) were prepared from male rats, and incubated with INH (0.018 mol/L) for 2 h after 1 h preincubation. DNA in the slices was extracted and digested into free nucleosides at 37 degrees C. The samples were injected into HPLC-MS/MS after the proteins were removed. The level of oxidative DNA damage was estimated using the ratio of 8-OHdG to deoxyguanosine (dG).</p><p><b>RESULTS</b>The limit of detection of 8-OHdG was 1 ng/mL (S/N=3) and the intra-assay relative standard variation was 3.38% when one transition 284.3/168.4 was used as a quantifier and another two transitions 284.3/140.2, 306.1/190.2 as qualifiers. 8-OHdG and dG were well separated, as indicated by elution at 10.02 and 7.37 min, respectively. INH significantly increased the ratio of 8-OHdG to dG in rat liver slices (P<0.05).</p><p><b>CONCLUSION</b>8-OHdG in precision-cut liver slices could be sensitively determined by HPLC-MS/MS. HPLC-MS/MS coupled with precision-cut tissue slices is a fast and reliable analytical technique to evaluate oxidative DNA damage of target tissues caused by procarcinogens and cytotoxins.</p>

Activation of the immunologic function of rat Kupffer cells by the polysaccharides of Angelica sinensis / 药学学报

<p><b>AIM</b>To observe the influence of polysaccharides of Angelica sinensis (ASP) on the immunologic function of rat Kupffer cells.</p><p><b>METHODS</b>Normal rat Kupffer cells were treated with ASP in vitro. Absorbance at 540 nm ( A540) of neutral red absorption and supernatant NO, TNF-alpha in the cells were measured to evaluate the immunologic function of Kupffer cells; LDH leakage was measured to estimate the severity of cellular damage; Rats were given ASP 0.025, 0.1, 0.25 and 1.0 g x kg(-1) ig (qd x 7 d) in vivo. The above indices and ACP of Kupffer cells were measured, sGST and sALT activity were detected as indices of hepatotoxicity.</p><p><b>RESULTS</b>ASP markedly enhanced the phagocytic activity, ACP and supernatant NO, TNF-alpha of Kupffer cells both in vitro and in vivo . The increase of sGST was observed after administration of ASP 1.0 g x kg(-1), but the LDH leakage of the hepatocytes was not increased in vitro.</p><p><b>CONCLUSION</b>ASP with suitable dose could activate the function of Kupffer cells. Slight liver injury was caused by ASP 1.0 g x kg(-1) in vivo, which was likely caused by factors, such as NO, TNF-alpha, indirectly.</p>

Antagonistic effect of sodium ferulate on glycerol-induced renal oxidative injury in mice / 药学学报

<p><b>AIM</b>To investigate the effect of sodium ferulate (SF) on glycerol-induced renal injury.</p><p><b>METHODS</b>Glycerol solution 50% was injected intramuscularly to establish a model of acute tubular necrosis in mice. SF was administered intraperitoneally at the dose of 100-200 mg.kg-1 at the beginning of establishing the model and its effect was observed by monitoring renal function, antioxidative functions and renal pathologic histology.</p><p><b>RESULTS</b>At 6 and 72 h after glycerol injection, SF treatment (100-200 mg.kg-1) showed significant and dose-dependent antagonistic actions on the increment of blood urea nitrogen (BUN), creatinine (Cr), and N-acetyl-beta-glucosaminidase (NAG) induced by glycerol. The increase of renal malondialdehyde (MDA) content and the decrease of glutathione content, glutathione peroxidase (GSH-Px), glutathione S-transferase (GST), catalase (Cat) and superoxide dismutase (SOD) activities resulting from glycerol injection were remarkably inversed by SF at the dose of 200 mg.kg-1. Meanwhile, improvement of the renal histology was observed as well.</p><p><b>CONCLUSION</b>SF showed beneficial effect on glycerol-induced acute tubular necrosis due to its antioxidative action.</p>

The effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice / 中国中药杂志

<p><b>OBJECTIVE</b>To observe the effects of silymarin on hepatic microsomal and mitochondrial membrane fluidity in mice.</p><p><b>METHOD</b>Liver microsomal and mitochondrial membranes were labled by ANS and DPH. Membrane fluorensent intensity (F), fluorensent polarization(P) and microviscosily(eta) of liver microsome and mitochondria were determined.</p><p><b>RESULT</b>Sil increased the external membrane fluidities of liver microsome and mitochondria, and decreased the internal membrane fluidities of liver microsome and mitochondria. Pretreatment with CCl4, the external membrane fluidity of liver microsome and mitochondria were increased, and the internal membrane fluidities of liver microsome and mitochondria were decreased. After given sil 140,280 mg.kg-1, the increased external membrane fluidities of liver microsome and mitochondria were lowered, and the decreased internal membrane fluidities of liver microsome and mitochondria were enhanced in a dose-dependent manner.</p><p><b>CONCLUSION</b>The protective effects of sil on liver injury may be related to the recovery of the membrane fluidities of liver microsome and mitochondria.</p>

Effects of Angelica sinensis polysaccharides on hepatic drug metabolism enzymes activities in mice / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of Angelica sinensis Polysaccharides (ASP) on the hepatic drug metabolism enzymes activities in normal mice and those prednisolone (PSL)-induced liver injury.</p><p><b>METHOD</b>The activities of phase II enzymes (GSH-related enzymes) and cytochrome P450 enzymes were measured by biochemical method.</p><p><b>RESULT</b>ASP increased the activities of glutathione S-transferase in liver microsomes and mitochondria. The cytochrome P450 content, NADPH-cytochrome c reductase, aminopyrine N-demethylase, and aniline hydroxylase activities in liver microsomes were also increased. PSL significantly increased serum ALT levels, and decreased the liver mitochondrial glutathione content. At the same time, other enzymes activities were all increased. When mice were treated with ASP 2.0 g.kg-1, the PSL-induced changes on cytochrome P450 enzymes, glutathione S-transferase, and GSH content were restored.</p><p><b>CONCLUSION</b>ASP can modulate the activities of drug metabolism enzymes.</p>