海参磷脂型EPA对血清及肝脏脂肪酸组成的改善作用

目的 本文研究了海参磷脂型EPA(Eicosapntemacnioc acid-enriched phosphatidylcholine from sea cucumber,EPA-PC) 对非酒精性脂肪肝(Nonalcoholic fatty live disease, NAFLD)大鼠血清和肝脏脂肪酸组成的改善作用。方法 以NAFLD大鼠为模型,灌胃EPA-PC 4w,检测血清中和肝脏中脂质水平及脂肪酸组成。结果 EPA-PC显著降低模型大鼠血清和肝脏总脂中甘油三酯(Triglyceride,TG)和总胆固醇(Total cholesterol,TC)水平,显著升高血清高密度脂蛋白(High density lipoprotein cholesterol,HDLC)/TC水平;显著升高血清和肝脏中多不饱和脂肪酸(Polyunsaturated fatty acids,PUFA)的比例,降低n6/n3PUFA比例,升高DHA比例,降低肝脏总脂和磷脂去饱和C18：1/C18：0指数的比例,改善脂肪酸组成。结论 EPA-PC可以使血清和肝脏脂质水平下降,改变血清和肝脏脂肪酸组成,使NAFLD大鼠脂质水平紊乱状态得到改进。     

三化汤对缺血性中风模型大鼠血清脂肪酸谱的影响

目的:观察三化汤对缺血性中风模型大鼠血清脂肪酸谱的影响.方法:采用线栓法建立大鼠大脑中动脉阻塞模型(MCAO模型),随机分为模型组、干预组,每组10只.另设正常组、假手术组,每组各10只.正常组、假手术组、模型组灌胃纯净水,干预组灌胃三化汤水煎液,连续给药10 d.10 d后处死大鼠,取血清样本,采用气相色谱-质谱联用...     

Evaluation of hepatoprotective efficacy of Majoon‐e‐Dabeed‐ul‐ward against acetaminophen‐induced liver damage: A Unani herbal formulation

A Unani herbal formulation known as Majoon‐e‐Dabeed‐ul‐ward (MD) was evaluated for hepatoprotective effect against acetaminophen (APAP; 2 g/kg p.o.)‐induced liver damage. The latter was evidenced by elevated levels of aspartate transaminase (AST), alanine transaminase (ALT), serum alkaline transaminase (SALP), lactate dehydrogenase (LDH), bilirubin, albumin, urea, and creatinine in experimental animals. Increased levels of lipid peroxidation were associated with a concomitant decline in reduced glutathione levels, adenosine triphosphatase (ATPase), and glucose‐6‐phosphatase (G‐6‐Pase) caused by APAP treatment. Treatment with MD (250,500, and 1,000 mg/kg p.o.) reverse the altered levels of AST, ALT, SALP, LDH, bilirubin, albumin, urea, and creatinine in a dose‐dependent manner. Significant restoration was found in LPO, GSH content and metabolic enzymes (ATPase and G‐6‐pase) were seen after therapy. The herbal formulation, MD showed hepatoprotective efficacy against APAP‐induced liver damage. Drug Dev Res 72: 346–352, 2011. © 2010 Wiley‐Liss, Inc.     

GC‐MS‐based metabolomics reveals mechanism of action for hydrazine induced hepatotoxicity in rats

Gas chromatography–mass spectrometry (GC‐MS) has great advantages for analyzing organic/amino acids, which are often targets in efficacy and/or toxicity studies. Although GC‐MS has been used for the detection of many metabolic disorders, applications of GC‐MS‐based metabolomics in pharmacology/toxicology are relatively underdeveloped. We intended to investigate applicability of a GC‐MS‐based metabolomics approach for toxicological evaluation, and tried to elucidate the mechanism of hydrazine‐induced hepatotoxicity. Rats were administered hydrazine chloride orally (120 and 240 mg kg^?1), and urine, plasma and liver samples were collected at 24 or 48 h post‐dosing. Conventional clinical chemistry and liver histopathology were performed, urine and plasma were analyzed by GC‐MS, and metabolic profiles were assessed using chemometric techniques. Principal component analysis score plots showed clear separation of the groups, indicating dose‐dependent toxicity and recovery. The mechanism of toxicity was investigated based on semi‐quantification data of identified metabolites. Amino acid precursors of glutathione (cystein, glutamate and glycine) and a product of glutathione metabolism (5‐oxoproline) were elevated dose‐dependently, accompanied with elevation of ascorbate levels. In addition, intermediates of the TCA cycle were decreased, whereas participants of the urea cycle and other amino acids were increased. These alterations were associated with histopathological changes such as fatty degeneration and glycogen accumulation. Application of GC‐MS‐based metabolomics revealed that oxidative stress and GSH consumption play important roles in the etiology of hydrazine‐induced hepatotoxicity, demonstrating that this approach is a useful tool in pharmacology and toxicology for screening, elucidating mode of action and biomarker discovery. Copyright © 2010 John Wiley & Sons, Ltd.     

Bioanalysis of PUFA metabolism and lipid peroxidation in coronary atherosclerosis

Twenty eight men (age 34-77 years) who underwent an elective coronary angiography for coronary artery disease (CAD), were studied. They were divided into group A (luminal narrowing < 50%; n = 11) and group B (luminal narrowing > 50%; n = 17). Capillary gas chromatography was used for determination of fatty acids. Retinol and alpha-tocopherol were analyzed by reversed-phase high-performance liquid chromatography (HPLC), other parameters were determined spectrofluorometrically and spectrophotometrically. Severe coronary atherosclerosis in group B was associated with higher serum low density lipoprotein/high density lipoprotein (LDL/HDL) cholesterol ratio, triacylglycerols, and phospholipids (P < 0.05). Erythrocyte membrane fatty acids C14:0, C16:1 and C22:6n3 were significantly higher in group B (P < 0.05). We found significantly higher plasma polyunsaturated fatty acids (PUFA) C18:3n6 in group B, whereas plasma linoleic acid was not changed significantly. There was a significant increase of IDL-C18:0, LDL-C14:0 and HDL-C22:6n3 PUFA in group B. We conclude that disturbances in saturated fatty acids (SUFA) and PUFA metabolism are associated with coronary atherogenesis. Such abnormalities may include enhanced extrahepatic transport of C14:0 SUFA via LDL and its incorporation into cell membranes, and enhanced clearance of anti atherosclerotic C22:6n3 PUFA via serum HDL.     

Taurine ameliorates cholesterol metabolism by stimulating bile acid production in high‐cholesterol‐fed rats

This study was designed to investigate the effects of dietary taurine on cholesterol metabolism in high‐cholesterol‐fed rats. Male Sprague‐Dawley rats were randomly divided into two dietary groups (n = 6 in each group): a high‐cholesterol diet containing 0.5% cholesterol and 0.15% sodium cholate, and a high‐cholesterol diet with 5% (w/w) taurine. The experimental diets were given for 2 weeks. Taurine supplementation reduced the serum and hepatic cholesterol levels by 37% and 32%, respectively. Faecal excretion of bile acids was significantly increased in taurine‐treated rats, compared with untreated rats. Biliary bile acid concentrations were also increased by taurine. Taurine supplementation increased taurine‐conjugated bile acids by 61% and decreased glycine‐conjugated bile acids by 53%, resulting in a significant decrease in the glycine/taurine (G/T) ratio. Among the taurine‐conjugated bile acids, cholic acid and deoxycholic acid were significantly increased. In the liver, taurine supplementation increased the mRNA expression and enzymatic activity of hepatic cholesterol 7α‐hydroxylase (CYP7A1), the rate‐limiting enzyme for bile acid synthesis, by three‐ and two‐fold, respectively. Taurine also decreased the enzymatic activity of acyl‐CoA:cholesterol acyltransferase (ACAT) and microsomal triglyceride transfer protein (MTP). These observations suggest that taurine supplementation increases the synthesis and excretion of taurine‐conjugated bile acids and stimulates the catabolism of cholesterol to bile acid by elevating the expression and activity of CYP7A1. This may reduce cholesterol esterification and lipoprotein assembly for very low density lipoprotein (VLDL) secretion, leading to reductions in the serum and hepatic cholesterol levels.     

GC-MS analysis and hepatoprotective activity of the n-hexane extract of Acrocarpus fraxinifolius leaves against paracetamol-induced hepatotoxicity in male albino rats

Context: In Egypt, the burden of liver diseases is exceptionally high.

Objective: To investigate the components of the n-hexane extract of Acrocarpus fraxinifolius Arn. (Leguminosae) and its hepatoprotective activity against paracetamol (APAP)-induced hepatotoxicity in rats.

Material and methods: TRACE GC ultra gas chromatogaphic spectrometry was used for extract analysis. Thirty albino rats were divided into six groups (five rats in each). Group 1 was the healthy control; Groups 2 and 3 were healthy treated groups (250 and 500?mg/kg b.w. of the extract, respectively) for seven days. Group 4 was hepatotoxicity control (APAP intoxicated group). Groups 5 and 6 received APAP?+?extract 250 and APAP?+?extract 500, respectively.

Results: Chromatographic analysis revealed the presence of 36 components. Major compounds were α-tocopherol (18.23%), labda-8 (20)-13-dien-15-oic acid (13.15%), lupeol (11.93%), phytol (10.95%) and squalene (7.19%). In the acute oral toxicity study, the mortality rates and behavioural signs of toxicity were zero in all groups (doses from 0 to 5?g/kg b.w. of A. fraxinifolius). LD₅₀ was found to be greater than 5?g/kg of the extract. Only the high dose (500?mg/kg b.w.) of extract significantly alleviated the liver relative weight (4.01?±?0.06) and biomarkers, as serum aspartate aminotransferase (62.87?±?1.41), alanine aminotransferase (46.74?±?1.45), alkaline phosphatase (65.96?±?0.74), lipid profiles (180.39?±?3.51), bilirubin profiles (2.30?±?0.06) and hepatic lipid peroxidation (114.20?±?2.06), and increased body weight (11.58?±?0.20), serum protein profile (11.09?±?0.46) and hepatic total antioxidant capacity (23.78?±?0.66) in APAP-induced hepatotoxicity in rats.

Conclusion: Our study proves the antihepatotoxic/antioxidant efficacies of A. fraxinifolius hexane extract.     

Protective effects of coffee‐derived compounds on lipopolysaccharide/d‐galactosamine induced acute liver injury in rats

Objectives The protective effects of coffee‐derived compounds on lipopolysaccharide/d‐galactosamine (LPS/d‐GalN) induced acute liver injury in rats were investigated. Methods Wistar rats were orally administered saline (control) or one of the test compounds (caffeine, chlorogenic acid, trigonelline, nicotinic acid or eight ***pyrazinoic acids) at a dose of 100 mg/kg, respectively. This was followed by intraperitoneal injection with LPS (100 μg/kg)/d‐GalN (250 mg/kg) 1 h after administration of the test compounds. Blood samples were collected up to 12 h after LPS/d‐GalN injection, followed by determination of plasma aspartate aminotransferase, alanine aminotransferase, tumour necrosis factor α (TNF‐α) and interleukin 10 (IL‐10) levels. Key findings Plasma aspartate aminotransferase and alanine aminotransferase levels were significantly increased after LPS/d‐GalN‐treatment, but were suppressed by pretreatment with caffeine (n = 5), nicotinic acid, non‐substituted pyrazinoic acid or 5‐methylpyrazinoic acid (n = 6, respectively) 12 h after LPS/d‐GalN‐treatment (P < 0.01, respectively). Moreover, the animals pretreated with these test compounds showed significantly higher survival rates (83–100%) compared with the control (23%). Only pretreatment with caffeine significantly suppressed the LPS/d‐GalN induced elevation of plasma TNF‐α levels 1 and 2 h after LPS/d‐GalN‐treatment (P < 0.01, respectively). Pretreatment with caffeine, nicotinic acid or non‐substituted pyrazinoic acid activated the LPS/d‐GalN induced elevation of plasma IL‐10 levels at 1 and 2 h, although there were no statistically significant differences in IL‐10 levels between control and nicotinic acid or non‐substituted pyrazinoic acid treated rats. Conclusions The results suggest that caffeine, nicotinic acid, non‐substituted pyrazinoic acid and 5‐methylpyrazinoic acid can protect against LPS/d‐GalN induced acute liver injury, which may be mediated by the reduction of TNF‐α production and/or increasing IL‐10 production.     

Protective effects of syringic acid against acetaminophen-induced hepatic damage in albino rats

The protective effect of the phenolic compound syringic acid, one of the major benzoic acid derivatives from edible plants and fruits, was evaluated against acetaminophen (APAP)-induced hepatotoxicity in rats. Toxicity was induced in adult male albino Wistar rats by the administration of APAP (750 mg/kg body weight) intraperitoneally. Rats were treated with syringic acid (25, 50, and 100 mg/kg body weight) by the oral route. We assessed the activity of hepatic markers aspartate aminotransferase, alanine aminotransferase, alkaline phosphatase, gamma-glutamyl transferase, and bilirubin. Lipid peroxidative markers thiobarbituric acid reactive substances (TBARS), lipid hydroperoxides, and a decrease in enzymatic antioxidants superoxide dismutase, catalase, glutathione peroxidase, and non-enzymatic antioxidants vitamin C, vitamin E and reduced glutathione levels. Liver histology also showed convincing evidence regarding their protective nature against fatty changes induced during APAP intoxication. Syringic acid administered at a dose of 50 mg/kg body weight significantly decreased the activities of hepatic and renal function markers to near normal values when compared with the other two doses. The results suggest that syringic acid could afford a significant protective effect against APAP induced hepatic damage in rats.     

Lipid metabolism in liver of rat exposed to cadmium.

We investigated the effect of exposition to cadmium (Cd, 15ppm for 8 weeks) through drinking water on liver lipid metabolism in adult male Wistar rats. As compared to metal non-exposed (control) rats, the serum triglycerides, cholesterol and LDL+VLDL cholesterol concentrations increased. This was associated to a decrease of lipoprotein lipase activity in post heparinic plasma. The VLDL secretion from liver was not modified. Cd treatment increased triglycerides and decreased esterified cholesterol contents in liver. The high triglyceride mass was related to the increased glycerol-3-phosphate acyltransferase mRNA expression. In addition, the liver fatty acids synthesis increased, as determined by an increment of fatty acid synthetase and isocitrate dehydrogenase activities, and [(14)C]-acetate incorporation into saponifiable lipid fraction. The relative percentage of palmitic acid (16:0) and total saturated fatty acids were increased compared with control. Hepatic glucose-6-phosphate dehydrogenase, malic dehydrogenase and cholesteryl ester hydrolase activities were unchanged. In liver, the Cd treatment decreased triglyceride and cholesterol in mitochondria, also increased triglyceride in cytosol, and cholesterol and phospholipid contents in nuclei, compared with control. In addition, an increase of nuclei phosphatidylcholine synthesis was observed. Cd exposure alters directly or indirectly the serum lipid content and liver lipid metabolism.     

Sex- and Age-Dependent Acetaminophen Hepato- and Nephrotoxicity in Sprague-Dawley Rats: Role of Tissue Accumulation, Nonprotein Sulfhydryl Depletion, and Covalent Binding

Acetaminophen (APAP) produces sex-dependent nephrotoxicity andhepatotoxicity in young adult Sprague-Dawley (SD) rats and age-dependenttoxicity in male rats. There is no information re garding thesusceptibility of aging female SD rats to APAP toxicity. Therefore,the present studies were designed to determine if sex-dependentdifferences in APAP toxicity persist in aging rats and to elucidatefactors contributing to sex- and age-dependent APAP hepatotoxicityand nephrotoxicity. Young adult (3 months old) and aging (18months old) male and female rats were killed from 2 through24 hr after receiving APAP (0–1250 mg/kg, ip) containing[ring-¹⁴C]APAP. Trunk blood was collected for determinationof blood urea nitrogen (BUN) concentration, serum alanine aminotransferase(ALT) activity, and plasma APAP concentration; urine was collectedfor determination of glucose and protein excretion; and liverand kidneys were removed for determination of tissue glutathione(GSH) concentration, APAP concentration, and covalent binding.APAP at 1250 mg/kg induced nephrotoxicity (as indicated by elevationsin BUN concentration) in 3-month-old females but not males,whereas APAP induced hepatotoxicity (as indicated by elevationsin serum ALT activity) in 3-month-old males but not females.Sex differences in APAP toxicity were no longer apparent in18-month-old rats. APAP at 750 mg/kg ip produced liver and kidneydamage in 18-month-old but not 3-month-old male and female rats.No consistent sex- or age-dependent differences in serum, hepatic,and renal APAP concentrations were observed that would accountfor differences in APAI toxicity. No sex- or age-dependent differencesin tissue GSH depletion or covalent binding of radiolabel fromAPAP in livers or kidneys were observed following APAP administration.Utilizing an affinity-purified polyclonal antibody raised againstAPAP, arylated proteins with electrophoretic mobility similarto those observed in mice were prominent in rat livers followingAPAP administration to 3- and 18-month-old rats of both sexes.In contrast, no arylated proteins were detected in any rat kidneysfollowing APAP administration. Absence of immunochemically detectableproteins in rat kidney following APAP administration is in directcontrast to observations in mice and supports the hypothesisthat mechanisms of APAP hepatotoxicity and nephrotoxicity inrats and mice are distinctly different. In conclusion, sex differencesin APAP toxicity are observed only in young adult (3-month-old)rats and sex differences are organ-specific with males moresusceptible to hepatotoxicity and females more susceptible tonephrotoxicity. Aging rats are more susceptible to APAP-induceddamage to both the liver and the kidney than are 3-month-oldrats but sex differences are no longer apparent in 18-month-oldrats. The mechanisms contributing to sex- and age-dependentdifferences in APAP toxicity cannot be attributed to differencesin tissue APAP concentrations, GSH depletion, or covalent binding.     

Sympatholytic drugs and hyperlipaemia induced in rats by intraperitoneal injections of surface-active agent

Hyperlipaemia and hypercholesterolaemia were induced in white rats by intraperitoneal injections of tyloxapol. Various sympatholytics and adrenolytics, including blocking agents of β-receptors, were given simultaneously with tyloxapol. Bretylium tosylate prevented the increase in the serum levels of esterified fatty acids and cholesterol caused by tyloxapol. Phentolamine decreased the enhancement by tyloxapol of cholesterol and total lipid concentrations in the serum. Guanethidine and phenoxybenzamine reduced the increase in the concentration of esterified fatty acids, whereas dichloroisoprenaline insignificantly increased the tyloxapol-induced hyperlipaemia. A small dose of pronethalol slightly increased the esterified fatty acid level in tyloxapol-treated animals; a large dose significantly decreased the serum cholesterol concentration.     

Induction of hepatic CYP2E1 by a subtoxic dose of acetaminophen in rats: increase in dichloromethane metabolism and carboxyhemoglobin elevation.

Dichloromethane (DCM) is metabolically converted to carbon monoxide mostly by CYP2E1 in liver, resulting in elevation of blood carboxyhemoglobin (COHb) levels. We investigated the effects of a subtoxic dose of acetaminophen (APAP) on the metabolic elimination of DCM and COHb elevation in adult female rats. APAP, at 500 mg/kg i.p., was not hepatotoxic as measured by a lack of change in serum aspartate aminotransferase, alanine aminotransferase, and sorbitol dehydrogenase activities. In rats pretreated with APAP at this dose, the COHb elevation resulting from administration of DCM (3 mmol/kg i.p.) was enhanced significantly. Also blood DCM levels were reduced, and its disappearance from blood appeared to be increased. Hepatic CYP2E1-mediated activities measured with chlorzoxazone, p-nitrophenol, and p-nitroanisole as substrates were all induced markedly in microsomes of rats treated with APAP. Aminopyrine N-demethylase activity was also increased slightly, but significantly. Western blot analysis showed that APAP treatment induced the expression of CYP2E1 and CYP3A proteins. Neither hepatic glutathione contents nor glutathione S-transferase activity was changed by the dose of APAP used. The results indicate that, contrary to the well known hepatotoxic effects of this drug at large doses, a subtoxic dose of APAP may induce CYP2E1, and to a lesser degree, CYP3A expression. This is the first report that APAP can increase cytochrome P450 (P450)-mediated hepatic metabolism and the resulting toxicity of a xenobiotic in the whole animal. The pharmacological/toxicological significance of induction of P450s by a subtoxic dose of APAP is discussed.     

Removal of Xenobiotic Dichlorostearic Acid from Phospholipids and Neutral Lipids in Cultured Human Cell Lines by ß‐Oxidation and Secretion of Dichloromyristic Acid

Abstract: Chlorinated fatty acids represent a recently discovered group of potentially hazardous organochlorine pollutants in the environment. The ability of human cells to incorporate and metabolise this type of fatty acids has never been investigated. The aim of the present study was, therefore, to investigate if two human cell lines, INT 407 and SH‐SY5Y, incorporate and metabolise extracellular dichlorostearic acid. Cells were incubated with 9,10‐dichlorostearic acid for 24 hr, and the amounts of chlorinated fatty acids in cells and culture medium analysed every two days for up to 6 or 10 days. Lipids were separated by solid phase extraction, transesterified to fatty acid methyl esters, and analysed by gas chromatography in combination with a halogen specific detector (GC/XSD). Dichlorostearic acid, dichloropalmitic acid and dichloromyristic acid were found in phospholipids and in neutral lipids of the INT 407 cells. Both cell lines secreted considerable amounts of dichloromyristic acid into the culture medium. Cellular or secreted metabolites shorter than dichloromyristic acid were not found. Taken together, the results suggest that human cells may (1) incorporate chlorinated fatty acids into membrane lipids and storage lipids, (2) metabolise cellular dichlorostearic acid to dichloropalmitic acid and dichloromyristic acid by ß‐oxidation; but that further metabolism is hindered, possibly because of the chlorine atoms, and (3) remove formed dichloromyristic acid by secretion. The removal of cellular dichloromyristic acid might represent an important cellular defence mechanism and deserves further investigations.     

Geranylgeranylacetone preconditioning may attenuate heat‐induced inflammation and multiorgan dysfunction in rats

Objectives Geranylgeranylacetone, an acyclic isoprenoid, is a non‐toxic inducer of heat shock protein (HSP)70. HSP70 overproduction is associated with heat tolerance in rats. This study aimed to investigate whether geranylgeranylacetone preconditioning of rats reduced heat‐induced inflammation and multiple organ dysfunction. Methods Anaesthetised rats were given vehicle or geranylgeranylacetone (800 mg/kg) orally. After 48 h they were exposed to ambient temperature of 43°C for 70 min to induce heatstroke. Another group of rats kept at room temperature were used as normothermic controls. Key findings Vehicle‐treated rats all succumbed to heat stress; their survival time was 25 ± 4 min. Pretreatment with geranylgeranylacetone significantly increased survival time to 92 ± 15 min. Compared with normothermic controls, all vehicle‐treated heatstroke rats displayed hepatic and renal dysfunction (e.g. increased plasma levels of serum urea nitrogen, creatinine, aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase) and active inflammation (e.g. increased plasma and brain levels of interleukin‐1β, tumour necrosis factor‐α and interleukin‐6). These heat‐stress response indicators were all significantly suppressed by geranylgeranylacetone pretreatment. In addition, the plasma and brain levels of interleukin‐10 (an anti‐inflammatory cytokine) and brain levels of HSP70 were significantly increased after geranylgeranylacetone preconditioning during heatstroke. Conclusions Geranylgeranylacetone preconditioning attenuates heat‐induced inflammation and multiorgan dysfunction in rats.     

Long-term effects of a single oral dose of polybrominated biphenyls on serum and liver lipids in rats

Adult (5 months) male Sherman strain rats received a single dose of either 0 or 500 mg polybrominated biphenyls (PBB) in corn oil/kg body weight by stomach tube. After an 18-month recovery period, serum and liver samples were examined. The primary serum lipid response was an increase in cholesterol (both free and esterified) and in total phospholipids. The percentage of esterified cholesterol was not significantly different from that of the controls, and no significant differences in the cholesterol ester fatty acid composition were observed. Serum triglycerides were also unaffected. In the PBB-dosed animals, the total hepatic fatty acids contained significantly less palmitic acid and more stearic acid, consistent with an increase in palmitic acid chain elongation activity. No significant differences could be detected in the n-3 or n-6 acids except for a slight decline in the content of 22:6 (n-3). Hepatic microsomal phospholipids were slightly higher (per milligram protein) in the PBB-dosed animals, and the cholesterol content was lower. Consequently, the cholesterol-phospholipid ratio was reduced, and microsomes from the latter group appeared to have an altered lipid domain on the basis of steady-state fluorescence anisotrophy measurements. In addition, total hepatic thiobarbituric acid-reactive substances (assayed as malondialdehyde) were significantly increased in the PBB-dosed animals. This observation appeared to reflect an increased susceptibility to peroxidative stress in the latter group, probably resulting from reduced membrane antioxidant concentrations. The PBB-dosed rats had significantly lower serum retinol levels and a reduced content of this vitamin in liver microsomes. Microsomes were also deficient in alpha-tocopherol in the PBB-dosed animals, although serum levels were normal.     

Ebselen Protects against the Reduction in Levels of Drug‐Metabolizing Enzymes in Livers of Rats with Deoxycholic Acid‐Induced Liver Injury

Abstract: Ebselen is a seleno‐organic compound that inhibits oxidative stress by lipid peroxidation through a glutathione peroxidase‐like activity. We studied the effect of ebselen on the expression of hepatic drug‐metabolizing enzymes in rats with deoxycholic acid‐induced liver injury. Hydrophobic bile acids, such as deoxycholic acid, are known to cause cholestatic liver injury, and it was reported that expression of hepatic cytochrome P‐450 (CYP) was reduced by deoxycholic acid administration in rats. Hydrophobic bile acids induce lipid peroxidation in the liver, and this may be one mechanism of the development of liver injury. In the present study, we investigated the effect of ebselen (30 mg/kg/day for 10 days) on rats ingesting deoxycholic acid (1% of diet for 10 days). Deoxycholic acid decreased levels of CYP1A1, 2B1, 2E1 and 3A2 to 34, 58, 62 and 37% of control values, respectively, and increased serum alkaline phosphatase (ALP) and alanine aminotransferase (ALT) activities to 1.8 and 8.6 times the levels of controls, respectively. Administration of ebselen with deoxycholic acid prevented the decreases in levels of CYP1A1 and 3A2 (86 and 65% of control, respectively) and the increases in serum ALP and ALT activities (1.4 and 1.9 times of control, respectively) caused by deoxycholic acid. These results indicate that ebselen may have a protective effect against hydrophobic bile acid‐induced liver injury.     

Arachidonic acid‐containing phosphatidylcholine characterized by consolidated plasma and liver lipidomics as an early onset marker for tamoxifen‐induced hepatic phospholipidosis

Lipid profiling has emerged as an effective approach to not only screen disease and drug toxicity biomarkers but also understand their underlying mechanisms of action. Tamoxifen, a widely used antiestrogenic agent for adjuvant therapy against estrogen‐positive breast cancer, possesses side effects such as hepatic steatosis and phospholipidosis (PLD). In the present study, we administered tamoxifen to Sprague–Dawley rats and used lipidomics to reveal tamoxifen‐induced alteration of the hepatic lipid profile and its association with the plasma lipid profile. Treatment with tamoxifen for 28 days caused hepatic PLD in rats. We compared the plasma and liver lipid profiles in treated vs. untreated rats using a multivariate analysis to determine differences between the two groups. In total, 25 plasma and 45 liver lipids were identified and altered in the tamoxifen‐treated group. Of these lipids, arachidonic acid (AA)‐containing phosphatidylcholines (PCs), such as PC (17:0/20:4) and PC (18:1/20:4), were commonly reduced in both plasma and liver. Conversely, tamoxifen increased other phosphoglycerolipids in the liver, such as phosphatidylethanolamine (18:1/18:1) and phosphatidylinositol (18:0/18:2). We also examined alteration of AA‐containing PCs and some phosphoglycerolipids in the pre‐PLD stage and found that these lipid alterations were initiated before pathological alteration in the liver. In addition, changes in plasma and liver levels of AA‐containing PCs were linearly associated. Moreover, levels of free AA and mRNA levels of AA‐synthesizing enzymes, such as fatty acid desaturase 1 and 2, were decreased by tamoxifen treatment. Therefore, our study demonstrated that AA‐containing PCs might have potential utility as novel and predictive biomarkers for tamoxifen‐induced PLD. Copyright © 2017 John Wiley & Sons, Ltd.