Treatment of Toxocara canis infections in mice with liposome-incorporated benzimidazole carbamates and immunomodulator glucan

Benzimidazole carbamates (mebendazole, albendazole and fenbendazole) are the most commonly used anthelmintic drugs for the treatment of larval toxocariasis (Toxocara canis) in paratenic hosts. However, the bioavailability of these drugs for tissues is very low due to their extremely low solubility, resulting in the administration of relatively high doses over a long period. To overcome this problem, neutral, negatively or positively charged and stabilized liposome drug carriers were examined in the chronic phase of T. canis infections in mice each orally inoculated with 1000 eggs. Moreover, liposomized albendazole and fenbendazole were co-administered with liposomized immunomodulator glucan. The highest efficacy of both drugs, evaluated 4 weeks after treatment, was recorded after their subcutaneous administration (ten doses of 25 mg kg(-1)) in stabilized liposomes and intramuscular co-administration of liposomized glucan (two doses of 5 mg kg(-1)). Fenbendazole was more effective in muscles (91.5%) whereas albendazole was more effective in the brain (92.2%). Liposomes with incorporated benzimidazole carbamate anthelmintics provide sustained drug-release reservoirs and can considerably enhance drug efficacy. Moreover, despite suppression by T. canis antigens, stimulation of the immune system by the immunomodulator glucan potentiates the effects of these antiparasitic drugs.     

Effects of vitamin C on liver enzymes and biochemical parameters in rats anesthetized with halothane

Halothane is an important human and veterinary anesthetic, which produces free radicals during biotransformation. Occasionally, these free radicals may cause hepatic injury, especially in case of multiple halothane exposures over short periods. Vitamin C may protect cellular lipids and lipoproteins against oxidative damage by the free radicals. This study investigated the effects of vitamin C on liver enzymes and other biochemical parameters in rats anesthetized with halothane. One group of rats was used as a control, and saline (0.9% NaCl) was injected intraperitoneally into these animals as a placebo. The second group of rats was used as an anesthesia control group and was only anesthetized by halothane for 2 h. The third group was anesthetized by halothane and injected vitamin C intraperitoneally. Activities of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase enzymes were significantly increased (p < 0.05, p < 0.01, p < 0.05, respectively) by halothane anesthesia, but decreased (p < 0.05, p < 0.05, p < 0.05, respectively) with administration of vitamin C. Concentrations of triglycerides, cholesterol, total bilirubin and creatinine were statistically affected (p < 0.05, p < 0.01, p < 0.05, and p < 0.01, respectively) by injection of vitamin C. Values of erythrocyte counts, packet cell volumes, hemoglobin concentration, leukocyte counts, rates of neutrophils and lymphocytes were significantly affected (p < 0.01, p < 0.05, p < 0.05, p < 0.01, p < 0.001 and p < 0.01, respectively) by halothane anesthesia. The values of erythrocyte counts, leukocyte counts, neutrophil and lymphocyte rates were significantly decreased (p < 0.05, p < 0.05, p < 0.05, p < 0.01 and p < 0.01, respectively) with administration of vitamin C. Based upon these results, vitamin C may play an important role in the prevention of hepatic cellular injury inflicted by halothane anesthesia.     

Enzyme activities in plasma, liver and kidney of black ducks and mallards

Activities of alanine aminotransferase (ALT), aspartate aminotransferase (AST), creatine phosphokinase (CPK), alkaline phosphatase (ALP), and lactate dehydrogenase (LDH) were measured in plasma, liver, and kidney, and gamma-glutamyl transferase (GGT) was measured in liver and kidney of black ducks (Anas rubripes). Activities of ALT, AST, GGT, and ornithine carbamyl transferase (OCT) were assayed in plasma, liver, and kidney of game-farm mallards (Anas platyrhynchos). Appreciable OCT and AST activity occurred in both liver and kidney. Activities of ALT, CPK, ALP and GGT were higher in kidney, while LDH was higher in liver, GGT was detected in plasma from one of four mallards.     

Vitamin E Improves the Aminotransferase Status of Patients Suffering from Viral Hepatitis C: A Randomized,Double-Blind,Placebo-Controlled Study

Vitamin E has been shown to protect against liver damage induced by oxidative stress in animal experiments. Based on our previous findings of diminished vitamin E levels in patients suffering from viral hepatitis, we treated 23 hepatitis C patients refractory to a-interferon therapy with high doses of vitamin E (2 × 400 IU RRR-α-tocopherol/day) for 12 weeks. Study design: pro-spective randomized double-blind crossover design. Clinical parameters including alanine aminotransferase (ALT) and aspartate aminotransferase (AST) were determined for monitoring the disease state, in parallel vitamin E plasma levels and plasma lipids were determined. The plasma levels of the a-tocopherol were increased about 2-fold in all 23 patients. In 11 of 23 patients the clinical parameters indicative of liver damage were improved during the phase of vitamin E treatment (48% responders). ALT levels in responders were lowered by 46% and AST levels were lowered by 35% after 12 weeks of vitamin E treatment. Cessation of vitamin E treatment was followed by a rapid relapse of ALT and AST elevation, whereas retreatment led to a reproducible ALT decrease by 45% and AST decrease of 37% after a 6 months followup. Since vitamin E is non-toxic even at elevated doses ingested over extended periods, we suggest the treatment of patients refractory to α-interferon therapy suffering from hepatitis C with vitamin E as a supportive therapy.     

Impact of treatment with praziquantel, silymarin and/or beta-glucan on pathophysiological markers of liver damage and fibrosis in mice infected with Mesocestoides vogae (Cestoda) tetrathyridia

Mesocestoides vogae tetrathyridia infection in mice causes hepatocyte injury, hepatic granulomatous inflammmation, liver fibrosis and chronic peritonitis manifested with portal hypertension. To reduce the detrimental effect of parasites on the host liver, the effect of the anthelmintic drug praziquantel (PZQ) in combination with natural products silymarin (an antioxidant) and beta-glucan (an immunomodulator) was investigated. The therapeutic effect of drugs was assessed by means of aminotransferase (alanine aminotransferase (ALT) and aspartate aminotransferase (AST)) activities, content of albumin, total proteins and hyaluronic acid (HA) in sera of ICR mice infected with M. vogae larvae. Animals were treated with PZQ suspended in oil emulsion (Group 1), PZQ combined with silymarin incorporated into lipid microspheres (LMS) (Group 2), PZQ combined with beta-glucan incorporated into liposomes (LG) (Group 3), PZQ co-administered with LMS and LG (Group 4). Untreated animals (Group 5) served as the control. Treatment of animals started at the early chronic phase of infection (day 14 p.i.) and lasted 10 days; serum samples were collected on days 0, 7, 14, 25, 28, 31, 35 and 45 p.i. ALT and AST activities were significantly (P < 0.05) decreased in Groups 2, 3 and 4. HA content was significantly (P < 0.05 and 0.01) lower in Groups 2 and 4. Albumin levels were decreased in Groups 2 and 4, total protein concentration decreased in Groups 1 and 3 (P < 0.05 and 0.01). These results showed that combined treatment of PZQ with silymarin and/or beta-glucan was able to ameliorate or suppress fibrogenesis in the liver, protect liver cells from oxidative damage and, possibly, stimulate regeneration of the parenchyma.     

The Influence of Methionine, Selenomethionine, and Vitamin E on Liver Metabolic Pathways and Steatosis in High-Cholesterol Fed Rabbits

Significant disorders of liver metabolic pathways enzymes after high-cholesterol diet could give information on liver steatosis development. This process could probably also be inhibited by some compounds, as examined in rabbits. Forty-two male rabbits were served a high-cholesterol diet (2 g%) (0.67 g/kg b.m./24 h) with addition of d,l-methionine (70 mg/kg b.m./24 h) or seleno-d,l-methionine (12.5 μg/kg b.m./24 h) or α-tocopherol (10 mg/kg b.m./24 h) for 3 months to compare the protection effect of used compounds on liver metabolism and steatosis. At the beginning and every month, blood was taken. After the experiment was completed, livers were dissected for histological examinations. The concentration of total cholesterol (t-CH), triacylglycerol (TG), and the activities of aldolase (ALD), sorbitol dehydrogenase (SDH), glutamate dehydrogenase (GLDH), lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and alanine aminotransferase (ALT) were determined. Plasma t-CH and TG concentrations were significantly higher in all experimental groups vs control group. Blood serum AST and ALT activities did not undergo change but there were observed not significant increase in the CH group vs control group. Activities of SDH, GLDH, and LDH increased in blood serum and decreased in the liver in all experimental groups. Activities of LDH and SDH increased in the liver in the CH+Met group vs CH group. ALD activity decreased in the liver only in the CH and CH+Se groups. This data support a lipotoxic model of cholesterol-mediated hepatic steatosis. Prolonged administration of high-cholesterol diet not only disturbs the structure of cell membranes, which is expressed by decreased activity of enzymes in the liver and the migration of those enzymes to plasma but as well leads to steatosis of the liver, which has been confirmed by histological examinations. The applied compounds appear to have a varying influence upon the activity of enzymes determined in serum and liver. Obtained results showed a beneficial influence of methionine and vitamin E supplementation on liver steatosis development.     

Distribution of negatively charged liposomes on rat liver hepatocytes and non-hepatocytes in cell suspension

The in vitro interactions between negatively charged multilamellar liposomes and purified rat liver parenchymal and non-parenchymal cells were studied. The liposomes were labelled with [¹⁴C]cholesterol and contained [³H]methotrexate. For both cell types the time course of liposomal attachment to the cells slowed down gradually after a rapid initial phase lasting ca 90 min. The rate of attachment at 4 °C was 3–7 times lower than that at 37 °C, and the metabolic inhibitors dinitrophenol and iodoacetic acid caused reduction of 20–30%. Up to 45% of the cell-associated liposomal radioactivity could be detached within 1 h incubation with unlabelled liposomes. Whereas liver parenchymal cell suspension seemed to exhibit similar characteristics in vitro as in vivo, the non-parenchymal cells in vitro showed a 20–50-fold reduction in the rate of liposomal attachment compared to in vivo.     

Protective Effect of a Fermented Substance from Saccharomyces cerevisiae on Liver Injury in Mice Caused by Acetaminophen

The protective effect of a fermented substance from Saccharomyces cerevisiae (FSSC) on liver injury caused by acetaminophen (AAP) was studied in mice. Mice were pretreated with FSSC (0.5–2.0 g/kg, p.o.) for 4 d, and on the fourth day, the mice received an overdose of AAP (500 mg/kg, i.p.). Subsequently, they were sacrificed at 7 h, and blood was drawn from the abdominal vein and liver samples were collected. Histological and biochemical examinations revealed that the administration of AAP caused liver injury in the mice, including increases in plasma alanine aminotransferase and asparate aminotransferase activities and decreases in the hepatic reduced form of glutathione (GSH) content and antioxidant enzyme activities. Prior to AAP treatment, the mice pretreated with FSSC showed significantly reduced levels of alanine aminotransferase (ALT) and aspirate aminotransferase (AST) activity. Liver histology in the FSSC-pretreated mice was significant. In these mice, pretreatment with FSSC also served to reduce hepatic GSH depletion and the inhibition of antioxidant enzyme activity caused by AAP overdose. In conclusion, oral administration of FSSC significantly reduced AAP-induced hepatic injury in the mice.     

Protective effect of a fermented substance from Saccharomyces cerevisiae on liver injury in mice caused by acetaminophen

The protective effect of a fermented substance from Saccharomyces cerevisiae (FSSC) on liver injury caused by acetaminophen (AAP) was studied in mice. Mice were pretreated with FSSC (0.5-2.0 g/kg, p.o.) for 4 d, and on the fourth day, the mice received an overdose of AAP (500 mg/kg, i.p.). Subsequently, they were sacrificed at 7 h, and blood was drawn from the abdominal vein and liver samples were collected. Histological and biochemical examinations revealed that the administration of AAP caused liver injury in the mice, including increases in plasma alanine aminotransferase and asparate aminotransferase activities and decreases in the hepatic reduced form of glutathione (GSH) content and antioxidant enzyme activities. Prior to AAP treatment, the mice pretreated with FSSC showed significantly reduced levels of alanine aminotransferase (ALT) and aspirate aminotransferase (AST) activity. Liver histology in the FSSC-pretreated mice was significant. In these mice, pretreatment with FSSC also served to reduce hepatic GSH depletion and the inhibition of antioxidant enzyme activity caused by AAP overdose. In conclusion, oral administration of FSSC significantly reduced AAP-induced hepatic injury in the mice.     

Clinical relevance of lipid panel and aminotransferases in the context of hepatic steatosis and fibrosis as measured by transient elastography (FibroScan®)

BackgroundNonalcoholic fatty liver disease (NAFLD) is one of the most common causes of chronic liver disease and is associated with various co-morbidities. Transient elastography (FibroScan®) is a non-invasive method to detect NAFLD using the controlled attenuation parameter (CAP). We aimed to evaluate the association of the lipid panel and aminotransferases concentrations with the presence or absence of steatosis and fibrosis.MethodsOne hundred and five patients with NAFLD were included. Hepatic steatosis was quantified by CAP (dB/m) and liver stiffness by Kilopascals (kPa), these values were then analyzed against patient lipid panel and serum concentrations of the liver enzymes aspartate aminotransferase (AST) and alanine aminotransferase (ALT). A correlation and multiple regression were used. Mann-Whitney U test was used as non-parametric analysis.ResultsWe observed an association between hepatic steatosis and total cholesterol (B = 0.021, p = 0.038, Exp (B) = 1.021, I.C = 1.001-1.041) as well as serum triglycerides (B = 0.017, p = 0.006, Exp (B) = 1.018 and I.C = 1.005-1.030). Similarly, we found an association between significant hepatic fibrosis and lower concentrations of total cholesterol (B = -0.019, p = 0.005, Exp (B) = 0.982 I.C = 0.969-0.995) and elevated AST (B = 0.042, p = 3.25 × 10^-4, Exp (B) = 1.043 I.C = 1.019-1.068) independent of age, gender and BMI.ConclusionsOur results suggest that, total cholesterol and triglyceride concentrations positively correlate with hepatic steatosis while significant hepatic fibrosis is associated with lower total cholesterol and higher AST concentrations.     

Liposomes with entrapped doxorubicin exhibit extended blood residence times

The blood residence time of liposomes with entrapped doxorubicin is shown to be significantly longer than for identically prepared empty liposomes. Liposomal doxorubicin systems with a drug-to-lipid ratio of 0.2 (w/w) were administered at a dose of 100 mg lipid/kg. Both doxorubicin and liposomal lipid were quantified in order to assess in vivo stability and blood residence times. For empty vesicles composed of phosphatidylcholine (PC)/cholesterol (55:45, mole ratio) and sized through filters of 100 nm pore size, 15-25% of the administered lipid dose was recovered in the blood 24 h after i.v. injection. The percentage of the dose retained in the circulation at 24 h increased 2-3-fold when the liposomes contain entrapped doxorubicin. For 100 nm distearoyl PC/chol liposomal doxorubicin systems, as much as 80% of the injected dose of lipid and drug remain within the blood compartment 24 h after i.v. administration.     

Simvastatin and vitamin E effects on cardiac and hepatic oxidative stress in rats fed on high fat diet

High fat diet (HFD) is a common cause of metabolic syndrome and type 2 diabetes mellitus. Published data showed that HFD and subsequent dyslipidemia are major triggers for oxidative stress. Forty-eight male Sprague–Dawley rats, weighing 170–200 g, were divided into six groups: control, control with vitamin E (100 mg/kg/day, i.p.), control with simvastatin (SIM) (10 mg/kg of body weight/day), HFD, HFD with vitamin E, and HFD with SIM. Standard and high cholesterol diets were given for 15 weeks and SIM and vitamin E were added in the last 4 weeks. In all rats, serum vitamin E, total cholesterol (TC), triglycerides (TG), low (LDL) and high (HDL) density lipoproteins, alanine (ALT) and aspartate (AST) transaminases, alkaline phosphatase (ALP), and gamma glutamyl transpeptidase (GGT) as well as cardiac and hepatic thiobarbituric acid-reactive substances (TBARS) and antioxidants (reduced glutathione (GSH), superoxide dismutase (SOD), and catalase (CAT)) were measured. Also, electrocardiogram (ECG) was recorded. HFD significantly increased QTc interval, heart rate (HR), serum TC, TG, LDL, ALT, AST, ALP, GGT, liver TG, and cardiac and hepatic TBARS but decreased antioxidants and HDL, while SIM decreased HR, liver TG, serum TC, TG, and LDL and increased HDL in HFD rats. Vitamin E had no effect. Moreover, SIM and vitamin E decreased QTc interval, serum ALT, AST, ALP, GGT, and cardiac and hepatic TBARS and increased antioxidants in HFD rats. Histopathological observations confirm the biochemical parameters. SIM and vitamin E slow progression of hypercholesterolemia-induced oxidative stress in liver and heart and improve their functions.     

Lysosomal unesterified cholesterol content correlates with liver cell death in murine Niemann-Pick type C disease

Niemann-Pick type C (NPC) disease is a multisystem disorder resulting from mutations in the NPC1 gene that encodes a protein involved in intracellular cholesterol trafficking. Significant liver dysfunction is frequently seen in patients with this disease. The current studies used npc1 mutant mice to investigate the association between liver dysfunction and unesterified cholesterol accumulation, a hallmark of NPC disease. Data from 92 npc1(-/-) mice (age range, 9-56 days) revealed a significant positive correlation between the plasma activities of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) and whole liver cholesterol content. In 56 day old npc1(-/-) mice that had been fed from 35 days of age a rodent diet or the same diet containing either cholesterol (1.0%, w/w) or ezetimibe (a sterol absorption inhibitor; 0.0125%, w/w), whole liver cholesterol content averaged 33.5 +/- 1.1, 87.9 +/- 1.7, and 20.8 +/- 0.9 mg, respectively. Again, plasma ALT and AST activities were positively correlated with hepatic cholesterol content. In contrast, plasma transaminase levels remained in the normal range in npc1(+/+) mice, in which hepatic esterified cholesterol content had been increased by 72-fold by feeding a high-cholesterol, high-fat diet. These studies suggest that the late endosomal/lysosomal content of unesterified cholesterol correlates with cell damage in NPC disease.     

归脾汤对大鼠心肌缺血的干预作用*

目的:观察归脾汤(GPT)对心肌缺血大鼠的保护作用。方法:将40只SD大鼠随机分为5组(n=8):空白对照组(Control),模型组(Model)、归脾汤低剂量组(Gpt 7.52 g/kg)、归脾汤高剂量组(Gpt 15.04 g/kg),阳性对照药曲美他嗪组(Trimetazidine,2 mg/kg)。应用饲喂高脂饮食联合注射异丙肾上腺素(ISO)的方法建立大鼠心肌缺血模型,灌胃给药15 d后,各组再次腹腔注射ISO 3 d,随后大鼠进行心电图检测,取材,检测血液中甘油三酯(TG)、总胆固醇(TC)、低密度脂蛋白胆固醇(LDL-C)、高密度脂蛋白胆固醇(HDL-C)、丙氨酸氨基转移酶(ALT)、天冬氨酸氨基转移酶(AST)、肌酸激酶(CK)、乳酸脱氢酶(LDH)和葡萄糖(GLU)的变化,HE及Masson染色观察心肌病理改变,Western blot检测心肌组织中CollagenⅠ和CollagenⅢ的蛋白表达。结果:与正常对照组相比,模型组大鼠心电图出现S-T段下移,血清TC、AST、CK、LDH和GLU水平显著升高(P＜0.05),心肌组织CollagenI和CollagenIII蛋白表达显著升高(P＜0.05),心肌受损严重。TG,HDL-C,LDL-C和ALT变化不显著(P＞0.05)。与模型组相比,归脾汤低、高剂量组和曲美他嗪能抑制心肌缺血大鼠心电图S-T段下移,降低血清中TC、AST、CK、LDH和GLU水平(P＜0.05),降低心肌组织CollagenⅢ的表达(P＜0.05),减轻心肌病理损伤程度,归脾汤高剂量组可显著降低CollagenⅠ的蛋白表达(P＜0.05)。结论:归脾汤具有改善心脏功能,减轻心肌缺血损伤的作用,尤以高剂量效果更为显著。     

Isoenzyme patterns in parenchymal and non-parenchymal cells isolated from regenerating and regenerated rat liver

Parenchymal and non-parenchymal cells were isolated from adult rat liver that had been fully regenerated after a 70% partial hepatectomy. The characteristics of the parenchymal cell preparations from regenerated rat liver indicated that they were a homogeneous population and comparable with parenchymal cells isolated from intact liver. The parenchymal cells from regenerated adult rat liver contain glucokinase, hexokinase, pyruvate kinase type I and aldolase B. The non-parenchymal cells contain hexokinase, pyruvate kinase type III and aldolase B. When cells were isolated at different times of the day from rats on controlled feeding schedules, variation of tyrosine aminotransferase activity and liver glycogen content were observed in the parenchymal cells in keeping with the reported diurnal oscillations found in whole liver extracts. When parenchymal cells were isolated from rats 48 and 72h after partial hepatectomy, different isoenzyme patterns were observed. These cells appeared to synthesize pyruvate kinase type III, a function that was assigned previously to non-parenchymal cells or to foetal rat liver hepatocytes.     

Hepatic uptake and antihepatotoxic properties of vitamin E and liposomes in the mouse

Intravenous administration of soybean phosphatidylcholine liposomes containing different amounts of tocopherol acetate leads to a dose and time dependent increase of mouse liver tocopherol content, which was not observed when the preparation was given orally. When benzo[a]pyrene pretreated mice intoxicated with 400 mg/kg AAP were pretreated 2 h before with 1 g/kg phosphatidylcholine liposomes containing 4 mg/kg vitamin E acetate, these animals were protected against liver damage. Vitamin E alone or liposomes lacking vitamin E showed no protection. In an inflammatory liver disease model, i.e. fulminant hepatitis induced by intraperitoneal administration of 700 mg/kg galactosamine and 1 microgram/kg lipopolysaccharide phosphatidylcholine liposomes protected at a dose of 1 g/kg i.v. In this case, however, the protection was not due to the presence of vitamin E. These findings demonstrate the usefulness of phosphatidylcholine for liver protection and show that the protective spectrum is improved when they contain vitamin E. The data suggest that phosphatidylcholine is an excellent carrier for delivery of vitamin E to the liver.     

Intrahepatic distribution of small unilamellar liposomes as a function of liposomal lipid composition

We investigated the intrahepatic distribution of small unilamellar liposomes injected intravenously into rats at a dose of 0.10 mmol of lipid per kg body weight. Sonicated liposomes consisting of cholesterol/sphingomyelin (1:1), (A); cholesterol/egg phosphatidylcholine (1:1), (B); cholesterol/sphingomyelin/phosphatidylserine (5:4:1), (C) or cholesterol/egg-phosphatidylcholine/phosphatidylserine (5:4:1), (D) were labeled by encapsulation of [3H]inulin. The observed differences in rate of blood elimination and hepatic accumulation (A much less than B approximately equal to C less than D) confirmed earlier observations and reflected the rates of uptake of the four liposome formulations by isolated liver macrophages in monolayer culture. Fractionation of the liver into a parenchymal and a non-parenchymal cell fraction revealed that 80-90% of the slowly clearing type-A liposomes were taken up by the parenchymal cells while of the more rapidly eliminated type-B liposomes even more than 95% was associated with the parenchymal cells. Incorporation of phosphatidylserine into the sphingomyelin-based liposomes caused a significant increase in hepatocyte uptake but a much more substantial increase in non-parenchymal cell uptake, resulting in a major shift of the intrahepatic distribution towards the non-parenchymal cell fraction. For the phosphatidylcholine-based liposomes incorporation of phosphatidylserine did not increase the already high uptake by the parenchymal cells while uptake by the non-parenchymal cells was only moderately elevated; this resulted in only a small shift in distribution towards the non-parenchymal cells. The phosphatidylserine-induced increase in liposome uptake by non-parenchymal liver cells was paralleled by an increase in uptake by the spleen. Fractionation of the non-parenchymal liver cells in a Kupffer cell fraction and an endothelial cell fraction showed that even for the slowly eliminated liposomes of type A endothelial cells do not participate to a measurable extent in the elimination process, thus excluding involvement of fluid-phase pinocytosis in the uptake process.     

Protective role of Vitamin E pre-treatment on N-nitrosodiethylamine induced oxidative stress in rat liver

Nitrosamine compounds are known hepatic carcinogens. In the metabolism of nitrosamines, such as N-nitrosodiethylamine (NDEA), there is evidence of the formation of reactive oxygen species (ROS) resulting in oxidative stress, which may be one of the factors in the etiology of cancer. The formation of ROS may alter the antioxidant system, while the presence of Vitamin E may counteract NDEA induced oxidative stress. This study was planned to determine whether pre-treatment with Vitamin E (40 mg/kg body weight, i.p., twice a week for 4 weeks) to NDEA induced rats provides protection against oxidative stress in liver caused by the carcinogen. A single necrogenic dose of NDEA (200mg/kg body weight) was administered i.p. to the male albino rats with or without Vitamin E pre-treatment and the animals were sacrificed on Days 7, 14 or 21 after the administration of NDEA. The result showed enhanced levels of hepatic lipid peroxidation (LPO) and conjugated dienes of NDEA treated rats as the indices of oxidative stress, however, Vitamin E pre-treated rats administered NDEA showed decreased LPO and conjugated dienes (Day 21). Superoxide dismutase (SOD) activity in liver was not altered significantly in NDEA treated rats with or without Vitamin E pre-treatment. Catalase (CAT) activity was inhibited with NDEA treatment, however, Vitamin E pre-treatment showed recovery in hepatic CAT activity (Days 14 and 21). Total and Se-glutathione peroxidase (GSH-Px) activities and glutathione-S-transferase (GST) activity in liver increased in NDEA treated rats irrespective of Vitamin E pre-treatment. Glutathione reductase (GSH-R) activity as well as total glutathione (GSH) content in liver decreased in NDEA treated animals, both of which were recovered in Vitamin E pre-treated rats administered NDEA. Activities of serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP) and lactate dehydrogenase (LDH) were increased significantly following NDEA treatment to rats with or without Vitamin E pre-treatment. The activities of AST and ALT enzymes were significantly reduced on Days 14 and 21 and ALP activity was reduced on Day 21 in NDEA+Vitamin E treated animals when compared to NDEA treated alone. LDH enzyme activity was normalized on Day 14 in Vitamin E pre-treated animals administered NDEA. However, the AST, ALT and ALP enzyme activities remained high in all treatment groups as compared to control group. Normal control and Vitamin E treated alone rats revealed normal histology of liver. On the other hand, NDEA treated animals showed alterations in normal hepatic histoarchitecture, which comprised of necrosis and vacuolization of the cells. However, the rats treated with Vitamin E+NDEA showed that the liver cells were normal, with very little necrosis (Day 21). This study concludes that the pre-treatment with Vitamin E prior to the administration of NDEA, reduced the degree of oxidative stress, although this vitamin produced only slight changes in the hepatic injury, in a time-dependent manner.     

Distribution of [3H]cholesterol-labelled liposomes with or without praziquantel in mice infected with Mesocestoides corti (Cestoda) tetrathyridia

The anthelmintic drug praziquantel (PZQ) has a short half-life in the circulation, necessitating repeated daily administration of PZQ for the therapy of larval stages of cestodes. The effect of incorporation of PZQ into multilamellar liposomes on their biodistribution in Mesocestoides corti (syn. M. vogae) infected mice has been examined using [3H]cholesterol as a liposomal marker. Incorporation of PZQ significantly increased the average size of liposomes with 70.3% of [3H]lip.PZQ particles up to 1.9 microm, whereas higher portion of [3H]liposomes (66.3% of total) were of smaller (up to 1.3 microm). Both liposome preparations were given intraperitoneally to avoid rapid sequestration in the liver. There were significant differences between [3H]liposomes and [3H]lip.PZQ-associated radioactivity in peritoneal adherent cells, liver- and peritoneal larvae, liver, spleen and lymph nodes within 16 days of examination. The highest uptake (about 2-fold more [3H]lip.PZQ than [3H]liposomes from the total dose) was found in peritoneal cells on day 1 post therapy (p.t.) followed by a rapid decline. The kinetic of decline in these cells recovered on day 1 p.t. was studied also in vitro. Disappearance of the marker due to the breakdown of liposomes and efflux of lipids and PZQ from cells was slower for [3H]lip.PZQ in comparison with drug-free liposomes and was not completed after 4 days-incubation. Significantly increased levels of radioactivity, more in [3H]liposomes treated groups, were recorded in the liver- and peritoneal larvae between days 8-16 p.t. indicating re-utilization of cholesterol by the larvae. The data suggest that incorporation of PZQ into liposomes contributes to the enlargement of liposome average size and slows down their degradation in phagocytosing cells. In this respect, these cells could serve as the secondary circulating depots for PZQ releasing it slowly to the circulation.