Polysaccharide isolated from wax apple suppresses ethyl carbamate-induced oxidative damage in human hepatocytes / 浙江大学学报（英文版）（B辑：生物医学和生物技术）

Wax apple (Syzygium samarangense) has received growing research interest for its high nutritional and medicinal value due to its constituents such as polysaccharide, organic acids, flavonoids, minerals, and other substances. In this study, wax apple polysaccharide (WAP) was isolated from this plant and its protective effect against ethyl carbamate (EC)‍-induced oxidative damage was evaluated in human hepatocytes (L02 cells). Firstly, a series of analyses such as high-performance liquid chromatography (HPLC), high-performance gel permeation chromatography (HPGPC), Fourier transform infrared spectroscopy (FT-IR), gas chromatography/mass spectrometry (GC/MS), and 1H and 13C nuclear magnetic resonance (NMR) were conducted to identify the structure of WAP. Thereafter, in vitro cell experiments were performed to verify the protective effects of WAP against EC-induced cytotoxicity, genotoxicity, and oxidative damage in L02 cells. Our results revealed that WAP is composed of mannose, rhamnose, glucuronic acid, galacturonic acid, glucose, galactose, arabinose, and fucose in a molar ratio of 2.20:‍3.94:‍4.45:‍8.56:‍8.86:‍30.82:‍39.78:‍1.48. Using a combination of methylation and NMR spectroscopic analysis, the primary structure of WAP was identified as Araf-(1→, Glcp-(1→, →2)‍-Araf-(1→, →3)‍-Galp-(1→, →3)‍-Araf-‍(1→, and →6)‍-Galp-‍(1→. Cell experiments indicated that WAP exhibited significant protective effects on EC-treated L02 cells via suppressing cytotoxicity and genotoxicity, reducing reactive oxygen species (ROS) and O2•- formation, as well as improving mitochondrial membrane potential (MMP) and glutathione (GSH). In a nutshell, WAP has the potential as an important therapeutic agent or supplement for hepatic oxidative damage. Meanwhile, further studies are needed to prove the above effects in vivo at the biological and clinical levels.

Lipid nanoparticle delivery of siRNA targeting Cyp2e1 gene attenuates subacute alcoholic liver injury in mice / 浙江大学学报·医学版

OBJECTIVES@#To investigate the effect and mechanism of lipid nanoparticle (LNP) delivery of small interfering RNA (siRNA) targeting Cyp2e1 gene on subacute alcoholic liver injury in mice.@*METHODS@#siRNA targeting Cyp2e1 gene was encapsulated in LNP (si-Cyp2e1 LNP) by microfluidic technique and the resulting LNPs were characterized. The optimal dose of si-Cyp2e1 LNP administration was screened. Forty female C57BL/6N mice were randomly divided into blank control group, model control group, si-Cyp2e1 LNP group, LNP control group and metadoxine group. The subacute alcoholic liver injury mouse model was induced by ethanol feeding for 10 d plus ethanol gavage for the last 3 d. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and the superoxide dismutase (SOD) activity as well as malondialdehyde, reactive oxygen species, glutathione, triacylglycerol, total cholesterol contents in liver tissue were measured in each group, and liver index was calculated. The expression of genes related to oxidative stress, lipid synthesis and inflammation in each group of mice were measured by realtime RT-PCR.@*RESULTS@#Compared with the model control group, the levels of liver index, serum ALT, AST activities, malondialdehyde, reactive oxygen species, triacylglycerol, total cholesterol contents in liver tissue decreased, but the SOD activity as well as glutathione increased in the si-Cyp2e1 LNP group (all P<0.01). Hematoxylin-eosin staining result showed disorganized hepatocytes with sparse cytoplasm and a large number of fat vacuoles and necrosis in the model control group, while the si-Cyp2e1 LNP group had uniformly sized and arranged hepatocytes with normal liver tissue morphology and structure. Oil red O staining result showed si-Cyp2e1 LNP group had lower fat content of the liver compared to the model control group (P<0.01), and no fat droplets accumulated. Anti-F4/80 monoclonal antibody fluorescence immunohistochemistry showed that the si-Cyp2e1 LNP group had lower cumulative optical density values compared to the model control group (P<0.01) and no significant inflammatory reaction. Compared with the model control group, the expression of catalytic genes P47phox, P67phox and Gp91phox were reduced (all P<0.01), while the expression of the antioxidant enzyme genes Sod1, Gsh-rd and Gsh-px were increased (all P<0.01). The mRNA expression of the lipid metabolism genes Pgc-1α and Cpt1 were increased (all P<0.01) and the lipid synthesis-related genes Srebp1c, Acc and Fasn were decreased (all P<0.01); the expression of liver inflammation-related genes Tgf-β, Tnf-α and Il-6 were decreased (all P<0.01).@*CONCLUSIONS@#The si-Cyp2e1 LNP may attenuate subacute alcoholic liver injury in mice mainly by reducing reactive oxygen levels, increasing antioxidant activity, blocking oxidative stress pathways and reducing ethanol-induced steatosis and inflammation.

The beneficial effects of virgin olive oil against oxidative stress induced by hypercholesterolemia in rats

Cardiovascular disease(CVD) remains the major cause of mortality in the world, typically claiming a third of all deaths. The primary cause of CVD is atherosclerosis. Therefore, timely prevention and therapy of atherosclerosis are able to reduce the risk of the development of its clinical manifestations. Anti-atherosclerotic activity of medicinal plants mainly appears in their multiple effects.This study was carried out to evaluate the hypolipidemic activity of virgin olive oil in experimentally induced hyperlipemic Wistar. A total of 24 rats were randomly allocated to 4 equal groups and treated as follows for 50 days: (1) Normal control (NC); that were fed with a standart diet; (2) High Cholesterol Diet Control (HCD); which received high cholesterol diet for 50 days; (3) Animals receiving high cholesterol diet for 50 days, after this period the animals are fed for eight days by the standard foodand receiving by gavage virgin olive oil (HCD+VOO) and(4) Animals fed for eight days with the standard food and receiving by gavage olive oil (VOO). High Cholesterol Diet containing yolk egg and coconut oil. Results showed that olive oil caused a significant (p < 0.01) reduction in serum levels of Total Cholesterol (TC), Triglycerides (TG), Low­Density Lipoprotein Cholesterol (LDL) and Atherogenic Index Serum (AIS). The results also demonstrated a significant (p < 0.01) increase in High­Density Lipoprotein Cholesterol (HDL). Moreover, virgin olive oil induced a significant reduction in liver lipid content. On the other hand, a High cholesterol diet induced oxidative stress was measured by estimating reduced glutathione level and amount of thiobarbituric acid reactive substances (TBARS) formed as an index of lipid peroxidation in a liver and a heart. Virgin olive oil supplementation attenuated all these variations. Our observations of the study indicate that the virgin olive oil has a significant antihyperlipidemic potential.

Angiotensin II inhibits Na+/K+ATPase activity in pulmonary artery smooth muscle cells via glutathionylation and with the involvement of a 15.6 kDa inhibitor protein.

The role of angiotensin II in regulating Na+/K+-ATPase activity has been investigated in bovine pulmonary artery smooth muscle cells (BPASMCs). Our study reveals that angiotensin II inhibits the Na+/K+ATPase activity via glutathionylation of the pump with the involvement of an increase in NADPH oxidase-derived O2.-. Additionally, angiotensin II treatment to the cells increases the inhibitory potency of the 15.6 kDa inhibitor towards the Na+/K+ATPase activity.

Comparative experimental study of myocardial protection with crystalloid solutions for heart transplantation / Estudo comparativo experimental da proteção miocárdica com soluções cristalóides para transplante cardíaco

BACKGROUND: There is a growing need to improve myocardial protection, which will lead to better performance of cardiac operations and reduce morbidity and mortality. Therefore, the objective of this study was to compare the efficacy of myocardial protection solution using both intracellular and extracellular crystalloid type regarding the performance of the electrical conduction system, left ventricular contractility and edema, after being subjected to ischemic arrest and reperfusion. METHODS: Hearts isolated from male Wistar (n=32) rats were prepared using Langendorff method and randomly divided equally into four groups according the cardioprotective solutions used Krebs-Henseleit-Buffer (KHB), Bretschneider-HTK (HTK), St. Thomas-1 (STH-1) and Celsior (CEL). After stabilization with KHB at 37ºC, baseline values (control) were collected for heart rate (HR), left ventricle systolic pressure (LVSP), maximum first derivate of rise left ventricular pressure (+dP/dt), maximum first derivate of fall left ventricular pressure (-dP/dt) and coronary flow (CF). The hearts were then perfused at 10ºC for 5 min and kept for 2 h in static ischemia at 20ºC in each cardioprotective solution. Data evaluation was done using analysis of variance in completely randomized One-Way ANOVA and Tukey's test for multiple comparisons. The level of statistical significance chosen was P<0.05. RESULTS: HR was restored with all the solutions used. The evaluation of left ventricular contractility (LVSP, +dP/ dt and -dP/dt) showed that treatment with CEL solution was better compared to other solutions. When analyzing the CF, the HTK solution showed better protection against edema. CONCLUSION: Despite the cardioprotective crystalloid solutions studied are not fully able to suppress the deleterious effects of ischemia and reperfusion in the rat heart, the CEL solution had significantly higher results followed by HTK>KHB>STH-1.

INTRODUÇÃO: Existe crescente necessidade de aprimorar a proteção miocárdica, para melhor desempenho das operações cardíacas e diminuição da morbimortalidade. Portanto, o objetivo deste estudo foi comparar a eficácia da proteção miocárdica usando tanto solução cristaloide tipo intracelular como extracelular quanto ao desempenho do sistema de condução elétrica, contratilidade do ventrículo esquerdo e edema, após parada isquêmica e posterior reperfusão. MÉTODOS: Corações isolados de ratos Wistar foram montados em Langendorff e aleatoriamente divididos em quatro grupos. de acordo com as soluções cardioprotetoras utilizadas Krebs-Henseleit-Buffer (KHB), Bretschneider-HTK (HTK), St. Thomas-1(STH-1) e Celsior (CEL). Após a estabilização com KHB a 37ºC, valores basais (controle) foram coletados para frequência cardíaca (FC), pressão sistólica do ventrículo esquerdo (PSVE), derivada máxima de aumento da pressão ventricular esquerda (+dP/dt), derivada máxima de queda da pressão ventricular esquerda (-dP/dt) e fluxo coronariano (FCo). Os corações foram então perfundidos a 10ºC por 5 min e mantidos por 2 h em isquemia estática a 20ºC em cada solução cardioprotetora. Avaliação dos dados foi por análise de variância inteiramente casualizados em One-Way ANOVA e teste de Tukey para comparações múltiplas. O nível de significância estatística escolhido foi P<0,05. RESULTADOS: Houve recuperação da FC com todas as soluções utilizadas. A avaliação da contratilidade ventricular esquerda (PSVE, +dP/dt e -dP/dt) demonstrou que o tratamento com a solução CEL foi melhor em comparação às outras soluções. Ao analisar o CF, a solução HTK indicou melhor proteção contra edema. CONCLUSÃO: Apesar das soluções cristaloides cardioprotetoras estudadas não serem capazes de suprimir os efeitos deletérios da isquemia e reperfusão no coração de ratos, a solução CEL apresentou resultado superior seguido por HTK>KHB>STH-1.

Effects of ischemic preconditioning associated to different preservation solutions in protecting the intestinal graft / Efeitos do precondicionamento isquêmico associado a diferentes soluções de preservação na proteção do enxerto intestinal

PURPOSE: To evaluate the effects of ischemic preconditioning (IPC) associate with different preservation solutions, in the protecting of gut. METHODS: Four groups of 14 rats underwent laparotomy and collecting 20 cm of ileum, for preservation, at 4ºC, in Belzer (Belz), Ringer (RL), Celsior (Cs) and Custodiol (Cust) solutions, for 24 hours. Prior to collection, half of the animals in each group were subjected to IPC. During preservation, in the periods of zero, 12, 18 and 24 hours, were conducted evaluating the degree of mucosal injury and dosage of malondialdehyde acid (MDA). RESULTS: In all periods the RL group, with and without IPC, presented MDA values higher than the Belz and Cs. The degree of mucosal injury in the non-ipc RLgroup with 12h preservation was higher than the others; with 18 and 24h, the RL and Cust had higher degrees of damage than Cs and Belz. With IPC, in all periods, the group Cs and Belz had lower degrees of injury. CONCLUSION: The Celsior and Belzer solutions had better protective effects on the gut and these effects were enhanced by IPC.

OBJETIVO: Avaliar os efeitos do precondicionamento isquêmico (PCI) associado a diferentes soluções de preservação, na proteção do intestino delgado. MÉTODOS: Quatro grupos de 14 ratos Wistar, foram submetidos à laparotomia e coleta de 20 cm de íleo, para preservação, a 4ºC, nas soluções de Belzer (Belz), Ringer (RL), Celsior (Cs) e Custodiol (Cust) por 24 horas. Previamente à coleta, em metade dos animais de cada grupo, o intestino foi submetido ao PCI. Durante a preservação, nos períodos de Zero, 12, 18 e 24 horas, foram realizados avaliação do grau de lesão da mucosa e dosagem do ácido malondialdeído (MDA). RESULTADOS: Em todos os períodos o grupo RL, sem e com pci, apresentou valores maiores de MDA do que o Belz e Cs. O grau de lesão da mucosa nos grupos sem pci com preservação de 12h, no grupo RL, foi maior que nos demais; com 18h e 24h o grupo RL e Cust apresentaram maiores graus de lesão do que Cs e Belz. Com o pci, em todos os períodos, os grupos Belz e Cs apresentaram menores graus de lesão CONCLUSÃO: As Soluções Celsior e Belzer tiveram melhores efeitos na proteção do intestino e estes efeitos foram incrementados pelo precondicionamento isquêmico.

Comportamento rotacional em Teste de Nado Livre como um modelo em roedores para estudo da neurotoxicidade do chumbo durante a vida adulta / Rotational behavior in free-swimming test as a model in rodents to study the neurotoxicity of lead during adulthood

A exposição ao chumbo ainda permanece como um sério problema de saúde pública, especialmente nos países em desenvolvimento como o Brasil. Apesar do número crescente de estudos mostrando déficits neurocomportamentais em indivíduos expostos ocupacionalmente ao chumbo, os mecanismos envolvidos com a manifestação destes transtornos permanecem pouco conhecidos. Desta forma, o uso de modelos animais abre grandes possibilidades, não somente de investigação dos mecanismos biológicos envolvidos com a toxicidade do chumbo, mas também na elaboração de estratégias para proteção e/ou reversão dos seus efeitos. Portanto, o objetivo central deste trabalho foi avaliar o potencial do comportamento rotacional, medido em testes de nado livre, como um modelo em roedores para estudo dos efeitos neurocomportamentais da exposição ao chumbo durante a vida adulta. Para tanto, foram realizados três estudos. No primeiro, avaliamos os efeitos da exposição subcrônica (60-90 dias) ao chumbo sobre a atividade locomotora no teste de nado livre e em um teste tradicionalmente utilizado para avaliar a ação de substâncias neurotóxicas sobre a locomoção, o campo aberto. Enquanto no campo aberto não foram encontradas diferenças significativas entre o grupo exposto e o grupo controle, no teste de nado livre, os animais expostos ao chumbo apresentaram maior atividade natatória e menor quantidade de alternâncias espontâneas no sentido de natação que o grupo controle. No segundo estudo, observamos que a magnitude dos efeitos do chumbo no teste de nado livre variou em função da consistência da lateralidade, sendo os resultados mais pronunciados no grupo de animais não consistentes (com menor lateralidade). Nos dois estudos, os efeitos do chumbo foram independentes do nível de chumbo em sangue (PbS) dos animais expostos. No terceiro estudo, mostramos um aumento dos níveis de glutationa oxidada no cérebro somente no grupo de animais com PbS acima de 60 ug/dL...

Lead exposure continues to be a serious public health problem, particularly in developing countries such as Brazil. Despite the increasing number of studies showing neurobehavioral deficits in people occupationally exposed to lead, the mechanisms involved in the manifestation of these problems remain largely unknown. In this sense, the use of animal models opens up the possibility of not only investigating the biological mechanisms associated with lead toxicity but also of elaborating strategies aiming at protecting individuals against its ill effects or even reversing those that already present. Therefore, the main objective of the present work was to assess the potential of the rotatory behavior in the free-swimming test as a rodent model for studying of the neurobehavioral effects adult life lead exposure. In the first study, we analyzed the effect of subchronic lead exposure on motor activity in the free-swimming test and in open-field test, which has been traditionally used to assess the effects of toxic substances on locomotion. While no significant differences were observed between the exposed and control groups in the open-field, in the free-swimming test, lead exposed animals displayed increased natatory activity and fewer spontaneous alterations in the direction of locomotion in comparison with the control group. In the second study, we observed that the magnitude of the effects of lead exposure varied as a function of the consistency of the lateralization, being the results more pronounced in inconsistent animals (lesser degree of lateralization). In both studies, the effects of lead were not dependent on blood levels of lead exposed animals. In the third study, we demonstrated a significant increase in the levels of oxidized glutathione in the brain (indicative of oxidative stress) only in the group of animals that had lead levels above 60 ug/dL. Based in these results, we can conclude that: 1) Rotatory behavior in the free-swimming test...

Effect of glutathione on arecanut treated normal human buccal fibroblast culture.

BACKGROUND: Experimental studies have shown arecanut to be a cytotoxic substance with mutagenic and carcinogenic potential. OBJECTIVE: The present study was undertaken to evaluate the effect of glutathione on arecanut treated human buccal fibroblast culture and its potential as a chemopreventive agent. MATERIALS AND METHODS: Fibroblast culture was done in Dulbecco's Modified Eagle's Medium MEM) supplemented with 10% Fetal Calf Serum (FCS) and antibiotic at 370C degrees in an atmosphere of 5% carbon di-oxide and 95% air. The fibroblast cells were subjected to different concentrations of aqueous extracts of raw and boiled arecanut. Fibroblasts were plated in two 24-well culture plates and in each plate, cells were dividt,ednto 2 groups; 600gg microml of reduced glutathione was added to the first group of cells; subsequently, aqueous extracts of raw and boiled arecanut at least and highest concentrations i.e., 20j. microml and 100lg microml were added to the first group of cells in the respective plates whereas the second group served as a control. The morphological alterations and cell survival were assayed at 24, 48, 72, and 96 hours. Results Morphologically, the initial (10 hours) attached fibroblast cells were converted from spheroidal shape towards hexagonal and finally to a fully extended spindle shaped configuration. The three morphological types of fibroblasts at 48 hours were F-I, F-II and F-III. Aqueous extract of raw arecanut exhibited significant cytotoxicity (p < .0 001) at all time periods studied, when compared against the control values of untreated fibroblasts. Addition of reduced glutathione to cultures showed a significant (p < 0. 001) reduction in cytotoxicity, as indicated by higher optical density values and morphological reversion to the spindle-shaped configuration. CoCONCLUSION:Addition of glutathione reduced the cytotoxic and morphological alterations of the fibroblasts treated with aqueous extracts of both raw and boiled arecanut.

Effect of simultaneous exposure to lead and cadmium on gonadotropin binding and steroidogenesis on granulosa cells: an in vitro study.

Effects of lead (Pb) and cadmium (Cd) both alone or in combination on the binding of LH and FSH on isolated granulosa cells were studied. Granulosa cells isolated from proestrous rats were incubated (in vitro) with lead acetate and/or cadmium acetate (0.03 microM of Pb or Cd) for 1 hr. LH binding was dropped to 84% in Pb treated cells, 72.5% in Cd treated cells and 74.8% in combined metal treated cells compared to control. FSH binding dropped to 85.5% in Pb treated cells, 71.16% in Cd treated cells and 72.5% in combined metal treated cells compared to control. Activity of 17beta Hydroxy Steroid Dehydrogenase (17betaHSDH), a key steroidogenic enzyme was reduced by 52% in Cd and 37% in combined metal exposed cells whereas Pb exposed cells showed 31% reduction in the enzyme activity. Pretreatment with SH groups protectants (glutathione [GSH], dithiothretol [DTT]) and zinc caused an ameriolation in enzyme activity whereas Zn pretreatment showed an increase in gonadotropin binding in metal exposed cells. These results suggest that both Pb and Cd can cause a reduction in LH and FSH binding, which significantly alters steroid production in vitro and exerts a direct influence on granulosa cell function.

Antioxidant Effects of Sulfur-Containing Amino Acids

Sulfur is an essential element for the entire biological kingdom because of its incorporation into amino acids, proteins and other biomolecules. Sulfur atoms are also important in the iron-containing flavoenzymes. Unlike humans, plants can use inorganic sulfur to synthesize sulfur-containing amino acids. Therefore, plants are an important source of sulfur for humans. Sulfur-containing compounds are found in all body cells and are indispensable for life. Some of sulfur-containing antioxidant compounds are, cysteine, methionine, taurine, glutathione, lipoic acid, mercaptopropionylglycine, N-acetylcysteine, and the three major organosulfur compounds of garlic oil, diallylsulfide, diallyldisulfide and diallyltrisulfide. In a comparison of the structure-function relationship among these sulfur-containing antioxidant compounds, dihydrolipoic acid (the reduced form of LA) is the most effective antioxidant. Dihydrolipoic acid contains two sulfhydryl groups and can undergo further oxidation reaction to form lipoic acid. The antioxidative activities of sulfur-containing compounds follow a general trend, the more highly reduced forms are stronger antioxidants and the number of sulfur atoms determine, at least in part, their modulatory activites on the glutathione related antioxidant enzymes. In this article, the antioxidant effects and the antioxidative activities, of sulfur-containing amino acids, are reviewed. In addition, the general antioxidant effects and the structure-function relationship of some sulfur-containing compounds are also reviewed.

Evaluation of glutathione and ascorbic acid as suppressors of drug-induced lipid peroxidation.

In different sets of experiment lipid peroxidation induction capacity of two drugs, viz., ceftizoxime sodium, a third generation cephalosporin antibiotic, and acyclovir, an antiviral agent, was studied using goat whole blood as the lipid source. Ceftizoxime sodium caused significant extent of lipid peroxidation. Lipid peroxidation being a toxicity mediating process, such observation may be related to the toxic potential of the drug. Insignificant induction of lipid peroxidation was found in case of acyclovir and this is in good agreement with the safety record of the drug. Glutathione and ascorbic acid could significantly reduce ceftizoxime sodium induced lipid peroxidation, suggesting that free radical scavenging action of antioxidants may be exploited by possible antioxidant co-therapy to reduce iatrogenicity of the drug in persons with impaired endogenous antioxidant defence. Glutathione and ascorbic acid appear to be promising candidates for further investigation in this regard.

Hydrogen peroxide mediates doxorubicin-induced transglutaminase 2 expression in PC-14 human lung cancer cell line

Increased expression of Transglutaminases 2 (TGase 2, TGase C) was observed in PC-14 human lung cancer cells in association with doxorubicin resistance and the reduction of the enzyme expression was correlated with the increasing cytotoxicity of the drug (Han and Park, 1999). Hydrogen peroxide was suggested to be a key mediator for doxorubicin-induced DNA fragmentation leading to apoptosis. A possible role of hydrogen peroxide as a putative mediator of TGase 2 expression in the doxorubicin sensitive PC-14 cells was examined. TGase 2 expression was increased in PC-14 cells treated with doxorubicin in a dose-dependent manner resulting in the concomitant increase of reactive oxygen species. The rise of TGase 2 expression by doxorubicin treatment was inhibited by N-acetylcysteine or glutathione treatment, while direct addition of hydrogen peroxide to PC-14 cells induced TGase 2 expression. These results suggest that generation of hydrogen peroxide induced by doxorubicin treatment is one of the key factors in an enhancement of TGase 2 expression in PC-14 cells.

Mechanistic aspects of modification of radiobiological damage in barley seeds by glutathione and buthionine sulfoximine.

Buthionine sulfoximine (BSO) enhances the radiosensitivity of in vitro mammalian cells, possibly by inhibiting de novo biosynthesis of glutathione (GSH); however, administration of BSO to intact animals results in no effect or possibly radioprotection. Keeping in view that BSO affords radioprotection its physico-chemical action in dry (metabolically inert) and pre-soaked (metabolizing) barley seeds has been investigated with a view that the effects of GSH and BSO on the radiation-induced O2-dependent and - independent components of damage could be unambiguously resolved. It was observed that (i) BSO does not inhibit the uptake of GSH in dry or metabolizing seeds, (ii) BSO also, like GSH, affords radioprotection against post-irradiation O2-dependent damage, and (iii) both additives enhance the O2-independent (i.e. N2- or N2O-mediated) component of damage. An equimolar mixture of these two additives also behaves as either alone on the oxic and anoxic components of radiation damage. Since GSH more efficiently reacts with electrons than it donates an H-atom to the damaged target molecules, and the glutamyl moiety is common to both GSH and BSO, physico-chemical mechanisms possibly involved in the differential modification of oxic and anoxic components are briefly discussed.

Hepatoprotective and toxicological evaluation of hepatomed, an ayurvedic drug.

Hepatoprotective effect of Hepatomed (an ayurvedic drug containing water extract of 6 medicinal plants) has been studied on cumene hydroperoxide (CHP) induced lipid peroxidation and reduced glutathione content in rat liver homogenate. In vitro experiments show significant reduction in the level of malondialdehyde (MDA) induced by 1.5 mM cumene hydroperoxide(CHP). Glutathione content was almost maintained to normal in drug treated rats. Oral treatment of drug up to 3 ml/100 g body weight for 15 days did not show any rise in serum GOT and GPT. On similar doses, significant choleratic effect was observed without any adverse histological changes after 4 days treatment. The results suggest that 'Hepatomed' is a strong hepatoprotective ayurvedic medicine with no detectable adverse effects.

Keratinase of a streptomycete.

Keratinase produced from Streptomyces Sp.A11 decomposed human hair, chicken feather, wool, silk and pure keratin extracted from human epidermis. Purification of the enzyme by DEAE-cellulose column chromatography resulted in 7.5-fold increase in activity relative to the activity of the culture filtrate. The enzyme was inducible, extracellular, homogeneous with a molecular weight of 49,000. The enzyme activity was inhibited by reduced glutathione, phenylmethyl sulphonyl fluoride and 2-mercaptoethanol.

Glutathione as an inhibitor of trypsin induced proteolysis.

Glutathione has been shown to inhibit trypsin induced proteolytic activity. A concentration of 6 mM of glutathione was found to completely inhibit proteolysis of 3H-proline labelled underhydroxylated procollagen as a substrate, whereas a concentration of 2.1 mM of glutathione caused 50% inhibition of proteolysis. When azocoll was used as a substrate for trypsin 50% inhibition of proteolysis was achieved with 1.4 mM of glutathione, though a complete proteolytic inhibition was attained at 4 mM glutathione. The results suggest that glutathione may be playing an important role in protein metabolism in a variety of disease and stress states.

Effect of alpha-tocopherol on the microsomal lipid peroxidation induced by doxorubicin: influence of ascorbic acid.

alpha-Tocopherol (40 mg/rat/day) was administered, orally, to doxorubicin treated rats (2 mg/kg, twice weekly, for 4 weeks) singly and also in combination with ascorbic acid (1 g/100 ml/day) in drinking water. The vitamin therapy was carried out for a period of 1 month. The microsomal lipid peroxide levels in liver and heart were found to be increased in doxorubicin treated rats. alpha-tocopherol and ascorbic acid treatment decreased the lipid peroxide level and also NADPH-dependent lipid peroxidation. A significant depletion of glutathione in liver and heart of doxorubicin treated animals was found to be ameliorated by vitamin therapy. Ascorbic acid was found to maintain the level of microsomal alpha-tocopherol. The activities of the detoxifying enzymes like catalase, superoxide dismutase and glutathione peroxidase were suppressed in doxorubicin treated rats and vitamins coadministration maintained the levels of these enzymes. Ascorbic acid was found to potentiate the antioxidant nature of alpha-tocopherol.

In vitro effect of certain compounds on the lysosomal release of polymorphonuclear leukocytes.

From studies on the release of acid phosphatase and B-glucuronidase, it was observed that quercetin, a vitamin P like compound and ascorbic acid stablise while dehydroascorbate, acetoacetate and B-hydroxybutyrate labilise the leukocytic lysosomes in vitro. These effects were compared with chloroquine and progesterone, known stabiliser and destabiliser, respectively. The possible mode of lysosomal labilisation by ketone bodies and dehydroascorbate has been suggested.