Herbal extracts differentially inhibit oxidative effects caused by the biotransformation of nifurtimox, nitrofurantoin and acetaminophen on rat liver microsomes / Extractos herbales inhiben diferencialmente los efectos oxidativos causados por la biotransformación de nifurtimox, nitrofurantoína y acetaminofeno en microsomas hepáticos de rata]

Inflammation is a cellular defensive mechanism associated to oxidative stress. The administration of nitrofurantoin, nifurtimox and acetaminophen generates oxidative stress by their biotransformation through CYP450 system. The main adverse effect described for the first two drugs is gastrointestinal inflammation and that of the last, hepatitis. Therefore, standardised dry extracts from Rosmarinus officinalis, Buddleja globosa Hope, Cynara scolymus L., Echinacea purpurea and Hedera helix were tested to evaluate their capacity to decrease drug-induced oxidative stress. For that, rat liver microsomes were incubated with drugs in the presence of NADPH (specific CYP450 system cofactor) to test oxidative damage on microsomal lipids, thiols, and GST activity. All drugs tested induced oxidation of microsomal lipids and thiols, and inhibition of GST activity. Herbal extracts prevented these phenomena in different extension. These results show that antioxidant phytodrugs previously evaluated could alleviate drugs adverse effects associated to oxidative stress.

Inflamación es un mecanismo de defensa el cual está asociado a estrés oxidativo. La administración de nitrofurantoína, nifurtimox y paracetamol genera estrés oxidativo al metabolizarse a través del sistema CYP450. El principal efecto adverso de los dos primeros fármacos es inflamación gastrointestinal y del tercero, hepatitis. Por lo tanto, utilizamos diversos extractos herbales para disminuir el estrés oxidativo inducido por estos fármacos. Para esto se incubaron microsomas hepáticos de rata con dichos fármacos en presencia de NADPH (cofactor específico del sistema CYP450) y se evaluó el daño oxidativo generado sobre los lípidos, los tioles y la actividad GST microsómica. Todos los fármacos indujeron oxidación de los lípidos y los tioles microsómicos e inhibieron la actividad GST. Los extractos herbales previnieron estos fenómenos oxidativos en diferente extensión. Estos resultados indican que fitofármacos antioxidantes previamente evaluados, podrían aliviar los efectos adversos asociados a estrés oxidativo de los fármacos.

Mapeamento cruzado: títulos diagnósticos formulados segundo a CIPE® versus diagnósticos da NANDA Internacional / Cross-Mapping: diagnostic labels formulated according to the ICNP® versus diagnosis of NANDA International / Cruz mapeo: etiquetas diagnósticas formuladas de acuerdo con la CIPE® y comparación con los diagnósticos de la NANDA Internacional

Estudo descritivo cujos objetivos foram elaborar títulos diagnósticos de enfermagem segundo a CIPE®, realizar mapeamento cruzado entre as formulações diagnósticas e os títulos diagnósticos da NANDA-I, identificar dentre os títulos diagnósticos formulados os constantes e não constantes na NANDA-I e realizar mapeamento dos títulos formulados com as Necessidades Humanas Básicas. Utilizou-se técnica de oficina, com 32 enfermeiros de unidades de terapia intensiva, de mapeamento cruzado e de validação por concordância com peritos. Na oficina foram elaborados 1.665 títulos diagnósticos submetidos a processo de refinamento que resultou em 120 títulos, submetidos a mapeamento cruzado com títulos diagnósticos da NANDA-I e com as necessidades humanas básicas. Os produtos do mapeamento foram submetidos à validação de conteúdo por dois enfermeiros peritos, obtendo-se índices de concordância de 92% e 100%. Constatou-se que 63 títulos constavam na NANDA-I e 47 não.

This descriptive study aimed at elaborating nursing diagnostic labels according to ICNP®; conducting a cross-mapping between the diagnostic formulations and the diagnostic labels of NANDA-I; identifying the diagnostic labels thus obtained that were also listed in the NANDA-I; and mapping them according to Basic Human Needs. The workshop technique was applied to 32 intensive care nurses, the cross-mapping and validation based on agreement with experts. The workshop produced 1665 diagnostic labels which were further refined into 120 labels. They were then submitted to a cross-mapping process with both NANDA-I diagnostic labels and the Basic Human Needs. The mapping results underwent content validation by two expert nurses leading to concordance rates of 92% and 100%. It was found that 63 labels were listed in NANDA-I and 47 were not.

Estudio descriptivo cuyos objetivos fueron la elaboración de etiquetas de diagnósticos de enfermería según la CIPE®, para llevar a cabo lo mapeo cruzado entre el diagnóstico formulado y las etiquetas de los diagnósticos NANDA-I, para identificar entre los títulos de diagnósticos formulados los que eran constantes y no constantes en NANDA-I y asignarlos a las necesidades humanas básicas. Fueron conducidas técnica de oficina con 32 enfermeros de las unidades de cuidados intensivos, mapeo cruzado y validación de acuerdo con los expertos. Se elaboró 1665 títulos diagnósticos en la oficina sometidos a un proceso de refinamiento. El resultado fue de 120 títulos que se presentaron a un proceso de mapeo con los títulos de diagnósticos de la NANDA-I y con las necesidades humanas básicas. Validación de contenido se realizó con los productos de lo mapeo por dos enfermeras expertas y las tasas de concordancia del 92% y 100% fueron obtenidas. Se encontró que 63 títulos estaban contenidos en la NANDA-I y 47 no lo hicieron.

Free radical induced damages to rat liver subcellular organelles: inhibition by Andrographis paniculata extract.

Aqueous extract of Andrographis paniculata was examined for antioxidant activity using rat liver subcellular organelles as model systems. The study deals with two important biological oxidative agents, ascorbate-Fe(+2) and AAPH generating hydroxyl and peroxyl radical, respectively. Oxidative damage was examined against the inhibition of membrane peroxidation, protein oxidation and restoration in decreased SOD and catalase activity. The antimutagenic activity of Ap was examined following inhibition in AAPH induced strand breaks in plasmid pBR322 DNA. Extract was a potent scavenger of DPPH, ABTS radicals, exemplified by ESR signals, O2-*, *OH and H2O2, displayed excellent reducing power, FRAP potentials to reduce Fe (III) --> Fe (II) and had considerable amount of phenolics/ flavonoids contents, an effective antioxidant index. The observed antioxidant effect might be primarily due to its high scavenging ability for ROS. Effect was confirmed ex vivo following inhibition in peroxidation, restoration in SOD enzyme, SOD band intensity and protein degradation in Ap fed liver homogenate. Based on these results, it was concluded that the aqueous extract of Andrographis paniculata might emerge as a potent antiradical agent against various pathophysiological oxidants.

Protective effect of Aquilegia vulgaris (L.) on carbon tetrachloride-induced oxidative stress in rats.

The ethyl ether extract of A. vulgaris inhibited in vitro microsomal lipid peroxidation (IC50 58.8 microg/ml) and showed moderate ability to scavenge superoxide radicals and to chelate iron ions. The extract (100 mg/kg body weight, po) decreased uninduced and enzymatic microsomal lipid peroxidation in the liver of male rats pretreated with CCl4 (1 ml/kg body weight) by 27 and 40%, respectively. Activity of antioxidant and related enzymes (catalase and glucose-6-phosphate dehydrogenase) inhibited by CCl4 was significantly restored after administration of the extract. The extract itself significantly enhanced superoxide dismutase activity. There was no effect of the extract on hepatic glutathione level and cytochrome P450 content, both were decreased by CCl4. Neither CCl4 nor the tested extract affected activities of NADPH-cytochrome P450 reductase and two monooxygenases, aniline hydroxylase and aminopyrine n-demethylase. It can be concluded that the protective effect of the A. vulgaris extract in CCl4-induced liver injury is mediated by inhibition of microsomal lipid peroxidation and restoring activity of some antioxidant and related enzymes.

Effect of picroliv administration on hepatic microsomal mixed function oxidases and glutathione-conjugating enzyme system in cholestatic rats.

The effect of Picroliv on hepatic microsomal mixed-function oxidases (MFO) and glutathione conjugating enzyme system in cholestatic rats was studied. Bile duct ligation in male rats for one weeks caused significant increase in both serum sorbitol dehydrogenase activity and serum bile acide concentration indicating cholestatic liver injury. Furthermore, a rise in the hepatic hydroxyproline level indicating collagen accumulation was observed. As a result of these alterations, the hepatic microsomal MFO system was imparied as evidenced by a decrease in cytochrome P-450 system content and in the activities of NADPH-cytochrome C reductase and aminopyrine demethylase. While the hepatic glutathione content remained unaffected, the cytosolic glutathione S-transferase activity was clearly suppressed due to subchronic cholestasis. Oral administration of Picroliv (25 mg/kg/day for 21 days)--a standardized irioid glycoside fraction of Picrorhiza kurroa in bile ligation induced cholestatic rats, singnificantly prevented the biochemical changes induced in liver and serum of cholestatic rats. These results suggested that picroliv has anti-cholestatic activity which may be attributed to antioxidant property or it's specific role in protein synthesis.

Modulation of antioxidant potential in liver of mice by kernel oil of cashew nut (Anacardium occidentale) and its lack of tumour promoting ability in DMBA induced skin papillomagenesis.

Cashew nut shell oil has been reported to possess tumour promoting property. Therefore an attempt has been made to study the modulatory effect of cashew nut (Anlacardium occidentale) kernel oil on antioxidant potential in liver of Swiss albino mice and also to see whether it has tumour promoting ability like the shell oil. The animals were treated orally with two doses (50 and 100 microl/animal/day) of kernel oil of cashew nut for 10 days. The kernel oil was found to enhance the specific activities of SOD, catalase, GST, methylglyoxalase I and levels of GSH. These results suggested that cashew nut kernel oil had an ability to increase the antioxidant status of animals. The decreased level of lipid peroxidation supported this possibility. The tumour promoting property of the kernel oil was also examined and found that cashew nut kernel oil did not exhibit any solitary carcinogenic activity.

Inhibition of rat microsomal lipid peroxidation by the oral administration of D002

The effect of D002, a defined mixture of higher primary alcohols purified from bee wax, on in vivo and in vitro lipid peroxidation was studied. The extent of lipid peroxidation was measured on the basis of the levels of thiobarbituric acid reactive substances (TBARS). When D002 (5-100 mg/kg body weight) was administered orally to rats for two weeks, a partial inhibition of the in vitro enzymatic and non-enzymatic lipid peroxidation was observed in liver and brain microsomes. Maximal protection (46 percent) occurred at a dose of 25 mg/kg. D002 behaved differently depending on both the presence of NADPH and the integrity of liver microsomes, which suggests that under conditions where microsomal metabolism was favored the protective effect of D002 was increased. D002 (25 mg/kg) also completely inhibited carbon tetrachloride- and toluene-induced in vivo lipid peroxidation in liver and brain. Also, D002 significantly lowered in a dose-dependent manner the basal level of TBARS in liver (19-40 percent) and brain (28-44 percent) microsomes. We conclude that the oral administration of D002 (5, 25 and 100 mg/kg) for two weeks protected rat liver and brain microsomes against microsomal lipid peroxidation in vitro and in vivo. Thus, D002 could be useful as a dietary natural antioxidant supplement. More studies are required before these data can be extrapolated to the recommendation for the use of D002 as a dietary antioxidant supplement for humans

Effect of nitric oxide and plant antioxidants on microsomal content of lipid radicals

The antioxidant ability of nitric oxide (NO) generated by a chemical donor and of commercially available antioxidant preparations was assayed. SNAP (S-Nitroso-N-acetylpenicilamine) was used as the NO donor, and Ginkgo biloba, wheat and alfalfa preparations were tested. Lipid peroxidation was assayed by EPR employing a reaction system consisting of rat liver microsomes, ADP, FeCl3, NADPH and POBN in phosphate buffer, pH=7.4. In vitro NO exposure decreased microsomal lipid peroxidation in a dose-dependent manner. The dose responsible for inhibiting the microsomal content of lipid radical adducts by 50% (LD50) for SNAP was 550 microM (NO generation rate 0.1 microM/min). The addition of 50 microM hemoglobin to the incubation media prevented NO effect on lipid peroxidation. The addition of an amount of the antioxidant preparations equivalent to the LD50 doses inhibited lipid peroxidation by 21, 15, and 33% for wheat, alfalfa, ginkgo biloba preparations respectively in the presence of 550 microM SNAP. We detected a decrease in the content of lipid radical adducts after simultaneous supplementation, although it was less than 50%, even when LD50 doses of the products were added. This suggests that NO and the natural antioxidants inhibit lipid peroxidation by a mechanism that has both common and non-shared features.

Hepatoprotective activity of ellagic acid against carbon tetrachloride induced hepatotoxicity in rats.

Administration of CCl4 to normal rats and consequent oral feeding with ellagic acid (50 mg/kg) provided a significant protection against the biochemical alterations in serum and liver produced by CCl4. In vitro experiments showed that liver microsomes from animals treated with ellagic acid and CCl4, decreased lipid peroxidation compared to microsome prepared from rats exposed to CCl4 alone.

Quantitative structure-activity relationship of 4,5-diphenyl-2-(substituted thio)-1H-imidazoles as the inhibitors of acyl CoA: cholesterol acyltransferase.

A quantitative structure-activity relationship (QSAR) analysis of 4,5-diphenyl-2-(substituted thio)-1H-imidazoles as the potential inhibitors of acyl CoA: cholesterol acyltransferase is presented with a view to reflect upon the parametric requirement of various substitutions. For this purpose the van der Waals volume, Vw which is the measure of molecular bulk/size of substituents present at R1- and R2-positions has emerged as the befitting correlative parameter. A number of correlations obtained amongst different subclasses of the title compounds have helped in ascertaining the relative importance of X-substituents and the role of Vw(R1) and Vw(R2). Finally, a significant correlation between the sum of van der Waals volume of R1- and R2-substituents, sigma Vw and biological activities of the entire series was also derived. From the resulting parabolic QSAR equation, an optimum molecular bulk of 1.846 x 10(2) A3 leading to the highest potent compound of the series, specially among those congeners which have X = -NH-, was predicted. This finding has, therefore, hinted at the existence of a cavity, capable of accommodating the maximum steric bulk, on to the receptor.

Inhibition of microsomal activation of aflatoxin B1 by 3-dehydroretinol and 3-dehydroretinyl palmitate.

Two vitamin A2 compounds (3-dehydroretinol and 3-dehydroretinyl palmitate) which are predominantly present in fresh water fish have been found to be very effective in inhibiting the microsome catalysed formation of DNA adduct by the carcinogen aflatoxin B1. The inhibition appears to be due to modulation of microsomal enzymes which activate the carcinogen. Such inhibition may suggest a potential chemopreventive role of these compounds against carcinogenesis induced by aflatoxin B1.

Effect of inducers on hepatic microsomal mixed function oxidase system of male rats during food restriction.

Phenobarbital (PB; 80 mg/kg, ip) or 3-methylcholantrene (3-MC; 20 mg/kg, ip) was administered to Wistar male rats at the end of the feeding period of 30 days and the effects of food restriction (FR) and FR followed by inducer treatment on hepatic drug metabolizing enzymes, microsomal electron transport components, NADPH dependent lipid peroxidation and glutathione-s-transferase activities were studied. In both, PB and 3-MC treatment, the magnitude of increase in microsomal protein content, cytochrome b5 and aminopyrine N-demethylase (APND) activity was less in FR animals than in ad libitum fed; while cytochrome P-450 levels and activities of cytochrome c reductase and acetanilide hydroxylase (ACOH) were higher in FR animals. NADPH dependent lipid peroxidation and cytosolic glutathione-s-transferase activity were also enhanced due to PB and 3-MC treatment but the magnitude of increase was less in FR animals. The ACOH activity increased to a greater extent than APND activity in FR animals following PB and 3-MC treatment. It is suggested that the response to inducers in the FR animals differ from that in the ad libitum fed rats.

Effect of 6-MFA, an interferon inducer obtained from fungus Aspergillus ochraceus on hepatic mixed function oxidase system in rats.

Effect of 6-MFA (sixth mycelial fraction of acetone), an interferon inducer obtained from fungus A. ochraceus on hepatic mixed function oxidase system (MFO) of rat has been investigated. Treatment with 6-MFA, 100 mg/kg/day, ip for 1-5 days to adult rats inhibited significantly the different indices of MFO system, viz. hepatic cytochrome P-450, cytochrome b5 content, cytochrome c reductase, aminopyrine-N-demethylase and acetanilide hydroxylase activities. Similar treatment for 3 days in young growing rats significantly inhibited MFO system's components except acetanilide hydroxylase activity which showed marked elevation. These effects seem to be specific as in vitro experiments suggested that 6-MFA does not compete with subsdtrates nor it acts as a sponge reacting with the end product to give false inhibitory effect. It is concluded from the present study that 6-MFA like other interferon inducers depresses MFO system in rats. Its possible clinical implications are discussed.

Influence of Ca2+ on kinetics and thermodynamics of the NADPH-dependent microsomal lipid peroxidation.

The effect of Ca2+ on kinetics and thermodynamics of lipid peroxidation in microsomes prepared from liver of male Swiss albino mice (7-8 weeks old) was studied. Ca2+ was found to increase the Vmax in temperature dependent manner. Michaelis-Menten constant (Km) also increased with temperature. However, the linearity and extent of change in Km remained unaffected in presence of Ca2+, and was suggestive of non-competitive and mixed type of activation. The activation constant (Ka) obtained by the replotting of slopes of the Lineweaver-Burk plots against the reciprocal of Ca2+ concentration showed linear variation with temperature. The linear pattern of Arrhenius plots indicated non-involvement of parallel reactions of other intermediate species in the lipid peroxidation. Thermodynamic parameters delta H degree, delta S degree and delta G degree, associated with lipid peroxidation process were studied. The positive value of delta H degree is suggestive of the endothermic nature of the process. It appears that the NADPH induced lipid peroxidation is an entropy driven process.

Effect of Ca(2+)-channel blockers, Ca(2+)-ionophore and increased pyrene excimer formation on the microsomal glucose-6-phosphatase.

The dependence of microsomal glucose-6-phosphatase (G-6-Pase) activity on Ca2+ as well as the membrane lipid microviscosity was studied by the effect of Ca(2+)-channel blockers (namely verapamil and nifedipine), Ca(2+)-ionophore, A23187 and pyrene excimer formation. Channel blockers depressed the G-6-Pase and Ca(2+)-ATPase while the ionophore increased these activities. Dimethyl sulfoxide, a known membrane surface active agent showed no change. Ca(2+)-uptake into the membrane has expectedly been lowered by the channel blockers while the ionophores facilitated the ion flux. Excimer formation of the fluorescent probe, pyrene as an indicator of increased membrane fluidity, and microviscosity calculated from there on, showed that Ca(2+)- and lipid microenvironment in the membrane significantly influenced the activity of G-6-Pase. Membrane lipid composition such as phospholipid/cholesterol molar ratio which also indicates an increased membrane fluidity is markedly increased with the ionophore but decreased with the channel blockers, while protein/phospholipid ratio remained unchanged. Microsomal G-6-Pase is a multicomponent multifunctional protein. It is argued that Ca2+ may play the role of an obligatory cofactor not only for the hydrolysis of G-6-P (catalytic part of the enzyme) but also involved in the regulation of substrate and product transport in or out of the endoplasmic reticulum lumen.

Cyclodiene insecticides-induced changes in the central depressive effect of chlorpromazine in rats.

Spontaneous motor activity (SMA), conditioned avoidance response (CAR), muscle coordination (MC) and pentobarbital sleep were tested in rats treated orally for 90 days with tolerated doses of the cyclodiene insecticides, aldrin (1 mg/kg) and endosulfan (2 mg/kg). The same tests were repeated in similarly treated animals after injecting chlorpromazine (4 mg/kg, i.p.). Both the insecticides shortened pentobarbital sleeping time indicating their microsomal enzyme inducing property. Aldrin suppressed SMA, CAR and MC, whereas endosulfan stimulated SMA, inhibited CAR and unaltered MC. However, their concurrent action with CPZ did not result in change in the central depressive effects of the latter, but its potency during the course of its action was altered. Its potency 15 min after injection was greater and 60-180 min later was lesser in these animals than that observed in control animals. This finding was interpreted to suggest that aldrin and endosulfan has quickened the biotransformation of CPZ and thereby shortened its duration of action. A temporary promotion of its potency was accounted to its active metabolites, since prior to inactivation, CPZ is known to be metabolized by the microsomal enzymes to active compounds.

Influence of Ca2+ on microsomal lipid peroxidation.

Lipid peroxidation in microsomes prepared from liver of mice was initiated by NADPH, ascorbic acid and ferrous ions. The presence of Ca2+ modulated the lipid peroxidation in all these three systems. The mode and magnitude depend on the system and concentration of cofactors used for initiation of lipid peroxidation. In ascorbate system, Ca2+ enhanced the lipid peroxidation up to 30 microM concentration of ascorbic acid and beyond 30 microM concentration it inhibited. Ca2+ increased NADPH-dependent lipid peroxidation at all concentrations. Depending on concentration of Fe2+, lipid peroxidation was either decreased or increased in presence of Ca2+. It suggested that the in vitro findings may be cautiously extrapolated to the animal systems. In absence of cofactors, Ca2+ enhanced lipid peroxidation. EGTA inhibited Ca2+-enhanced lipid peroxidation. However in presence of ionophore A23187, Ca2+ potentiated lipid peroxidation. Since Ca2+ has a closed-shell electronic state and lacks electronic transitions, it may not participate directly in lipid peroxidation process. The effect of Ca2+ on lipid peroxidation may be through some biochemical processes or its interactions with membranes leading to various changes in their characteristics.

Interaction of pargyline with tolbutamide in rabbits.

Acute treatment of rabbits with pargyline (50 mg/kg, ip, 30 min before tolbutamide) significantly increased the elimination half life and AUC0-->infinity of tolbutamide resulting in prolonged hypoglycaemia. Similar treatment also prolonged the half life of antipyrine which is used as model drug to indicate hepatic microsomal enzyme activity in vivo confirming that pargyline treatment delayed the elimination of tolbutamide in rabbits by inhibiting its hepatic metabolism.

Mutagenic and genotoxic effects of mate (Ilex paraguariensis) in prokaryotic organisms

1. The mutagenic and genotoxic effects of mate (Ilex paraguariensis) aqueous solutions were analyzed in bacterial cells. 2. Mate solutions showed mutagenic activity in the Ames test (TA97, TA98, TA100 and TA102 strains) at concentrations of 20 to 50 mg/plate (mutagenic factors of 3.5 to 5.6) and genotoxic activity in the inductest (WP2s (lambda) strain), with a maximal phage induction at concentrations of 10 to 20 mg/plate. Above these concentrations the mate solutions were cytotoxic. 3. Addition of 5 U/ml catalase, 20 microliters/ml S9 rat liver microsomal fraction, 100 mM thiourea or 10 mM dipyridyl completely inhibited the lysogenic induction produced by mate; however, the addition of 1,000 U/ml superoxide dismutase was almost ineffective. 4. Oxygen reactive species may be present in mate solutions playing an essential role in its genotoxicity.