Chlorophytum borivilianum as potential terminator of free radicals in various in vitro oxidation systems

Chlorophytum borivilianum is a very popular herb in traditional Indian medicine and used as a potent “Rasayana” drug in “Ayurveda” as a rejuvenator. Currently, a large body of evidence supports the key role of free radicals in diverse pathological conditions such as aging and atherosclerosis. The present investigation essentially focuses on the comprehensive account of in vitro antioxidant activity exerted by C.borivilianum root extracts (i.e., aqueous and ethanolic), to clarify the pharmacological antagonism of chemicals/metals-mediated oxidation. Graded-dose (25 to 1000 µg/ml) of aqueous extract exhibited higher antioxidant potency as evidenced by powerful nitric oxide, superoxide, hydroxyl, DPPH and ABTS^·+ radicals scavenging activity along with reducing capacity (Fe³⁺/ferricyanide complex and FRAP assays), metal chelating ability, as well as markedly suppressed the lipid peroxidation in mitochondrial fractions as compared to ethanolic extract. Further, aqueous extract significantly decreased (P?<?0.05) copper-mediated human serum and kinetics of LDL oxidation, as demonstrated by prolongation of lag phase time with decline of oxidation rate, conjugated dienes, lipid hydroperoxides and thiobarbituric acid reactive substances. In addition, the total polyphenol and flavonoid contents of aqueous extract were higher than that of ethanolic extract, which indicated a positive correlation between antioxidant activity and contents of total phenols. The IC₅₀ values of both extracts were also compared with appropriate antioxidant standards. Overall, aqueous extract of C.borivilianum root has significant powerful antioxidant activity and may favorably affect atherosclerosis risk status by reducing LDL oxidation susceptibility.     

Prevention by alpha-tocopherol and rutin of glutathione and ATP depletion induced by oxidized LDL in cultured endothelial cells.

1. Oxidized low density lipoproteins (LDL) are thought to play an important role in atherogenesis. Mildly oxidized LDL are cytotoxic to cultured endothelial cells. Toxic doses of oxidized LDL promote the peroxidation of cellular lipids (beginning at 6 h and being maximal after 12 h of pulse with oxidized LDL) and glutathione and ATP depletion (beginning after 15 h of pulse and evolving concurrently with the cytotoxicity). 2. Antioxidants from 3 different classes (rutin, ascorbic acid and alpha-tocopherol) were compared as to their ability to inhibit the cytotoxic effect of oxidized LDL to endothelial cells. 3. Effective concentrations of alpha-tocopherol inhibited cellular lipid peroxidation, glutathione and ATP depletion and the cytotoxic effect. 4. Ascorbic acid was less effective than alpha-tocopherol and rutin, and exhibited a dose-dependent biphasic effect in the presence of oxidized LDL. 5. Effective concentrations of rutin inhibited glutathione and ATP depletion as well as cytotoxicity, but did not block cellular lipid peroxidation. This suggests that the glutathione and ATP depletion is directly correlated to the cytotoxicity of oxidized LDL, whereas cellular lipid peroxidation is probably not directly the cause of cellular damage leading to cell death. 6. The association of antioxidants of 3 different classes allowed the suppression of the biphasic effect of ascorbic acid and increased the efficacy of the protective effect. The potential consequences for prevention of the pathogenic role of oxidized LDL in endothelial injury are discussed.     

Defibrotide Protects Endothelial Cells,but not L929 Tumour Cells,from Tumour Necrosis Factor-α-mediated Cytotoxicity

The effect of defibrotide on the cytotoxicity of tumour necrosis factor-α was investigated in cultured bovine pulmonary artery endothelial cells and L929 mouse tumour cells. In endothelial cells, a 72-h incubation with tumour necrosis factor-α (1 and 10 ng mL^?1) reduced the number of viable cells to 63 and 51% of control, respectively. Simultaneous incubation with defibrotide (0·03-0·3 mg mL^?1) protected endothelial cells from tumour necrosis factor-α-mediated cytotoxicity, and increased viability in a concentration-dependent fashion to 98% of control at 1 ng mL^?1 tumour necrosis factor-α and to 80% of control at 10 ng mL^?1 tumour necrosis factor-α. However, under the same conditions a similar cytotoxic response to tumour necrosis factor-α in L929 tumour cells remained unaltered in the presence of defibrotide. These findings demonstrate protection from tumour necrosis factor-α-mediated toxicity by defibrotide in endothelial cells but not in a tumour cell line. It is concluded that defibrotide might serve as a therapeutic agent to limit the vascular toxicity of tumour necrosis factor-α without affecting its antineoplastic activity.     

Tournefortia sarmentosa extract attenuates acetaminophen-induced hepatotoxicity

Context: Tournefortia sarmentosa Lam. (Boraginaceae), a Chinese herbal medicine, is commonly used as a detoxicant or anti-inflammatory agent.

Objective: As acetaminophen (APAP) is a well-known hepatotoxin, we investigated the effect of the aqueous extract of the T. sarmentosa on APAP-induced hepatotoxicity in vivo and in vitro.

Materials and methods: Levels of liver function markers serum glutamate oxaloacetate transaminase (SGOT), glutamate pyruvate transaminase (SGPT), and alkaline phosphatase (ALP), inflammatory markers tumor necrosis factor (TNF)-α, interleukin (IL)-1b, and IL-6 in serum, and antioxidant enzymes catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx), as well as lipid peroxidation were determined.

Results: T. sarmentosa significantly reduced the elevated liver function (SGOT, SGPT, and ALP, p?<?0.01) and inflammatory markers (TNF-α, IL-1β, and IL-6, p?<?0.01) in serum of APAP-intoxicated rats. Malondialdehyde level (p?<?0.05) and antioxidant enzyme levels (CAT, SOD, and GPx, p?<?0.05) were also reduced in APAP-intoxicated rats treated with T. sarmentosa. Incubation of rat hepatocyte cell line clone-9 cells with APAP reduced cell viability and increased the extent of lipid peroxidation. APAP stimulation also reduced the level of glutathione (GSH) and caused reduction in the activities of the antioxidant enzymes, CAT, SOD, and GPx. Pretreatment of hepatocytes with T. sarmentosa aqueous extract before and during APAP stimulation attenuated the extent of lipid peroxidation, increased cell viability and GSH level, and enhanced the activities of antioxidant enzymes.

Discussion and conclusion: These data suggest that the aqueous extract of T. sarmentosa can prevent APAP-induced hepatotoxicity.     

Cardioprotective effects of a proanthocyanidin-rich fraction from Croton celtidifolius Baill: Focus on atherosclerosis

Proanthocyanidins are the most abundant polyphenols in human diets. Epidemiological studies have pointed to proanthocyanidins as promising molecules that could prevent the development of several coronary syndromes by inhibiting the atherogenic process. The present study was designed to investigate the antiatherogenic effects of a proanthocyanidin-rich fraction (PRF) obtained from Croton celtidifolius Baill (Euphorbiaceae) barks. In isolated human LDL, PRF caused a concentration-dependent inhibition of Cu²⁺-induced oxidative modifications, evidenced by the increasing of the lag phase of lipid peroxidation and decreasing in the oxidation rate (V_max), moreover, the protein moieties from LDL were protected against Cu²⁺-induced oxidation. In human umbilical vein endothelial cells (HUVECs), PRF reduced the ROS production stimulated by oxidized LDL. Herein, we demonstrate that oral treatment with PRF improved endothelium-dependent vasorelaxation in hypercholesterolemic LDL receptor knockout mice (LDLr^−/−), however, the fraction did not modify plasma lipids and atherosclerotic lesion size in this experimental model. Finally, our results showed for the first time that PRF prevent isolated LDL oxidation, decrease oxidative stress in endothelial cells and improve endothelial function in mice.     

Estrogen treatment inhibits vascular endothelial senescence and asymmetrical dimethylarginine in ovariectomized rabbits

To investigate the effects of estrogen treatment on aortic endothelial senescence and atherosclerosis, an ovariectomized female rabbit model was constructed, and human umbilical vein endothelial cells were utilized to explore the potential mechanisms. Twenty-eight female rabbits were randomized into 4 groups (7 each): sham operation, ovariectomized, ovariectomized plus low-dose estradiol treatment, and ovariectomized plus high-dose estradiol treatment. All rabbits were fed on high-cholesterol diet for 12 weeks. Blood samples were collected to determine the serum estradiol, asymmetric dimethyl L-arginine (ADMA), and lipid levels, and the aortas were separated for histopathologic analysis. After ovariectomy and high-fat diet, the concentration of serum estradiols declined significantly (P < 0.01) and the levels of ADMA and serum lipids increased (all P < 0.01) as the area of senescent endothelium and atherosclerotic lesions enlarged (both P < 0.01). However, administration of estradiols reduced the levels of ADMA, total cholesterol, and low-density lipoprotein (LDL) cholesterol and inhibited endothelial senescence and atherosclerosis (all P < 0.01). Simultaneously, the concentration of high-density lipoprotein cholesterol and triglyceride increased (all P < 0.01). In vitro experiments also confirmed that estradiols could decrease the ADMA levels induced by oxidized LDL and inhibited oxidized LDL–induced and ADMA-induced human umbilical vein endothelial cell senescence. These results indicate that estrogens can inhibit endothelial senescence and atherosclerosis with reduced ADMA levels and improved lipid profile.     

Natural phenylpropanoids protect endothelial cells against oxidized LDL-induced cytotoxicity

There is increasing evidence that oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis of atherosclerosis and it has been reported that polyphenols inhibit LDL peroxidation and atherosclerosis. Minimally oxidized LDL (mOx-LDL) induce cytotoxicity in cultured bovine aortic endothelial cells (BAEC). The goal of this study was to test the protective effect of five natural polyphenols isolated from the aerial parts of Marrubium vulgare L. against mOx-LDL-induced cytotoxicity in BAEC. Four phenylpropanoid glycosides (acteoside 1, forsythoside B 2, arenarioside 3, ballotetroside 4) and one non-glycosidic derivative (caffeoyl-l-malic acid 5) were tested. These compounds inhibited both copper (Cu 2+)- and 2,2'-azobis(2-amidinopropane) dihydrochloride (AAPH)-induced in vitro LDL oxidation and preserved the morphological aspects of BAEC during their incubation with mOx-LDL. Furthermore, they reduced the accumulation of aldehydes in the cultured medium during the incubation of BAEC with mOx-LDL and prevented cellular LDH leakage during this period. These data suggest that natural phenylpropanoids inhibit mOx-LDL-induced cellular toxicity and that inhibition of lipid peroxidation could be a key mechanism in the cytoprotective effect of these molecules.     

Antioxidant,antihemolytic, and inhibitory activities of endemic Primula heterochroma against Fe2+-induced lipid peroxidation and oxidative stress in rat brain in vitro

Context: The genus Primula (Primulaceae) has been used in traditional medicine to treat convulsion and microbial or viral infections.

Objective: In the present study, we evaluate antioxidant, antihemolytic, and protective effects of flavonoid-rich fractions of endemic Primula heterochroma Stapf. (Primulaceae) against Fe²⁺-induced lipid peroxidation and oxidative stress in rat brain in vitro.

Materials and methods: Aerial parts of plant were defatted and extracted with 60% acetone. Then, 60% acetone extract was fractionated sequentially with n-hexane, ethyl acetate, and water. Antioxidant activity of fractions was evaluated by employing six different assays, i.e., 1,1-diphenyl-2-picryl hydrazyl (DPPH) and hydrogen peroxide scavenging, metal chelating and reducing power activities and hemoglobin-induced linoleic acid system and Fe²⁺-induced lipid peroxidation and oxidative stress in rat brain. Also, its antihemolytic activity was determined using 2,2′-azobis(2-amidinopropane) dihydrochloride-induced hemolysis in rat erythrocyts.

Results: Among the flavonoid-rich fractions of Primula heterochroma, aqueous fraction demonstrated the most protective effect through decreasing brain thiobarbituric acid reactive substances (TBARS) levels at a dose 200?μg mL^?1 (40%, p < 0.001 versus iron group). Also, the aqueous fraction showed better activity in Fe²⁺ chelating (89 ± 3.8 μg mL^?1) and DPPH radical scavenging (394.4 ± 18.4 μg mL^?1) models than other fractions. The probable protective mechanism of flavonoid-rich fractions may be attributed to their Fe²⁺ chelating, DPPH radical scavenging and reducing power activities. Also, the n-hexane fraction demonstrated a higher protective effect in the hemoglobin-induced linoleic acid system and 2,2′-azobis(2-amidinopropane) dihydrochloride-induced hemolysis (67 ± 2.6 μg mL^?1).

Discussion and conclusion: Results of this study demonstrate Primula heterochroma is a rich source of natural antioxidant compounds.     

Hepatoprotective activity of Feronia limonia root

Objectives The aim of this study was to evaluate the hepatoprotective potential of a methanolic extract and of marmesin isolated from the root bark of Feronia limonia. Methods Activity levels of aspartate aminotransaminase (AST) and alanine aminotransaminase (ALT), cell viability and cell death were evaluated in HepG2 cells (human liver hepatoma cells) treated with CCl₄ in the presence or absence of F. limonia extract or marmesin. Plasma activity levels of AST, ALT, bilirubin, alkaline phosphatase, protein, hepatic antioxidants, lipid peroxidation and histopathological evaluations were carried out in rats treated with CCl₄ alone or co‐supplemented with F. limonia extract or marmesin in a dose‐dependent manner. Key findings In‐vitro co‐supplementation of F. limonia methanolic extract or marmesin significantly minimized alteration in levels of AST and ALT and improved cell viability. Oral administration of F. limonia methanolic extract or marmesin significantly prevented CCl₄‐induced elevation in the plasma markers of hepatic damage and hepatic lipid peroxidation and a decrease in hepatic antioxidants. In‐vivo hepatoprotective potential of F. limonia methanolic extract and marmesin was evident from the minimal alterations in the histoarchitecture of liver. Conclusions This has been the first scientific report on the hepatoprotective potential of F. limonia root bark methanolic extract and marmesin.     

Morin attenuates oxidized low‐density lipoprotein‐mediated injury by inducing autophagy via activating AMPK signalling in HUVECs

Endothelial dysfunction is a precursor of cardiovascular disease, and oxidized low‐density lipoprotein (ox‐LDL) has been implicated in the development of atherosclerosis by directly targeting endothelial cells. Morin, a natural flavonol, has been shown to protect endothelial cells from dysfunction. The present study was designed to evaluate the effect of morin on ox‐LDL‐induced injury and to investigate the underlying molecular mechanisms in human umbilical vein endothelial cells (HUVECs). The results showed that morin alleviated ox‐LDL‐induced endothelial injury and promoted the viability of HUVECs exposed to ox‐LDL. Morin significantly inhibited the oxidative stress induced by ox‐LDL by inhibiting the production of reactive oxygen species and malondialdehyde, and downregulating the level of superoxide dismutase. Moreover, morin markedly attenuated the overexpressed mRNA levels of the inflammatory factors interleukin (IL)‐1β, IL‐6, and the adhesion molecules ICAM‐1 and VCAM‐1 induced by exposure to ox‐LDL. We found that morin attenuated ox‐LDL‐induced injury in HUVECs by inducing autophagy. The protective effects of morin against ox‐LDL‐induced injury were dramatically reversed by chloroquine phosphate (CQ) treatment. Furthermore, morin up‐regulated the expression of p‐AMPK and down‐regulated the level of p‐mTOR in HUVECs exposed to ox‐LDL, and this was significantly reversed by the AMPK inhibitor Compound C (CC). Taken together, our results demonstrated that morin attenuates ox‐LDL‐mediated injury by inducing autophagy via activating AMPK signalling in HUVECs.     

Inhibition of LDL Oxidation and Oxidized LDL-induced Cytotoxicity by Dihydropyridine Calcium Antagonists

Purpose. The antioxidant activity of dihydropyridinecalcium channel antagonists was evaluated based on LDL oxidation kinetics,oxidative cell injury associated with reactive species generation, andincreases in free intracellular calcium (Ca²⁺) levels.Interactions with ascorbic acid were studied under conditions representativeof LDL oxidation in plasma and tissue. Methods. Analysis of antioxidant activity utilizedmeasurements of one-electron oxidation potentials and scavenging of peroxyradical-mediated oxidation. LDL antioxidant potency was determinedspectrophotometrically using copper-mediated oxidation kinetics in theabsence and presence of 100 M ascorbic acid. Prevention ofoxidant-induced endothelial cell injury was determined from the formation ofreactive oxygen species generation and increases in intracellular freecalcium concentrations following addition of oxidized LDL or linoleic acidhydroperoxide. Results. Felodipine and amlodipine effectively inhibitperoxyl radical-mediated oxidation in lipoproteins and cells that ismarkedly enhanced in the presence of ascorbic acid. In the presence ofascorbic acid, inhibition of LDL oxidation is over four times greater thanin LDL treated without antioxidants, and oxidized LDL and linoleic acidhydroperoxide-induced reactive oxygen species formation is effectivelysuppressed in cells. Inhibition of intracellular calcium increases wasachieved using nM concentrations of felodipine or amlodipine. Conclusions. The additive effect for ascorbic acid and thecalcium channel antagonist is postulated to involve a combination ofperoxide-degrading and peroxyl radical scavenging reactions, demonstratingthe importance of lipid peroxides during LDL oxidation and oxidizedLDL-induced cytotoxicity. Cytoprotection is associated with inhibition ofoxidant-induced increases in intracellular free calcium. Both thecytoprotective and LDL antioxidant activity for these compounds ismanifested at concentrations approaching the therapeutic levels found inplasma.     

Analgesic activity of Eugenia jambolana leave constituent: A dikaempferol rhamnopyranoside from ethyl acetate soluble fraction

Context: Eugenia jambolana Lam. (Myrtaceae) is a medicinal plant used in folk medicine for the treatment of diabetes, inflammation, and pain.

Objective: We investigated the antinociceptive effect of kaempferol-7-O-α-l-rhamnopyranoside]- 4′-O-4′-[kaempferol-7-O-α-l-rhamnopyranoside (EJ-01), isolated from the E. jambolana leaves.

Materials and methods: EJ-01 (3, 10, and 30?mg?kg^?1, orally) was assessed for peripheral (formalin-nociception and acetic acid-writhing) and central (hot plate and tail flick test) analgesic activity in mice and the in vitro anti-inflammatory activity (25, 50, and 100?µg?mL^?1) in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells.

Results and discussion: EJ-01 (10 and 30?mg?kg^?1) significantly inhibited mean writhing counts (37.74 and 36.83) in acetic acid writhing and paw licking time (55.16 and 45.66?s) in the late phase of the formalin test as compared with the respective control (60.66 and 104.33?s). EJ-01 did not show analgesic activity in central pain models. Significant reduction in the tumor necrosis factor (TNF)-α (295.48, 51.20, and 49.47?pg?mL^?1) and interleukin (IL)-1β (59.38, 20.08, and 15.46?pg?mL^?1) levels were observed in EJ-01-treated medium (25, 50, and 100?µg?mL^?1) as compared with vehicle-treated control values (788.67 and 161.77?pg?mL^?1), respectively. Significant reduction in total nitrite plus nitrate (NO_x) levels (70.80?nmol) was observed in the EJ-01-treated medium (100?µg?mL^?1) as compared with the vehicle-treated value (110.41?nmol).

Conclusion: EJ-01 is a valuable analgesic constituent of E. jambolana leaves and this study supports the pharmacological basis for the use of this plant in traditional medicine for curing inflammatory pain.     

Antioxidant activity of piperlactam S: prevention of copper-induced LDL peroxidation and amelioration of free radical-induced oxidative stress of endothelial cells

The protective effects of piperlactam S, an alkaloid isolated from Piper kadsura (Choisy) Ohwi, on lipid peroxidation and free radical-mediated cell injuries were investigated. Piperlactam S (1 to 20 microM) concentration-dependently prevented the copper-catalyzed oxidative modification of human low-density lipoproteins (LDL) measured through (i) the lag period, (ii) the slope of the propagation phase, (iii) the total amount of conjugated dienes formed, and (iv) the electrophoretic mobility of LDL. Fe2+-induced oxidative modification of cell membrane was also significantly attenuated by piperlactam S as measured by thiobarbituric acid-reactive substances (TBARS). Furthermore, piperlactam S effectively minimized the loss of cell viability induced by Fenton's reagent (H2O2/FeSO4) in cultured endothelial cells and significantly reversed H2O2/FeSO4-induced impairment of endothelium-dependent relaxation to acetylcholine in rat aorta. Since the oxidative modification of LDL plays an important role in the genesis of atherosclerosis, piperlactam S may help to reduce the risk of atherosclerosis, not only by protecting LDL and membrane lipids from oxidative modification but also by reducing free radical-induced endothelial injury and/or dysfunction.     

Hyparrhenia hirta: A potential protective agent against hematotoxicity and genotoxicity of sodium nitrate in adult rats

The present study was carried out to examine the adverse hematotoxic and genotoxic effects of water nitrate pollution on male adult rats and the use of hyparrhenia hirta methanolic extract in alleviating these effects. Sodium nitrate (NaNO₃) was administered to adult rats by oral gavage at a dose of 400 mg kg^?1 bw daily for 50 days, while hyparrhenia hirta methanolic extract was given by drinking water at a dose of 1.5 mg mL^?1 (200 mg kg^?1 bw). The NaNO₃‐treated group showed a significant decrease in red blood cell count, hemoglobin and hematocrit and a significant increase in total white blood cell, in neutrophil and eosinophil counts. Platelet count, mean corpuscular volume, mean corpuscular hemoglobin, and mean corpuscular hemoglobin concentration remained unchanged in treated groups compared to those of controls. Meanwhile, the results showed a marked reduction in the antioxidant enzyme activities, such as superoxide dismutase, catalase, and glutathione peroxidase, along with an elevation in the level of lipid peroxidation and a reduction in the total glutathione content, indicating the induction of oxidative stress in the erythrocytes of NaNO₃‐treated group. Interestingly, NaNO₃ treatment showed a significant increase in the frequencies of total chromosomal aberrations, aberrant metaphases and micronucleus in bone‐marrow cells. The oxidative stress induced by nitrate treatment might be the major cause for chromosomal rearrangements as free radicals leading to DNA damage. Hyparrhenia hirta methanolic extract appeared to be effective against hematotoxic and genotoxic changes induced by nitrate, as evidenced by the improvement of the markers cited above. © 2014 Wiley Periodicals, Inc. Environ Toxicol 30: 1275–1284, 2015.     

Cumene hydroperoxide-mediated lipid peroxidation in rat alveolar macrophages following induction of phospholipidosis with chlorphentermine

Rats were treated for 4 weeks with chlorphentermine hydrochloride (30 mg/kg, i.p., 5 days/week), a regiment which causes a profound phospholipidosis in the alveolar macrophages (AMs). The susceptibility of these lipid-laden cells to lipid peroxidation was examined and compared to AMs from control (untreated) rats. Lipid peroxidation was induced in cells in vitro by incubation with cumene hydroperoxide (10^?5 M?10^?3 M). A dose dependent increase in malonyl dialdehyde (MDA) formation was observed with both populations of AMs. Two to three times more MDA was found in lipidotic AMs than controls at the higher dose of cumene hydroperoxide. Under these conditions, less loss of cellular viability resulted with the lipidotic AMs than controls. The partial depletion of reduced glutathione in the cells led to an even greater MDA formation by both cell-types with the lipidotic AMs being more markedly affected. Both populations of AMs experienced a greater loss of viability associated with loss of reduced glutathione with the control AMs showing more toxicity than the lipidotic cells. Therefore, while the induction of phospholipidosis renders AMs more susceptible to lipid peroxidation, they show less of a loss in cellular viability than control cells. The previously reported augmentation in the antioxidant defense mechanisms in the lipidotic cells may be partially responsible for these results.     

Antioxidant properties of Taraxacum officinale fruit extract are involved in the protective effect against cellular death induced by sodium nitroprusside in brain of rats

Context: Taraxacum officinale Weber (Asteraceae), known as dandelion, is used for medicinal purposes due to its choleretic, diuretic, antitumor, antioxidant, antiinflammatory, and hepatoprotective properties.

Objective: We sought to investigate the protective activity of T. officinale fruit extract against sodium nitroprusside (SNP)-induced decreased cellular viability and increased lipid peroxidation in the cortex, hippocampus, and striatum of rats in vitro. To explain the mechanism of the extract’s antioxidant activity, its putative scavenger activities against NO^˙, DPPH^˙, OH^˙, and H₂O₂ were determined.

Methods: Slices of cortex, hippocampus, and striatum were treated with 50 μM SNP and T. officinale fruit ethanolic extract (1–20 µg/mL) to determine cellular viability by MTT reduction assay. Lipid peroxidation was measure in cortical, hippocampal and striatal slices incubates with SNP (5 µM) and T. officinale fruit extract (1–20 µg/mL). We also determined the scavenger activities of T. officinale fruit extract against NO^˙, DPPH^˙, OH^˙, and H₂O₂, as well as its iron chelating capacity.

Results: The extract (1, 5, 10, and 20 μg/mL) protected against SNP-induced decreases in cellular viability and increases in lipid peroxidation in the cortex, hippocampus, and striatum of rats. The extract had scavenger activity against DPPH^˙ and NO^˙ at low concentrations and was able to protect against H₂O₂ and Fe²⁺-induced deoxyribose oxidation.

Conclusion: T. officinale fruit extract has antioxidant activity and protects brain slices against SNP-induced cellular death. Possible mechanisms of action include its scavenger activities against reactive oxygen species (ROS) and reactive nitrogen species (RNS), which are attributed to the presence of phenolic compounds in the extract.     

Separation and Quantification of Murein and Precursors from Enterobacter cloacae after Treatment with Trimethoprim and Sulphadiazine

Abstract— The intracellular concentrations of the soluble murein precursors UDP-Mur-NAc-pentapeptide in the cytoplasm, the membrane-bound lipid precursor disaccharide pentapeptide and the muropeptides of Enterobacter cloacae cultures treated with trimethoprim (12·5μg mL^?1) and sulphadiazine (250 μg mL^?1) were determined by using capillary zone electrophoresis analysis. In the presence of trimethoprim, UDP-Mur-NAc-pentapeptide as well as disaccharide pentapeptide accumulated. In the case of sulphadiazine-treated cells, the concentration of UDP-Mur-NAc-pentapeptide roughly paralleled the control cells but sulphadiazine caused a slow incremental accumulation of disaccharide pentapeptide. The muropeptide composition of the murein indicated that the differences between the peptidoglycans produced by the control cells and the cells grown in the presence of either trimethoprim or sulphadiazine alone or in combination were quite marked. The results suggest that the enhanced activity of trimethoprim plus sulphadiazine against E. cloacae is caused by an additional effect on the inhibition of the bacterial peptidoglycan biosynthesis and that this additional effect is a fundamental part of the antibacterial action of the antimetabolites. This effect leads to changes of cell morphology and resultant changes in bacterial cell permeability.     

Stanozolol promotes lipid deposition in the aorta through an imbalance in inflammatory cytokines and oxidative status in LDLr knockout mice fed a normal diet

The aim of the study was to evaluate the effect of an anabolic steroid, stanozolol, in a model of atherosclerosis and to investigate the involvement of the modulation of the inflammatory cytokines and oxidative stress in vascular lipid deposition. Low‐density lipid receptor‐deficient (LDLr?/?) mice were fed a standard chow diet and were each week injected subcutaneously either saline (control C group) or 20 mg/kg stanozolol (S group). After 8 weeks, the levels of cholesterol, oxidized LDL (OxLDL) and cytokines were measured in plasma, lipid deposition in aorta was evaluated by en face analysis, and thiobarbituric acid‐reactive substances and oxidation protein were determined in liver. The S group demonstrated increases in vascular lipid deposition, triglycerides and non‐HDL cholesterol levels. Stanozolol increased tumour necrosis factor alpha (TNF‐α) and decreased interleukin‐10 as well as increased the TNF‐α/IL‐10 ratio. Furthermore, oxidative stress was observed in the S group, as indicated by an increase in the plasma OxLDL, as well as by lipid peroxidation and oxidation of proteins in the liver. Chronic treatment with stanozolol promoted lipid deposition in the LDLr^?/? mice that could be attributed to a modification of the circulating cytokine levels and systemic oxidative stress. Our results suggest that the anabolic steroid stanozolol in the absence of functional LDL receptors by increasing systemic inflammation and oxidative stress may increase the risk of development and progression of atherosclerosis.     

Natural phenylpropanoids inhibit lipoprotein-induced endothelin-1 secretion by endothelial cells

There is increasing evidence that oxidized low-density lipoproteins (Ox-LDL) might be involved in the pathogenesis of atherosclerosis and it has been reported that polyphenols inhibit LDL peroxidation and atherosclerosis. Endothelin-1 (ET-1) is a potent vasoconstrictor peptide isolated from endothelial cells and it induces smooth muscle cell proliferation. ET-1 secretion is increased in atheroma and induces deleterious effects such as vasospasm and atherosclerosis. The goal of this study was to test the effect of four natural phenolic compounds against copper-oxidized LDL (Cu-LDL)-induced ET-1 liberation by bovine aortic endothelial cells (BAEC). The tested compounds were phenylpropanoid glycosides previously isolated from the aerial parts of Marrubium vulgare L. (acteoside 1, forsythoside B 2, arenarioside 3 and ballotetroside 4). ET-1 secretion increased when cells were incubated with Cu-LDL but the compounds 1-4 inhibited this increase. These results were confirmed by quantitative-polymerase chain reaction (QPCR) analysis. Since ET-1 plays an important role in atherosclerosis development, our work suggests that the tested phenylpropanoids could have a beneficial effect in inhibiting atherosclerosis development.     

Hepatoprotective Activity of Xanthones and Xanthonolignoids Against tert-Butylhydroperoxide-Induced Toxicity in Isolated Rat Hepatocytes—Comparison with Silybin

Purpose. Synthesize and evaluate the protective activity against tert-butylhydroperoxide-induced toxicity in freshly isolated rat hepatocytes of trans-kielcorin, trans-isokielcorin B, as well as their respective building blocks 3,4-dihydroxy-2-methoxyxanthone and 2,3-dihydroxy-4-methoxyxanthone. Methods. Wistar rats, weighing 200-250g were used. Hepatocyte isolation was performed by collagenase perfusion. Incubations were performed at 37°C, using 1 million cells per milliliter in modified Krebs—Henseleit buffer. The protective activity was evaluated by measuring reduced and oxidized glutathione, lipid peroxidation and cell viability after inducing toxicity with tert-butylhydroperoxide (1.0 mM, 30 min), with or without the studied compounds in the concentrations of 0.025, 0.050, 0.100 and 0.200 mM. Silybin was tested in the same experimental conditions to serve as a positive control. Results. Using these concentrations, the tested compounds prevented tert-butylhydroperoxide-induced lipid peroxidation and cell death in freshly isolated rat hepatocytes. All compounds were also effective in preventing perturbation of cell glutathione homeostasis in some extent. 3,4-Dihydroxy-2-methoxyxanthone and 2,3-dihydroxy-4-methoxyxanthone were more effective than trans-kielcorin and trans-isokielcorin B respectively. Silybin was less effective in protecting cells against lipid peroxidation and loss of cell viability than the four xanthonic derivatives. Conclusions. The tested compounds protected the freshly isolated rat hepatocytes against tert-butylhydroperoxide-induced toxicity.