Overblog Suivre ce blog
Administration Créer mon blog
18 avril 2011 1 18 /04 /avril /2011 11:39

Parasitol Res. 2010 Dec 14. [Epub ahead of print]

Antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (black cumin) in mice infected with Plasmodium yoelli nigeriensis.

Okeola VOAdaramoye OANneji CMFalade COFarombi EOAdemowo OG.

Department of Biochemistry, College of Medicine, University of Ibadan, Ibadan, Nigeria.

The antimalarial and antioxidant activities of methanolic extract of Nigella sativa seeds (MENS) were investigated against established malaria infection in vivo using Swiss albino mice.

 

The antimalarial activity of the extract against Plasmodium yoelli nigeriensis (P. yoelli) was assessed using the Rane test procedure.

 

Chloroquine (CQ)-treated group served as positive control.

The extract, at a dose of 1.25 g/kg body weight significantly (p < 0.05) suppressed P. yoelli infection in the mice by 94%, while CQ, the reference drug, produced 86% suppression when compared to the untreated group after the fifth day of treatment. P. yoelli infection caused a significant (p < 0.05) increase in the levels of

red cell and hepatic malondialdehyde (MDA), an index of lipid peroxidation (LPO) in the mice. Serum and hepatic LPO levels were increased by 71% and 113%, respectively, in the untreated infected mice.

Furthermore, P. yoelli infection caused a significant (p < 0.05) decrease in the activities of superoxide dismutase, catalase, glutathione-S-transferase and the level of reduced glutathione in tissues of the mice.

Treatment with MENS significantly (p < 0.05) attenuated the serum and hepatic MDA levels in P. yoelli-infected mice.

In addition, MENS restored the activities of red cell antioxidant enzymes in the infected mice to near normal.

Moreover, MENS was found to be more effective than CQ in parasite clearance and, in the restoration of altered biochemical indices by P. yoelli infection.

These results suggest that N. sativa seeds have strong antioxidant property and, may be a good phytotherapeutic agent against Plasmodium infection in malaria.

 

PMID: 21153838 [PubMed - as supplied by publisher]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:37

J Food Prot. 2010 Dec;73(12):2291-5.

In vitro antifungal effect of black cumin seed quinones against dairy spoilage yeasts at different acidity levels.

Halamova KKokoska LFlesar JSklenickova OSvobodova BMarsik P.

Department of Crop Sciences and Agroforestry, Institute of Tropics and Subtropics, Nutrition and Dietetics, Faculty of Agrobiology, Food and Nature Resources, Czech University of Life Sciences Prague, Kamycka 129, Prague 6-Suchdol, 165 21, Czech Republic.

The antiyeast activity of the black cumin seed (Nigella sativa) quinones dithymoquinone, thymohydroquinone (THQ), and thymoquinone (TQ) were evaluated in vitro with a broth microdilution method against six dairy spoilage yeast species.

Antifungal effects of the quinones were compared with those of preservatives commonly used in milk products (calcium propionate, natamycin, and potassium sorbate) at two pH levels (4.0 and 5.5).

THQ and TQ possessed significant antiyeast activity and affected the growth of all strains tested at both pH levels, with MICs ranging from 8 to 128 μg/ml. With the exception of the antibiotic natamycin, the inhibitory effects of all food preservatives against the yeast strains tested in this study were strongly affected by differences in pH, with MICs of ≥16 and ≥512 μg/ml at pH 4.0 and 5.5, respectively.

 

These findings suggest that HQ and TQ are effective antiyeast agents that could be used in the dairy industry as chemical preservatives of natural origin.

PMID: 21219751 [PubMed - indexed for MEDLINE]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:33

J Zhejiang Univ Sci B. 2011 Mar;12(3):201-9.

Potential immunomodulation effect of the extract of Nigella sativa on ovalbumin sensitized guinea pigs.

Boskabady MHKeyhanmanesh RKhameneh SDoostdar YKhakzad MR.

Pharmaceutical Research Centre, Department of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran. boskabadymh@mums.ac.ir

Several different pharmacological effects have been described for Nigella sativa (Siah-Daneh), including an anti-inflammatory effect.

 

In the present study, the effect of the extract of N. sativa on lung pathology and blood interleukin-4 (IL-4) and interferon-γ (IFN-γ) of sensitized guinea pigs was examined. Three groups (n=8 for each group) of guinea pigs sensitized to ovalbumin (OA) were given drinking water alone, and drinking water containing low and high concentrations of the plant extract, respectively.

 

The animals of the control group (n=8) were treated with saline instead of OA and were given drinking water.

The pathological changes of the lung, including infiltration of eosinophils and lymphocytes, local epithelial necrosis, the presence of oedema, thickening of the basement membrane, smooth muscle layer hypertrophy, mucosal secretion, and the presence of mucosal plug, and blood IL-4 and IFN-γ of sensitized guinea pigs were evaluated.

 

The lungs of the sensitized group showed significant pathological changes (P<0.001).

Blood IL-4 and IFN-γ were increased in sensitized animals compared to the controls (P<0.01 and P<0.001, respectively).

Treatment of sensitized animals with the extract led to a significant decrease in pathological changes of the lung (P<0.01 to P<0.001), except for the oedema in the sensitized group treated with low concentration of the extract, but an increased IFN-γ.

 

These results confirm a preventive effect of N. sativa extract on lung inflammation of sensitized guinea pigs.

PMID: 21370505 [PubMed - in process]PMCID: PMC3048935

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:29

Pak J Pharm Sci. 2011 Apr;24(2):227-31.

Report: Treatment of Nigella sativa in experimental sepsis model in rats.

Alici OKavakli HSKoca CAltintas ND.

Department of Infectious Diseases and Clinical Bacteriology, Medical Park Hospital, Istanbul,Turkey.

This experimental study was designed to determine effects of Nigella sativa oil (NSO) on endothelin-1 (ET-1) level and oxidative stress parameters, superoxide dismutase (SOD) and malondialdehyde (MDA) in a rat sepsis model.

 

Twenty four adult Wistar albino rats were divided randomly into three groups: sham group (group 1), sepsis group (group 2), sepsis group pretreated with NSO (group 3).

 

Serum ET-1, tissue SOD and tissue MDA levels were measured in all groups.

Compared to group 1, ET-1 and MDA levels were higher in group 2. ET-1 and MDA levels in NSO pretreated group 3 were lower with respect to group 2 (p<0.03, and p<0.02, respectively).

 

Additionally, SOD levels in group 3 were found to be higher than group 2 (p<0.02).

 

Based on our results, it can be concluded that NSO may have a positive impact on ET-1 levels and oxidative stress induced by sepsis in experimental rat models.


PMID: 21454175 [PubMed - in process]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:18

BMC Complement Altern Med. 2011 Apr 13;11(1):29. [Epub ahead of print]

Antibacterial activity of Thymoquinone, an active principle of Nigella sativa and its potency to prevent bacterial biofilm formation.

Chaieb KKouidhi BJrah HMahdouani KBakhrouf A.

ABSTRACT:

 

BACKGROUND: Thymoquinone is an active principle of Nigella sativa seed known as "Habbah Al-Sauda" in Arabic countries and "Sinouj" in Tunisia. Bacterial biofilms tend to exhibit significant tolerance to antimicrobials drugs during infections.

METHODS: The antibacterial activity of Thymoquinone (TQ) and its biofilm inhibition potencies were investigated on 11 human pathogenic bacteria. The growth and development of the biofilm were assessed using the crystal violet (CV) and the 2, 3-bis [2-methyloxy-4-nitro-5-sulfophenyl]-2H-tetrazolium-5-carboxanilide (XTT) reduction assay.

RESULTS: TQ exhibited a significant bactericidal activity against the majority of the tested bacteria (MICs values ranged from 8 to 32 ug/ml) especially Gram positive cocci (Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis CIP 106510). Crystal violet assay demonstrated that the minimum biofilm inhibition concentration (BIC50) was reached with 22 ug/ml and 60 ug/ml for Staphylococcus aureus ATCC 25923 and Staphylococcus epidermidis CIP 106510 respectively. In addition our data revealed that cells oxidative activity was influenced by TQ supplementation. In the same way, TQ prevented cell adhesion to glass slides surface.

CONCLUSIONS: The ability of TQ to prevent biofilm formation warrants further investigation to explore its use as bioactive substances with antibiofilm potential.

 


PMID: 21489272 [PubMed - as supplied by publisher]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:14

J Psychosom Res. 2002 Oct;53(4):873-6.

Depression and immune function: central pathways to morbidity and mortality.

Kiecolt-Glaser JKGlaser R.

Department of Psychiatry, The Ohio State University College of Medicine, 1670 Upham Drive, Columbus, OH 43210, USA. kiecolt-glaser.l@osu.edu

OBJECTIVE: The increased morbidity and mortality associated with depression is substantial. In this paper, we review evidence suggesting that depression contributes to disease and death through immune dysregulation.


METHOD: This review focuses on recent human studies addressing the impact of depression on immune function, and the health consequences of those changes.


RESULTS: There is growing evidence that depression can directly stimulate the production of proinflammatory cytokines that influence a spectrum of conditions associated with aging, including cardiovascular disease, osteoporosis, arthritis, type 2 diabetes, certain cancers, periodontal disease, frailty, and functional decline.

Additionally, depression can down-regulate the cellular immune response; as a consequence, processes such as prolonged infection and delayed wound healing that fuel sustained proinflammatory cytokine production may be promoted by depression.


CONCLUSIONS: These direct and indirect processes pose the greatest health risks for older adults who already show age-related increases in proinflammatory cytokine production. Thus, aging interacts with depression to enhance risks for morbidity and mortality.

PMID: 12377296 [PubMed - indexed for MEDLINE]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 11:09

Brain Behav Immun. 2006 Jul;20(4):389-400. Epub 2006 Jan 11.

Hostility and pain are related to inflammation in older adults.

Graham JERobles TFKiecolt-Glaser JKMalarkey WBBissell MGGlaser R.

Department of Molecular Virology, Immunology, and Medical Genetics, Ohio State University College of Medicine, USA. graham.422@osu.edu

Chronically elevated systemic inflammation has a dramatic impact on health for older individuals.

As stress-related responses, both hostility and pain perception may contribute to inflammation which in turn may maintain negative emotion and pain over time.

We used structural equation modeling to examine the degree to which trait hostility and pain were uniquely associated with C-reactive protein (CRP) and serum IL-6 levels over a 6-year span in a sample of older adults. The sample included 113 present or former caregivers of a spouse with dementia and 101 non-caregivers.

After accounting for depression, health behaviours, and other risk factors, which were also assessed longitudinally, pain and, to a lesser extent, hostility were uniquely associated with plasma levels of CRP but not IL-6. When examined separately, the association between pain and CRP was significant only for caregivers, while the association between hostility and CRP was comparable for the two groups.

These findings suggest that hostility may play a role in a cycle of inflammation among older adults, and that pain may be particularly problematic for those under chronic stress.

Our results also shed light on inflammation as a mechanism underlying the effects of hostility on cardiovascular disease morbidity and mortality.

PMID: 16376518 [PubMed - indexed for MEDLINE]

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
18 avril 2011 1 18 /04 /avril /2011 10:18

Brain Behav Immun. 2008 Feb;22(2):215-23. Epub 2007 Sep 12.

Epstein-Barr virus-encoded dUTPase enhances proinflammatory cytokine production by macrophages in contact with endothelial cells: evidence for depression-induced atherosclerotic risk.

Waldman WJ, Williams MV Jr, Lemeshow S, Binkley P, Guttridge D, Kiecolt-Glaser JK, Knight DA, Ladner KJ, Glaser R.

Department of Pathology, The Ohio State University Medical Center, Columbus, OH 43210, USA.

 


Increased levels of proinflammatory cytokines, TNF-alpha and IL-6, predict mortality and morbidity. In cardiovascular disease patients, they are observed in atherosclerotic lesions and serum.

 

Factors behind the increased levels of these cytokines are multifaceted and may include latent herpesviruses, such as Epstein-Barr virus (EBV) that can be reactivated by stress.

 

Previously, we showed that the EBV-encoded deoxyuridine triphosphate nucleotidohydrolase (dUTPase), a protein synthesized in the early phase of virus replication, can induce human monocytes/macrophages to produce TNF-alpha and IL-6. In this study, we modeled the interactions that take place between macrophages and endothelial cells in vivo using human umbilical vein endothelial cells (HUVEC).

 

HUVEC were stimulated by soluble factors induced by EBV dUTPase-treated monocyte-derived macrophages (MDM) that resulted in the upregulation of VCAM-1 and ICAM-1.

These changes were related to MDM production of TNF-alpha following the activation of NF-kappaB.

In a previous study, chronically stressed dementia caregivers had elevations in plasma IL-6 levels, a risk for cardiovascular disease.

We found a relationship between plasma IL-6 levels and neutralizing antibody titers to EBV dUTPase suggesting that one source of the plasma IL-6 observed in our previous study could be related to the effect of EBV-encoded dUTPase on macrophages.

 

The results suggest that EBV-encoded dUTPase can enhance production of proinflammatory cytokines by monocytes/macrophages in contact with endothelial cells of blood vessels, and may play a role in cardiovascular pathology and chronic inflammation.

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
16 avril 2011 6 16 /04 /avril /2011 09:58

Une nouvelle étude publiée cette semaine dans Nature met en évidence un lien entre la capacité de la flore intestinale à métaboliser la lécithine, et la sensibilité aux maladies cardiaques.


Rapportée par Science et Avenir, la nouvelle étude révèle une potentielle influence de la lécithine sur la sensibilité aux maladies cardiovasculaires.

La lécithine, naturellement produite par le foie est métabolisée par la flore intestinale autrement appelée microbiote.


Elle se retrouve couramment dans de nombreux aliments comme la viande, l'œuf ou encore les suppléments alimentaires.


Selon les chercheurs de la clinique Cleveland, de grandes concentrations de trois métabolites de la lécithine, à savoir la bétaïne, la triméthylamine N-oxyde et la choline, entraînerait un risque plus important de maladies cardiovasculaires chez l'Homme.

Pour parvenir à ce résultat, les chercheurs ont mis au point plusieurs expériences.

Le principal auteur de l'étude, Stanley Hazen explique : "Quand deux personnes ont un même régime alimentaire, mais qu’une seule développe une maladie cardiaque, nous estimons actuellement que cette maladie cardiaque apparaît en raison de leurs différences génétiques, mais nos recherches montrent que ce n’est seulement qu'une partie de l'équation. En fait, les différences de métabolisme du microbiote d'une personne à l'autre semblent avoir un effet important dans la génèse d’une maladie cardiaque."


Plus inquiétant encore, l'étude a mis en avant le rôle de la choline, qui une fois métabolisée par les bactéries du tube digestif, aurait un rôle important dans la formation de la plaque d'athérome, qui peut alors entraîner des accidents cardiaques.

Or, M. Hazen explique : "Nous avons vu une énorme augmentation de l'addition de choline dans les multivitamines - même dans celles qui sont commercialisées à nos enfants".

Pour l'heure, cette recherche fait l'objet d'une véritable sensibilisation qui devrait pousser les autorités sanitaires à développer des contrôles du taux de lécithine dans les aliments afin de s'assurer que ces taux ne présentent aucun risque pour la santé des consommateurs.

 

 

Nature. 2011 Apr 7;472(7341):57-63.

Gut flora metabolism of phosphatidylcholine promotes cardiovascular disease.

Wang ZKlipfell EBennett BJKoeth RLevison BSDugar BFeldstein AEBritt EBFu XChung YMWu YSchauer PSmith JDAllayee HTang WHDiDonato JALusis AJHazen SL.

Department of Cell Biology, Cleveland Clinic, Cleveland, Ohio 44195, USA.

Comment in:

 

Metabolomics studies hold promise for the discovery of pathways linked to disease processes.

Cardiovascular disease (CVD) represents the leading cause of death and morbidity worldwide. Here we used a metabolomics approach to generate unbiased small-molecule metabolic profiles in plasma that predict risk for CVD.

Three metabolites of the dietary lipid phosphatidylcholine--choline, trimethylamine N-oxide (TMAO) and betaine--were identified and then shown to predict risk for CVD in an independent large clinical cohort. Dietary supplementation of mice with choline, TMAO or betaine promoted upregulation of multiple macrophage scavenger receptors linked to atherosclerosis, and supplementation with choline or TMAO promoted atherosclerosis.

Studies using germ-free mice confirmed a critical role for dietary choline and gut flora in TMAO production, augmented macrophage cholesterol accumulation and foam cell formation.

Suppression of intestinal microflora in atherosclerosis-prone mice inhibited dietary-choline-enhanced atherosclerosis.

Genetic variations controlling expression of flavin monooxygenases, an enzymatic source of TMAO, segregated with atherosclerosis in hyperlipidaemic mice.

Discovery of a relationship between gut-flora-dependent metabolism of dietary phosphatidylcholine and CVD pathogenesis provides opportunities for the development of new diagnostic tests and therapeutic approaches for atherosclerotic heart disease.

PMID: 21475195 [PubMed - in process]


 

Repost 0
Published by Chronimed - dans Infections froides
commenter cet article
16 avril 2011 6 16 /04 /avril /2011 09:39

 

L’équipe de recherche INRA dirigée par le Pr Dusko-Ehrlich a réussi à décrypter plus de 3 millions de gènes du microbiote intestinal.

Une performance qui permet de détecter les espèces bactériennes associés aux maladies chroniques, à l’image du rôle joué par l’hélicobacter pylori dans l’ulcère de l’estomac.

Mais la perturbation de la flore intestinale est-elle une cause ou une conséquence de la pathologie ? 


Video : 

http://www.pratis.com/shared/skins/pratis_med/modules/webtv/video_player.php?id=2555

 

 

Le séquençage du métagénome intestinal humain est réalisé à 80%

 

En 2008, une cinquantaine de chercheurs se lançaient dans l’étude MetaHIT :
l'analyse du microbiote intestinal de l'homme. Ce travail colossal, comparable au séquençage du génome humain, s’inscrit dans un vaste programme européen coordonné par Dusko Ehrlich, chercheur à l’Inra.
Neuf organismes de recherche européens, quatre industriels et un institut chinois ont été mobilisés pour cet inventaire.
Les chercheurs ont réalisé un catalogue de 3,3 millions de gènes bactériens, qui recenserait 80% de la totalité du métagénome intestinal humain.
L’étude devrait permettre de mieux appréhender l’importance de l’intestin, en dehors de la digestion. "L'ensemble des microbes présents dans le corps humain représente au moins 100 milliards de milliards de cellules, soit dix fois plus que les cellules humaines et près de cent fois plus de gènes que le génome humain, notent les auteurs de l’étude.
La majorité de ces microbes se trouvent dans notre intestin", qui jouerait un rôle clé dans l’organisation du système immunitaire.
Le poids total de la flore intestinale, qui représente un véritable écosystème propre à chaque individu, est estimé à 1,5 kg par ces chercheurs.
Dusko Ehrlich explique : "Ces nouvelles données génétiques nous permettront de mettre au point des diagnostics et d'affiner des pronostics pour de nombreuses maladies comme l'obésité, le diabète, l'autisme, la maladie de Crohn ou la rectocolite hémorragique. Une connaissance bien plus approfondie de la biologie de l'homme devrait en résulter".
Le Figaro – 05/03/10

Gastroenterol Clin Biol. 2010 Sep;34 Suppl 1:S23-8.

Metagenomics of the intestinal microbiota: potential applications.

Dusko Ehrlich SMetaHIT consortium.

 

Institut National de la Recherche Agronomique, MetaHIT coordinator, Microbiology and the Food Chain Division, Jouy-en-Josas, France. dusko.ehrlich@jouy.inra.fr

A major challenge in the human metagenomics field is to identify associations of the bacterial genes and human phenotypes and act to modulate microbial populations in order to improve human health and wellbeing.

MetaHIT project addresses this ambitious challenge by developing and integrating a number of necessary approaches within the context of the gut microbiome.

Among the first results is the establishment of a broad catalog of the human gut microbial genes, which was achieved by an original application of the new generation sequencing technology.

The catalog contains 3.3 million non-redundant genes, 150-fold more than the human genome equivalent and includes a large majority of the gut metagenomic sequences determined across three continents, Europe, America and Asia.

Its content corresponds to some 1000 bacterial species, which likely represent a large fraction of species associated with humankind intestinal tract.

The catalog enables development of the gene profiling approaches aiming to detect associations of bacterial genes and phenotypes.

These should lead to the speedy development of diagnostic and prognostic tools and open avenues to reasoned approaches to the modulation of the individual's microbiota in order to optimize health and well-being.


PMID: 20889001 [PubMed - indexed for MEDLINE]

 

 

Video : 

http://www.pratis.com/shared/skins/pratis_med/modules/webtv/video_player.php?id=2555

 


Repost 0
Published by Chronimed - dans Infections froides
commenter cet article