44 research outputs found

    Toxicity of south Morocco Rosmarinus officinalis essential oil: antibacterial and histopathological effects

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    Le romarin (Rosmarinus officinalis) possĂšde de nombreuses propriĂ©tĂ©s mĂ©dicinales. Il est connu pour ses effets antimicrobiens et anti-oxydatifs. Le but de ce travail est d’étudier la toxicitĂ© de son huile essentielle (HE) via un test antibactĂ©rien selon la technique de micro-atmosphĂšre et un autre histopathologique au niveau des organes de souris (Swiss albinos). L’analyse de la composition chimique de cette HE a Ă©tĂ© effectuĂ©e par CPG. Les constituants majoritaires de l’HE de R. officinalis sont le 1,8-cinĂ©ole (42%), l’alpha-pinĂšne (11,92%) et le camphre (13.99%). Les quantitĂ©s minimales inhibitrices des souches bactĂ©riennes testĂ©es varient entre 40 ?l et 90 ?l. Au plan histopathologique, une dilatation des alvĂ©oles pulmonaires et une hypertrophie des cellules corticales et mĂ©dullaires des surrĂ©nales ont Ă©tĂ© relevĂ©es. En conclusion, l’HE de R. officinalis ne prĂ©sente pas de toxicitĂ© Ă  la dose 50 ?l/g mais possĂšde des effets stimulants des glandes surrĂ©nales et du systĂšme respiratoire

    Phenotypic and Functional Changes in Blood Monocytes Following Adherence to Endothelium

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    Blood monocytes are known to express endothelial-like genes during co-culture with endothelium. In this study, the time-dependent change in the phenotype pattern of primary blood monocytes after adhering to endothelium is reported using a novel HLA-A2 mistyped co-culture model.Freshly isolated human PBMCs were co-cultured with human umbilical vein endothelial cells or human coronary arterial endothelial cells of converse human leukocyte antigen A2 (HLA-A2) status. This allows the tracking of the PBMC-derived cells by HLA-A2 expression and assessment of their phenotype pattern over time. PBMCs that adhered to the endothelium at the start of the co-culture were predominantly CD11b+ blood monocytes. After 24 to 72 hours in co-culture, the endothelium-adherent monocytes acquired endothelial-like properties including the expression of endothelial nitric oxide synthase, CD105, CD144 and vascular endothelial growth factor receptor 2. The expression of monocyte/macrophage lineage antigens CD14, CD11b and CD36 were down regulated concomitantly. The adherent monocytes did not express CD115 after 1 day of co-culture. By day 6, the monocyte-derived cells expressed vascular cell adhesion molecule 1 in response to tumour necrosis factor alpha. Up to 10% of the PBMCs adhered to the endothelium. These monocyte-derived cells contributed up to 30% of the co-cultured cell layer and this was dose-dependent on the PBMC seeding density.Human blood monocytes undergo rapid phenotype change to resemble endothelial cells after adhering to endothelium

    Chemomodulation of human dendritic cell function by antineoplastic agents in low noncytotoxic concentrations

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    The dose-delivery schedule of conventional chemotherapy, which determines its efficacy and toxicity, is based on the maximum tolerated dose. This strategy has lead to cure and disease control in a significant number of patients but is associated with significant short-term and long-term toxicity. Recent data demonstrate that moderately low-dose chemotherapy may be efficiently combined with immunotherapy, particularly with dendritic cell (DC) vaccines, to improve the overall therapeutic efficacy. However, the direct effects of low and ultra-low concentrations on DCs are still unknown. Here we characterized the effects of low noncytotoxic concentrations of different classes of chemotherapeutic agents on human DCs in vitro. DCs treated with antimicrotubule agents vincristine, vinblastine, and paclitaxel or with antimetabolites 5-aza-2-deoxycytidine and methotrexate, showed increased expression of CD83 and CD40 molecules. Expression of CD80 on DCs was also stimulated by vinblastine, paclitaxel, azacytidine, methotrexate, and mitomycin C used in low nontoxic concentrations. Furthermore, 5-aza-2-deoxycytidine, methotrexate, and mitomycin C increased the ability of human DCs to stimulate proliferation of allogeneic T lymphocytes. Thus, our data demonstrate for the first time that in low noncytotoxic concentrations chemotherapeutic agents do not induce apoptosis of DCs, but directly enhance DC maturation and function. This suggests that modulation of human DCs by noncytotoxic concentrations of antineoplastic drugs, i.e. chemomodulation, might represent a novel approach for up-regulation of functional activity of resident DCs in the tumor microenvironment or improving the efficacy of DCs prepared ex vivo for subsequent vaccinations

    Antibacterial and Antioxidant Potency of Floral Honeys from Different Botanical and Geographical Origins

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    In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin–Ciocalteu method and the free radical scavenging activity by the Fe3+ reducing power (FRAP) assay. Manuka honey was the most effective against Staphylococcus aureus Oxa R and S. aureus Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against Pseudomonas aeruginosa, with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (r value was 0.9079 at P < 0.05) was observed between the total polyphenolic content and the Fe2+ content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations

    Antibacterial and Antioxidant Potency of Floral Honeys from Different Botanical and Geographical Origins

    No full text
    In order to assess their physicochemical and antioxidant properties as well as their antimicrobial potency, four varieties of honey from different botanical and geographical origins were used. The agar incorporation method was used to determine the antimicrobial potency of honeys. The total phenol content was determined by a modified Folin–Ciocalteu method and the free radical scavenging activity by the Fe&lt;sup&gt;3+&lt;/sup&gt; reducing power (FRAP) assay. Manuka honey was the most effective against &lt;em&gt;Staphylococcus aureus &lt;/em&gt;Oxa R and &lt;em&gt;S. aureus &lt;/em&gt;Oxa S with a Minimum Inhibitory Concentration (MIC) of 6% and 7%, respectively, whereas wild carrot honey was the most effective against &lt;em&gt;Pseudomonas aeruginosa&lt;/em&gt;,&lt;em&gt; &lt;/em&gt;with a MIC of 12%. Lavender honey was the least effective against all tested strains, even though was found to have the lowest pH and water content. Manuka honey had the highest content of polyphenols, with 899.09 ± 11.75 mg gallic acid/kg, whereas lavender honey had the lowest, with 111.42 ± 3.54 mg gallic acid/kg. A very significant correlation (&lt;em&gt;r&lt;/em&gt; value was 0.9079 at &lt;em&gt;P&lt;/em&gt; &lt; 0.05) was observed between the total polyphenolic content and the Fe&lt;sup&gt;2+&lt;/sup&gt; content formed in the presence of the honey antioxidants. The differences between honey samples in terms of antibacterial and antioxidant activity could be attributed to the natural variations in floral sources of nectar and the different locations
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