Comparative study of in vitro antioxidant activity of foliar endophytic fungi and leaves extracts of Peganum harmala of Dayate aiat (Laghouat, Algeria)

Endophytic fungi that reside in plant tissues are a potential source of secondary metabolites with biological activities. In our study, we investigated the detection of the antioxidant activity of the crude fungal extract of the genera Cladosporium, Alternaria, Aspergillus and Penicillium: endophytic fungi isolated from the leaves of Peganum harmala harvested in Laghouat and extract of these same leaves. The extraction of these metabolites was carried out using ethyl acetate. The antioxidant activity of the latter was carried out by the DPPH test. Our tests reveal that the extracts studied have a low antioxidant activity. The inhibitory concentrations show a higher antioxidant effect for the Penicillium extract compared to the other extracts studied. The antioxidant molecules are related to the content of polyphenols. Penicillium extract has the highest polyphenol content. Our results confirm that endophytic fungi are a potential and limited source of natural antioxidant compounds, in the same way as plants.Key words: Leaf extract; Extracts of endophytic fungi; Antioxidant activity; Content ofpolyphenols and Peganum harmala

Risque dû à la consommation des boissons rafraichissantes sans alcool édulcorées

L’objectif de la présente étude est d’estimer la qualité chimique et microbiologique des différents types de boissons rafraichissantes sans alcool (BRSA) commercialisées dans la région de Djelfa. Les résultats obtenus montrent que 36.66% des échantillons sont non conformes à la réglementation Algérienne. 23.33% sont relatives à la qualité chimique (dépassement des doses de la saccharine pour 20% des échantillons et présence d’un édulcorant non autorisé, le cyclamate dans un seul échantillon) et 13.33% relatives à la qualité microbiologique (dû principalement à la flore fongique, plus particulièrement aux levures et secondairement aux coliformes). Quatre classes sont issues de la classification hiérarchique et confirment l’analyse en composante principale; ces classes ne se distinguent que pour les paramètres acésulfame K et aspartame.Mots-clés: édulcorants, CLHP, BRSA, contrôle de qualité, Djelfa.Risque result of sweaters refreshing soft drinks without alcohol consumption The aim of this study is predict chemical and microbiological quality of different type of refreshing soft drinks without alcohol (BRSA) marketed in Djelfa city. The result obtained has proved that 36.66% of samples are no conforming of Algerian regulation. 23.33% are concerning a chemical quality (the exceed of the doses of saccharin for 20% of samples and presence of a Sweetener no permit, the cyclamate in one sample) and 13.33% related to microbiological quality (to resist especially of fungal flore, more specific of yeast and secondarily of coliform). Four cases are resulted of the hierarchic classification and proved the analysis of principal compound; those classes no distinct that for acesulfam K and aspartam permanents.Keywords: sweeteners, HPLC, BRSA, quality control, Djelfa

A new diagnostic marker for secreted Epstein-Barr virus-encoded LMP1 and BARF1 oncoproteins in the serum and saliva of patients with nasopharyngeal carcinoma

Purpose: EBV has been associated with nasopharyngeal carcinomas (NPC). In North Africa, the incidence is bimodal - the first peak occurring at ∼20 years of age and the second peak occurring at ∼50 years. Standard diagnostic tests based on immunofluorescence using anti-IgA EBV have shown that young North African patients have a negative serology compared with older patients. We are interested in two EBV-encoded oncoproteins, LMP1 and BARF1, which have thus far not been studied in terms of their potential as diagnostic markers for NPC. These two viral oncoproteins have been detected in cell culture media, so we tested whether they could be detected in the serum and saliva of patients with NPC. Experimental Design: LMP1 and BARF1 proteins were analyzed in the sera and saliva of young patients and adult patients with NPC from North Africa and China. We then examined whether the secreted proteins had biological activity by analyzing their mitogenic activity. Results: Both LMP1 and BARF1 were present in the serum and saliva from North African and Chinese patients with NPC. All young North African patients secreted both proteins, whereas 62% and 100% of adult patients secreted LMP1 and BARF1, respectively. From animal studies, the secreted LMP1 was associated with exosome-like vesicles. These secreted EBV oncoproteins showed a powerful mitogenic activity in B cells. Conclusion: Both proteins will be a good diagnostic marker for NPC whereas BARF1 is a particularly promising marker for all ages of patients with NPC. Their mitogenic activity suggests their implication in the oncogenic development of NPC. © 2007 American Association for Cancer Research.link_to_subscribed_fulltex

Human tumor virus utilizes exosomes for intercellular communication

The Epstein–Barr virus (EBV) latent membrane protein 1 (LMP1) is expressed in multiple human malignancies and has potent effects on cell growth. It has been detected in exosomes and shown to inhibit immune function. Exosomes are small secreted cellular vesicles that contain proteins, mRNAs, and microRNAs (miRNAs). When produced by malignant cells, they can promote angiogenesis, cell proliferation, tumor-cell invasion, and immune evasion. In this study, exosomes released from nasopharyngeal carcinoma (NPC) cells harboring latent EBV were shown to contain LMP1, signal transduction molecules, and virus-encoded miRNAs. Exposure to these NPC exosomes activated the ERK and AKT signaling pathways in the recipient cells. Interestingly, NPC exosomes also contained viral miRNAs, several of which were enriched in comparison with their intracellular levels. LMP1 induces expression of the EGF receptor in an EBV-negative epithelial cell line, and exosomes produced by these cells also contain high levels of EGF receptor in exosomes. These findings suggest that the effects of EBV and LMP1 on cellular expression also modulate exosome content and properties. The exosomes may manipulate the tumor microenvironment to influence the growth of neighboring cells through the intercellular transfer of LMP1, signaling molecules, and viral miRNAs