Hayat Azouri

Saint Joseph University, Lebanon, Beyrouth, Beyrouth, Lebanon

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Publications (6)14.35 Total impact

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    ABSTRACT: This paper reports for the first time a method for determining deoxynivalenol (DON) in crushed wheat (bulgur) using an high-performance liquid chromatography (HPLC) method with ultraviolet light detection. Linearity (r (2) > 0.999), selectivity and recovery (70-110%) were acceptable. Results show that the limit of detection (LOD) was 50 µg kg(-1) and the limit of quantification (LOQ) was 80 µg kg(-1). The level of DON was determined in 165 samples of cereals - wheat, forkha (wheat flour special for cake) and bulgur (crushed wheat) - marketed in Lebanon. The results showed that the contamination with DON was 8.75%, 7.5% and 5.0% in bulgur, wheat and forkha, respectively. The LOD and LOQ for wheat (or forkha) were, respectively, 40 and 50 µg kg(-1). The level of DON in all samples was below 1250 µg kg(-1) as recommended by European Union Directives (Commission Regulation (EC) No. 1126/2007), except for one sample of wheat which contained 2307 µg kg(-1). These data suggest that the Lebanese population is exposed to DON through food ingestion at concentrations lower than the tolerable daily intake (TDI) and suggest that measures must be performed routinely to avoid high levels of DON contamination to be found on Lebanese market.
    Food Additives and Contaminants: Part B Surveillance 03/2010; 3(1):45-51.
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    ABSTRACT: Dendritic cells (DCs) play a major role in the regulation of immune responses to a variety of antigens (Ag) and haptens which participate in the process of DC maturation. Indeed, metallic haptens are able to induce DC maturation in vitro but the mechanism of this maturation is not well understood. We and others have already shown that NiSO(4) activates p38 mitogen-activated protein kinases (p38MAPK), c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK) and the transcription factor NF-kappaB during the early events of DCs maturation. However, the effect of other metallic haptens on DC maturation is still poorly understood. In the present study, using dendritic cells derived from CD34(+) cord blood cells, we showed that both NiSO(4) and CoCl(2) induced the expression of CD86, CD83, HLA-DR and CD40 and the production of IL-6 in human DCs while K(2)Cr(2)O(7) induced only a slight upregulation of CD86. Interestingly, only NiSO(4) was able to induce the production of IL-12p40. NiSO(4) and CoCl(2) but not K(2)Cr(2)O(7) were able to activate the MAPK pathway and the transcription factor NF-kappaB. The role of MAPKs in metals-induced DC maturation was then evaluated using well-described pharmacological inhibitors. Our results suggest that p38MAPK activation regulates the expression of CD86 and CD83 induced by NiSO(4) while it only affects the expression of CD83 induced by CoCl(2). IL-6 production induced by NiSO(4) and CoCl(2) strongly depended on all MAPKs. IL-12p40 synthesis after NiSO(4) treatment was regulated by both p38MAPK and JNK pathways whereas ERK may play an inhibitory role. Our results show that both NiSO(4) and CoCl(2) activate similar signaling pathways that are playing different roles in DC maturation depending on the hapten used.
    Toxicology in Vitro 01/2009; 23(2):227-34. · 2.65 Impact Factor
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    ABSTRACT: Five hundred and ten strains of filamentous fungi were isolated from Lebanese grapes during 2005 at veraison and harvesting periods. Four hundred eighty-seven isolates belonged to the Aspergillus spp. (95.5%) and 23 belonged to the Penicillium spp. (4.5%). Black aspergilli constituted 56.9% (52.2% Aspergillus niger aggregates, 2.9% Aspergillus japonicus and 1.8% Aspergillus carbonarius) while the isolation rate of Aspergillus flavus the none habitual member of grape mycobiota was 43.1% of the total Aspergillus spp. isolated. All isolates were tested for the ability to produce the Ochratoxin A (OTA) and the Aflatoxin B1 (AFB1). A. carbonarius showed that it is the only species able to produce the OTA with a production ability of 100% and a maximum concentration reaching 8.38microg/g CYA. As for the aflatoxigenic ability, 43.4% of A. flavus isolates produced this mycotoxin with a maximum production reaching 22.6microg/g CYA while none of the other isolates showed a production capacity of this mycotoxin. Forty-seven samples of must produced from the collected grapes were also analyzed. None of these samples was contaminated by OTA at a detectable limit while 40% of these same samples were found to contain AFB1 with concentrations ranging from 0.01 to 0.46microgl(-1).
    Food and Chemical Toxicology 07/2008; 46(6):2244-50. · 3.01 Impact Factor
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    ABSTRACT: This paper reports the results of an extensive survey on the occurrence of filamentous fungi isolated from wine-grapes in Lebanon and to test their ability to produce ochratoxin A (OTA) and aflatoxin B1 (AFB1) on CYA culture medium, in order to assess their potential for producing these mycotoxins on grapes. From the 470 grapes samples taken during season 2004, 550 fungi strains were isolated with 490 belonging to Aspergillus spp. and 60 belonging to Penicillium spp. All these isolated fungi starins were tested for their ability to produce OTA and AFB1. Aspergillus carbonarius shows that it is the only species able to produce OTA with a production percentage reaching 100% and a maximum concentration of 52.8 microg/g of Czapek yeast extract agar (CYA). In its turn, Aspergillus flavus was considered as the only AFB1-producing species with production percentage of 45.3% and a maximum concentration reaching 40 microg/g CYA. A total of 47 handmade musts produced from the collected grapes were also analyzed in order to correlate the presence of OTA in must and the occurrence of filamentous fungi on grapes; 57.4% were contaminated with OTA at low level with concentrations ranging between 0.011 and 0.221 microg OTA L(-1). The analysis of these must samples was not performed with regard to AFB1. Seventy samples of finish red wine were also assayed for OTA content. The results showed that 42 of the tested samples (60%) were found to be positive for OTA with low levels (0.012-0.126 microg OTA L(-1)).
    Journal of Agricultural and Food Chemistry 12/2006; 54(23):8977-82. · 2.91 Impact Factor
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    ABSTRACT: Ochratoxin A (OTA) is a widespread mycotoxin which contaminates food such as cereals, beer, coffee, wine and products of animal origin. OTA is known for its nephrotoxic, immunotoxic and carcinogenic properties. The prevalence of OTA in human blood and foodstuffs has been investigated in many countries. In this study, exposure of the Lebanese population to OTA was evaluated and the contamination of the most commonly consumed foods in Lebanon by OTA was assessed. Plasma samples from healthy individuals and also cereals and beer samples obtained from markets were collected from the different regions of Lebanon. OTA was detectable in 33% of tested plasma samples (n =250) with a concentration ranging from 0.1 to 0.87 ng/mL and a mean of 0.17+/-0.01ng/mL. No sex and age differences were found. The frequency of OTA-positive plasma samples obtained in the South of Lebanon and in the Bekaa valley (50 and 47%, respectively) was significantly higher compared to plasma samples obtained in the Beirut/Mount Lebanon region (19%). Food analyses showed that wheat, burghul and beer were contaminated with a mean value of 0.15+/-0.03 microg/kg, 0.21+/-0.04 microg/kg and 0.19+/-0.12 ng/mL, respectively. These data suggest that the Lebanese population is exposed to OTA through food ingestion at concentrations lower than the tolerable daily intake.
    Human &amp Experimental Toxicology 11/2004; 23(10):495-501. · 1.45 Impact Factor
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    Hind Assaf, Hayat Azouri, Marc Pallardy
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    ABSTRACT: Ochratoxin A (OTA) is a widespread mycotoxin contaminating feed and food. Besides its potent nephrotoxicity, OTA also affects the immune system. We demonstrate here a role for Bcl-x(L) in OTA-induced apoptosis in human lymphocytes. In particular, human peripheral blood lymphocytes and the human lymphoid T cell line, Kit 225 cells, underwent apoptosis in a time- and dose-dependent manner. This apoptosis was inhibited by z-VAD.fmk, suggesting that caspases were responsible for the induction of apoptosis. Moreover, OTA triggered mitochondrial transmembrane potential (Deltachim) loss and caspase-9 and caspase-3 activation. Interestingly, Bcl-x(L) protein expression was decreased by OTA treatment, whereas Bcl-2 protein level was not affected. Down-regulation of bcl-x(L) mRNA was not observed in cells treated with OTA. Overexpression of Bcl-x(L) in Kit 225 cells protected them against mitochondrial perturbation and retarded the appearance of apoptotic cells. Taken together, our data indicate that mitochondria are a central component in OTA-induced apoptosis and that the loss of Bcl-x(L) may participate in OTA-induced cell death.
    Toxicological Sciences 07/2004; 79(2):335-44. · 4.33 Impact Factor