[Polymorphism of human platelet antigens in Tunisian population: Clinical and anthropological interests]. / Polymorphisme des antigènes plaquettaires humains dans la population tunisienne : intérêt clinique et anthropologique.

OBJECTIVES: Human Platelet Antigens (HPA) are of considerable interest in obstetric transfusion medicine and anthropological genetics. This study aims to provide clinicians with a detailed database of HPA antigenic variants, which allows them to estimate the probability of allo-immunisation of each antigen. In addition, it aims to make an interethnic comparison of the Tunisian population with other populations. METHODS: The target population consists of 324 healthy and unrelated Tunisian blood donors recruited from the National Blood Transfusion Center in Tunis. DNA extraction was performed by the Salting Out method and molecular genotyping was performed by the PCR-SSP technique. The statistical analysis was performed using two approaches: manual calculation and computerized calculation. Phylogenetic trees were constructed through the use of Standard Genetic Distances that were calculated from allelic frequencies. RESULTS: With the exception of the HPA-4 system, statistical analysis showed that all HPA systems are polymorphic especially the two systems HPA-3 and HPA-15. The inter-ethnic analysis showed that Tunisians are closer to North Africans and Caucasians than Sub-Saharan and Asian populations, which shows genetic mixing between Tunisians, Arabs, Europeans and Africans. CONCLUSION: The results of this study could be exploited to prepare a ready-to-use genotyping plate dedicated to HPA antigens, with the aim of ensuring better management, especially for polytransfused patients.

Chemical investigation of different crude extracts from Teucrium ramosissimum leaves. Correlation with their antigenotoxic and antioxidant properties.

The effect of extracts obtained from Teucrium ramosissimum leaves on genotoxicity and SOS response induced by aflatoxin B(1) (0.5 µg/assay) as well as nitrofurantoin (5 µg/assay) was investigated in a bacterial assay system, i.e., the SOS chromotest with Escherichia coli PQ37. The T. ramosissimum tested extracts exhibited no genotoxicity either with or without the external S9 activation mixture. However, all the extracts, particularly the total oligomers flavonoids (TOF) extract significantly decreased the genotoxicity induced by aflatoxin B(1) and nitrofurantoin. Antioxidant capacity of the tested extracts was evaluated using the enzymatic (xanthine/xanthine oxidase assay) (X/XOD) and the non-enzymatic (NBT/Riboflavine assay) systems. TOF extract was the most effective one in inhibiting both xanthine oxidase activity and NBT reduction. Our findings emphasize the potential of T. ramosissimum to prevent mutations and also its antioxidant effect.

[Choice of primers: a determining element in molecular diagnosis of cutaneous leishmaniasis]. / Choix des amorces: élément déterminant dans le diagnostic moléculaire de la leishmaniose cutanée.

The cutaneous leishmaniasis (CL) is a parasitic disease which represents a serious problem for the public health not only in Tunisia but also all over the world. Its diagnosis is based on the techniques which are usually used, direct examination and in vitro culture. Because of several factors, these techniques lack sensitivity. The molecular biology, which is indeed more rapid and more sensitive, has proved its effectiveness in diagnosis of the CL. There are two main aims for our research work. First, to show the contribution of the Polymerase Chain Reaction (PCR) during the diagnosis of CL (of course by comparing the results obtained when using this technique with those found through the direct examination); second, to compare the two pairs of primers which amplify the leishmanien gene coding for the 18s ribosomal sub-unit: the pair R221/R332 (PCR1) and the pair Lei70L/Lei70R (PCR2). Our work was carried out upon 299 samples. One hundred and eighty-eight of them were positive using the direct examination and/or the PCR and 111 were negative. Only two samples were positive using of course the direct examination in comparison with 74 which were positive when using only the PCR (PCR1 and/or PCR2). Among these 74 samples, 64 where positive using only PCR2 in comparison with two samples which were positive using only PCR1. The eight remaining samples were at once positive for the PCR1 and the PCR2. The PCR (notably the PCR2) has proved a more significant percentage of positivity in comparison with direct examination: 98.98% for the PCR and 60.6% for direct examination.

Assessment of phenolic content, free-radical-scavenging capacity genotoxic and anti-genotoxic effect of aqueous extract prepared from Moricandia arvensis leaves.

The present study was undertaken to provide a set of data on the safety of an aqueous extract (AQE) from Moricandia arvensis. For this reason, Escherichia coli tested strains PQ35 and PQ37 were used to detect induction of DNA lesions by AQE. The SOS Chromotest showed that AQE induced a marginally genotoxic effect, as expressed by the induction factor (IF) value only with E. coli PQ37 tested strain (IF=1.77 at a dose of 250 microg/assay). The measurement of the anti-genotoxic activity of the AQE was also studied by inhibition of beta-galactosidase induction. A significant anti-genotoxic effect was observed with different tested doses of AQE, which suggests that M. arvensis extract has the potential to protect DNA from the action of nitrofurantoïn (NF) and free radicals generated by hydrogen peroxide (H2O2). In addition to anti-genotoxic activity, AQE showed a free-radical-scavenging capacity towards ABTS+* and DPPH*. Total phenolic content was also evaluated following Folin-Ciocalteu method and results indicated high correlation between total phenol content and anti-genotoxic and antioxidant activities for AQE, but the highest correlation was showed with its capacity to stabilize ABTS+* (R2=0.9944).

Antigenotoxic and antioxidant activities of Pituranthos chloranthus essential oils.

The SOS-chromotest in Escherichia coli is a widely used bacterial genotoxicity assay to test potential carcinogens. The aim of this work is to evaluate the genotoxic and antigenotoxic activities of essential oils obtained from aerial parts of Pituranthos chloranthus. The tested essential oils were not genotoxic towards both E. coli PQ37 and PQ35 strains. These essential oils reduced significantly Nifuroxazide and H(2)O(2)-induced genotoxicity. Essential oils showed a protective effect against damages induced by radicals, obtained from the photolysis of H(2)O(2), on DNA plasmid through free radical scavenging mechanisms. The scavenging capacity of these essential oils was also estimated by evaluating the inhibition of ABTS(+.) radical.

Mutagenic, antimutagenic, cytotoxic, and apoptotic activities of extracts from Pituranthos tortuosus.

Mutagenic and antimutagenic activities against direct acting mutagens, nifuroxazide (NF) and sodium azide (SA), and indirect acting mutagen aflatoxin B1 (AFB1) of extracts prepared from aerial parts of Pituranthos tortuosus were investigated in bacterial assay systems (i.e., the Ames test with Salmonella typhimurium TA100, TA98, TA1538, TA1535, and the SOS chromotest with Escherichia coli PQ 37). It was found that all extracts obtained from P. tortuosus decreased the mutagenicity induced by AFB1 (10 microg/assay), SA (1.5 microg/assay), and NF (20 microg/assay). Ethyl acetate, acetone, methanol, and total oligomer flavenoid extracts exhibited the highest inhibition level of mutagenicity induced by the indirect mutagen AFB1. In addition, antiproliferative and apoptotic properties of these extracts have also been reported using two leukemia cell lines, L1210 and K562. The results revealed that all extracts showed a significant cytotoxic effect on these cell lines, and the effect was greater in the presence of human K562 chronic myelogenous leukemia cells, whereas they do not induce apoptosis.

Antigenotoxic and free radical scavenging activities of extracts from Moricandia arvensis.

This study evaluates genotoxic and antigenotoxic effects of extracts from leaves of Moricandia arvensis, which are used in traditional cooking and medicines. Extracts showed no genotoxicity when tested with the SOS Chromotest using E. coli PQ37 and PQ35 strains, except for the total oligomers flavonoids enriched extract. Petroleum ether and methanol extracts are the most active in reducing nitrofurantoin genotoxicity, whereas methanol and total oligomers flavonoids enriched extracts showed the most important inhibitory effect of H2O2 genotoxicity. In addition, these two extracts showed important free radical scavenging activity toward the DPPH. radical, whereas the chloroform extract exhibited the highest value of TEAC against ABTS+. radical.