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المنشورات العلمية

الرئيسية // المنشورات العلمية
Composition and antimicrobial activity of essential oils of Artemisia judaica, A. herba-alba and A. arborescens from Libya
Journal Article

Abstract: The essential oils obtained by hydrodistillation from the aerial parts of Artemisia judaica L., Artemisia herbaalba Asso. and Artemisia arborescens L. (cultivated) from Libya, were analyzed by GC and GC-MS. The antimicrobial properties were determined using the broth microdilution method against eight bacterial species: Bacillus cereus (clinical isolate), Micrococcus flavus (ATCC10240), Listeria monocytogenes (NCTC7973), Staphylococcus aureus (ATCC6538), Escherichia coli (ATCC35210), Pseudomonas aeruginosa (ATCC27853), Salmonella typhimurium (ATCC13311), Enterobacter cloacae (human isolates) and eight fungal species: Aspergillus niger (ATCC6275), A. ochraceus (ATCC12066), A. versicolor (ATCC11730), A. fumigatus (ATCC1022), Penicillium ochrochloron (ATCC9112), P. funiculosum (ATCC10509), Trichoderma viride (IAM5061) and Candida albicans (human isolate). The major constituents of A. arborescens oil were sesquiterpene hydrocarbons (47.4%). Oxygenated monoterpenes were the dominant constituents in the A. judaica and A. herba-alba oils (54.2% and 77.3%, respectively). Camphor (24.7%) and chamazulene (20.9%) were the major components in the essential oil of A. arborescens, chrysanthenone (20.8%), cis-chrysanthenyl acetate (17.6%) and cis-thujone (13.6%) dominated in the A. herba-alba oil, and the major constituents in the A. judaica oil were piperitone (30.21%) and cis-chrysanthenol (9.1%). The best antimicrobial activity was obtained for A. judaica oil and the lowest effect was noticed in A. arborescens oil. The effect of the tested oils was higher against Gram (+) than Gram (-) bacteria. All three oils showed the best antibacterial activity against Listeria monocytogenes and the lowest against Pseudomonas aeruginosa, Escherichia coli, Enterobacter cloacae, compared to streptomycin and ampicillin. All three oils showed better antifungal activities than ketoconazole, except A. arborescens oil against Aspergillus niger. Keywords: Artemisia judaica; Artemisia herba-alba; Artemisia arborescens; essential oils; antimicrobial activity

Abdulhamid Ahmed Massoud Giweli, (02-2015), Serbia: Srpsko biološko društvo, Beograd, i dr., 67

Insecticidal Activity and Expression of Cytochrome P450 Family 4 Genes inAedes albopictus After Exposure to Pyrethroid Mosquito Coils
Journal Article

Mosquito coils are insecticides commonly used for protection against mosquitoes due to their toxic effects on mosquito populations. These effects on mosquitoes could induce the expression of metabolic enzymes in exposed populations as a counteractive measure. Cytochrome P450 family 4 (CYP4) are metabolic enzymes associated with a wide range of biological activities including insecticide resistance. In this study, the efficacies of three commercial mosquito coils with different pyrethroid active ingredients were assessed and their potential to induce the expression of CYP4 genes in Aedes albopictus analyzed by real-time quantitative PCR. Coils containing 0.3 % d-allethrin and 0.005 % metofluthrin exacted profound toxic effects on Ae. albopictus, inducing high mortalities (≥90 %) compared to the 0.2 % d-allethrin reference coil. CYP4H42 and CYP4H43 expressions were significantly higher in 0.3 % d-allethrin treated mosquitoes compared to the other treated populations. Short-term (KT50) exposure to mosquito coils induced significantly higher expression of both genes in 0.005 % metofluthrin exposed mosquitoes. These results suggest the evaluated products provided better protection than the reference coil; however, they also induced the expression of metabolic genes which could impact negatively on personal protection against mosquito.

Fatma Mosbah Ali Al gorj, (10-2014), مجلة The protein journal: Springer US, 33

Chemical composition, antimicrobial, antioxidant and antitumor activity of Thymus serpyllum L., Thymus algeriensis Boiss. and Reut and Thymus vulgaris L. essential oils
Journal Article

Aromatic plant species of genus Thymus are important medicinal plants, highly recommended due to a range of therapeutic properties of their essential oils, commonly known as thyme oil: antirheumatic, antiseptic, antispasmodic, antimicrobial, cardiac, carminative, diuretic and expectorant. The oil is also beneficial in boosting the immune system and helps to fight colds, flu, infectious diseases and chills. It is proved to be a urinary antiseptic, being very helpful for cystitis and urethritis. Scientific validation of traditional uses, and phytochemical and bioactivity evaluation of essential oils from Thymus serpyllumThymus algeriensis and Thymus vulgaris were performed.

GC/MS analysis revealed thymol as a major component of T. algeriensisT. vulgaris and T. serpyllum, with its contribution to the oil 56.0%, 48.9% and 38.5%, respectively. All three essential oils (EOs) exhibited a significant antimicrobial activity against all

Abdulhamid Ahmed Massoud Giweli, (01-2014), Serbia: Elsevier, 52

Botryodiplodia sp. canker on Ficus benjamina in Egypt.
Journal Article

Abstract- Botryodiplodia sp. AUMC 9468 was isolated in pure culture from canker on Ficus benjamina, on side of Ibraheemia bank stream at Assiut governorate, Egypt. The analysis of growth condition suggested the trees were stressed induced by light, nutrient and medium factors. This report is the first for Botryodiplodia canker on F. benjamina in Egypt. The pathogenicity test were resulted on that the fungus was introduced with the trees, penetrated through bark wounds, and incubated under conditions stressful to the well-being of the tree.

Keywords- Canker,Ficus benjamina, Botryodiplodia.


Mohamed Ahamed Al-Ryani, (12-2013), World Research.: Journal of Agricultural Biotechnology, 1

Tirmania pinoyi: Chemical composition, in vitro antioxidant and antibacterial activities and in situ control of Staphylococcus aureus in chicken soup
Journal Article

Abstract

Desert truffleTirmania pinoyi (Maire) Malençon from Libya was chemically characterized in nutritional value, primary and secondary metabolites. Antioxidant (scavenging activity, reducing power and inhibition of lipid peroxidation) and antibacterial activity of its methanolic extract alone and in combination with potassium metabisulfite (E224) were evaluated under in vitro conditions. Furthermore, the effect of the extract on the control of Staphylococcus aureus was examined in a contaminated soup under in situ conditions. T. pinoyi was shown to be rich in carbohydrates (82.60 g/100 g dw) and proteins (8.06 g/100 g dw), being identified four free sugars (rhamnose, fructose, trehalose and mannitol) and three tocopherol isoforms (β-, δ- and γ-tocopherols). Oleic (32.29%), linoleic (29.72%) and palmitic (27.97%) acids were the main fatty acids. p-Hydroxybenzoic (300.65 μg/100 g dw) and cinnamic (8.30 μg/100 g dw) acids were quantified, as also four organic acids: quinic (0.83 g/100 g dw), malic (0.35 g/100 g dw), fumaric (0.05 g/100 g dw) and citric (1.26 g/100 g dw) acids. The methanolic extract of the mushroom showed in vitro antioxidant and antimicrobial activities. Sterilized distillated water containing 0.02% Tween 80 proved to be the most convenient solvent for in situ antimicrobial activity; the extract successfully inhibited the growth of S. aureus in chicken soup in a dose dependent manner.


Abdulhamid Giweli, (08-2013), Serbia: Elsevier, 53

Molecular Cloning and Characterization a Novel Gene Encoding CYP4H28v2from the Mosquito, Aedes aegypti
Conference paper

Cytochrome P450 is a group of heme-containing enzymes. They have been detected in virtually all organisms examined from bacteria to mammals. In insects, P450s are involved in the oxidative metabolism of a large number of exogenous compounds (xenobiotics) from natural or anthropogenic origins (plant allelochemicals and insecticides) and endogenous compounds such as steroid hormones ecdysteroid hormones and pheromones. Thus the P450s have an important role in controlling insect growth, development, and evolutionary adaptation to environments containing potentially toxic compounds. A novel cDNA clone encoding a cytochrome P450 gene has been isolated from the mosquito, Ae. aegypti strain VCRU. The cDNA is 1731 bp in length and has an open reading frame from 277 bp to 1647 bp encoding a protein of 529 aa. The classic heme-binding characteristic motifs of P450s (FXXGXRXCXG, RxxR and EVLR) are present and conserved in this gene. The EVDTFMFEGHDTT motif characteristic of CYP4 family is also found in this new gene. The full length cDNA clone for CYP4H28v2 is 98% identical to CYP4H28 of The Liverpool strain Ae. aegypti. So, we propose that  this is an allele of that gene.

Fatma Mosbah Ali Al gorj, (04-2013), مؤتمر: International Journal of Chemical, Environmental & Biological Sciences (IJCEBS), 1

The chemical composition, antimicrobial and antioxidant activities of the essential oil of Salvia fruticosa growing wild in Libya
Journal Article

The composition of essential oil isolated from Salvia fruticosa, wild growing in Libya, was analyzed by GC and GC-MS. Forty-five compounds could be identified. The essential oil contained 1,8-cineole (49.34%), camphor (7.53%), β-pinene (7.38%), myrcene (7.38%), α-pinene (5.15%), β-caryophyllene (4.13%) and α-terpineol (3.25). Antioxidant activity was analyzed using the DPP H free radical scavenging method and low antioxidant activity was found (IC50 = 15.53 mg/ml). The oil was also screened for its antimicrobial activity against eight bacteria (four Gram-negative and four Gram-positive) and eight fungi. The essential oil of S. fruticosa showed minimal inhibitory activity (MIC) at 0.125-1.5 mg/ml and bactericidal (MBC) at 0.5-2.0 mg/ml. In addition, it exhibited fungistatic (MIC) at 0.125-1.0 mg/ml and fungicidal effect (MFC) at 0.125-1.5 mg/ml

Abdulhamid Ahmed Massoud Giweli, (04-2013), Serbia: Archives of Biological Sciences, 65

The Cytochrome P450s
Journal Article

Cytochrome P450 monooxygenases are versatile biocatalysts that incorporate oxygen into an enormous range of molecules. The cytochrome P450 proteins are involved in the catalysis of different reactions and these properties have been used for drug improvement. The protein family also includes compounds producing properties such as resistance to insecticides, and the synthesis of valuable chemicals. In this review, we will discuss various aspects of the structure and function of the cytochrome P450s

Fatma Mosbah Ali Al gorj, (02-2013), Asia-Pacific Journal: ., 21

Antimicrobial and Antioxidant Activities of Essential Oils of Satureja thymbra Growing Wild in Libya
Journal Article

The composition of essential oil isolated from Satureja thymbra, growing wild in Libya, was analyzed by GC and GC-MS. The essential oil was characterized by γ-terpinene (39.23%), thymol (25.16%), p-cymene (7.17%) and carvacrol (4.18%) as the major constituents. Antioxidant activity was analyzed using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method. It possessed strong antioxidant activity (IC50 = 0.0967 mg/mL). The essential oil was also screened for its antimicrobial activity against eight bacterial and eight fungal species, showing excellent antimicrobial activity against the microorganisms used, in particular against the fungi. The oil of S. thymbra showed bacteriostatic activity at 0.001–0.1 mg/mL and was bactericidal at 0.002–0.2 mg/mL; fungistatic effects at 0.001–0.025 mg/mL and fungicidal effects at 0.001–0.1 mg/mL. The main constituents thymol, carvacrol and γ-terpinene also showed strong antimicrobial activity. The commercial fungicide bifonazole showed much lower antifungal activity than the tested oil

Abdulhamid Ahmed Massoud Giweli, (04-2012), Serbia: MDPI, 5

High resolution melt analysis to track infections due to ribotype 027 Clostridium difficile
Journal Article

 The increased prevalence of hypervirulent ribotype 027 Clostridium difficile requires rapid identification of iso lates in ordertoimplementtimelyinfectioncontrol strategies. Highresolution melt(HRM) analysisof PCRprod ucts can identify strain variation amongst genera of bacteria. The intergenic (16S–23S rDNA) spacer region contains sequenceregionsconserved withingeneraandothersequenceregionvariablesbetweenspecieswithin genera. Wewished toinvestigate whether HRM analysis of PCR ribotyping products could identify ribotype 027 C. difficile. Ribotyping was performed on 93 clinical isolates and five control strains and band patterns were ana lysedusingGelComparII(AppliedMaths,USA).Real-timePCRusingribotypingprimerswasperformedandnor malised melt curves were generated. The HRM data was then imported into ScreenClust software (QIAGEN) to generate principal component analysis graphs depicting clustered relationships of strains. Ribotyping produced clear PCR bands for 88/98 isolates tested. Dendrograms generated by GelCompar showed a diversity of ribotype patterns amongst these 88 isolates with 18 groups identified with 70% homology. One clinical isolate showed 100%homologywiththecontrol027strains. ScreenClustanalysisofthe same88HRMresultsshowedclustering of isolates, with 027 strains identifiable as a unique cluster. HRM analysis correctly identified the control 027 stains and the clinical isolate shown to be 027. HRM combined with ScreenClust analysis of real-time PCR prod ucts of the 16S–23S rDNA spacer region successfully identified ribotype 027 strains. For infection control pur poses this was achieved within 2–3 h of colony isolation.

MOHAMED MOFTAH MOKHTAR SAID, Mohamed M. Said, (03-2012), ScienceDirect: Journal of Microbiological Methods, 89