Phytochemical Diversity,Classification and Antibacterial Activity of Some Medicinal Plant Species from Tabuk (Saudi Arabia)

The main objectives of this study were to investigate the intra-specific and inter-specific phytochemical diversity and classification of nine important medicinal plant species from Tabuk region (KSA), namely (Pulicaria undulata L., Pulicaria incisa Lam., Artemisia herba-alba Asso., Artemisia monosperma Delile, Artemisia judaica L. and Achillea fragrantissima Forssk. from Asteraceae family, Ducrosia flabellifolia Boiss. from Apiaceae family, Thymus vulgaris L. and Lavandula coronopifolia Poir. from Lamiaceae family); to evaluate the antibacterial potentials of the plant extracts, and to inspect the possible associations between phytochemical diversity and contents of different phytochemical classes with the antibacterial activities of plant extracts. GC/MS technique was used to identify phytochemicals in the plant extracts. The standard disk diffusion technique was used to conduct the antibiotic susceptibility against four pathogenic bacterial species (two Gram positive: Staphylococcus aureus and Bacillus subtilis and two Gram negative species: Pseudomonas aeruginosa and Escherichia coli. A total of 160 different phytochemicals belonging to 30 compound classes were separated and identified. A. fragrantissima had the highest phytochemical diversity and P. incisa had the lowest one. Phytochemical beta diversity was 6.2362. Ethanol outperformed other extraction solvents in terms of antibacterial activity, while Pulicaria undulata and T. vulgaris ranked highest among plants in this regard. Gram positive bacterial species were more sensitive to plant extracts compared to Gram negative species. Phytochemical diversity and antibacterial activity of plant extracts against E. coli and P. aeruginosa were positively correlative, terpenoid and benzene & substituted derivative contents exhibited significant (p<0.05) positive correlations with the antibacterial activity against E. coli, terpenoid contents also showed positive correlation with activity against P. aeruginosa; benzene & derivative showed positive correlation with activity against the rest of bacterial species,     

Prevalence of glucose-6-phosphate dehydrogenase deficiency (G6PDd), CareStart qualitative rapid diagnostic test performance,and genetic variants in two malaria-endemic areas in Sudan

Glucose-6-phosphate dehydrogenase deficiency (G6PDd) is the most common enzymopathy globally, and deficient individuals may experience severe hemolysis following treatment with 8-aminoquinolines. With increasing evidence of Plasmodium vivax infections throughout sub-Saharan Africa, there is a pressing need for population-level data at on the prevalence of G6PDd. Such evidence-based data will guide the expansion of primaquine and potentially tafenoquine for radical cure of P. vivax infections. This study aimed to quantify G6PDd prevalence in two geographically distinct areas in Sudan, and evaluating the performance of a qualitative CareStart rapid diagnostic test as a point-of-care test. Blood samples were analyzed from 491 unrelated healthy persons in two malaria-endemic sites in eastern and central Sudan. A pre-structured questionnaire was used which included demographic data, risk factors and treatment history. G6PD levels were measured using spectrophotometry (SPINREACT) and first-generation qualitative CareStart rapid tests. G6PD variants (202 G>A; 376 A>G) were determined by PCR/RFLP, with a subset confirmed by Sanger sequencing. The prevalence of G6PDd by spectrophotometry was 5.5% (27/491; at 30% of adjusted male median, AMM); 27.3% (134/491; at 70% of AMM); and 13.1% (64/490) by qualitative CareStart rapid diagnostic test. The first-generation CareStart rapid diagnostic test had an overall sensitivity of 81.5% (95%CI: 61.9 to 93.7) and negative predictive value of 98.8% (97.3 to 99.6). All persons genotyped across both study sites were wild type for the G6PD G202 variant. For G6PD A376G all participants in New Halfa had wild type AA (100%), while in Khartoum the AA polymorphism was found in 90.7%; AG in 2.5%; and GG in 6.8%. Phenotypic G6PD B was detected in 100% of tested participants in New Halfa while in Khartoum, the phenotypes observed were B (96.2%), A (2.8%), and AB (1%). The African A- phenotype was not detected in this study population. Overall, G6PDd prevalence in Sudan is low-to-moderate but highly heterogeneous. Point-of-care testing with the qualitative CareStart rapid diagnostic test demonstrated moderate performance with moderate sensitivity and specificity but high negative predicative value. The two sites harbored primarily the African B phenotype. A country-wide survey is recommended to understand GP6PD deficiencies more comprehensively in Sudan.     

Semi‐field evaluation of the effects of sub‐lethal doses of pesticides,with and without adult Schistocerca gregaria pheromone,on hoppers

Previously, we reported a chain of effects induced by phenylacetonitrile, the gregarious‐phase adult cohesion pheromone of the desert locust, Schistocerca gregaria (Forskål) (Orthoptera: Acrididae), on conspecific hoppers. Specifically, the nymphs became hyperactive and displayed high levels of intraspecific predation, as surviving individuals gradually shifted to the solitary phase. The findings suggested that the pheromone could induce a significant level of mortality of the nymphs and predispose them to greater sensitivity to lower doses of insecticides. In this study, we compared the effects of the pheromone and various doses of three pesticides (fipronil, malathion, and carbosulfan) to pheromone‐exposed and unexposed crowd‐reared hoppers in semi‐field enclosures. The pheromone on its own displayed a high level of cumulative mortality of the nymphs (89%). Although combinations with fractional pesticide doses gave control efficiencies that were, in most cases, higher than with individual pesticides, pheromonal and pesticidal effects were only partially complementary, probably because of the feeding‐deterrent effects of the pesticides and the resulting reduction in cannibalism. However, our results demonstrate the possibility of significantly reducing the levels of pesticides used in hopper control and, thus, their negative environmental effects.     

Droplet aerodynamics,cellular uptake,and efficacy of a nebulizable corticosteroid nanosuspension are superior to a micronized dosage form

Inhaled corticosteroids are considered to be an effective prophylactic against the morbid symptoms of several lung diseases, but scope remains for improvement in drug delivery technology to benefit bioavailability and treatment compliance. To ascertain whether dosage form might influence bioavailability, the emission characteristics and efficacy of a nanoparticulate budesonide formulation (Nanagel®) were compared with those of a proprietary micronized suspension (Pulmicort®) when delivered as a nebulized aerosol to human airway epithelial cells in a culture model. Having the visual appearance of a clear solution, Nanagel® was delivered by both jet and vibrating mesh nebulizers as an increased fine particle fraction and with a smaller mass median aerodynamic diameter (MMAD) compared to the micronized suspension. Quantitative high performance liquid chromatography (HPLC) analysis of cultured epithelia one hour after treatment with Nanagel® revealed a significantly greater cellular accumulation of budesonide when compared with Pulmicort® for an equivalent dose, a differential which persisted 24 and 48 h later. A quantitative in vitro assay measuring the activity of enzymes involved in superoxide production revealed that stressed HaCaT cells (a long‐lived, spontaneously immortalized human keratinocyte line) treated with Nanagel® continued to show significantly greater attenuation of inflammatory response compared with Pulmicort®‐treated cells 24 h after the application of an equivalent budesonide dose. The present in vitro findings suggest that formulation of inhalable drugs such as budesonide as aerosolized nanoparticulate, rather than microparticulate, suspensions can enhance bioavailability with concomitant improvements in efficacy. © 2012 American Institute of Chemical Engineers Biotechnol. Prog., 2012     

Liquid chromatographic assay of dityrosine in human cerebrospinal fluid

A micro-scale method for separation and measurement of dityrosine in human cerebrospinal fluid (CSF) is described utilizing liquid-liquid extraction and ion-paired, reversed-phase high-performance liquid chromatography with fluorimetric detection. A mobile phase containing 1-heptanesulfonic acid linearly increased in methanol from 0 to 100% over 30 min allows the resolution of dityrosine from other fluorescent compounds with excitation at 285 nm and emission at 410 nm. As little as 0.15 ml CSF sample can be utilized with a detection limit of 60 pg dityrosine on the column. This method facilitates the use of CSF dityrosine as a measure of free radical mediated protein damage in the central nervous system.     

The aryl hydrocarbon receptor mediates degradation of estrogen receptor alpha through activation of proteasomes

2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and other aryl hydrocarbon receptor (AhR) ligands suppress 17beta-estradiol (E)-induced responses in the rodent uterus and mammary tumors and in human breast cancer cells. Treatment of ZR-75, T47D, and MCF-7 human breast cancer cells with TCDD induces proteasome-dependent degradation of endogenous estrogen receptor alpha (ERalpha). The proteasome inhibitors MG132, PSI, and PSII inhibit the proteasome-dependent effects induced by TCDD, whereas the protease inhibitors EST, calpain inhibitor II, and chloroquine do not affect this response. ERalpha levels in the mouse uterus and breast cancer cells were significantly lower after cotreatment with E plus TCDD than after treatment with E or TCDD alone, and our results indicate that AhR-mediated inhibition of E-induced transactivation is mainly due to limiting levels of ERalpha in cells cotreated with E plus TCDD. TCDD alone or in combination with E increases formation of ubiquitinated forms of ERalpha, and both coimmunoprecipitation and mammalian two-hybrid assays demonstrate that TCDD induces interaction of the AhR with ERalpha in the presence or absence of E. In contrast, E does not induce AhR-ERalpha interactions. Thus, inhibitory AhR-ERalpha cross talk is linked to a novel pathway for degradation of ERalpha in which TCDD initially induces formation of a nuclear AhR complex which coordinately recruits ERalpha and the proteasome complex, resulting in degradation of both receptors.     

Regulation of vascular endothelial growth factor receptor-2 expression in pancreatic cancer cells by Sp proteins

Vascular endothelial growth factor receptor-2 (VEGFR2/KDR) is an important mediator of angiogenesis, and VEGFR2 mRNA is expressed in several pancreatic cancer cell lines. Deletion analysis of the VEGFR2 promoter in Panc-1, AsPC-1, and MiaPaCa-2 pancreatic cancer cells shows that the proximal region of the promoter is primarily responsible for VEGFR2 expression, and two GC-rich sites at -58 and -44 are critical elements in all three cell lines. Panc-1, AsPC-1, and MiaPaCa-2 cells also express Sp1, Sp3, and Sp4 proteins which bind to the GC-rich region of the VEGFR2 promoter in electrophoretic mobility shift and chromatin immunoprecipitation assays. RNA interference with small inhibitory RNAs for Sp1, Sp3, and Sp4 decreases VEGFR2 mRNA and reporter gene activity in transfection assays, confirming that VEGFR2 expression in pancreatic cancer cells is regulated by Sp proteins. These results suggest that VEGFR2 cannot only be targeted by receptor tyrosine kinase inhibitors but also by drugs that downregulate Sp proteins or block Sp-dependent transactivation.