Elham Al-kaissi

Studies on the kinetics of killing and the proposed mechanism of action of microemulsions against fungi

Microemulsions are physically stable oil/water clear dispersions, spontaneously formed and thermodynamically stable. They are composed in most cases of water, oil, surfactant and cosurfactant. Microemulsions are stable, self-preserving antimicrobial agents in their own right. The observed levels of antimicrobial activity associated with microemulsions may be due to the direct effect of the microemulsions themselves on the bacterial cytoplasmic membrane. The aim of this work is to study the growth behaviour of different microbes in presence of certain prepared physically stable microemulsion formulae over extended periods of time. An experiment was designed to study the kinetics of killing of a microemulsion preparation (17.3% Tween-80, 8.5% n-pentanol, 5% isopropyl myristate and 69.2% sterile distilled water) against selected test microorganisms (Candida albicans, Aspergillus niger, Schizosaccharomyces pombe and Rhodotorula spp.). Secondly, an experiment was designed to study the effects of the microemulsion preparation on the cytoplasmic membrane structure and function of selected fungal species by observation of 260 nm component leakage. Finally, the effects of the microemulsion on the fungal membrane structure and function using S. pombe were studied using transmission electron microscopy. The results showed that the prepared microemulsions are stable, effective antimicrobial systems with effective killing rates against C. albicans, A. niger, S. pombe and Rhodotorula spp. The results indicate a proposed mechanism of action of significant anti-membrane activity, resulting in the gross disturbance and dysfunction of the cytoplasmic membrane structure which is followed by cell wall modifications, cytoplasmic coagulation, disruption of intracellular metabolism and cell death.

Synthesis and biological evaluation of N1,N2-bis-[4-(t-amino)-2-butynyl]phthalamides as oxotremorine and acetylcholine antagonists

A series of N1,N2-bis-[4-(t-amino)-2-butynyl]phthalamides have been synthesized and investigated for the blocking of the motor effect of oxotremorine in intact mice and for their antagonistic activity towards acetylcholine on isolated guinea pig ileum preparations. All N1,N2-bis-[4-(t-amino)-2-butynyl]phthalamides showed more selectivity as oxotremorine antagonists than atropine and less potent than atropine on peripheral cholinergic antagonistic activity.

Water-in-oil microemulsions exhibit antimicrobial activity

Objectives: Previous research from this group has identified significant antimicrobial activity associated with oil-in-water (O/W) microemulsions. This activity has been exhibited against both bacteria and fungi (including yeasts) and bacterial biofilms and is dependent upon the position of the microemulsion within its stability zone. This novel work aims to identify antimicrobial activity of water-in-oil (W/O) microemulsions. Materials & Methods: A simple, thermodynamically stable water-in-oil microemulsion was tested for its time-related antimicrobial activity against a selected panel of test microorganisms (i.e.: Pseudomonas aeruginosa ATCC 9027, Escherichia coli ATCC 8739, Candida albicans ATCC 10231 and Staphylococcus aureus ATCC 6538P) and its effectiveness as a self-preserving system against a similar panel (Pseudomonas aeruginosa ATCC 9027, Candida albicans ATCC 10231, Staphylococcus aureus ATCC 6538P and Aspergillus niger ATCC 16404). Results: The microemulsion exhibited significant antimicrobial activity against all the selected microorganisms. Decreases in the viability of cultures (P. aeruginosa, C. albicans, E. coli and S. aureus) were observed over a short period of time after exposure to a known concentration of the first microemulsion. The results for the four samplings in the preservative effectiveness test according to the European Pharmacopeia requires a significant reduction in bacterial count, and this requirement was achieved in all samplings. Conclusions: Thermodynamically stable water-in-oil microemulsions are antimicrobially active, self-preserving systems, as are their oil-in-water counterparts.

ACETYLENIC DIMERIZATION UNDER BASIC CONDITIONS

Objective: Cerebrovascular accident (CVA), formally called as stroke is the second leading cause of death worldwide. Recent studies in different parts of India also documented that the prevalence of stroke varies from 40 to 270 per 100,000 populations. Identifying the risk factors of the disease helps to improve the effectiveness of the therapy. Our present study aims in accessing the risk aspects and utilization of drugs in CVA patients. Methods: A prospective Interventional study was carried out on stroke patients in Medicine Department, Viswabarathi Hospital, Kurnool, AP from January to September 2015. Required demographic and laboratory data, along with general neurological evaluation and brain CT was analyzed. Results: A total of 100 patients was analyzed. Among them, the incidence of ischemic stroke (96%) was greater compared to hemorrhagic stroke (4%). Prevalence of disease was higher in males (69%) than females (31%) with notable occurrence in the age group of 61-70 (26%). Higher percentage of patients were found to have>3 risk factors (34%), including hypertension (68%), age (58%), diabetes (39%), smoking (22%), alcoholism (21%), CAD (10%) and percentage with no risk element accounts7%. The prescribing pattern includes antihypertensives (16.25%), Gastrointestinal agents (12.2%), anti-platelets (9.16%), hyperlipidemic (8.4%), Nootropics (7.97%) followed by other classes and nitrates (0.62%) occupies the last place in prescribing. Conclusion: The present study emphasizes on the need to identify risk factors and providing awareness among the patients by a pharmacist in minimizing the disease burden. It also points the rationality in prescribing of drugs based on therapeutic guidelines.

Synthesis and pharmacological evaluation of N-(4-(t-amino)-2- butynyloxy) phthalimides

A series of aminoacetylenicoxyphthalimide namely N-(4-(t-amino)-2-butynyloxy) phthalimides were synthesized from the reaction of N-hydroxyphthalimide with propargyl bromide in sodium ethoxide to generate N-(2-butynyloxy)phthalimide. The desired compounds were prepared through Mannich reaction of N-(2-butynyloxy)phthalimide with formaldehyde, appropriate amine in peroxide-free dioxin and cuprous chloride as catalyst. The N-(4-(t-amino)-2-butynyloxy) phthalimides were investigated for their rectal temperature, motor activity and palpebral pitosis effects in comparison with harmaline, all compounds showed similar activity to harmaline, however compound 4 was more potent than harmaline.