Research in Pharmaceutical Sciences
Volume:2 Issue: 2, Oct 2007

Aptamers define a new interesting class of receptor molecules with capability of binding to potentially any kind of molecules of interest. Structurally, they are composed of nucleic acids (RNA, DNA or a mixture of both) with high specificity and affinity to amino acids, drugs, proteins and other molecules. Apatmers are isolated from complex libraries of synthetic nucleic acids against the desired target molecules. They can be chemically modified to increase their stability and availability in biological environments. These molecules have potential applications in diagnostic assays such as conventional immunoassays, and in analytical devices including biosensors. Aptamers have been recently applied as antibodies against viral antigens and several key target molecules in cellular metabolic pathways. In this article, aptamers and their application in nanomedicine have been reviewed.

The most frequent adverse effects of indomethacin like other NSAIDs are gastro–intestinal and central nervous system disturbances. Extended release or enteric release formulations minimize these symptoms. The objective of this study was to develop an extended release pellet formulation of indomethacin by the centrifugation (rotary fluid bed granulation) or powder layering method. Layered, nonpareil pellets composed of sugar, Avicel PH 101 and lactose were prepared using FREUND CF-granulator and were treated by a binder solution (HPC-L) applied by spray gun. A conical designed powder-feeding unit applied the drug powder. Drug content of pellets was determined by HPLC method. Eudragit NE 30 D was used for coating the prepared pellets. The results show that increasing the amount of Eudragit NE 30 D, Opadray and SDS in coating solution adjusts release of the pellets. The dissolution profile achieved from pellets containing 500 g nonpareil, 400 g indomethacin, 400 ml HPC 8%, 61g talc, 50 g Opadray® and coating consisted of 37.5 g Eudragit NE 30 D, 1.8 g SDS, 7.5 g Opadray® passed USP30 standards for indomethacin release and was comparable with retard Indocid®75 Capsule from MDS company.

Previous reports showed that elevated levels of glucocorticoids following morphine withdrawal play an important role in memory impairment. In addition, glucocorticoid receptor (GR) inhibitors improved memory perfor-mance in morphine withdrawal mice. Since mineralocorticoid receptor (MR) and GRs complement each other, the aim of the current study was to evaluate the effects of spironolactone on memory performance after withdrawal in morphine dependent mice. To assess memory performance, the object recognition task was used. Novel object recognition task was carried out in a square wooden open-field apparatus using objects. The test was comprised of three sections: habituation for 15 min, first trial for 12 min and test trial for 5 min. In this learning paradigm, the difference in exploration between a previously seen object and a novel object is taken as an index of memory performance (recognition index, RI). Male mice were made dependent by increasing doses of morphine (30-90 mg/kg) subcutaneously twice daily for three days. Withdrawal was elicited either by injection of naloxone (0.1 mg/kg) 3 h after last morphine injection or spontaneously 4 h after the last dose of morphine on the third day. Spironolactone (50, 100 mg/kg) was used subcutaneously before the first trial and the effects were compared with control values. After naloxone precipitated withdrawal spironolactone at 50 and 100 mg/kg improved RI to 10.8% ± 6.0 and 24.0% ± 6.1 which were significantly different from vehicle (RI=-24.1 % ± 6.6, P

A series of 1,4-dihydropyridine calcium channel blockers bearing 1-(4-X -benzyl)-5-imidazolyl substituent at 4 position (5a-e) (X=H, F) were synthesized and tested for antihypertensive activity in desoxycorticosterone acetate (DOCA)-induced hypertension in rats. Amlodipine was used as the standard dihydropyridine. All compounds tested showed lower antihypertensive activity than that of amlodipine. The most active compound (5e) had fluorine substituent (X=F).

Echium amoenum (Boraginaceae), a very popular medicinal plant in Iran traditional medicine, is used as a tonic, tranquillizer, diaphoretic, cough and sore throat remedy, and antipneumonia. Preliminary phytochemical studies of the plant showed that it contains saponins, flavonoids, unsaturated terpenoids and sterols. In this study, an aqueous extract from petals of this plant was used 125 mg/kg as compared to diazepam 1 mg/kg, i.p., during two different treatment courses, 15 and 30 days. The aqueous extract was prepared by Soxhlet apparatus with distilled water. A sample size of 36 rats in 6 groups was selected for this experiment. Three groups were treated by saline, diazepam and extract daily for 15 days and the other groups for 30 days. Anxiolytic effect of extract was investigated in rat using the elevated plus-maze model of anxiety. After finishing these courses and 30 min after the last injections, the test was performed. The results revealed that in 30-day treatment course, time spent in open arms was significantly higher than that of 15-day treatment in both diazepam and extract groups and this effect was the highest in the diazepam group. So, the results of the study indicated a significant durationdependent increase in time spent in open arms of plus-maze.

There are controversial reports about the effect of captopril on pain modulation. Also while captopril may potentiate morphine analgesia، enalapril has not such an effect and interaction of morphine with angiotensin II receptor antagonists and other angiotensin converting enzyme inhibitors has not been studied yet. Therefore، this study was designed to assess the effect of captopril، lisinopril and losartan on pain sensation and the possible modifying effect of these drugs on morphine antinociception. Male Swiss mice (25-35 g) in groups of 6 animals per each received vehicle (10 ml/kg)، captopril (20 mg/kg)، lisinopril (10 mg/kg) and losartan (10 mg/kg) alone or in combination with morphine (5 mg/kg، i. p.) and analgesic response was assessed using light tail flick test. Reaction latencies to a light beam were recorded at 15 minute intervals until 2 hours. The maximum possible analgesic effect was calculated and compared. Lisinopril and captopril when administered alone could not change the pain response but losartan per se induced a hyperalgesic state. Pretreatment with captopril potentiated morphine analgesic response and losartan and lisinopril did not modify morphine analgesia. It is concluded that although angiotensin converting enzyme inhibitors have the same mechanism of action on renin-angiotensin system but they do not have the same interaction with morphine. Also since losartan، an antagonist of angiotensin receptor type 1 did not alter morphine response، it seems that these receptors are not involved in captopril potentiation of morphine analgesia.

Quantitative structure-activity relationship (QSAR) studies of a series of substituted 3-hydroxy-pyridine-4-ones and 3-hydroxy-pyran-4-ones as antibacterial and antifungal agents against a variety of microorganisms were performed. Multiple linear regression approach was used as variable selection method. The antimicrobial activities of these compounds against Staphylococcus aureus, Aspergilus niger and Candida albicans were subjected to QSAR analysis. The best QSAR models were achieved for the antimicrobial activity of the studied compounds against Staphylococcus aureus and Candida albicans Quantum, constitutional and geometrical parameters had important roles in the antimicrobial activity against Staphylococcus aureus. Geometrical, functional group and topological parameters of the compounds had important effect on the antimicrobial activity against Candida albicans. The equation describing this effect had a good statistical quality (R2=0.81, SE=0.14, Q2=0.73)

Some of pathogenic and food spoilage bacteria can attach on food contact surfaces and form a biofilm, the source of contamination of foods. Biofilm is a functional consortium of microorganisms attached to the surface and is embedded in the extracellular polymeric substances (EPS) produced by the microorganisms. Biofilms due to special structure and EPS are more resistant to antimicrobial agents. Thus control of biofilm formation in food processing is important. Nisin is a peptidic bacteriocin that is used for biocontrol of biofilm formation. The aim of the present study was to assess the effect of various concentration of nisin on biofilm formation of Listeria monocytogenes, Staphylococcus aureus and Salmonella enteritidis. The reduction percent of biofilms was obtained using microtiter plate method and ELISA reader machine. Also, bactericidal effect of nisin was determined by Triphenyl Tetrazolium Chloride. The results indicated that 4103 IU/ml nisin is more effective on biofilm of S. enteritidis (87%) than L. monocytogenes (57%) and Staph. aureus (30%) with significant difference (P