Tehran University of Medical Sciences

About: Tehran University of Medical Sciences is a education organization based out in Tehran, Iran. It is known for research contribution in the topics: Population & Medicine. The organization has 35661 authors who have published 57234 publications receiving 878523 citations. The organization is also known as: TUMS.

Effects of intrahippocampal injection of GABAergic drugs on memory retention of passive avoidance learning in rats.

Abstract: The effect of post-training intrahippocampal injection of gamma-aminobutyric acid (GABA) receptor agonists and antagonists, immediately after a training session on memory retention of passive avoidance learning in rats, was measured in the presence and absence of physostigmine. Post-training treatments were carried out in all the experiments. The different doses of the GABAA receptor agonist muscimol (2, 4 and 6 microg/rat) decreased memory retention in rats dose-dependently. The higher response was obtained with 6 microg/rat of the drug. When the GABAA receptor antagonist bicuculline (0.5, 1, 2 and 4 microg/rat) was administered, only one dose of the drug (1 microg/rat) increased memory retention; however, the antagonist reduced the effect of muscimol. The GABAB receptor agonist, baclofen (0.25, 0.5, 1 and 2 microg/rat) also reduced memory retention in the animals. Intrahippocampal injection of lower doses of the GABAB receptor antagonist CGP35348 (P-[3-aminopropyl]-p-diethoxymethyl-phosphinic acid) (2.5, 5, 10 microg/rat) did not effect memory retention, although the higher doses of the drug (25 and 50 microg/rat) decreased memory retention. The doses of antagonist (2.5, 5 and 10 microg/rat), which did not elicit any response alone, reduced the effect of baclofen. The inhibitory response of CGP35348 was also decreased by bicuculline. In another series of experiments, physostigmine improved memory retention. The GABA receptor agonists, muscimol and baclofen, as well as the GABA receptor antagonists bicuculline and CGP35348, decreased the effect of physostigmine. Atropine decreased memory retention by itself and potentiated the response of muscimol and baclofen. It is concluded that GABAA and GABAB receptor activation may be involved in the impairment of memory retention.

Cell-penetrating peptides as a novel transdermal drug delivery system.

Abstract: In the last decade, almost one-third of the newly discovered drugs approved by the US FDA were biomolecules and biologics. Effective delivery of therapeutic biomolecules to their target is a challenging issue. Innovations in drug delivery systems have improved the efficiency of many of new biopharmaceuticals. Designing of novel transdermal delivery systems has been one of the most important pharmaceutical innovations, which offers a number of advantages. The cell-penetrating peptides have been increasingly used to mediate delivery of bimolecular cargoes such as small molecules, small interfering RNA nucleotides, drug-loaded nanoparticles, proteins, and peptides, both in vitro and in vivo, without using any receptors and without causing any significant membrane damage. Among several different drug delivery routes, application of cell-penetrating peptides in the topical and transdermal delivery systems has recently garnered tremendous attention in both cosmeceutical and pharmaceutical research and industries. In this review, we discuss history of cell-penetrating peptides, cell-penetrating peptide/cargo complex formation, and their mechanisms of cell and skin transduction.

Efficacy and tolerability of Hypericum perforatum in major depressive disorder in comparison with selective serotonin reuptake inhibitors: A meta-analysis

Abstract: Hypericum perforatum is a medicinal plant with established antidepressant properties. The aim of this meta-analysis was to compare the efficacy and tolerability of this antidepressant with selective serotonin reuptake inhibitors (SSRIs) as a group of standard antidepressants. For this purpose, Pubmed, Embase, Scopus, Web of Science, and Cochrane Central Register of Controlled Trials were searched for studies comparing efficacy and/or tolerability of Hypericum with SSRIs in the management of major depressive disorder (MDD). The search terms were: "Hypericum" or "St. John's wort" and "fluoxetine", "paroxetine", "citalopram", "serteraline", "escitalopram", or "fluvoxamine". Data were collected from 1966 to 2008 (up to June). "Clinical response", "remission", "mean reduction in Hamilton Rating Scale for Depression (HAMD) score from baseline", "total adverse events", and "withdrawals due to adverse events" were the key outcomes of interest. Thirteen randomized placebo controlled clinical trials met our criteria and were included. Comparison of SSRIs with placebo yielded a significant relative risk (RR) of 1.22 (95% confidence interval: 1.03-1.45, P=0.02) for clinical response (n=4), a non significant RR of 0.96 (95% CI: 0.71-1.29, P=0.76) for remission (n=4), and a significant effect size [weighted mean difference (wmd+)] of 1.33 (95% CI: 1.15-1.51, P<0.0001) for mean reduction in HAMD score from baseline (n=3). Comparison of Hypericum with SSRIs yielded a non significant relative risk (RR) of 0.99 (95% confidence interval: 0.91-1.08, P=0.83) for clinical response, a non significant RR of 1.1 (95% CI: 0.90-1.35, P=0.35) for remission, and a non-significant wmd+ of 0.32 (95% CI: -1.28-0.64, P=0.52) for mean reduction in HAMD score from baseline, a non significant RR of 0.85 (95% CI: 0.7-1.04, P=0.11) for any adverse events, and a significant RR of 0.53 (95% CI: 0.35-0.82, P=0.004) for withdrawals due to adverse events. Hypericum does not differ from SSRIs according to efficacy and adverse events in MDD. Lower withdrawal from study due to adverse events by Hypericum is an advantage in management of MDD.