Iranian Journal of Basic Medical Sciences
Year:2007 | Volume:10 | Issue:1 (33)|Papers Count:11

As adenosine and NO are believed to have effect on memory, in this study, the effect of adenosine Al receptor agonist (R-PIA=R-phenylisopropyladenosine) and nitric oxide on memory was evaluated in rats performing the Morris water maze task.Materials and MethodsR-PIA (0.0625 mg/kg and 0.125 mg/kg) was injected intraperitoneally to rats one hour before and L-NAME (NO synthese inhibitor, 100 mg/kg) and L-Arg (64.6 mg/kg, NO donor) 30 min before training for 5 consecutive days. During the training period, four trial episodes were carried out each day. On the 5th day of the experiment, the locomotor activity was assesed using open field test.Results R-PIA and L-NAME both increased the latency time to find the platform. L-Arg did not change the latency time significantly during the five days but blocked the inhibitory effect of R-PIA and L-NAME on memory. In the open field activity test, L-Arg and L-NAME did not change the locomotion activity.R-PIA significantly reduced the factors of open field test.ConclusionOn the basis of these results, R-PIA and L-NAME impaired acquisition/performance activity. It seems R-PIA mediates this effect indirectly via the inhibition of NO availability.

ACA1 is a preparation of an Iranian medicinal herb which would be used in Iranian Traditional Medicine (ITM). Our previous studies have been shown that ACA1 causes a cytotoxic effect on AGS and SK-MEL3 in vitro. The purpose of this study is the evaluation of immunomodulatory effect of ACA1 on macrophage response.Materials and MethodsIntraperitoneal macrophage activation and proliferation was evaluated after 5 day I.P. injection of ACA1 by the use of MTT assay. Nitric oxide (NO) production was determined by Grees method.Results Our data showed that MTT reduction significantly increased by intraperitoneal macrophages from 20 mg/kg ACA1 treated mice in the presence of PMA (p < 0.001). NO production significantly increased in all test groups in comparison with control group (p< 0.01).ConclusionThe results of this study demonstrated that ACA1 induces the activation and NO production of intraperitoneal macrophage.

ObjectiveFloating drug delivery systems offer a good protection against early and random gastric emptying of nondigestible forms such as oral controlled release dosage forms. The aim of this study was the development of an intragastric floating and extended release system (microballoon) for diclofenac sodium using emulsification-solvent diffusion method. The gastric side effects of diclofenac can be reduced by sustaining release device and decreasing the tree drug concentration in stomach.Materials and MethodsDiclofenac sodium, ethyl cellulose (100 cps) and dibutyl phthalate were dissolved in dichloromethane/alcohol mixture, added to 0.1 N HCl containing polysorbate 80. The mixture was stirred at different speeds for 3 hours. Resultant microspheres were separated from solution by filtration. The influence of variations in formulation and microencapsulation process on shape, size distribution, in vitro floating capability, drug loading and kinetic of drug release from resultant microspheres was investigated. ResultsResultant microspheres had spherical porous shape and tended to float over the simulated gastric medium for more than 12 hours. As the speed of agitation increased from 400rpm to 600rpm the mean particle size of microspheres decreased from 1030±12 to 790±7. Regardless of different speed of agitation, drug loading of microballoons with similar size was equal. Addition of PEG4000 to dispersed phase increased the rate of drug release, such that dissolution deficiency increased from 22.1% to 35.1- 43.4%. The kinetics of the formulation devoid of PEG4000, followed second root of time but in presence of this polymer it inclined to zero order.ConclusionRapid diffusion of alcohol into aqueous medium and evaporation of dichloromethane results in the formation of pores in microspheres and decreases their densities. Due to water solubility of PEG4000 it leaves matrix and produced channels which facilitates water diffusion inside the system. So, microballoons, prepared with PEG 4000, had more rapid drug release profiles.

ObjectiveIn order to to study the therapeutic effects of high doses of vitamine A on male fertility, the histological effects on mice testis were investigated.Materials and MethodsIn this study 48 adult white male mice in the same age were applied. The animals were divided into control and experimental groups and were kept in controlled conditions. The experimental group received the daily dosage of 25000 IU vitamine A (Retinol palmitate) intramuscularly. After the last injection, at 2, 4, and 8 day intervals, changes in testicular weight, volume, consistency and histological sections of testis were studied. In addition, each time, epididymal spermatozoa were observed. Group 1 control animals received normal saline and the group 2 control animals received palmitic acid.ResultsThe results indicated that the testis weight (p£0.002), volume (p£0.03), and consistency (p £0.001), decreased significantly. Also histological studies revealed a severe lossening of connective tissue in tunica albuginea and tunicavascularis. Lydig cells and somniferous tubes showed degeneration.ConclusionThese findings indicated that hypervitaminosis A can affect the male fertility.

ObjectiveZataria multiflora Boiss. is a plant endemic to Iran, Pakistan and Afghanistan, the most important components of essential oil and extract of which are carvacrol and thymol. The antimicrobial effects of these components are approved.Materials and MethodsDried Zataria herb was prepared and ground into powder, extracted with hydroalcholic solvent using maceration method and then the extract was concentrated. To confirm its compatibility with standard values, ash value and pH of the extract were determined. In the next step, minimal anti-dermatophyte concentration of the extract was determined. Standard dermatophytous species were grown in a proper culture media and suspensions of certain concentrations of each fungi were prepared. Fungeous species were inoculated into cultures media having different concentrations of the extract. Minimal Inhibitory Concentration (MIC) of Zataria extract against dermatophytous species was determined, by measuring fungeous growth in culture media and determination of fungeous coloni diameters. In order to find a proper formulation, a general formula of a cleansing cream containing Bees wax, Spermaceti, Borax, liquid paraffin and water were considered and then modified.ResultsThe best formula was chosen according to its monotonousness, straightness and acceptability of the appearance. Then formulations containing 1, 2 and 3 percent of the Zataria extract were prepared. Finally, physicochemical properties and stability of the product were determined.ConclusionThe final product was a w/o emulsion type cream with desirable anti-dermatophyte effect, suitable appearance and acceptable microbial and physicochemical stability.

ObjectiveAneuploidy is believed to be the main reason for cancer incidence in human populations. Vinblastin is being used as a mitotic block for treatment of some types of cancer. At the same time vinblastin is being counted as an alkaloid member of Vinca family which all of those are believed to be non-mutagenic carcinogens. Due to its dual nature, analyzing the effect of vinblast in and the relationship of aneuploidy and cancer is very active line of work in biological studies.Materials and Methods In this study to evaluate the doses and time course of vinblastin treatment for induction of aneuploidy in mouse bone marrow cells, using Micronucleus assay, frequency of Micronucleus was calculated in doses of 1, 2, 3, and5 mg/kg of body weight at 6, 18, 24, and 30 hours post treatment.ResultsData revealed that 2 mg/kg of bodyweight of vinblast in could induce a high frequency of aneuploidy, estimated by high frequency of Micronucleus, at 24 hours post-treatment. All the dose and time- interval used in this experiment, the frequency of induced- micronucleus was increased up to 5 to control.ConclusionOn the basis of this study we introduce an in vivo model for studying the relationship between aneuploidy and cancer and also in cancer therapy.

ObjectiveIschemic preconditioning (IP) is a process triggered by brief ischemia, which enables hearts to resist against injuries of prolonged period of ischemia. Carnitine is a vital biologic substance for transporting fatty acids into myocytes in order to produce energy. In this study, effects of IP and pharmacologic preconditioning (PP) by using L-Carnitine (L-Car) on infarct size in the ischemic-reperfused isolated rat hearts were investigated and compared.Materials and MethodsMale Sprague-Dawley rats (270-330 g) were divided into five groups randomly (control, IP group, and three PP groups treated by L-Car, n=6 in each group) and were anesthetized by sodium pentobarbital (50 mg/kg-i.p). Heart was removed and quickly mounted on a Langendorff apparatus and perfused under constant pressure by a modified Krebs-Henseleit (K/H) solution that was previously equilibrated with 95% O2-5% CO2. The hearts were subjected to 30 min regional ischemia followed by 120 min reperfusion. In the control and IP groups, the hearts were perfused by normal K/H solution during stabilization, regional ischemia and reperfusion, while in the PP groups, they were perfused by 0.5, 2.5 and 5 mM of L-Car-enriched K/H solution 10 minbefore and 10 min after ischemia. At the end of reperfusion, Evans Blue solution was infused to stain the non-ischemic area. Then the heart was cut into slices, incubated by 1% triphenyltetrazolium chloride solution, and fixed by formalin. The area of infracted tissue and area at risk was determined by using a computerized planimetry package.ResultsInfarct size significantly was decreased in both IP and PP groups. In the control group, infarct size was 46.3±2.9%, however, IP reduced it to 22.2±2.7% (p<0.001). Application of 0.5, 2.5 and 5mM of L – Car enriched K/H solution 10min before and after ischemia in the PP groups, markedly reduced infarct size in the control group value to 25.9±3.0, 19.3±1.7 and 17.2±1.5%, respectively (p<0.001 for all). There was no significant difference between IP and PP groups on infarct size reduction.Conclusion Considering the results, it may be concluded that IP and PP (by L-Car) have protective effects against cardiac ischemia-reperfusion injuries as a reduction of infarct size without significant statistical difference between their effects.

ObjectiveThe aim of this study was to investigate the effects of aqueous extract from Teucrium polium L. on rat gastric motility in basal and vagal stimulated conditions. Materials and MethodsTwenty four Wister rats (weighing 200-250g) were randomly divided in to groups of 12 as case and control. Animals were anesthetized by sodium thiopental (50 mg/kg, ip) and tracheostomy, laparatomy and gastrodeodenostomy were done for each rat. Aqueous extract of the plant was prepared by maceration and 1ml of 20, 40 and 80mg/kg doses were introduced into he stomach of each rat in case group and the same volume of saline was used in control group. Gastric motility was measured by pressure transducer.The results were analyzed by t-test and multivariate analysis and p<0.05 was considered to be significant.ResultsT.polium aqueous extract has decreased frequency of contraction in case vs control group in both conditions, but the intragastric pressure decreased in case group, although did not have insignificant encompassing with control group. T.polium aqueous extract has got effects on contraction frequency, showding time-response manner only in basal condition. Its effects on intragastric pressure in basal condition in presence of 20 mg/kg and in vagal stimulation in presence of 40 mg/kg dose of the extract were time- response. Intragastric pressure in vagal stimulation was dose dependent, but contraction frequency was not dose dependent, in both conditions.ConclusionIntragastric pressure with 3 different doses of aqueous extract of T.poliumin control and case groups had insignificant difference in two conditions, but the frequency of contraction significantly decreased in both conditions.

Anti-Rh (D) immunoglobulin is used for the prevention of Anti-Rh antibody production in Rh-individuals who have been exposed to Rh+ red blood cells. The purification and preparation processes of this product can directly effect its shelf life. Also, during the purification process using column chromatography methods, protein solutions are diluted and lose some of their stability due to adsorption and fragmentation. Therefore, they should be concentrated with a proper procedure. The objective of this study was to concentrate the Anti-Rh (D) preparation using ultrafiltration system and optimize the conditions during concentrating process.Materials and Methods For ultrafiltration studies, 100ml of purified Anti-Rh(D) solutions containing 0.3 M Glycine and different concentrations of sucrose (30, 60, 90 mM) were concentrated to 27 ml in 50 min using Minitan-S system (filter type: polysulfon, cut off 30,000 Daltons) and pressure of 80 kPs. The clean water flux was used for the determination of suitable pump rate. Bradford protein assay was used for the quantification of total proteins in filtrate, SRID (Single Radial Immunodiffusion) for the determination of total IgG before and after concentrating of samples, gel filtration chromatography for the determination of the amount of aggregates and fragments and ELAT (Enzyme-Linked Antiglobulin Test) for the quantification of Anti- Rh (D) of the ultrafiltrated samples.ResultsWith mentioned conditions, the results of study showed that insignificant amount of protein and IgG transited from filter. Gel filtration studies using Sephadex G-200 showed that the amount of aggregates, fragments and monomer molecules in the concentrated Anti-Rh (D) solutions were 2.31%, 2.5% and 95%, respectively. The ELAT test showed that the amount of Anti-Rh (D) in concentrated-unformulated sample was reduced about 8%. For formulations containing 0.3 M Glycine, and sucrose with concentrations of 30, 60 and 90 mM, in phosphate buffer (pH 7.5,25 mM), the amounts of loss of Anti- Rh(D) were 2.3%,0.7% and 1.6%, respectively.Conclusion This study showed that ultrafiltration with the mentioned conditions is suitable for the concentrating of Anti-Rh (D) solutions. To prevent denaturation of IgG during ultrafiltration, it is better to add stabilizers, such as, Glycine and sucrose to Anti-Rh (D) Immunoglobulin solutions before the process of ultrafiltration.