Iranian Journal of Basic Medical Sciences
Volume:10 Issue: 3, Autumn 2007

Articular cartilage as an avascular skeletal tissue possesses limited capacity to heal. On the other hand, it is believed that the regeneration capacity of each tissue is largely related to its stem cell contents. Little is known about the presence of mesenchymal stem cells in articular cartilage tissue. This subject is investigated in the present study. Articular cartilage was obtained from rats of Wistar strain and subjected to enzymatic digestion using 1:1 ratio of 0.2% collagenase I and 0.1% pronase. The released cells were then collected and cultivated in 25 cm2 culture flask, which was resulted in the appearance of two morphologically distinct cell populations. Fibroblastic population were purified and expanded through several subcultures, using their loose adherence on culture surfaces and examined in terms of differentiation potential.The primary culture mainly contained polygonal cells with few fibroblastic cells among them. Upon the first subculture, the fibroblastic cells appeared as aggregates of few cells among the polygonal cartilage cells. It was found that the fibroblastic cell population could easily detach from the culture surface following to a brief exposure to tripsin solution. Using this property, these cells purified and expanded by several subcultures. According to the results, the isolated cells were able to easily differentiate into chondrocytic, osteocytic and adipocytic cell lineages. It seems that articular cartilage contains a distinct fibroblastic cell population with mesenchymal stem cell nature. These cells can be purified and expanded by cell culture methods, thanks to their loose adherence on the culture dish surfaces.

In previous studies, the relaxant, anticholinergic (functional antagonism), antihistaminic and its stimulatory effects on b-adrenoceptors of Nigella sativa have been demonstrated on guinea pig tracheal chains. In the present study, the relaxant effects of hydro-ethanolic, macerated aqueous (MA) and lipid-free macerated aqueous (LFMA) extract of Nigella sativa on tracheal chains of guinea pigs were examined. The relaxant effects of four cumulative concentrations of each extract (0.8, 1.2, 1.6 and 2.0 g%) was compared with saline as negative control and four cumulative concentrations of theophylline (0.2, 0.4, 0.6 and 0.8 mM) on precontracted tracheal smooth muscle of guinea pig (60 mM KCl in group 1 and 10 µM methacholine in group 2, n=6 for each group). In group 1 all concentrations of theophylline, the last two concentrations of MA and the last three concentrations of LFMA extracts showed significant relaxant effects compared to that of saline (p<0.05 – p<0.005). Two final concentrations of hydro-ethanolic extract caused contraction in comparison with saline in this group. In group 2 all concentrations of theophylline, MA and LFMA and the last three concentrations of hydro-ethanolic extracts showed significant relaxant effects relative to that of saline (p<0.005 – p<0.001). The relaxant effect of different concentrations of MA, the last three concentrations of hydro-ethanolic and LFMA extract was significantly greater in group 2 as compared with group 1. However, there was no significant difference in the relaxant effect of different concentrations of theophylline, between group 1 and 2. In both groups, the relaxant effect of most concentrations of MA, hydro-ethanolic LFMA extracts was significantly less than those of theophylline (p<0.05 – p<0.001). In group 1 and 2, the relaxant effect of all concentrations of hydro-ethanolic extract was significantly lower than most concentrations of others (p<0.05 – p<0.01). There was a significant positive correlations between the relaxant effects and concentrations for theophylline and all extracts (except hydro-ethanolic extract in group1) in both groups (p<0.05 – p<0.001). These results showed that mainly water soluble substances of Nigella sativa were responsible for the relaxant effect of the plant on tracheal chains of guinea pigs.

Some lines of evidences demonstrate that opioids are involved in water and food intake. On the other hand the dopaminergic mesolimbic system that consists of ventral tegmental area (VTA), nucleus accumbens (NAc) and medial prefrontal cortex is considered to be crucial in the rewarding actions of opiates. There are also reports showing that this system has some roles in appetite and drinking behaviors. The aim of this study was to investigate the effects of morphine self- administration on food and water intake in rats.Male Wistar rats were first trained to receive small pellets of food by pressing active lever in self-administration apparatus. Rats were anaesthetized with ketamine and their jugular vein was cannulated. After recovery the animals were placed in self-administration apparatus and allowed to self-administer morphine (0.5 mg in 0.1 ml per infusion, in morphine group) or 0.1 ml saline (in saline group) during 10 consecutive days for 2 h /sessions. The amount of 24 h water and food intake during the last 3 days compared between saline and morphine groups. The results showed that water and food intake in morphine group in days 8, 9 and 10 was lower than saline group. This study indicates that morphine self - administration alters food intake and drinking water but the exact mechanism(s) need to be more investigated.

Some lines of evidences demonstrate that opioids are involved in water and food intake. On the other hand the dopaminergic mesolimbic system that consists of ventral tegmental area (VTA), nucleus accumbens (NAc) and medial prefrontal cortex is considered to be crucial in the rewarding actions of opiates. There are also reports showing that this system has some roles in appetite and drinking behaviors. The aim of this study was to investigate the effects of morphine self- administration on food and water intake in rats.Male Wistar rats were first trained to receive small pellets of food by pressing active lever in self-administration apparatus. Rats were anaesthetized with ketamine and their jugular vein was cannulated. After recovery the animals were placed in self-administration apparatus and allowed to self-administer morphine (0.5 mg in 0.1 ml per infusion, in morphine group) or 0.1 ml saline (in saline group) during 10 consecutive days for 2 h /sessions. The amount of 24 h water and food intake during the last 3 days compared between saline and morphine groups. The results showed that water and food intake in morphine group in days 8, 9 and 10 was lower than saline group. This study indicates that morphine self - administration alters food intake and drinking water but the exact mechanism(s) need to be more investigated.

During the last three decades sesquiterpenoid lactones have emerged as one of the largest groups of plant products with over 3000 naturally occurring substances known. The genus Artemisia characteristically contains this biologically active type of secondary metabolites. With respect to increasing interest in the cytotoxic, antibiotic, phototoxic and antineoplastic activities of sesquiterpene lactones, identification of these compounds in Khorasanian Artemisia species, that some of them are endemic to Iran, can be worth while.Ten species of Artemisia were collected from different parts of Khorasan Provinces of Iran. IR spectra recorded as KBr disks and in CH2Cl2 on a Unicam dp 110 spectrometer (UK). 1H-NMR (500 MHz) spectra were measured in CDCl3 using a Bruker DRX 500 spectrometer. Number of scans was 32 for all of the samples. The Herz-Högenauer technique was applied for preparation of the terpenoid extracts.Our findings revealed that A. absinthium,A. ciniformis,A. fragrans, A. khorassanica, A. kopetdaghensis, A. santolina and A. sieberi had a high amount of sesquiterpene lactones. A little or no sesquiterpene lactone had been detected in other species. Differentiation of saturated and unsaturated sesquiterpene lactones was one of the advantages of 1H-NMR application in this method.Many of tested Khorasanian Artemisia species contained high amounts of sesquiterpene lactones.

In traditional medicine, Echium spp., including E. vulgare L., are utilized as exhilarant and mood stimulant. On the other hand, depression is a state of intense sadness, melancholia or despair that has advanced to the point of being disruptive to an individual''s social functioning and/or activities of daily living. Therefore, finding effective and safe treatments is a hotly contested area in the present time. In this study, the antidepressant effects of aqueous and alcoholic extracts of Echium vulgare L. aerial parts were investigated on mice.Boiling and percolation were used for aqueous and alcoholic extractions, respectively. Toxicity and anti-depressant studies were performed in male BALB/C mice. Three doses of 0.05, 0.2 and 0.35 g/kg for aqueous extracts and five doses of 0.01, 0.04, 0.07, 0.3 and 0.5 g/kg for alcoholic extracts were selected in the forced swimming test employing 8 mice in each group. Open field activity test was used to differentiate antidepression and locomotion effects. ANOVA and Tukey-Kramer tests were used for statistical analysis.The LD50 values of aqueous and ethanolic extracts were 1.22 g/kg and 1.21 g/kg, respectively. Aqueous and alcoholic extracts showed significant antidepressant effects starting at 0.05 g/kg and 0.07 g/kg, respectively. Open field test showed no significant changes in the activities of animals which received the ethanolic extract, but the aqueous extract decreased locomotor activities at higher doses.The results showed that the aqueous extract at low doses and ethanolic extract at high doses have significant antidepressant effects. The effects of extracts were similar to imipramine and they may affect neurotransmitters, norepinephrine and serotonin. This herb might be considered as a useful drug in the management of depression.

Eudragits are widely used polymers in the production of oral sustained release dosage forms. The application of these polymers in the production of inert insoluble matrices has been investigated. However the effect of particle size, compaction force and presence of Aerosil 200 as a glidant on the properties of Eudragit RS and RL matrices prepared by direct compression of their physical mixtures with drug have not been fully investigated. This study was performed in order to investigate the effect of above mentioned factors on physicomechanical and release properties of propranolol hydrochloride and Eudragit RS or RL matrices.Polymers were separated to different size fractions using series of sieves. Matrices were prepared in 1:3 ratio by direct compression of physical mixture of drug and polymer. To study the effect of Aerosil 200, matrices were prepared from different size fractions containing 1%w/w Aerosil 200. To investigate the effect of compaction force, the 125-177µm size fraction of polymer was chosen and compression carried out at 5, 10, 15, 20 and 30 kN compaction force. Matrices were characterized for their hardness and dissolution.The results showed that due to decrease in tablet hardness the release rate increased with increase in polymer particle size. Drug release rates were almost the same for both polymers at similar particle size range. The same trend was also observed for matrices containing Aerosil 200. Addition of Aerosil 200 decreased the rate of drug release from all matrices except those prepared from 250-350 µm size fraction. This was attributed to increase in the tablet hardness. Increase in compaction force from 5kN to 20kN increased the tablet hardness and consequently decreased the release rate, however, further increase in compaction force from 20 to 30 kN did not significantly affect the release rates of drug.Polymer particle size, presence of Aerosil and compaction force are important factors affecting drug release from Eudragit RS or RL matrices. Eudragit RS and RL polymers alone are not suitable for preparation of sustained release matrices containing water soluble drugs