Iranian Journal of Basic Medical Sciences
Year:2002 | Volume:5 | Issue:2 (14)|Papers Count:8

The aim of this study was to prepare and evaluate a solid dosage form of insulin (INS) for oral administration capable to protect insulin from acid and enzymatic degradation in stomach. Insulin was formulated in granules by wet granulation method and microencapsulated with Eudragit L100, an entric coating polymer, using Wurster method. Sodium cholate (SC), aprotinin (AP) and carbopol 934 (CP) were also incorporated into granules as penetration enhancer, protease inhibitor and mucoadhesive respectively. INS content of microcapsules (MC) and the release rate of INS from MC were determined by radioimmunoassay (RIA). The effects of SC, AP and CP on the release of INS were also investigated. The results showed that the present method would be appropriate for preparation of small batches of MC to which active ingredient and excipeints could be easily incorporated. Secondly, formulation conditions could provide insulin stability in the stomach. Eudragit was found to be able to prevent release of insulin in artificial stomach medium. The formulation prepared by the aforementioned method released all its insulin content after 30 mins in a buffer with pH 7.4. It was also shown that CP could delay the release of insulin while AP and SC had no significant effect on the release of INS from coated granules. Finally the formulation marked as ACSF which contained AP, CP and SC was chosen as the most appropriate formulation. It was found that ACSF was able to protect INS from degradation by the stomach medium and release more than 75% of its insulin content into small intestine where INS should be released and absorbed.      

Due to the interaction of Rosmarinus officinalis with opioid system we decided to evaluate the effects of the aerial parts of this plant on withdrawal syndrome. Dependence was induced using subcutaneous injections of morphine (50,50 and 75 mg/kg) for 3 days. On day 4, morphine was injected2h before the intraperitoneal injection of naloxone. The number of episodes of jumping during the 30 minutes after injection of naloxone was considered as intensity of the withdrawal syndrome. The results indicated that the aqueous extracts at doses of 1.68 g/kg and 2.4 g.kg (i.p.) were pharmacologically equal to 5 mg/kg of diazepam in the inhibition of withdrawal syndrome. The ethanolic extract was less effective and only a dose of 0.96 g/kg reduced the number of jumping. Phytochemical study also indicated that only the aqueous extract has an alkaloid component. It is concluded that the aqueous and ethanolic extracts of R. officinalis aerial parts could diminish the withdrawal syndrome of morphine.      

In this study, intensity of ANS (1-Anilino-8-Naphtalen Sulfunate) fluorescence at 480nm has been taken as a measure of the amount of hCG (Human Chorionic Gonadotropinr) in the solution. The rate of subunit dissociation of hCG has been turned out to be as a first order reaction in the range of pH=2 to 10 at different temperature. The dissociation rate constant in acid medium is higher than in other mediums. Gel filtration study has shown that the elution volume of hCG decreases as the pH decreases. Sodium Dodecyl Sulfate (SDS) slows down the subunit dissociation of hCG through the concentration range used. The best inhibitory concentration of SDS is found to be 0.7mM. The activation energies increase, in all pH in the presence of SDS. The maximum value of activation energies are corresponding to the concentration of 0.7mM of SDS. It has been evident that the gel filtration causes, in all pH and the presence of SDS (0.7 mM), the increase of elution volume of hCG. The decrease in the rate of subunit dissociation in addition to the increase in activation energy in the presence of SDS could be accounted for the partial folding of hCG.      

Although fingerprints and handprints are widely used in criminology, it is only recently that this approach has been applied to the field of medical and genetic diagnosis. In order to investigate dermatoglyphics in Insulin Dependent Diabetes Mellitus (IDDM), quantitative and qualitative characteristics were analyzed in 30 diabetic patients and 30 normal subjects. The X 2 test was used for quantitative and t - test for qualitative data analysis. The results showed finger line counts (ab count) in the males and females of diabetic patients compared to control subjects decreases but this reduction was not significant. The forms of Loop and Whrols are heterogenous and compared to control group were significant (P= 0/001, P= 0/004). In conclusion, dermatoglyphics seem to be an interesting tool for genetic studies related to IDDM.      

Zizyphus spina-christi leaf from Rhamnaceae growing in southern Iran is used in herbal medicine for hair washing. Also its antifungal, antimicrobial, antidiabetic and antinociceptive activities have been reported. The sweet fruit of Zizyphus spina-christi is eaten fresh or dried. The aim of the present study was to investigate the effect of Zizyphus spina christi leafhydroalcoholic extract on isolated rat ileum tone. To achieve this aim, pieces of rat ileum (2 cm) were placed in an organ bath containing 10 ml standard Tyrode's solution; pH 7.9 and 36-38 °C with 1 g initial tension which bubbled with pure O2. An isotonic transducer recorded the ileum tone after 30-60 min recovery period. Extract was prepared using the percolation method with 70% alcohol for 72 hr. The tissue was exposed to final extract concentrations of 0.125, 0.25, 0.5, 1, 2, 4 and 8 mg/ml for 1.5to 2.5 min. Also, the effect of the extract on ileum KCI - induced contraction in the presence and absence of propranolol (2 µM) were investigated. The results showed that, the extract reduced the ileum basal tone, especially at higher concentrations, dose dependently (P<0.001).The ileum contractions, induced by KCI (40 mM) were also significantly reduced by 1, 2 and 4 mg/ml of extract in a dose dependent manner (P<0.01).This inhibition was not reduced by 2 µM propranolol (P>0.05). It is postulated, therefore, that the β2 receptors are not involved in this inhibition; and possibly, the extract contains voltage dependent calcium channel blocker.        

Hypericum perforatum is traditionally used for the treatment of many diseases. This oral drop drug is recommended for relief of migraine pain and is also used as an anti - depressant. In this research we surveyed mutagenicity effects of Hypiran. Conducting the Ames test, we used Salmonella typhimurium which has mutated histidine operan and depends on histidine for its growth. The tester strains used were, TA98 and TA100 which can determine point mutations including frame shift and base pair substitution mutations. These strains can also grow and produce colonies in the presence of mutagen substances in minimal glucose agar medium. Hypiran drops were prepared in different volumes such as 10, 20, 50, 100, 200, 250 and 300 microliter and were exposed to TA98 and TA100 strains. TA98 and TA100 were cultured in media with minimum glucose agar; and the produced colonies were counted after 48 hours. The mean of revertant colonies in each group was compared with the mean of each corresponding control revertant colony. Using evaluation indices, the rates of mutation was calculated and dose -response curve plotted. Hypiran oral drops in many applied volumes can revert TA98 and TA100.It can establish point mutations including frame shift and base pair substitution mutation. Based on evaluation indices related to the Ames test, Hypiran drops are a mutagen. However, in order to obtain higher certainty, other mutagenicity tests must be performed.      

The carbohydrate side-chain of glycoconjugates can show a developmentally regulated expression pattern. In order to analyse these changes during development of mesenchyme ventral to neural tube to their cartilagenous fate, two lectins were used to reveal glycoconjugates histochemically in 12 to 16- days old mouse embryos. During days 12 to 13, sclerotomal cells condense around the notochord and differentiate into a precartilage ventral to neural tube. The results showed that alpha-fucose has no role in differentiation of mesenchyme into cartilage since OFA fail to react with peroxidase-conjugated lectine specific for alpha-fucose. Our finding also revealed that wistaria floribonda (WFA) lectin specific for D-GalNac reacts with sclerotomal cells during precartilage stages. Beginning with day 16 of gestation, all WFA reacted cells differentiate into cartilage of future vertebrate body and intervertebral disc. The results suggest that WFA-positive glycoconjugate might play some role in differentiating sclerotomal mesenchyme into cartilage and also may correlate with interaction between notochord, neural tube and sclerotomal cells in early histogenesis of neural tube as well as cartilage formation.