Chitosan exhibits favorable biological properties such as no toxicity, biocompatibility and biodegradability; therefore, it has attracted great attention in both pharmaceutical and biomedical fields. Chitosan exhibits poor solubility at... more
Chitosan exhibits favorable biological properties such as no toxicity, biocompatibility and biodegradability; therefore, it has attracted great attention in both pharmaceutical and biomedical fields. Chitosan exhibits poor solubility at pH values above 6 that prevents enhancing effects at the sites of absorption of drugs. In the present work, N-diethyl methyl chitosan (DEMC) was prepared and the enhancing effect of this polymer was investigated. Ex vivo studies have shown a significant increase in absorption of brilliant blue in the presence of diethyl methyl chitosan in comparison with chitosan. DEMC with positive charges is able to interact with tight junctions of colon epithelial cells and hence increases permeability of brilliant blue across the tight junctions. In vivo investigations have exhibited the absorption enhancer effects of DEMC on the colon absorption of insulin in normal and diabetic rats. The insulin absorption from the rat's colon was evaluated by its hypoglyce...
Publication Date: Jan 11, 2005
Publication Name: International journal of pharmaceutics
The effects of cadmium, l-arginine (nitric oxide precursor) and N(omega)-nitro-l-arginine methyl ester (l -NAME) as a nitric oxide synthesis inhibitor and cotreatment of them on rat submandibular secretory function were studied. Pure... more
The effects of cadmium, l-arginine (nitric oxide precursor) and N(omega)-nitro-l-arginine methyl ester (l -NAME) as a nitric oxide synthesis inhibitor and cotreatment of them on rat submandibular secretory function were studied. Pure submandibular saliva was collected intraorally by micro polyethylene cannula from anaesthetized rats using pilocarpine as secretagogue. Fourteen days treatment with 10 mg l(-1)cadmium as cadmium chloride in drinking water caused significant alterations on salivary function. Salivary flow rate, total protein concentration and amylase activity of saliva were decreased while secretion of calcium was increased by cadmium. Two weeks treatment of rats with l -arginine (2.25%) in drinking water caused an increase in submandibular gland weight. Flow rate was reduced by l-NAME. The total protein concentration of saliva was increased by l-arginine while decreased by l-NAME. Calcium concentration of saliva was reduced by l-arginine and increased by l-NAME. Cotreatment of cadmium with l-arginine prevented cadmium-induced reduction of flow rate while l-NAME cotreatment potentiated cadmium-induced reduction of flow rate. l-arginine showed a preventive effect on cadmium-induced decrease of protein concentration and reached control levels. l-arginine potentiated cadmium-induced increase of saliva calcium concentration. It is confirmed that nitric oxide (NO) has a role in salivary gland function. It is also concluded that cadmium inhibitory effects on salivary gland function are modulated by the NO system as it is observed that the cadmium inhibitory effect on submandibular gland function is diminished by l-arginine and extended by l-NAME. Considering the properties of cadmium substitution for calcium in many intracellular events, different types of alterations can be discussed.
Nicotine, the main pharmacologically active component in tobacco and cigarette, has some toxic effects and also high potential for addiction. In this study, the effect of artichoke (Cynara scolymus L.) and zeolite nano-materials on... more
Nicotine, the main pharmacologically active component in tobacco and cigarette, has some toxic effects and also high potential for addiction. In this study, the effect of artichoke (Cynara scolymus L.) and zeolite nano-materials on urinary excretion of nicotine and consequently elimination of systematically absorbed nicotine was investigated. A simple, valid and highly sensitive high performance liquid chromatography method has been developed for determination of nicotine in rat urine according to guidelines for bioanalysis.It was found that nano-zeolites can cause increase in urinary concentration of nicotine due to its high surface adsorption. Artichoke leaf extract can cause increase in urinary excretion of nicotine in longer post administration times. It was observed that co-administration of nanozeolites and the leaf extract has the synergetic effect on increasing the urinary excretion of nicotine.
