Immunohistochemical studies on the effect of Aloe vera on the pancreatic â-cells in neonatal streptozotocin-induced type-II diabetic rats

Aloe vera is used worldwide for several medical purposes as alternative medicine. There are positive and negative reports on the hypoglycaemic effects of this plant. From previous acute studies, Aloe leaf gel and pulp extracts lead to significant decreases in blood glucose in neonatal streptozotocin (n0-STZ)-treated type-II diabetic rats, whereas lowering of blood glucose during chronic treatment with the same extracts was statistically insignificant. Here we try to detect whether Aloe leaf gel and pulp extracts affect pancreatic â-cells. Using n0-STZ type-IIdiabetic rats, the immunoreactivity of â-cells of the islets of Langerhans did not differ among treatments of control, glibenclamide-, Aloe vera leaf pulp- and gel extract-treated rats. These results suggest that treatment of diabetic rats with Aloe vera gel or pulp or glibenclamide has no beneficial influence on the pancreatic â-cells in type II diabetes

Separation and some properties of Aloe vera L. leaf pulp lectins

The separation and partial purification of two lectins from the leaf pulp of Aloe vera L. (=barbadensis Miller) is presented. The fraction shelving haemagglutinating activity was precipitated at 50% ammonium sulphate concentration from the crude leaf pulp extract. The precipitate thus obtained, after dialysis, was applied to a hydroxylapatite column. Stepwise elution resulted in two peaks showing haemagglutinating activity eluted with 5 mM (Aloctin I) and 20 mM (Aloctin II) phosphate buffers. Haemagglutinating activity was estimated visually by adding a 4% rabbit erythrocyte suspension to serial two-fold dilutions of the lectins in microtitration plates. None of the 20 sugars tested inhibited haemagglutinating activity of Aloctin I up a concentration of 500 mM. Aloctin II was inhibited by N-acetyl-D-galactosamine at 250 mh concentration. Of 10 metal ions tested, only Al3+ salts were found to activate Aloctin I and II. On the other hand, it was shown that neither lectin possessed any alpha- and beta- galactosidase or alpha- and beta- glucosidase activity. The lectins were of glycoprotein structure containing approximately 5% neutral sugar. The specificity of the lectins towards human and rat erythrocytes was investigated. Copyright (C) 1999 John Wiley & Sons, Ltd

Antioxidant activity of Smilax excelsa L. leaf extracts

Smilax excelsa L. leaves are used widely in the Black Sea region of Turkey for consumption in the daily diet and in folk medicine for their medicinal properties. In the present study, different antioxidant tests were employed in order to evaluate the antioxidant activities of water, infusion, ethanol and ethyl acetate extracts of S. excelsa leaves. In addition, the results were compared with natural and synthetic antioxidants. The levels of total phenolics, total flavonoids and anthocyanins of the extracts were also determined. The extracts were found to have different levels of antioxidant properties in the test models used. All extracts had good total phenolic and flavonoid contents, inhibited lipid peroxidation, showed radical scavenging and iron-chelating activities. Therefore, the leaves of the plant could be considered as a significant natural antioxidant source. (C) 2008 Elsevier Ltd. All rights reserved

In vivo studies on nasal preparations of ciprofloxacin hydrochloride

Gel formulations of ciprofloxacin hydrochloride (CPH) were prepared with bioadhesive polymers such as hydroxypropyl methylcellulose (HPMC), hydroxyethyl cellulose (HEC) and methylcellulose (MC). They were administered into the nasal cavity of rabbits. A nasal aqueous suspension of CPH with glycerol was also applied. In addition, the effect of Tween 80 as penetration enhancer was examined. The agar plate diffusion technique was applied for the assay of CPH. The results were compared with oral and intravenous administrations. The bioavailability of the CPH gel formulation prepared with HPMC was almost identical to that of the oral route. Other nasal formulations with HEC and MC had bioavailabilities lower than oral preparations. The relative bioavailabilities for the formulation containing HEC and MC were 48.7 and 45.54%, respectively. To increase the bioavailabilities, 1% (w/w) of Tween 80 was added. The bioavailability of these gel formulations increased to 63.54 and 55.72%, respectively. Experiments carried out on rabbits showed that the nasal administration of CPH bioadhesive gel formulation containing HPMC may be an alternative to the oral route