Evaluation of potential antiinflammatory activity of copper (ii) and zinc(ii) benzene-1, 4-diylbis(oxyacetates), free benzene-1, 4-diylbis(oxyacetic)acid and their mixtures in rats
Using rat paw dextran- and/or carageenan-induced edemas, the antiinflammatory activity of copper(II) and zinc(II) benzene-1,4-diylbis(oxyacetates) (compexes 1c and 1z) and free benzen-1,4-diylbis(oxyacetic)acid (1a) and their equimolar mixtures (1cz, 1ac and 12az) were evaluated plethysmometrically. All the tested compounds were administered intraperitoneally in the single dose 50μmol/kg of body weight (calculated for the carboxylate fragment) 30 minutes before injecting the irritant. The antiphlogistic activity of the compounds (expressed as a mean edema reduction) was found as: 1a 27.6 % / -23,0 % < 1c 44.2 % / 34.7 < 1z 69.2 % / 30.3 % < 1cz 59.7 % / 67.0 % < 1ac 53.1 % / 77.6 % < 1az 83.8 % / 85.5 %. The relationships between the coordination-chemical properties and the biological effects on the corresponding compounds are discussed.
The efficacy of newly synthesised agent and natural antioxidant treatment in diabetic and hypertensive rats
Hypertension that develops as the result of cardiovascular damage in diabetes is one of the serious complications of diabetes. The aim of this study was to evaluate the changes in levels of oxidative stress and in endothelial NO synthase (eNOS) and heat shock protein 90 (Hsp90) expressions after the treatment of diabetic rats with a newly synthesised heteroarylaminoethanolic derivative 4/1E with potentially beta-adrenergic blockade effects and a strong antioxidant Pycnogenol®. The treatment of 6-weeks duration was indicated in the group of diabetic Wistar rats (DL; streptozotocin (STZ) 3×25 mg/kg i.p.) and hypertensive rats (HL, STZ) with 4/1E in the dose 10 mg/kg i.p. or with Pycnogenol® (DP, HP) in the dose 20 mg/kg p.o. Animals in control groups (C, H, D) received vehiculum. The levels of oxidative stress were assessed in kidney andliver as the activity of N-acetyl-β-D-glucosaminidase (NAGA) and the levels of thiobarbituric acid reactive substances (TBARs). The expression of eNOS and Hsp90 was assessed from the hearts of all animals using SDS-Page and Western blotting.
In our study the effects of newly synthesised drug 4/1E and Pycnogenol® on the levels of oxidative stress were comparable only in diabetic animals. The expression of eNOS was decreased in diabetic, but not hypertensive animals. The treatment with 4/1E did not affect the expression of eNOS unlike the treatment with Pycnogenol® after which the expression was significantly increased. The expression of Hsp90 was increased in both hypertensive and diabetic animals. The treatment with 4/1E was more effective in decreasing Hsp90 expression in both groups of animals than the treatment with Pycnogenol®.
The present study evaluates antihyperglycemic activity of fractionated Pycnogenol® and its ability to improve endothelial dysfunction
in diabetic animals. The aim of this study was to isolate from Pycnogenol® mixture its active compounds and compare
their efficacy on observed parameters. Pycnogenol® mixture was fractioned by re-extracting with petroleum ether, chloroform,
ethyl acetate and butanol, subsequently. Pycnogenol® mixture and fractions (butanolic, water, ethyl acetate) were administered
during 6 weeks to diabetic rats. Blood glucose levels were assessed from the arterio-venous blood at the beginning of experiment
and at the end of experiment. Endothelial dysfunction was evaluated as the contractile responses to phenylephrine and
acetylcholine. The amount of collagen I and III was assessed from thoracic aorta after picrosirius red staining. For the confirmation
of the changes on molecular level, we determinated endothelial NO synthase (eNOS) and heat shock protein 90 (Hsp90)
expression from left ventricle.
Overall, the result suggest, that fractions are not so effective on observed parameters as Pycnogenol® mixture itself, indicating
synergistic effect of the plant constituents.