Effects of Glyprolines on DNA Synthesis and Free Radical Oxidation in Mouse Gastric Mucosa Under Physiological Conditions and During Therapy with Oral Non-Steroid Anti-Inflammatory Drugs

Studies by (3)H-thymidin autoradiography showed that injections of Pro-Gly-Pro and Arg-Gly-Pro peptides caused no changes in the DNA synthesis processes in the gastric mucosa. Both peptides induced a reduction of free radical oxidation activity, which was shown by chemiluminescence. Indomethacin induced lesions in the gastric mucosa, triggered oxidative stress, and reduced proliferative activity. Injection of Pro-Gly-Pro peptide before indomethacin corrected disorders in oxidative status and normalized DNA synthesis. Preinjection of Arg-Gly-Pro led to enlargement (by 4.6 times) of the focus of lesions in animals treated by indomethacin and augmented oxidative stress.

Effect of MGHPPGP Peptide Administered during the Post-Traumatic Period on Morphometric Parameters of the Neocortex and Hippocampus, Hepatocytes, and Epithelium of the Tongue and Small Intestine in Rats

The effect of glyproline-containing peptide MGHPPGP (Met-Glu-His-Phe-Pro-Gly-Pro) was studied in experiments on male Wistar rats with modeled traumatic brain injury. The peptide was administered intraperitoneally in a dose of 1 mg/kg in 3 h and on days 2, 3, 4, 5 after injury. We evaluated morphometric parameters of the epithelial cells of the tongue, small intestine, and liver cells (AgNOR staining), neuronal layers II and V of the neocortex of the parietal lobe and hippocampal CA1 field (staining with gallocyanin) were evaluated in the post-traumatic period. Traumatic brain injury (TBI) was induced in rats by using the impact model (WDM; weight drop method). MGHPPGP peptide corrected the activity indicators of the nuclear organizer regions in epitheliocytes of the tongue.

Application of anthocyanins as indicators for alkalimetric titration

Along with synthetic substances, various naturally-occurring pigments can response to pH variations in solutions by changing their colour. Such substances include, for example, anthocyanins. In this study, the possibility of applying a set of anthocyanins obtained from berry extracts as a potential acid-base indicator. This indicator can be a good alternative to the widely-used phenolphthalein test. Aqueous and alcoholic extracts derived from the fruit of ashberry, sea-buckthorn, lingonberry, blueberry, currant, blackberry, cranberry, rose hip, cherry and hawthorn plants were studied. The presence of anthocyanins in the test samples was confirmed by chemical and physicochemical methods of analysis, including qualitative tests, ascending thin-layer chromatography and direct spectrophotometry. Quantification of anthocyanins was carried out by pH-differential spectrophotometry. Compared to alcoholic extracts, aqueous berry extracts were found to contain anthocyanins in far lesser amounts. In order to compare the pH indicator potential of phenolphthalein and the studied set of anthocyanins, the content of ascorbic acid in the test samples was assessed by direct alkalimetry. A control experiment was performed using a 5% ascorbic acid solution for injection. The pH value of aqueous and alcoholic solutions of all berry extracts was determined by an instrumental procedure. The pH of the extracts ranged from 2.95 to 5.04. The content of the total amount of anthocyanins in aqueous and alcoholic extracts of blackberries, cranberries, black currants, blueberries and lingonberries in terms of cyanidin-3-glucoside was determined both quantitatively and qualitatively. A good agreement was achieved between the results of alkalimetric titration performed using phenolphthalein and the set of anthocyanins extracted from blackcurrant berries with 95% ethanol.

Effect of Proline-Containing Oligopeptides PGP and RGP on Proliferative and Protein-Synthesizing Activity of Cultured Pulmonary Fibroblasts under Conditions of Oxidative Stress

We studied the effect of glyprolines Pro-Gly-Pro (PGP) and Arg-Gly-Pro (RGP) on the primary culture of pulmonary fibroblasts from newborn albino rats under normal conditions and during oxidative stress. Under physiological conditions, the peptides had no effect on parameters of cell division. Hydrogen peroxide induced intensive oxidative stress accompanied by suppression of protein-synthesizing function. When hydrogen peroxide was added to the culture containing the test peptides, correction of the oxidative status was observed accompanied by activation of DNA-synthesizing activity and inhibition of lucigenin-dependent chemiluminescence.