Influence of natural polysaccharides on the morphology and properties of hybrid vaterite microcrystals.

Co-precipitation of biopolymers into calcium carbonate crystals changes their physicochemical and biological properties. This work studies hybrid microcrystals of vaterite obtained in the presence of natural polysaccharides, as carriers for the delivery of proteins and enzymes. Hybrid microcrystals with dextran sulfate, chondroitin sulfate, heparin, fucoidan, and pectin were obtained and compared. The impact of polysaccharides on the morphology (particle diameter, surface area, nanocrystallite and pore size), polysaccharide content and surface charge of hybrid microcrystals was studied. Only microcrystals with fucoidan and heparin exhibited antioxidant activity against •ОН radical. The surface charge and pore size of the hybrid microcrystals affected the sorption of albumin, catalase, chymotrypsin, mucin. A decrease in the catalytic constant and Michaelis constant was observed for catalase sorbed on the hybrid crystals. The biocompatibility of microcrystals depended on the nature of the included polysaccharide: crystals with sulfated polysaccharides increased blood plasma coagulation but not platelet aggregation, and crystals with dextran sulfate had the greatest cytotoxicity against HT-29 cells but not erythrocytes. Hybrid microcrystals with all polysaccharides except chondroitin sulfate reduced erythrocyte lysis in vitro compared with vaterite crystals. The obtained results enable to create novel carriers based on hybrid vaterite crystals with polysaccharides, beneficial for the delivery of protein drugs.

Anti-Bacterial and Anti-Inflammatory Effects of Toothpaste with Swiss Medicinal Herbs towards Patients Suffering from Gingivitis and Initial Stage of Periodontitis: from Clinical Efficacy to Mechanisms.

OBJECTIVE: To distinguish clinical effects and mechanisms of sodium monofluorophosphate plus xylitol and herbal extracts of Swiss medicinal plants (Chamomilla recutita, Arnica montana, Echinacea purpurea, and Salvia officinalis). MATERIALS AND METHODS: A 2-month-long comparative clinical study of toothpaste containing 1450 ppm sodium monofluorophosphate and xylitol (control, 15 patients) and toothpaste additionally containing extracts of the medicinal herbs (experiment, 35 patients) was performed on patients with gingivitis and the initial stage of periodontitis. Clinical indices of gingivitis/periodontitis were quantified by Loe & Silness's, CPITN, OHI-S, and PMA indexes. The pro-inflammatory and anti-inflammatory interleukins, nitrites/nitrates, total antioxidant activity, and bacterial pattern characteristic for gingivitis and periodontitis were quantified in the gingival crevicular fluid and plaque. In the in vitro tests, direct anti-bacterial effects, inhibition of catalase induction in Staphylococcus aureus, in response to oxidative burst of phagocytes, and intracellular bacterial killing were determined for the toothpastes, individual plant extracts, and their mixture. RESULTS: Experimental toothpaste was more efficient clinically and in the diminishing of bacterial load specific for gingivitis/periodontitis. Although the control toothpaste exerted a direct moderate anti-bacterial effect, herbal extracts provided anti-inflammatory, anti-oxidant, direct, and indirect anti-bacterial actions through inhibition of bacterial defence against phagocytes. CONCLUSIONS: Chemical and plant-derived anti-bacterials to treat gingivitis and periodontitis at the initial stage should be used in combination amid their different mechanisms of action. Plant-derived actives for oral care could substitute toxic chemicals due to multiple modes of positive effects.

Effects of Standardised Fermented Papaya Gel on Clinical Symptoms, Inflammatory Cytokines, and Nitric Oxide Metabolites in Patients with Chronic Periodontitis: An Open Randomised Clinical Study.

The clinical efficacy of topical administration of standardised fermented papaya gel (SFPG), known to have antioxidant and anti-inflammatory properties, versus conventional therapy was evaluated in a group of 84 patients with moderate-to-severe periodontitis, randomly assigned to control group (n = 45) undergoing traditional pharmacologic/surgical protocols or to experimental group (n = 39), additionally treated with intragingival pocket SFPG (7 g) applications (15 min daily for 10 days). Patients undergoing SFPG treatment showed significant (P < 0.05), durable improvement of three major clinical indices of disease severity: reduced bleeding (day 7), plaque and gingival conditions (day 14), and consistent gingival pocket depth reduction (day 45). Proinflammatory nitric oxide metabolites reached normal values in plasma (day 14) and gingival crevicular fluid (GCF) at day 45 with SFPG applications compared to controls that did not reach normalisation. Levels of highly increased proinflammatory (IL-1B, IL-6) and suppressed anti-inflammatory (IL-10) cytokines normalised in the SFPG group by days 14 (plasma) and 45 (GCF), but never in the control group. Although not acting directly as antibiotic, SFPG acted in synergy with human granulocytes blocking adaptive catalase induction in S. aureus in response to granulocyte-derived oxidative stress, thus enhancing intracellular bacterial killing.

Effect of cytokines on the level of free radicals in the blood of patients with systemic and local staphylococcus infection.

An increased extracellular production of free radicals with bactericidal activity does not improve the efficacy of intracellular digestion of Staphylococci. The amount of intracellular oxygen reactive species generated by the neutrophils from patients with an infectious condition has been found considerably decreased as compared to healthy donors. On the other hand, the excess of secretion of free radicals into the extracellular space leads inevitably to the adaptive increase of antioxidant enzymes and, as a result, to an increase in the total antioxidant capacity of the blood plasma. Indeed, patients with septicemia at its highest peak (at the moment of hospitalization) showed a significant increase (more than twice) in the parameters of catalase and superoxide dismutase activity; the antioxidant capacity of the plasma was elevated as well. The patients of the other two groups in our study (with a localized infection) did not show any statistically significant rise in these parameters. On the second day after the initiation of an intensive treatment the activity of the enzymes and the total antioxidant capacity of the plasma dropped sharply below the normal level. Therefore, the staphylococcus infection, especially its generalized from, is characterized by an increased extracellular secretion of radicals together with a decreased generation of intracellular radicals. On one hand this leads to the failure of the intracellular killing, on the other--to the inflammatory free radical-mediated damage of the host cells and tissues. Cytokines, such as interleukins and interferons, can regulate the free radical-mediated processes during the staphylococcus infections. The effect of the two recombinant cytokines (IL-1 beta, IFN-gamma) on the character of free radical production and intracellular killing of Staphylococci by neutrophils isolated from the blood of patients and healthy donors has been studied. The analysis of the effect of cytokines on the radical production by phagocytes revealed a redistribution of the extracellular and intracellular fractions of free radicals rather than a general increase of the oxygen active metabolite production. As expected, the increment in the number of intracellular radicals improved significantly the process of phagocytosis.