-Purpose. Experimental autoimmune myocarditis (EAM) in rats is an animal model of human giant cell myocarditis and post-myocarditis dilated cardiomyopathy. The pathogenesis of EAM has not been elucidated, but there is accumulating evidence that cytokines secreted from monocytes/macrophages and T cells play a crucial role in the induction and progression of disease. Flavonoids are a large group of polyphenolic compounds abundantly present in the human diet, which scavenge oxygen radicals and have anti-inflammatory activities. Having in mind in vivo beneficial effects of flavonoid quercetin in different animal models of immunoinflammatory diseases such as experimental autoimmune encephalomyelitis and adjuvant arthritis, on the one side, and its in vitro suppressive effect on production of tumor necrosis factor-alpha (TNF- on the other side, we investigated the effects of quercetin on EAM in rats. Methods. Myocarditis was induced in Dark Agouti (DA) rats by injection of porcine cardiac myosin and quercetin at doses of 10 or 20 mg/kg was orally administered from days 0 to 21 after induction of disease. The severity of myocarditis was evaluated by determination of heart weight/body weight ratio (Hw/Bw) and histopathological examination of hearts. The levels of cytokines (TNF-, IL-12, IL-17 and IL-10) in serum and lymph node cells (LNC) culture supernatants were measured by ELISA. Results. The rats treated with 20 mg/kg of quercetin had significantly decreased incidence of EAM, Hw/Bw, macroscopic and microscopic scores of hearts. Further, in EAM rats treated with quercetin levels of TNF- and IL-17 were significantly lower, while the level of IL-10 was significantly higher both in serum and culture supernatants of LNC stimulated with concanavalin A compared with vehicle-treated animals. Conclusions. The present study suggests that quercetin ameliorates EAM, at least in part, by interfering production of proinflammatory (TNF- and IL-17) and/or anti-inflammatory (IL-10) cytokines. _______________________________________________________________________________________

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In the present study, possibilities for using novel nanocomposites based on alginate and silver nanoparticles for wound treatment were investigated in a second-degree thermal burn model in Wistar rats. Silver nanoparticles (AgNPs) were electrochemically synthesized in alginate solutions that were further utilized to obtain the Ag/alginate solution and microfibers for subsequent in vivo studies. Daily applications of the Ag/alginate colloid solution, containing AgNPs, alginate and ascorbic acid (G3), wet Ag/alginate microfibers containing AgNPs (G5) and dry Ag/alginate microfibers containing AgNPs (G6) were compared to treatments with a commercial cream containing silver sulfadiazine (G2) and a commercial Ca-alginate wound dressing containing silver ions (G4), as well as to the untreated controls (G1). Results of the in vivo study have shown faster healing in treated wounds, which completely healed on day 19 (G4, G5 and G6) and 21 (G2 and G3) after the thermal injury, while the period for complete reepitelization of untreated wounds (G1) was 25 days. The macroscopic analysis has shown that scabs fell off between day 10 and 12 after the thermal injury induction in treated groups, whereas between day 15 and 16 in the control group. These macroscopic findings were supported by the results of histopathological analyses, which have shown enhanced granulation and reepithelization, reduced inflammation and improved organization of the extracellular matrix in treated groups without adverse effects. Among the treated groups, dressings based on Ca-alginate (G4-G6) induced enhanced healing as compared to the other two groups (G2, G3), which could be attributed to additional stimuli of released Ca. The obtained results indicated potentials of novel nanocomposites based on alginate and AgNPs for therapeutic applications in wound treatments.

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