Abstract-The immunomodulatory activity of ginsenoside Rg1 from Panax ginseng was studied in mice using sheep red cells as the antigen.

A new hemocyanin was isolated from the hemolymph of garden snails Helix vulgaris, composed of two isoforms, HvH1 and HvH2 separated on an ion exchange column DEAE-Sepharose 6CL. Structural and immunological properties of Helix vulgaris hemocyanin were studied in comparison with molluscan Hcs Rapana venosa and Megathura crenulata. The possibility of using HvH and RvH as carriers of small molecules (haptens) in immunizing protocols was studied in comparison with KLH, which is a widely used, highly immunogenic carrier protein. By using HvH as a carrier of the well-known hapten TNBS (2,4,6-trinitrobenzene sulfonic acid), an increasing with time production of hapten-specific TFN-gamma was detected in splenocyte cultures of mice, which lasted longer than in case of KLH and RvH carriers. Also, use of HvH or RvH as a carrier of the hapten ProT alpha[101-109] (i.e., the synthetic C-terminal fragment of the poorly immunogenic protein prothymosin alpha) showed that antisera of higher titres than that of the control conjugate (ProT alpha[101-109]-KLH) were obtained immediately after the second bleeding. HvH and RvH may prove to be useful for the development of new antiviral, antibacterial and antitumor vaccines, since they seem to launch strong and specific immune response against the conjugated antigens.

Summary — The effect of a complex of propolis constituents, cinnamic acid and L-lysine, on host defence mechanisms was investigated. After intraperitoneal (ip) application of cinnamic acid lysine complex (CN ·Ly) to mice at a dose of 3 mg/kg for 3 consecutive days prior to inoculation with Klebsiella pneumoniae, a protective effect was observed. The action of CN ·Ly was associated with its ability to provoke proliferation of thymic and splenic lymphocytes and to augment mitogen-induced proliferation, and the release of interleukin-1 (IL-1) and interleukin-2 (IL-2). In all experiments, a solution of L-lysine in a concentration equivalent to the lysine content in the complex was used for comparison. The results indicated that free lysine acted in a mitogen-like manner predominantly on T-lymphocytes. In the complex, lysine played the role of a carrier and exhibited a less pronounced effect.propolis / cinnamic acid / cytokine release / Klebsiella infection

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Coumarin and its derivatives have potent immunomodulatory activities. Here we describe the parameters of the protective effect of 7-hydroxycoumarin (7-OHC) in experimental Salmonella enterica Serovar Typhimurium infection in mice. The protective effect depended on the duration of treatment reaching its maximum after 10 days of pretreatment and lasted for at least 15 days after its end. Electron microscopy studies revealed that 7-OHC induced ultrastructural changes in macrophages consistent with their activation as well as faster destruction of ingested salmonellae. Superoxide and hydrogen peroxide secretion by macrophages was decreased in both healthy and Salmonella-infected 7-OHC treated animals, which is in line with the current view that some coumarins possess antioxidant and radical scavenging activity. Thus, 7-OHC pretreatment also appears beneficial to the host by limiting the harmful tissue damaging and immunosuppressive effects of the oxidative stress during a Salmonella infection but still activates the microbicidal capacity of exposed phagocytes.

The superoxide radical (O2·̅), hydrogen peroxide (H2O2) and nitric oxide (NO) are pleiotropic infl ammatory mediators which play an important role in infl ammatory joint diseases. They are overproduced during rheumatoid arthritis and its experimental model - adjuvantinduced arthritis in rodents - and may be detected both systemically and intra-articularly. Their secretion is up-regulated by proinfl ammatory cytokines such as IFN-γ, IL-12, IL-6 and TNF-α, and they are responsible for the destruction of joint tissue. In this work, the effect of superoxide dismutase (SOD) from a thermotolerant yeast strain, Kluyveromyces marxianus, on the production of proinfl ammatory cytokines, reactive oxygen and nitrogen species was studied. Mice received three intraperitoneal injections of yeast SOD at a dose of 10 mg/ kg body weight (30,000 U/kg) on consecutive days starting on the day after arthritic induction. On days 3, 8 and 14 post induction peritoneal macrophages were isolated and both spontaneous and stimulated production of reactive oxygen and nitrogen metabolites were measured. Early in arthritic development yeast SOD treatment did not infl uence the O2·̅ production, but on day 14 both spontaneous and PMA-induced secretion were dramatically reduced. Spontaneous H2O2 release was inhibited on day 14, while PMA-stimulated production was decreased from the beginning of the arthritic development. Yeast SOD treatment effectively suppressed the spontaneous and recombinant mouse IFN-γ + LPS induced release of NO as well. Serum levels of proinfl ammatory cytokines, IL-12, IFN-γ, IL-6 and TNF-α, were also signifi cantly reduced. The obtained results show some of the mechanisms of action of SOD in reducing the severity of arthritic infl ammation. Besides direct inhibition of joint tissue destruction exogenous SOD substantially limits the existing positive feedback between secretion of reactive oxygen species and infl ammatory cytokine production.

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