RED LIST OF BULGARIAN ALGAE. II. MICROALGAE.

The Red List presented in this paper is focused on Bulgarian non-marine microalgae which face a risk of extinction. The assignment to each IUCN Red List category is according to the seven specific criteria and their relative values in the new method for an evaluation of the threatened status of microalgae (STOYNEVA-GÄRTNER ET AL., this volume). The list contains 756 taxa (613 species, 82 varieties and 61 forms) from 7 divisions, classified in six IUCN categories and shows that threatened microalgae represent 14% the total algal biodiversity of Bulgaria

Septicaemia models using Streptococcus pneumoniae and Listeria monocytogenes: understanding the role of complement properdin

Streptococcus pneumoniae and Listeria monocytogenes, pathogens which can cause severe infectious disease in human, were used to infect properdin-deficient and wildtype mice. The aim was to deduce a role for properdin, positive regulator of the alternative pathway of complement activation, by comparing and contrasting the immune response of the two genotypes in vivo. We show that properdin-deficient and wildtype mice mounted antipneumococcal serotype-specific IgM antibodies, which were protective. Properdin-deficient mice, however, had increased survival in the model of streptococcal pneumonia and sepsis. Low activity of the classical pathway of complement and modulation of FcγR2b expression appear to be pathogenically involved. In listeriosis, however, properdin-deficient mice had reduced survival and a dendritic cell population that was impaired in maturation and activity. In vitro analyses of splenocytes and bone marrow-derived myeloid cells support the view that the opposing outcomes of properdin-deficient and wildtype mice in these two infection models is likely to be due to a skewing of macrophage activity to an M2 phenotype in the properdin-deficient mice. The phenotypes observed thus appear to reflect the extent to which M2- or M1-polarised macrophages are involved in the immune responses to S. pneumoniae and L. monocytogenes. We conclude that properdin controls the strength of immune responses by affecting humoral as well as cellular phenotypes during acute bacterial infection and ensuing inflammation

Elimination of neutrophils in zymosan-induced ankle inflammation by etoposide

Neutrophils play a crucial role in the pathogenesis of joint inflammatory diseases such as rheumatoid arthritis (RA). Therefore their elimination and/or a functional inhibition might have beneficial or even therapeutic effects in these diseases. In the present study we exploited the cytotoxic action of etoposide to deplete neutrophils. We administrated the drug twice (at day -3 and day -1) to SCID mice having intact innate immunity and a fail in T- and B-cell maturation. Ankle inflammation was induced by the injection of zymosan (ZY). Joint damage was evaluated by histology grading system for cell infiltration and proteoglycan loss and degree of cartilage erosion. The frequencies of mature Ly6G+CD11b+ cells in bone marrow (BM) were monitored at days -4, -2 and 0 by flow cytometry. At day 7 of ankle inflammation the amounts of pro-inflammatory cytokines tumor necrosis factor (TNF)-α and interleukin (IL)-17 were measured by enzyme-linked immunosorbent assay (ELISA). Histological analysis of the joint sections showed decreased scores for cell infiltration and cartilage proteoglycan loss and reduced cartilage erosion in drug-treated zymosan injected mice in comparison to untreated group with ankle inflammation. Etoposide diminished cell numbers in BM, inhibits granulopoiesis triggered by zymosan and decreased the frequencies of mature Ly6G+CD11b+ cells in BM and eliminated Ly6G+ cells from blood and synovial fluid. We observed reduced TNF-α and impaired IL-17 production in etoposide-treated ZY group. Our data provide a proof-of principle that the elimination of neutrophils might be exploited in a design of new therapeutic approaches for joint inflammatory diseases

A study of flavonoid composition and antimicrobial activity of Scutellaria altissima L. from different floristic regions of Bulgaria

Introduction: Scutellaria extracts and its constituents, especially the characteristic flavonoids such as baicalein and its glycoside baicalin, exhibit significant antimicrobial activity. Aim: To perform a comparative analysis of flavonoid composition and antimicrobial activity of extracts obtained from aerial parts and roots of Scutellaria altissima from the regions of Mezek and Bachkovo, Bulgaria. Materials and methods: 70% ethanol and aqueous extracts of aerial parts and roots of S. altissima were used. HPLC analysis of S. altissima extracts was performed. Microbiological tests were done on clinical isolates of Streptococcus mitis, Staphylococcus aureus, Escherichia coli, and Candida albicans. Minimal bactericidal and minimal bacteriostatic concentrations of S. altissima extracts were determined by the agar method. Results: The ethanol extracts contain flavonoids approximately twice as much in comparison with the aqueous extracts. The baicalin content in the aerial parts of S. altissima from the region of Mezek is 5 times higher than that in the roots. S. altissima extracts have effective antimicrobial activity against S. mitis only. The minimal bactericidal concentration of ethanol extracts of S. altissima aerial parts and S. altissima roots is 2000 µg/ml and 8000 µg/ml at 24 hours, respectively. The bactericidal effect of aqueous extracts occurs at 48 hours at minimal bactericidal concentration of S. altissima aerial parts – 2000 µg/ml and of S. altissima roots – 6000 µg/ml. Conclusions: The finding that extracts of Bulgarian S. altissima possess effective antimicrobial properties against S. mitis suggests that it can be used as a potential source for the development of natural antimicrobial agents to suppress oral pathogens and prevent some oral infections