Little is known regarding the significance for local people of peri-urban national parks as recreational areas. The main goal of the present article is to evaluate the social impact and importance of peri-urban parks for visitors as a green space for outdoor recreation. For this investigation on-site, face-to-face interviews were conducted. The main reason for visiting NP are: “to be near to nature” (64.71%), “to practice sport” (58.09%) and “relaxing” (43.38%). Spending time in NP is considered by most interviewed people to be of crucial importance both for physical (96.32%) and for mental (83.82%) health. It should be noted that high frequency of park visits was reported only by young, employed and well-educated people. Data collected shows that park management plan should encourage low-income groups (unemployed and elderly) to use outdoor recreation as a part of preventive healthcare. The access for older adults, people with disabilities and children to the park should be facilitated. Services like access to clean water, toilets and seating places must be improved. The data from the authors' survey could be useful for the peri-urban national parks development as green spaces for promoting health among all demographic groups of local inhabitants.

The continuous production and release of chemicals into the environment has led to the need to assess their genotoxicity. Numerous organophosphorus compounds with different structures have been synthesized in recent years, and several oxaphosphole derivatives are known to possess biological activity. Such chemical compounds may influence proliferating cells and cause disturbances of the genetic material. In this study, we examined the cytotoxicity and genotoxicity of 4-bromo-N,N-diethyl-5,5-dimethyl-2,5-dihydro-1,2-oxaphosphol-2-amine 2-oxide (Br-oxph). In A. cepa cells, Br-oxph (10 -9 M, 10 -6 M and 10 -3 M) reduced the mitotic index 48 h after treatment with the two highest concentrations, with no significant effect at earlier intervals. Mitotic cells showed abnormalities 24 h and 48 h after treatment with the two lowest concentrations but there were no consistent changes in interphase cells. Bone marrow cells from mice treated with Br-oxph (2.82 x 10 -3 mg/kg) also showed a reduced mitotic index after 48 h and a greater percentage of cells with aberrations (principally chromatid and isochromatid breaks). These findings indicate the cytotoxicity and genotoxicity of Br-oxph in the two systems studied. The chemistry of organophosphorus compounds is a subject of increasing interest, and a large number of compounds with different structures, properties and biological activites have been synthesized (Smee and Reist, 1996;Leblond et al., 2002). Heterocyclic organophosphorous compounds are an interesting group of molecules, especially oxaphosphole derivatives that contain oxygen and phosphorus. Enchev et al. (1986) demonstrated that some oxaphospholes possess biological activity. Chemical compounds that possess biological activity may influence proliferating cells and cause disturbances of the genetic material. Since many organophosphorus compounds are known to be mutagenic (Lieberman et al., 1998;Blasiak et al., 1999), there is need to screen new organophosphorus compounds for possible genotoxicity.To assess the potential genotoxicity of any compound, its ability to cause chromosomal damage needs to be evaluated in multiple tests (Repetto et al., 2001). Higher plants provide reliable bioassays for monitoring and testing genotoxins (Grant, 1999), with the Allium test being particularly sensitive and reproducible (Fiskesjö, 1985). Small mammals are also useful models for testing genotoxicity (Topashka-Ancheva et al., 2003). The aim of this work was to investigate the cytotoxicity and genotoxicity of 4-bromo-N,N-diethyl-5,5-dimethyl-2,5-dihydro-1,2-oxaphosphol-2-amine 2-oxide (Br-oxph) using Allium cepa L. root tip cells and ICR mouse bone marrow cells.Br-oxph was synthesized in the Laboratory of Organic Chemistry of the University of Shumen (Bulgaria) (Angelov and Enchev, 1987). Since Enchev et al. (1986) showed that some oxaphospholes affected plant growth at concentrations of 10 -9 M, 10 -6 M and 10 -3 M, these concentrations were also used in the Allium test. The solutions were prepared immediately before u...

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A possible alternative to synthetic agricultural chemicals is through the use of allelopathy. Adonis species are rich sources of secondary metabolites. Such allelochemicals offer potential for the development of future pesticides. Allelochemicals influence plant growth and cause morphological alterations. This visible effect could be due to primary effects at cellular or molecular level. Changes in the mitotic activity and disturbances in different phases of mitotic division are accepted as indicators of cytotoxic influence. Mitotic abnormalities and induction of micronuclei in interphase cells are parameters used to determine genotoxicity. The purpose of the current study was to establish the possible allelopathic effect of Adonis vernalis L. water extracts through evaluation of root growth inhibition effect and cytogenetic alterations. Adonis vernalis L. growing wild in Bulgaria was used in the present study. Two types of water extracts were prepared: Hot and Cold Water Extract of A. vernalis (HWЕА and СWЕА). A 72-h root growth inhibition test was provided in order to determine the toxicity level of extracts. EC50 values were determined. For toxicity test, seeds of Triticum aestivum L. cv. GTW were used. Cytotoxic and genotoxic potential of water extracts (EC50) were evaluated using Allium cepa L.-test. The EC50 for HWEA and CWEA was determined 1.83 g/l and 0.78 g/l respectively. Significant influence on mitotic activity values and a marked decrease in percentage of telophase cells were observed after treatment with both extracts. Adonis extracts also induced different mitotic abnormalities in root-tip cells of Allium cepa L. The percent of interphase cells with micronuclei increased significantly only after treatment with HWEA. The results indicated growth inhibitory, cytotoxic and genotoxic effects of crude water extracts of A. vernalis L. These effects demonstrated the presence of water soluble allelochemicals in Adonis aerial parts.

Increasing attention has been paid recently to soil pollution. The aim of this study was to evaluate the ecological risk of soils collected from Nature Park Shumen Plateau (Bulgaria) (NP) using physicochemical and cytogenetic approaches (pH analysis, analysis of the content of heavy metals included in Bulgarian soil pollution standards, and Allium cepa-test). Soil samples from NP were collected from seven sites. A sample from a heavily anthropogenic-influenced urban site was also collected. As signs for environmental risk used pH values, we found total concentration of heavy metals and mitotic abnormalities in Allium cepa root meristems included in Bulgarian legislation. Only two samples from NP were found to be slightly acidic. The other samples have slightly alkaline pH. The highest pH value was obtained in the urban sample. Heavy metal concentrations did not exceeded national standards for soil pollution. Several NP samples and urban samples exerted cytotoxic and genotoxic effects in Allium root meristems. Our data on soil pH and heavy metal concentrations did not indicate potential ecological risk, but cytogenetic endpoints showed the presence of harmful compounds in studied areas. In conclusion, the ecological risk for the investigated suburban area may be assessed as moderate.

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RESUMO: "Atividade alelopática de micropropagado Hyssopus officinalis L. infusãos aquosos". Os hábitats naturais de Hyssopus officinalis L. (Lamiaceae) na Bulgária não são suficientes para satisfazer as necessidades desta erva. A micropropagação poderia ser usada para obter plantas com características desejáveis. Hyssopus é uma planta aromática medicinal que não foi estudada muito. Recentemente plantas aromáticas foram investigadas como potentes plantas alelopáticas. A determinação dos modos da ação de aleloquímicos é um dos aspectos desafiantes em estudos alelopáticos. O objetivo deste estudo foi determinar a atividade alelopática de micropropagado Hyssopus officinalis L. infusãos aquosos. Foi avaliada a influência de infusões quentes e frias feito de partes aéreas de hyssopus sob condições de laboratório. Com este propósito nós testou os efeitos de infusões em germinação e alongamento de raiz de Cucumis sativus L. e Triticum aestivum L. Determinamos também o efeito na atividade mitótica usando os Allium cepa L. teste de aberração cromossômica. Os resultados demonstraram a presença de compostos alelopáticos solúveis de água em tecido de hyssopus. As infusões exibiram o efeito depressivo do crescimento que era mais forte na fase inicial de crescimento. Os efeitos inibitivos em germinação e alongamento de raiz foram mais fortes em T. aestivum que em C. sativus. Hyssopus também exerceu efeito genotóxico e mitodepressivo em células de ponta de raiz de Allium cepa.Unitermos: Allium cepa L. teste de aberração cromossômica, germinação, Hyssopus officinalis L., atividade mitótica, elongación de raiz, aleloquímicos solúvel em água. ABSTRACT:The natural habitats of Hyssopus officinalis L. (Lamiaceae) in Bulgaria are not sufficient to satisfy the needs of this herb. Micropropagation might be used for obtaining plants with desirable traits. Hyssopus is a medicinal aromatic plant that has not been studied very much. Recently aromatic plants were investigated as potent allelopathic plants. Determining the modes of action of allelochemicals is one of the challenging aspects in allelopathic studies. The objective of this study was to determine the allelopathic activity of micropropagated Hyssopus officinalis L. water infusions. We evaluated the influence of hot and cold infusions made from the aerial parts of hyssopus under laboratory conditions. For this purpose we tested the effects of infusions on germination and root elongation of Cucumis sativus L. and Triticum aestivum L. We determined also the effect on mitotic activity using Allium cepa L. chromosome aberration test. The results demonstrated the presence of water soluble allelopathic compounds in hyssopus tissue. Infusions exhibited growth depressive effect which was stronger at early stage of growth. The inhibitory effects on germination and root elongation were stronger in T. aestivum than in C. sativus. Hyssopus also exerted mitodepressive and genotoxic effect in Allium cepa root tip cells.