Traditional Use of Wild Edible Plants in Slovenia: A Field Study and an Ethnobotanical Literature Review.

No comprehensive research has been conducted on the traditional use of wild-grown edible plants in human nutrition for the Slovene ethnic area so far. In the literature on edible wild plants, authors often draw information about their use from foreign or international sources, such as books and databases, from which it is often unclear what people in different countries really include into their diet. Therefore, our purpose was to determine which edible wild-growing plant species have been used in Slovenia on a traditional basis. In our research, we gathered data using different methods. The data obtained from the literature review, i.e., the ethnobotanical literature and traditional cookbooks, were combined with those derived from the online sources and a field survey. This enabled us to create a database of 219 plant taxa encompassing more than 500 species from 62 families that are traditionally used in Slovenia. The most frequently represented families were Asteraceae, with 28 taxa, Rosaceae, with 22 taxa, Lamiaceae, with 18 taxa, Brassicaceae, with 17 taxa, Apiaceae, with 16 taxa, and Amaranthaceae, with 10 taxa. Plants are most often boiled, blanched, stewed or roasted, sometimes also baked in an oven or raw with additives, such as sour cream, sugar, salt or vinegar, but seldom fried. Selected traditional cookbooks and ethnological books provided good insight into the past use of wild plants, while an online and field survey enabled a comparison of their past and current state of use. The survey has shown that some very old wild plant recipes are still used within certain local communities, while younger people, influenced by new books about wild cuisine, are constantly introducing new plant species and recipes into their diet thereby establishing new traditions.

Cell Volume Changes and Membrane Ruptures Induced by Hypotonic Electrolyte and Sugar Solutions.

The cell volume changes induced by hypotonic electrolyte and sucrose solutions were studied in Chinese-hamster-ovary epithelial cells. The effects in the solutions with osmolarities between 32 and 315 mosM/L and distilled water were analyzed using bright-field and fluorescence confocal microscopy. The changes of the cell volume, accompanied by the detachment of cells, the formation of blebs, and the occurrence of almost spherical vesicle-like cells ("cell-vesicles"), showed significant differences in the long-time responses of the cells in the electrolyte solutions compared with the sucrose-containing solutions. A theoretical model based on different permeabilities of ions and sucrose molecules and on the action of Na+/K+-ATPase pumps is applied. It is consistent with the observed temporal behavior of the cells' volume and the occurrence of tension-induced membrane ruptures and explains lower long-time responses of the cells in the sucrose solutions.

The pore-forming action of polyenes: From model membranes to living organisms.

The incidence of resistant fungal pathogens has been increasing, especially in immuno-compromised people. As such, considerable research has been focused on discovering anti-fungal agents with new mechanisms of action and on optimizing the use of existing agents. In this context, interest in the polyene group of anti-fungals has recently been renewed, since they are known to be effective against a broad spectrum of fungal pathogens that only rarely develop a resistance to them. In the past 10 years considerable efforts have been made to improve their efficacy and, simultaneously, to reduce their toxicity. Knowledge about the basic mechanisms of their action will be of crucial importance to further optimizing their use. The mechanisms of polyene action at the membrane level are reviewed here, focusing primarily on their pore-forming activity and on the resulting osmotic responses of artificial lipid vesicles and different eukaryotic cells.

Osmotic Effects Induced by Pore-Forming Agent Nystatin: From Lipid Vesicles to the Cell.

The responses of Chinese hamster ovary epithelial cells, caused by the pore-forming agent nystatin, were investigated using brightfield and fluorescence microscopy. Different phenomena, i.e., the detachment of cells, the formation of blebs, the occurrence of "cell-vesicles" and cell ruptures, were observed. These phenomena were compared to those discovered in giant lipid vesicles. A theoretical model, based on the osmotic effects that occur due to the size-discriminating nystatin transmembrane pores in lipid vesicles, was extended with a term that considers the conservation of the electric charge density in order to describe the cell's behavior. The increase of the cellular volume was predicted and correlated with the observed phenomena.

European medicinal and edible plants associated with subacute and chronic toxicity part I: Plants with carcinogenic, teratogenic and endocrine-disrupting effects.

In recent decades, the use of herbal medicines and food products has been widely embraced in many developed countries. These products are generally highly accepted by consumers who often believe that "natural" equals "safe". This is, however, an oversimplification because several botanicals have been found to contain toxic compounds in concentrations harmful to human health. Acutely toxic plants are in most cases already recognised as dangerous as a result of their traditional use, but plants with subacute and chronic toxicity are difficult or even impossible to detect by traditional use or by clinical research studies. In this review, we systematically address major issues including the carcinogenicity, teratogenicity and endocrine-disrupting effects associated with the use of herbal preparations with a strong focus on plant species that either grow natively or are cultivated in Europe. The basic information regarding the molecular mechanisms of the individual subtypes of plant-induced non-acute toxicity is given, which is followed by a discussion of the pathophysiological and clinical characteristics. We describe the genotoxic and carcinogenic effects of alkenylbenzenes, pyrrolizidine alkaloids and bracken fern ptaquiloside, the teratogenicity issues regarding anthraquinone glycosides and specific alkaloids, and discuss the human health concerns regarding the phytoestrogens and licorice consumption in detail.

European medicinal and edible plants associated with subacute and chronic toxicity part II: Plants with hepato-, neuro-, nephro- and immunotoxic effects.

A tremendous surge of public interest in natural therapies has been reported in the past several decades in both developing and developed countries. Furthermore, edible wild-growing plants whose use had long been associated with poverty and famine have also gained in popularity among people in developed countries. An important fraction of herbal products evade all control measures and are generally perceived as safe. However, this may not always be true. It is important to recognize that some plants are not associated with acute toxicity but rather produce more insidious problems, which develop only with long-term exposure. In this review, we continue a systematic analysis of the subacute and chronic toxicity associated with the use of herbal preparations. The hepato-, neuro-, nephro- and immunotoxicity of plant species that either grow natively or are cultivated in Europe are discussed in some detail. The basic concepts regarding the molecular mechanisms implicated in their nonacute toxicity and their pathophysiological, clinical and epidemiological characteristics are included. Among others, we discuss the hepatotoxicity of pyrrolizidine alkaloids, the nephrotoxicity of aristolochic acid, the lathyrism associated with neurotoxin swainsonine, thiamine depletion and thyroid dysfunction of herbal cause, and finally address also the immunosuppressive effects of cannabinoids.

The role of sterols in the lipid vesicle response induced by the pore-forming agent nystatin.

The influences of ergosterol and cholesterol on the activity of the nystatin were investigated experimentally in a POPC model membrane as well as theoretically. The behavior of giant unilamellar vesicles (GUVs) under osmotic stress due to the formation of transmembrane pores was observed on single vesicles at different nystatin concentrations using phase-contrast microscopy. A significant shift of the typical vesicle behavior, i.e., morphological alterations, membrane bursts, slow vesicle ruptures and explosions, towards lower nystatin concentrations was detected in the ergosterol-containing vesicles and a slight shift towards higher nystatin concentrations was detected in the cholesterol-containing membranes. In addition, the nystatin activity was shown to be significantly affected by the ergosterol membrane's molar fraction in a non-proportional manner. The observed tension-pore behavior was interpreted using a theoretical model based on the osmotic phenomena induced by the occurrence of size-selective nystatin pores. The number of nystatin pores for different vesicle behavior was theoretically determined and the role of the different mechanical characteristics of the membrane, i.e., the membrane's expansivity and bending moduli, the line tension and the lysis tension, in the tension-pore formation process was quantified. The sterol-induced changes could not be explained adequately on the basis of the different mechanical characteristics, and were therefore interpreted mainly by the direct influences of the membrane sterols on the membrane binding, the partition and the pore-formation process of nystatin.

Effects of the pore-forming agent nystatin on giant phospholipid vesicles.

The effects of the polyene pore-forming agent nystatin were investigated on individual giant unilamellar phospholipid vesicles (GUVs), made of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC), in different methanol-water solutions using phase-contrast optical microscopy. Three characteristic effects were detected in three different nystatin concentration ranges: vesicle shape changes (between 150 and 250µM); transient, nonspecific, tension pores (between 250 and 400µM); and vesicle ruptures (above 400µM). Both the appearance of the transient tension pores and the vesicle ruptures were explained as being a consequence of the formation of size-selective nystatin channels, whose membrane area density increases with the increasing nystatin concentrations. Our results also show that nystatin is able to form pores in the absence of sterols. In addition, study of the cross-interactions between nystatin and methanol revealed mutually antagonizing effects on the vesicle behavior for methanol volume fractions higher than 10%.