Search

Breast cancer is the second leading cause of death among women, and the number of mortal cases in diagnosed patients is constantly increasing. The search for new plant compounds with antitumor effects is very important because of the side effects of conventional therapy and the development of drug resistance in cancer cells. The use of plant substances in medicine has been well known for centuries, but the exact mechanism of their action is far from being elucidated. The molecular mechanisms of cytotoxicity exerted by secondary metabolites and bioactive peptides of plant origin on breast cancer cell lines are the subject of this review. [ABSTRACT FROM AUTHOR]

The antioxidant capacity of numerous plant species with medical potential, as well as the tea plant (Camellia sinensis L.) have been extensively studied. On the other hand, such data for herbal tea blends, taken directly from the market are scarce. The aim of our study was to evaluate the antioxidant capacity and phenol content of tea and herbal tea blends available on Bulgarian market and to assess Haberlea rhodopensis leaves as a potential ingredient of herbal teas. We applied two methods to evaluate the antioxidant capacity - the Ferric reducing antioxidant power (FRAP) and Trolox equivalent antioxidant capacity (TEAC) assays, after a two step procedure of processing and extraction of water-soluble and lipo-soluble antioxidants. We did not find a direct relationship between the content of phenols and the antioxidant capacity of the studied herbal teas. The commercial samples of Camellia sinensis L. (North Vietnam cultivation, Tikanium, Green tea) had the highest antioxidant capacity. According to TEAC and FRAP assay Common St John's wort, Oregano, and Garden sage showed antioxidant capacity close to that of Green tea. Maximum antioxidant capacity and, hence maximal health benefits could be obtained from ca. 30 min infusions of Roselle tea and especially Haberlea leaves. This makes cultivated Haberlea rhodopensis a valuable potential ingredient for new blends of herbal tea with high antioxidant capacity. [ABSTRACT FROM AUTHOR]

Breast cancer is among the most problematic diseases and a leading cause of death in women. The methods of therapy widely used, so far, are often with many side effects, seriously hampering patients' quality of life. To overcome these constraints, new cancer treatment alternatives are constantly tested, including bioactive compounds of plant origin. Our aim was to study the effects of Haberlea rhodopensis methanol extract fractions on cell viability and proliferation of two model breast cancer cell lines with different characteristics. In addition to the strong reduction in cell viability, two of the fractions showed significant influence on the proliferation rate of the hormone receptor expressing MCF7 and the triple negative MDA-MB231 breast cancer cell lines. No significant effects on the benign MCF10A cell line were observed. We applied a large scale non-targeted approach to purify and identify highly abundant compounds from the active fractions of H. rhodopensis extracts. By the combined NMR/MS approach, myconoside was identified in the fractions and hispidulin 8-C-(6-O-acetyl-2″-O-syringoyl-β-glucopyranoside) was found in one of them. We further performed molecular docking analysis of possible myconoside interactions with several proteins, important for breast cancer proliferation. High probability of binding was established for GLUT1 transporter, estrogen receptor and MYST acetyltransferase. Our results are a good background for future studies on the use of myconoside for targeted breast cancer therapy. [ABSTRACT FROM AUTHOR]

We studied the diversity of ground beetles in a typical potato-growing region of South-Western Bulgaria for three consecutive years (2013-2015). The aim was to discuss the present data in relation to results obtained about ten years earlier for the same agricultural area. Totally, 2058 individuals of 45 species were recorded during the period of the study. Poecilus cupreus (Linnaeus) and Bembidion quadrimaculatum (Linnaeus) were the most numerous species during each of the three years of the study. In addition, Poecilus lepidus (Leske) was numerous in 2014 and Lionychus quadrillum (Duftschmid) in 2015. More than 1300 carabid specimens were collected in June 2013, while, in June 2014 and June 2015, they were less than 400. The present results are congruent with the hypothesis that the application of systemic insecticide in 2014 and 2015 affected the community of the ground beetles by elimination of larger zoophages, thus creating conditions for recolonisation by smaller zoophages, which have high dispersal capability; however, further studies are needed to test this supposition. [ABSTRACT FROM AUTHOR]

Resurrection plants are unique among higher plants because of their ability to withstand long periods of dehydration without damages. In this study, leaf epidermis and palisade mesophyll of three resurrection species, Haberlea rodopensis, Ramonda serbica and Ramonda myconi, grown under full desiccation and benign conditions, were analyzed by differential interference contrast microscopy. Detailed investigation of adaxial and abaxial leaf surfaces revealed species-specific differences in the size and number of epidermal cells and stomatal density. The applied full desiccation did not cause any significant deviations of these parameters from the controls. There were no changes in the size and number of mesophyll cells as well. Analysis of stomatal patterning displayed essentially hypostomatic leaves, having stomata mainly abaxially positioned. The most significant change detected in the leaves of dehydration-treated plants was the increased formation of adaxially positioned trichomes. This increase was very high in R. myconi, where the adaxial leaf surface was fully covered by trichomes. Despite the existence of small species-specific differences, the results showed uniform desiccation-related responses of the studied resurrection species. The quantified leaf epidermal and mesophyll features are discussed with respect to their possible contribution to the desiccation tolerance of resurrection species. [ABSTRACT FROM AUTHOR]

The fast-growing human population on our planet and the need for improved quality of life leads to a growing demand in food and feed production. This is the main challenge facing the world agriculture. Furthermore, this increase should be gained from the constantly decreasing land areas subject to environmental changes. Since crops are fundamental to the food pyramid, they must be able to realize their potential even under unfavorable environmental conditions and particularly under drought. Sources of drought tolerance in many important crops are more or less limited or widely exploited. In this respect, the so called "resurrection plants" represent a very useful model of desiccation tolerance. Their vegetative parts are able to withstand long periods of almost complete water loss and to recover fast upon rewatering. The Mediterranean region - one of the biodiversity "hot spots" in the world - is the only area where the several species of resurrection plants in Europe have their habitats. All of them - Haberlea rhodopensis, Ramonda serbica, R. nathaliae, and R. myconi - belong to one and the same botanical family of Gesneriaceae. The present review is focused on the common and specific traits of these interesting species, with an emphasis on the potential use and potential risk for their biodiversity. [ABSTRACT FROM AUTHOR]