410 research outputs found
Relevant and selective activity of Pancratium illyricum L. against Candida albicans clinical isolates: a combined effect on yeast growth and virulence
BACKGROUND: Alkaloids present in plants of the Amaryllidaceae family are secondary metabolites of high biological interest, possessing a wide range of pharmacological activities. In the search for new plant-derived compounds with antimicrobial activities, two alkaloid extracts obtained from bulbs and leaves of Pancratium illyricum L., a plant of the Amarillydaceae family, were tested for their effect on bacterial and yeast growth.
METHODS: The broth microdilution susceptibility test was applied to study the effect of plant extracts on the growth of reference bacterial strains and Candida albicans reference and clinical isolates strains. Extracts obtained from the different parts of the plant were tested and compared with the pure components identified in the extracts. Since matrix metalloproteinase enzymes play a role in the dissemination process of Candida albicans, the effect of the bulb extract and pure alkaloids on in vitro collagenase activity was tested. Cell viability test was carried out on human embryo lung fibroblasts (HEL 299).
RESULTS: Whilst both extracts did not show any inhibitory activity against neither Gram positive nor Gram negative bacteria, a strong antifungal activity was detected, in particular for the bulb extract. All clinical isolates were susceptible to the growth inhibitory activity of the bulb extract, with endpoint IC50 values ranging from 1.22 to 78 μg/mL. The pure alkaloids lycorine and vittatine, identified as components of the extract, were also assayed for their capacity of inhibiting the yeast growth, and lycorine turned very active, with endpoint IC50 values ranging from 0.89 to 28.5 μg/mL. A potent inhibition of the in vitro collagenase activity was found in the presence of the bulb extract, and this effect was much higher than that exerted by the pure alkaloids. Viability of cell lines tested was not affected by the extract.
CONCLUSIONS: Taken together, results suggest that the extract of Pancratium illyricum may act as antifungal agent both directly on the yeast growth and by altering the tissue invasion process
Biological Assays and Chemical Composition of Volatile Oils of Bupleurum fruticosum L. (Apiaceae)
The composition of supercritical CO 2 extracts and essential oils obtained by hydrodistillation of Bupleurum fruticosum L., growing spontaneously in Italy and Portugal, and its antifungal activity is reported. The collected extracts were analyzed by GC-FID and GC-MS methods. The minimal inhibitory concentration (MIC) and the minimal lethal concentration (MLC) were used to evaluate the antifungal activity of the oils against Candida albicans, C. tropicalis, C. krusei, C. guillermondii, C. parapsilosis, Cryptococcus neoformans, Trichophyton rubrum, T. mentagrophytes, Microsporum canis, M. gypseum, Epidermophyton floccosum, Aspergillus niger, A. fumigatus and A. flavus
Discovery of Yttrium, Zirconium, Niobium, Technetium, and Ruthenium Isotopes
Currently, thirty-four yttrium, thirty-five zirconium, thirty-four niobium,
thirty-five technetium, and thirty-eight ruthenium isotopes have been observed
and the discovery of these isotopes is discussed here. For each isotope a brief
synopsis of the first refereed publication, including the production and
identification method, is presented.Comment: To be published in Atomic Data and Nuclear Data Table
A Compact and Robust RFID Tag Based on an AMC Structure
A platform-tolerant RFID (Radio-Frequency Identification) tag is presented, designed to operate across the entire RFID band. This tag utilizes a small Artificial Magnetic Conductor (AMC) structure as a shielding element for an ungrounded RFID tag antenna. It can be easily mounted on various surfaces, including low permittivity dielectric materials, metal objects, or even attached to the human body for wearable applications. The key features of this RFID tag include its ability to be tuned within the worldwide RFID band, achieving a maximum theoretical read range of over 11 m. Despite its advanced capabilities, the design emphasizes simplicity and cost-effective manufacturing. The design and simulations were conducted using CST Studio Suite
A Low-Cost Printed Log-Periodic Dipole Array for DVB-T2 Digital TV Applications
A printed log-periodic dipole array (LPDA) for DVB-T2 Digital TV applications, covering the whole DVB-T2 UHF band from Channel 21 to Channel 69 (470 MHz–860 MHz), is presented. The presented antenna offers a compact size and a lower cost compared to both wire and similar printed LPDAs, with a normalized area of only 0.26 λ2 (where λ is the free-space wavelength at the central frequency) and a similar (or higher) average gain. It is composed of meandered radiating dipoles, and it is implemented on FR4, the cheapest dielectric substrate available on the market. Moreover, the antenna size has been reduced to an A4 sheet dimension (210 mm × 297 mm) to cut down the production cost. The antenna has been designed starting from Carrel’s theory and using a general-purpose 3D CAD, CST Studio Suite. The results show that the proposed antenna can be used for broadband applications (≈74% bandwidth) in the whole operating frequency band of Digital TV, with a satisfactory end-fire radiation pattern, a stable gain, and a radiation efficiency over the required frequency range (average values 6.56 dB and 97%, respectively)
Ethnopharmacobotany and diversity of Mediterranean endemic plants in Marmilla subregion, Sardinia, Italy
Human populations in various regions across the world exploit the medicinal properties of plants to treat a wide variety of diseases. Areas with both high rates of endemic taxa and persisting traditional uses of the local botanical resources are key sites for the investigation of Traditional Botanical Knowledge (TBK). Commonly, in these areas, information regarding the medicinal properties of native plants has been transmitted orally from generation to generation, however, a rapid decline in this knowledge has been observed, which can be attributed to socio-economic changes in recent years. The Mediterranean basin is one such site, where human history is intimately entwined with nature. The unique geographical situation and unrivaled environmental heterogeneity of the area, have allowed both the development of diverse civilizations as well as providing the basis for the evolution of extraordinary biodiversity. The Mediterranean basin can therefore be considered a global hotspot of endemic vascular plants, and of traditional knowledge of medicinal and aromatic species. This study researches the historical subregion of Marmilla (central-southern Sardinia, Italy), which was chosen because of its specific cultural and demographic characteristics: i.e., prolonged isolation and extreme longevity of the inhabitants of the area. Semi-structured interviews were conducted with 145 people from the region, and 137 medicinal plants belonging to 62 families were identified, of which around 57,3% were taxa exclusive to the Mediterranean Basin. Findings showed that the most used parts of the plant were the leaves (49%), while as far as preparations are concerned, decoction (50%) was the most used to prepare medicinal formulations, making this the highest number of medico-botanical taxa reported in a study carried out in Sardinia using a similar methodology. In addition, this study contributes towards preventing the loss of TBK by documenting the medicinal traditions, passed down orally for centuries, in the words of the participants, shedding new light on the traditional knowledge of the inhabitants of the island. The findings lay the foundations for future applied studies in the fields of phytotherapy and phytochemical investigation
Aqueous Extract of Rubus ulmifolius Schott (Rosaceae) against Pathogenic Gram-Positive Oral Bacteria: an in Vitro Evaluation
Different Gram-positive bacteria, S. mutans, S. intermedius, S. anginosus, and E. faecalis, are often associated with different oral diseases, such as tooth decay, endodontic infections, and the occurrence of abscesses. A set of in vitro evaluations has been performed to assess the aqueous leaf extract of Rubus ulmifolius Schott as antimicrobial/antibiofilm activity against the above-mentioned pathogens by agar diffusion method and using a Standard antibiofilm model. The antioxidant activity was measured with the ABTS test. The extract's phenolic and flavonoid quantitative profiles were determined using the Folin-Ciocalteu reagent and a colorimetric method. The results suggested an interesting antimicrobial profile with a formulate range concentration amounting to (6.25-0.78) %. The antioxidant activity was with an EC50 = (0.0087 0.0009) mg/mL. The total phenolic content, expressed as the equivalent mass of gallic acid with respect to the dry mass of the extract, was (149 17) mg/g, and the total flavonoid concentration, calculated using quercetin as a reference compound, was (60 7) mg/g. Considering that until now, R. ulmifolius has not been sufficiently tested for its biological proprieties, these preliminary results encourage additional investigations for its use in the field of oral infections
The elongation factor 1-alpha as storage reserve and environmental sensor in Nicotiana tabacum L. seeds
Given their critical role in plant reproduction and survival, seeds demand meticulous regulatory mechanisms to effectively store and mobilize reserves. Within seeds, the condition of storage reserves heavily depends on environmental stimuli and hormonal activation. Unlike non-protein reserves that commonly employ dedicated regulatory proteins for signaling, proteinaceous reserves may show a unique form of 'self-regulation', amplifying efficiency and precision in this process. Proteins rely on stability to carry out their functions. However, in specific physiological contexts, particularly in seed germination, protein instability becomes essential, fulfilling roles from signaling to regulation. In this study, the elongation factor 1-alpha has been identified as a main proteinaceous reserve in Nicotiana tabacum L. seeds and showed peculiar changes in stability based on tested chemical and physical conditions. A detailed biochemical analysis followed these steps to enhance our understanding of these protein attributes. The protein varied its behavior under different conditions of pH, temperature, and salt concentration, exhibiting shifts within physiological ranges. Notably, distinct solubility transitions were observed, with the elongation factor 1-alpha becoming insoluble upon reaching specific thresholds determined by the tested chemical and physical conditions. The findings are discussed within the context of seed signaling in response to environmental conditions during the key transitions of dormancy and germination
The translational power of Alzheimer’s-based organoid models in personalized medicine: an integrated biological and digital approach embodying patient clinical history
Alzheimer's disease (AD) is a complex neurodegenerative condition characterized by a multifaceted interplay of genetic, environmental, and pathological factors. Traditional diagnostic and research methods, including neuropsychological assessments, imaging, and cerebrospinal fluid (CSF) biomarkers, have advanced our understanding but remain limited by late-stage detection and challenges in modeling disease progression. The emergence of three-dimensional (3D) brain organoids (BOs) offers a transformative platform for bridging these gaps. BOs derived from patient-specific induced pluripotent stem cells (iPSCs) mimic the structural and functional complexities of the human brain. This advancement offers an alternative or complementary approach for studying AD pathology, including beta-amyloid and tau protein aggregation, neuroinflammation, and aging processes. By integrating biological complexity with cutting-edge technological tools such as organ-on-a-chip systems, microelectrode arrays, and artificial intelligence-driven digital twins (DTs), it is hoped that BOs will facilitate real-time modeling of AD progression and response to interventions. These models capture central nervous system biomarkers and establish correlations with peripheral markers, fostering a holistic understanding of disease mechanisms. Furthermore, BOs provide a scalable and ethically sound alternative to animal models, advancing drug discovery and personalized therapeutic strategies. The convergence of BOs and DTs potentially represents a significant shift in AD research, enhancing predictive and preventive capacities through precise in vitro simulations of individual disease trajectories. This approach underscores the potential for personalized medicine, reducing the reliance on invasive diagnostics while promoting early intervention. As research progresses, integrating sporadic and familial AD models within this framework promises to refine our understanding of disease heterogeneity and drive innovations in treatment and care
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