The generic term “melanin“ describes a black pigment of biological origin, although some melanins can be brown or even yellow. The pigment is characterized as a heterogenic polymer of phenolic or indolic nature, and the classification of eu-, pheo- and allo- melanin is broadly accepted. This classification is based on the chemical composition of the monomer subunit structure of the pigment. Due to the high heterogeneity of melanins, their analytical characterization can be a challenging task. In the present work, we synthesized the current information about the analytical methods which can be applied in melanin analysis workflow, from extraction and purification to high-throughput methods, such as matrix-assisted laser desorption/ionization mass-spectrometry or pyrolysis gas chromatography. Our thorough comparative evaluation of analytical data published so far on melanin analysis has proven to be a difficult task in terms of finding equivalent results, even when the same matrix was used. Moreover, we emphasize the importance of prior knowledge of melanin types and properties in order to select a valid experimental design using analytical methods that are able to deliver reliable results and draw consistent conclusions.
Abstract:The potential benefit of soy isoflavones in breast cancer chemoprevention, as suggested by epidemiological studies, has aroused the interest of numerous scientists for over twenty years. Although intensive work has been done in this field, the preclinical results continue to be controversial and the molecular mechanisms are far from being fully understood. The antiproliferative effect of soy isoflavones has been commonly linked to the estrogen receptor interaction, but there is growing evidence that other pathways are influenced as well. Among these, the regulation of apoptosis, cell proliferation and survival, inhibition of angiogenesis and metastasis or antioxidant properties have been recently explored using various isoflavone doses and various breast cancer cells. In this review, we offer a comprehensive perspective on the molecular mechanisms of isoflavones observed in in vitro studies, emphasizing each time the dose-effect relationship and estrogen receptor status of the cells. Furthermore, we present future research directions in this field which could provide a better understanding of the inner molecular mechanisms of soy isoflavones in breast cancer.
Despite substantial research, the understanding of the chemopreventive mechanisms of soy isoflavones remains challenging. Promising tools, such as metabolomics, can provide now a deeper insight into their biochemical mechanisms. The purpose of this study was to offer a comprehensive assessment of the metabolic alterations induced by genistein, daidzein and a soy seed extract on estrogen responsive (MCF-7) and estrogen non-responsive breast cancer cells (MDA-MB-231), using a global metabolomic approach. The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay showed that all test compounds induced a biphasic effect on MCF-7 cells and only a dose-dependent inhibitory effect on MDA-MB-231 cells. Proton nuclear magnetic resonance (1H-NMR) profiling of extracellular metabolites and gas chromatography-mass spectrometry (GC-MS) profiling of intracellular metabolites confirmed that all test compounds shared similar metabolic mechanisms. Exposing MCF-7 cells to stimulatory concentrations of isoflavones led to increased intracellular levels of 6-phosphogluconate and ribose 5-phosphate, suggesting a possible upregulation of the pentose phosphate pathway. After exposure to inhibitory doses of isoflavones, a significant decrease in glucose uptake was observed, especially for MCF-7 cells. In MDA-MB-231 cells, the glutamine uptake was significantly restricted, leading to alterations in protein biosynthesis. Understanding the metabolomic alterations of isoflavones represents a step forward in considering soy and soy derivates as functional foods in breast cancer chemoprevention.
Rosmarinus officinalis L. is a widely known species for its medicinal uses, that is also used as raw material for the food and cosmetic industry. The aim of the present study was to offer a novel perspective on the medicinal product originating from this species and to test its hepatoprotective activity. The tested sample consisted in a tincture obtained from the fresh young shoots. Compounds that are evaluated for this activity are polyphenols and terpenoids, that are identified and quantified by HPLC–UV–MS and GC–MS. Antioxidant activity was assessed in vitro, using the DPPH, FRAP and SO assays. Hepatoprotective activity was tested in rats with experimentally-induced hepatotoxicity. In the chemical composition of the tincture, phenolic diterpenes (carnosic acid, carnosol, rosmanol, rosmadial) and rosmarinic acid were found to be the majority compounds, alongside with 1,8-cineole, camphene, linalool, borneol and terpineol among monoterpenes. In vitro, the tested tincture proved significant antioxidant capacity. Results of the in vivo experiment showed that hepatoprotective activity is based on an antioxidant mechanism. In this way, the present study offers a novel perspective on the medicinal uses of the species, proving significant amounts of polyphenols and terpenes in the composition of the fresh young shoots tincture, that has proved hepatoprotective activity through an antioxidant mechanism.
The rapid development in the food supply chain has led to increased interest for quality in the food sector. In the last two decades, the human health and food safety have become essential. Health problems are highly related to diet and nutritional habits. The connection between nutrition and the development of various health problems is even more noticeable when close attention is given to every age group. Regarding the chemical composition of foods, a large number of bioactive compounds present in plants, fruits, vegetables, dairy products, meat, and fish are currently known. Bioactive compounds from food play an important role in prevention of illnesses. Covering essential aspects of health benefits of foods, the present chapter underlies without being exhaustive, the potential of valuable compounds such as soy isoflavones, phytochemicals, polysaccharides, probiotics, prebiotics, lipids, and marine proteins to be used as an effective prevention strategy for developing various human cancers, cardiovascular diseases, diabetes, and metabolic disorders.
The interactions of nanoparticles with living organisms are driven by an interface called the protein corona. This interface is formed when nanoparticles are introduced in biological milieu and proteins are adsorbed at nanoparticles’ surfaces. Understanding the factors that are responsible for the formation and the composition of the protein corona could reveal mechanistic insights that are involved in the interaction of nanoparticles with biological structures. Multiple studies have qualitatively described the protein corona, but just a few have proposed quantification methods, especially for gold nanoparticles. Using bovine serum albumin conjugated with fluorescein-5-isothiocyanate as a model protein, we developed a fluorescent-based quantification method for gold nanoparticles’ protein coronas. The impact of nanoparticle size and surface chemistry was studied, and our research emphasizes that size and surface chemistry are determinant factors: Bigger nanoparticles and amino-modified surface chemistry are responsible for higher protein adsorption compared to smaller ones and carboxyl- or methoxy-modified surface chemistry. The proposed method can be used to complete the full picture of the interactions of nanoparticles with biological milieu and to describe the parameters which govern these interactions for the better development of nanomedicines.
With the development of anti-human epidermal growth factor receptor 2 (HER2) monoclonal antibodies, trastuzumab-based therapy has become the standard of care among patients with early or advanced HER2-positive breast cancer. However, real-world data have shown that up to a half of patients do not receive trastuzumab or any other HER2-targeted agent, mainly due to high treatments costs. The prospect of a more enlarged access to trastuzumab treatment lies in the use of biosimilars, as the European and the US patent of the reference products has or will soon expire. Biosimilars are biologics highly similar in terms of quality characteristics, biological activity, safety and efficacy to already approved biologics. The biosimilarity of any European Union (EU)-approved biosimilar is guaranteed based on the comprehensive comparability exercise which includes comparative analytical, non-clinical and clinical studies. In the matter of biosimilars’ interchangeability and substitution, the European Medicines Agency (EMA) and US Food and Drug Administration (FDA) have adopted different positions, triggering various discussions on the potential immunogenicity and efficacy in individual patients. As more biosimilars are gaining approval, the present review aims to offer concise information for oncologists and pharmacists about the production, approval, interchangeability, and substitution policies of biosimilars used in breast cancer therapy, with a special focus on trastuzumab.
The transition from adolescence to adulthood can be a challenging period for many students. This period is associated with an increase in alcohol consumption (AC) which can develop a drinking behavior or shape the preferences for certain alcoholic beverages. The purpose of this study was to analyze the AC pattern among Romanian university students, by investigating the association between taste and consumption, including preferences for special beer. A 30-item omnibus-type questionnaire was distributed to undergraduate students and used to gather sociodemographic data, alcohol expectancies, drinking motives and consequences, and special beer consumption. Results showed a statistically significant relationship between the age of first alcohol use and the existence of an alcoholic family member. The main reasons for AC are taste, sensation, relaxation, and socialization. Both female and male students tend to drink occasionally, with a preference for public places. Female students prefer a sweet taste, choosing special beers over the regular ones. The students’ residence may also influence the choice of special beers. Understanding the students’ drinking behavior and taste preferences is essential to create useful strategies to discourage excessive AC. Special beer, a growing segment in the beverage industry, could represent a healthier and safety alternative to AC.
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