167 research outputs found
Chimica generale. Esercizi svolti. Raccolta di esercizi con soluzioni dettagliate per la preparazione alla prova scritta dell'esame di Chimica generale
No full textIl libro offre una ricca raccolta di esercizi che coprono gli argomenti fondamentali della Chimica Generale, partendo dalla nomenclatura e classificazione dei composti inorganici fino agli equilibri in soluzione acquosa. Gli esercizi sono organizzati in modo da fornire una progressione graduale di difficoltà, partendo dai problemi più semplici e procedendo verso quelli di complessità crescente. Gli esercizi proposti rivisitano anche i concetti chimici di base necessari alla loro risoluzione. Questo approccio rende il libro adatto sia all'uso in classe che allo studio individuale, fornendo una formazione completa e approfondita. Il testo è una risorsa preziosa per chiunque desideri approfondire la propria conoscenza della materia o prepararsi all'esame di Stechiometria
Potential use of plants and their extracts in the treatment of coagulation disorders in COVID-19 disease: a narrative review
No full textAbstract: Coronavirus disease, i.e., COVID-19, is caused by the virus called “severe acute respiratory
syndrome coronavirus 2 (SARS-CoV-2)”. Infection induces predominantly respiratory illness but is
also associated with coagulation disorders which play an important role in the pathogenesis, clinical
manifestations, and outcome of the disease. The treatment of hemostasis disorders of COVID-19 patients
is a difficult problem to solve. For example, heparin is quite effective drug in reducing mortality in severe
COVID-19 forms but not able to prevent venous and arterial thromboembolic complications. Moreover,
anticoagulant therapy with heparin is associated with several adverse reactions, such as thrombocytopenia,
osteoporosis, hypoaldosteronism and hypersensitivity reactions. New alternative anticoagulant molecules
can be obtained from plants which are rich in polyphenols and flavonoids. These compounds, besides being
potent antioxidants, also possess anti-inflammatory effect and, because able to inhibit the activity of many
enzymes, including serine proteases, also anticoagulant properties. The purpose of this narrative review
is to provide an overview of current literature data on coagulation disorders associated with COVID-19
disease and of the anticoagulant activity of plants and their extracts in order to evaluate their possible clinical
application as alternative sources of novel molecules with anticoagulant and antithrombotic activity for the
treatment of coagulation disorders in patients with COVID-19
Caratterizzazione fitochimica, proprietà biologiche e nuove prospettive di utilizzo di ribes, lamponi e mirtilli
No full textCaratterizzazione fitochimica, proprietà biologiche e nuove prospettive di utilizzo di ribes, lamponi e mirtill
FT-IR studies of protein adsorption on polymeric materials: influence of surface structure, hydrophobicity and charge
No full textBioactivity of hydro-alcoholic extract of Petroselinum crispum
No full textBackground: It is well known that the antioxidant and biological properties of plant extracts are due to their phytochemical composition and that phenolic compounds play an important role in the determination of extracts bioactivity. This study aimed to quantify the total phenolic content of an ethanolic extract obtained from Petroselinum crispum (P. crispum) leaves and to determine its in vitro bioactivity, both in non-cellular and cellular systems.
Methods: The extract was obtained from fresh leaves of P. crispum using hydro-alcoholic solution of 60% ethanol as extraction solvent. The quantification of total phenol was performed by Fast Blue BB (FBBB) test. The DPPH antiradical and antioxidant activity in gallic acid equivalent (GAE) was determined by electron paramagnetic resonance (EPR). Hydrogen peroxide scavenging activity was determined both in non-cellular and cellular assay. Cytotoxicity of the extract towards NIH3T3 mouse fibroblasts and human breast adenocarcinoma cells MDA-MB-231 was evaluated by neutral red uptake (NRU), mutagenicity by Ames test and anticoagulant activity by thrombin time (TT).
Results: Total phenolic content of the extract was 17.2±0.9 mg of GAE/g of dry material. The extract demonstrated to have both antioxidant activity and the capability to scavenge hydrogen peroxide in a concentration dependent manner. NIH3T3 mouse fibroblasts and human breast adenocarcinoma cells MDA-MB-231 viability was selectively influenced by the extract. The addition of the extract to the culture medium of both the above cell lines, resulted in the reduction of cell death after hydrogen peroxide treatment. The Ames test demonstrated that extract was not genotoxic towards both TA98 and TA100 Salmonella typhimurium strains, with and without metabolic activation. At last, the sample, by inactivating thrombin, showed to have also an anti-coagulant effect even at low concentration values.
Conclusions: The results of this study have demonstrated that the extract analysed possessed good antioxidant and radical scavenging activities when tested in cellular and non-cellular assays, as well as anti-proliferative effects towards both cancer and non-cancer cells, absence of genotoxic and ability to prolonge TT. All these bioactivities are tightly correlated to the phenolic content in a dose dependent manner
The importance of Structural and Functional Analysis of Extracts in Plants
No full textPlants and their extracts have traditionally been used against various pathologies and in some regions are the only therapeutic source for the treatment and prevention of many chronic diseases [...
Bioactive Natural Compounds with Antiplatelet and Anticoagulant Activity and Their Potential Role in the Treatment of Thrombotic Disorders
No full textNatural anticoagulant drugs can be obtained from plants, rich in secondary bioactive metabolites which, in addition to being effective antioxidants, also possess anticoagulant and antiplatelet properties and, for this reason, can be excellent candidates for the treatment of thrombotic diseases. This review reports an overview of the hemostatic process and thrombotic disorders together with data on plants, more and less common from around the world, containing bioactive compounds characterized by antiplatelet and anticoagulant activity. The reported literature was obtained from Medline, PubMed, Elsevier, Web of Science, Google Scholar considering only articles in the English language, published in peer-reviewed journals. The number of citations of the articles and the impact factor of the journals were other parameters used to select the scientific papers to be included in the review. The analysis of the literature data selected demonstrates that many plants’ bioactive compounds show antiplatelet and anticoagulant activity that make them potential candidates to be used as new natural compounds able to interfere with both primary and secondary hemostasis. Moreover, they could be used together with anticoagulants currently administered in clinical practice to increase their efficacy and to reduce complications in the treatment of thrombotic disorders
Stimuli-responsive hydrogels for controlled pilocarpine ocular delivery
No full textA series of vinyl hydrogels containing α-aminoacid (L-histidine, L-valine) residues was synthesized and their swelling properties evaluated at different pHs and temperatures. Unlike the zwitterionic compound containing only the L-histidine, a dual-stimuli responsiveness was improved in the carboxyl acid hydrogels carrying the L-valine residues (HVa). Besides the COOH functionality, the presence of either isopropyl and amido groups in the monomer structure renders the hydrogel also temperature-responsive, in a similar manner as the well-known poly(N-isopropylacrylamide) (pNIPAAm). The three HVa hydrogels (crosslinked with 1, 2, and 5 mol% of N,N0-ethylene-bisacrylamide, EBA) show a phase separation at the same critical pH4, although a different swelling was improved by the amount of EBA. In buffered solutions, the effect of increasing temperature led to decrease the swelling and, as the pH is close to the critical one, a further and sharper collapse of the hydrogel may be tuned. The release study of pilocarpine in physiological conditions showed a burst effect within the first few hours, followed by a sustained release for a week. The initial burst effect was strongly dependent on the kind of hydrogel investigated. As the pilocarpine is a basic molecule (pK a 7.2), it may interact more strongly with the free carboxyl groups in the ionized state of the HVa hydrogels than the zwitterionic species of the histidine compounds. The releasing profile shows a three time greater release of the pilocarpine loaded in the HVa hydrogels. The hydrogels were found to be non-toxic against the mouse fibroblast NIH3T3 cells. The presence of pilocarpine strongly increased the cell proliferation even after 2 days
Preliminary In Vitro Cytotoxicity, Mutagenicity and Antitumoral Activity Evaluation of Graphene Flake and Aqueous Graphene Paste
No full textThis study aimed to determine the in vitro cytotoxicity and mutagenicity of graphene flake (GF) and aqueous graphene paste (AGP) in order to evaluate their potential for application as biomaterials. Furthermore, their antitumor activity against adherent and suspended cells, namely, human breast adenocarcinoma cells (MDA-MB-231), and human monocytes from histiocytic lymphoma (U-937), was investigated. The results demonstrated that GF reduced the viability and proliferation of NIH3T3 immortalized murine fibroblasts for concentrations >0.8 µg/mL and incubation times of 48 and 72 h. AGP showed no toxic effects in any of the tested concentrations and incubation times. The same results were obtained for MDA-MB-231 cells. The viability of the U-937 cells was not affected by either GF or AGP. The Ames test showed that GF and AGP were not genotoxic against Salmonella typhimurium strains TA98 and TA100, with and without metabolic activation. The present study demonstrated good in vitro cellular compatibility of GF and AGP and. Among these, AGP was the best material as it did not interfere, at any of the tested concentrations, with cell viability and proliferation for up to 72 h of incubation. In any case, neither material induced alterations to cell morphology and were not mutagenic
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