Il test di Ames nella valutazione della genotossicità ambientale

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Valutazione della genotossicità delle frazioni fini di particolato atmosferico urbano (PM 10, PM 2.5)

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Biotecnologie delle piante officinali

Nella stesura di questo testo si sono voluti descrivere i correlati scientifici e concettuali che caratterizzano la botanica farmaceutica e la farmacognosia applicata rispetto all’evoluzione delle moderne biotecnologie, sviluppate con specifica attinenza alle piante officinali. Lo sviluppo di colture in vitro di cellule vegetali e di piante complete modificate geneticamente ha assunto negli ultimi decenni un ruolo di prorompente e progressiva rilevanza. Con specifico riferimento al contesto di quest’opera, le biotecnologie applicate alle piante officinali hanno trovato e trovano oggi grande propulsione nel miglioramento agronomico delle coltivazioni attraverso un’attenta selezione in vitro di linee cellulari, assecondando il moderno mercato dei prodotti erboristici che vedono nelle coltivazioni tradizionali il maggiore canale di approvvigionamento di droghe vegetali, nonché — e soprattutto — nel miglioramento qualitativo e quantitativo della produzione di principi attivi con finalità salutistiche e farmacologiche in contesti esclusivamente biotecnologici. Ciò attraverso il potenziamento della biomassa estrattiva e le strategie impiantistiche (bioreattori) che, dalla scala laboratoristica, consentono il trasferimento a livello industriale incrementando la produttività. La comprensione dei relati scientifici che sottendono l’ampia e sempre prolifica letteratura in questo contesto richiede una rivisitazione alla luce delle nuove tecnologie ed esigenze della moderna botanica farmaceutica, farmacognosia e produzione erboristica, attraverso la proposizione di nuovi moduli didattici che possano essere di ausilio all’apprendimento e, soprattutto, di strumenti concettuali che costituiscano i fondamenti per comprenderne la continua evoluzione. A tal fine, dopo un primo capitolo in cui si è cercato di qualificare questi correlati con l’esempio di un farmaco antitumorale la cui scoperta e sviluppo rappresentano un riferimento paradigmatico, nei capitoli successivi vengono affrontate la biosintesi dei metaboliti secondari, i fattori ecologici che ne condizionano la produzione, l’allestimento e modifica genetica delle colture cellulari, le metodiche di estrazione e analisi fino alla produzione massiva ed industriale in bioreattori. Gli ultimi tre capitoli riprendono alcuni esempi significativi della letteratura specialistica al fine di evidenziare i successi, i limiti e le potenzialità di sviluppo delle tecniche dei capitoli precedenti secondo l’attuale stato dell’arte. Con queste premesse gli autori non hanno pertanto inteso fornire una trattazione esaustiva su di una tematica così ampia ed in costante evoluzione, ma auspicano di essere stati efficaci, oltre che nel coadiuvare il lettore nell’apprendimento dei fondamenti, anche nell’orientarlo verso un corretto atteggiamento metodologico, utilizzando gli strumenti concettuali qui appresi come viatico intellettuale alla comprensione della dinamicità scientifica di questa disciplina

Mycochemicals against Cancer Stem Cells

Since ancient times, mushrooms have been considered valuable allies of human well-being both from a dietary and medicinal point of view. Their essential role in several traditional medicines is explained today by the discovery of the plethora of biomolecules that have shown proven efficacy for treating various diseases, including cancer. Numerous studies have already been conducted to explore the antitumoural properties of mushroom extracts against cancer. Still, very few have reported the anticancer properties of mushroom polysaccharides and mycochemicals against the specific population of cancer stem cells (CSCs). In this context, β-glucans are relevant in modulating immunological surveillance against this subpopulation of cancer cells within tumours. Small molecules, less studied despite their spread and assortment, could exhibit the same importance. In this review, we discuss several pieces of evidence of the association between β-glucans and small mycochemicals in modulating biological mechanisms which are proven to be involved with CSCs development. Experimental evidence and an in silico approach are evaluated with the hope of contributing to future strategies aimed at the direct study of the action of these mycochemicals on this subpopulation of cancer cells

Small-angle X-ray scattering from high-density polyethylene: lamellar thickness distributions

Small-angle X-ray diffraction patterns were recorded for a number of high-density polyethylene samples and were successively analysed by a fit with the calculated patterns corresponding to certain theoretical models. The parameters determined by the above fits were as follows: long-period, crystallinity, mean dimensions of the crystalline lamellae, amorphous thickness, crystallinity and lamellar dimension distributions. Regarding the latter, two mathematical functions were used for the fits, i.e. a symmetrical and an asymmetrical type, and for all of the samples examined the function was determined which gives the best results. Finally, a correlation is suggested between the polymer molecular weight and lamellar dimension distributions

17β-estradiol modulates prostaglandin E2 release from human amnion-derived WISH cells

In human amnion-derived WISH cells [(3)H]estradiol-17beta binding sites are not detectable, but they become measurable in cells exposed to cAMP elevating agents such as forskolin or Ro 20-1724. In cells unexposed to these drugs, 17beta-estradiol stimulates prostaglandin (PG)E(2) release but exerts an evident inhibitory effect in cells exposed to Ro 20-1724. Both stimulatory and inhibitory actions are inhibited by the estrogen receptor antagonist, tamoxifen, by cell pretreatment with cycloheximide, or when the hormone is bound to BSA. Our data demonstrate for the first time that 1) 17beta-estradiol modulates PGE(2) release from WISH cells, interacting with specific intracellular receptors and probably evoking new protein synthesis, and 2) WISH cell responsiveness to 17beta-estradiol seems to be modulated by cAMP, whose levels are significantly increased by the steroid hormone in the presence of Ro 20-1724. The nucleotide is presumably responsible for the enhacement of hormone receptor availability and for the inhibition of PGE(2) release observed in the presence of Ro 20-1724

Small- and wide-angle X-ray scattering characterization of 1-hexene linear low-density polyethylene

Four ethylene-1-hexene copolymer samples were studied by small-angle X-ray scattering in order to investigate the correlation between the crystalline lamellar thickness and the comonomer content. The lamellar thickness was determined from the identity period of the one-dimensional scattering function and from the analysis of the one-dimensional correlation function. The crystallinity and the volume of the crystalline unit cell were determined by wide-angle X-ray scattering. Some considerations are reported on the effect of the side chains during the crystallization and on the polydispersity of the lamellar thickness

In Vitro Study of the Cytotoxic, Cytostatic, and Antigenotoxic Profile of Hemidesmus indicus (L.) R.Br. (Apocynaceae) Crude Drug Extract on T Lymphoblastic Cells

In traditional Indian medicine, the crude drug Hemidesmus indicus root—commonly known as Indian sarsaparilla—is used alone or in poly-herbal preparations for the treatment of a wide range of diseases. The present study focuses on the cancer chemopreventive and therapeutic potential of H. indicus extracts on an acute lymphoblastic leukemia cell line (CCRF-CEM). With this aim in mind, we subjected H. indicus roots to two subsequent extractions (hydro-alcoholic extraction and soxhlet extraction). As DNA damage is an important prerequisite for the induction of mutations/cancer by genotoxic carcinogens, cancer chemoprevention may be achieved by preventing genotoxicity. Through an integrated experimental approach, we explored the genoprotective potential of the soxhlet H. indicus extract against different mutagenic compounds and its cytotoxic, proapoptotic, and cytostatic properties. In our experimental conditions, H. indicus induced a cytotoxic effect involving the activation of both intrinsic and extrinsic apoptotic pathways and blocked the cell cycle in the S phase. Moreover, the antigenotoxicity results showed that the extract was able to mitigate DNA damage, an essential mechanism for its applicability as a chemopreventive agent, via either the modulation of extracellular and intracellular events involved in DNA damage. These data add to the growing body of evidence that H. indicus can represent a noteworthy strategy to target early and late stages of cancer