Search

In our previous studies, Prunus spinosa fruit (PSF) ethanol extract was showed to exert antioxidant, antimicrobial, anti-inflammatory and wound healing activities. In the present study, an integrated bioinformatics analysis combined with experimental validation was carried out to investigate the biological mechanism(s) that are responsible for the reported PSF beneficial effects as an antioxidant during a pro-inflammatory TLR4 insult. Bioinformatics analysis using miRNet 2.0 was carried out to address which biological process(es) the extract could be involved in. In addition, Chemprop was employed to identify the key targets of nuclear receptor (NR) signaling and stress response (SR) pathways potentially modulated. The miRNet analysis suggested that the PSF extract mostly activates the biological process of cellular senescence. The Chemprop analysis predicted three possible targets for nine phytochemicals found in the extract: (i) ARE signaling, (ii) mitochondrial membrane potential (MMP) and (iii) p53 SR pathways. The PSF extract antioxidant effect was also experimentally validated in vitro using the human monocyte U937 cell line. Our findings showed that Nrf2 is modulated by the extract with a consequent reduction of the oxidative stress level. This was confirmed by a strong decrease in the amount of reactive oxygen species (ROS) observed in the PSF-treated cells subjected to lipopolysaccharide (LPS) (6 h treatment, 1 µg/mL). No visible effects were observed on p53 and MMP modulation. [ABSTRACT FROM AUTHOR]

The nuclear RNA surveillance mechanism is essential for cancer cell survival and is ensured by the RNA nuclear exosome including some co‐factors, such as the RNA helicase MTR4. Recent studies suggest an involvement of DNA repair proteins such as apurinic/apyrimidinic (AP) endodeoxyribonuclease 1 (APE1), a major endodeoxyribonuclease of Base Excision Repair (BER), in RNA metabolism and RNA decay of oxidized and abasic RNA. Cisplatin (CDDP) and 5‐fluorouracil (5‐FU) are commonly used for the treatment of solid tumours. Whether APE1 is involved in the elimination of CDDP‐ or 5‐FU‐damaged RNA is unknown, as is its possible interaction with the nuclear exosome complex. Here, by using different human cancer cell models, we demonstrated that: (a) APE1 is involved in the elimination of damaged‐RNA, upon CDDP‐ and 5‐FU‐treatments, in a MTR4‐independent manner; (b) the interaction between APE1 and MTR4 is stimulated by CDDP‐ and 5‐FU‐treatments through lysine residues in the APE1 N‐terminal region and is, in part, mediated by nucleic acids and (c) APE1‐ and MTR4‐depletion lead to the generation of R‐loop formation causing the activation of the DNA damage response (DDR) pathway through the ATM‐p53‐p21 axis. Our data demonstrate a role of MTR4 in DDR underpinning the function of APE1 in controlling the RNA quality upon genotoxic treatments with possible implications in chemoresistance. [ABSTRACT FROM AUTHOR]

Abstract: The reaction of formaldehyde with enantiomerically pure α-N-protected amino acid hydrazides is described. The system has been investigated in different solvents, including both aqueous formaldehyde and paraformaldehyde, with the [...]

[alpha]-Amino acids and [alpha]-amino methyl esters are easily converted to their N-monoalkyl derivatives by a reductive condensation reaction using several carbonyl compounds in the presence of sodium borohydride. This reducing agent has shown a wide versatility with minor but essential procedural variations. The reaction allows the [alpha]-monodeuterium labeling of the new N-substituent by use of sodium borodeuteride. Key words: [alpha]-amino acid, [alpha]-amino methyl esters, sodium borohydride, reductive N-monoalkylation, carbonyl compounds.

Prunus spinosa fruits (PSF) contain different phenolic compounds showing antioxidant and anti-inflammatory activities. Innovative drug delivery systems such as biomimetic nanoparticles could improve the activity of PSF extract by promoting (i) the protection of payload into the lipidic bilayer, (ii) increased accumulation to the diseased tissue due to specific targeting properties, (iii) improved biocompatibility, (iv) low toxicity and increased bioavailability. Using membrane proteins extracted from human monocyte cell line THP-1 cells and a mixture of phospholipids, we formulated two types of PSF-extract-loaded biomimetic vesicles differing from each other for the presence of either 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) or 1,2-dioleoyl-sn-glycero-3-phospho-(1′-rac-glycerol) (DOPG). The biological activity of free extract (PSF), compared to both types of extract-loaded vesicles (PSF-DOPCs and PSF-DOPGs) and empty vesicles (DOPCs and DOPGs), was evaluated in vitro on HUVEC cells. PSF-DOPCs showed preferential incorporation of the extract. When enriched into the nanovesicles, the extract showed a significantly increased anti-inflammatory activity, and a pronounced wound-healing effect (with PSF-DOPCs more efficient than PSF-DOPGs) compared to free PSF. This innovative drug delivery system, combining nutraceutical active ingredients into a biomimetic formulation, represents a possible adjuvant therapy for the treatment of wound healing. This nanoplatform could be useful for the encapsulation/enrichment of other nutraceutical products with short stability and low bioavailability. [ABSTRACT FROM AUTHOR]