Dietary flavonoids bind to mono-ubiquitinated annexin A1 in nuclei, and inhibit chemical induced mutagenesis

Cracking the code of Annexin A1-mediated chemoresistance

The annexin superfamily protein, Annexin A1, initially recognized for its glucocorticoid-induced phospholipase A2-inhibitory activities, has emerged as a crucial player in diverse cellular processes, including cancer. This review explores the multifaceted roles of Anx-A1 in cancer chemoresistance, an area largely unexplored. Anx-A1's involvement in anti-inflammatory processes, its complex phosphorylation patterns, and its context-dependent switch from anti-to pro-inflammatory in cancer highlights its intricate regulatory mechanisms. Recent studies highlight Anx-A1's paradoxical roles in different cancers, exhibiting both up- and down-regulation in a tissue-specific manner, impacting different hallmark features of cancer. Mechanistically, Anx-A1 modulates drug efflux transporters, influences cancer stem cell populations, DNA damages and participates in epithelial-mesenchymal transition. This review aims to explore Anx-A1's role in chemoresistance-associated pathways across various cancers, elucidating its impact on survival signaling cascades including PI3K/AKT, MAPK/ERK, PKC/JNK/P-gp pathways and NFκ-B signalling. This review also reveals the clinical implications of Anx-A1 dysregulation in treatment response, its potential as a prognostic biomarker, and therapeutic targeting strategies, including the promising Anx-A1 N-terminal mimetic peptide Ac2-26. Understanding Anx-A1's intricate involvement in chemoresistance offers exciting prospects for refining cancer therapies and improving treatment outcomes.

Evaluation of the healing properties of Garcinia brasiliensis extracts in a cutaneous wound model

ETHNOPHARMACOLOGICAL RELEVANCE

Wound healing is a complex process that can leave pathological scars, especially in case of infections from opportunistic microorganisms. In this context, herbal medicines open up great possibilities for investigation. One of the species of interest native to Brazil is Garcinia brasiliensis ("bacupari"). Traditionally known for treating wounds and ulcers, G. brasiliensis presents anti-inflammatory, antioxidant and antimicrobials properties. But, its wound healing profile in experimental models, in order to validate its efficacy, is still litle studied.

AIM OF THE STUDY

Thus, the objective of this work was to evaluate, in an infected cutanous wound model, the potential of formulations incorporated with G. brasiliensis leaves extracts.

MATERIALS AND METHODS

Crude extract (CE), Ethyl Acetate Fraction (EAF) and Hexanic Fraction (HF) were submitted to phytochemical assays, high performance thin layer chromatography (HTPLC) and cytotoxicity studies. CE and EAF were also tested for microbicidal properties and incorporated in cream and gel formulations at 10% concentration. After stability testing, the gel formulations with CE or EAF at 10% were selected and applied to skin wounds infected or not with Staphylococcus aureus in Wistar rats. The healing potenttial of the extracts was verified by the expression of the protein Annexin A1 (AnxA1), related to the processes of inflammation and antifibrotic function, the cells immunostaining for Gasdermin-D (GSDM-D), a marker of pyroptotic cell death, and the dosage of interleukin-10 (IL-10) and monocyte chemotactic protein (MCP)-1 inflammatory mediators.

RESULTS

Phytochemical studies indicated the presence of compounds of pharmacological interest, including Catechin, Quercetin and Berberine in addition to low cytotoxicity of CE and EAF at 10%. After the 6-day topical treatments, CE and EAF gel formulations demonstrated to control the pruritus formation process. The treatments decreased AnxA1 expression and the amount of cells immunostained for GSDM-D, and increased the expression of MCP-1 in infected wounds.

CONCLUSIONS

Together, the results show important anti-inflammatory profile and skin healing potential of CE and EAF from G. brasiliensis leaves, even in infected lesions, with therapeutic perspectives.

A Potential Inhibitor of MCR-1: An Attempt to Enhance the Efficacy of Polymyxin Against Multidrug-Resistant Bacteria

The irrational use of broad-spectrum antibiotics has led to increasing resistance of bacteria to antibiotics, and the emergence of the plasmid-mediated colistin resistance gene mcr-1 has led to the dilemma of infections with no available cure. Here, we have found a potential MCR-1 inhibitor for use against infections caused by MCR-1 positive resistant bacteria. A checkerboard MIC (minimum inhibitory concentration) assay, growth curve assay, kill curve assay, cytotoxicity assay, molecular dynamics simulation analysis, Western blot assay and mouse pneumonia model in vivo protection rate assay were used to evaluate the synergy effect between genistein and polymyxins. The results showed that genistein could restore the bactericidal activity against MCR-1-positive strains for which there was no antibacterial activity, and reduce the bacterial load to some extent. Genistein does not inhibit the expression of MCR-1, but inhibits the binding of MCR-1 to its substrate by binding to the amino acids of the active region of MCR-1, thereby inhibiting the biological activity of MCR-1. The in vivo results also showed that the protection rate of mice treated with the combination therapy of genistein and polymyxins increased by 20% compared to that of mice treated with polymyxins alone. Our results confirm that genistein is an inhibitor of MCR-1 and promote its potential use in combination with polymyxins to treat severe infections caused by MCR-1 positive Enterobacteriaceae.

DNA-BINDING and DNA-protecting activities of small natural organic molecules and food extracts

The review summarizes literature data on the DNA-binding, DNA-protecting and DNA-damaging activities of a range of natural human endogenous and exogenous compounds. Small natural organic molecules bind DNA in a site-specific mode, by arranging tight touch with the structure of the major and minor grooves, as well as individual bases in the local duplex DNA. Polyphenols are the best-studied exogenous compounds from this point of view. Many of them demonstrate hormetic effects, producing both beneficial and damaging effects. An attempt to establish the dependence of DNA damage or DNA protection on the concentration of the compound turned out to be successful for some polyphenols, daidzein, genistein and resveratrol, which were DNA protecting in low concentrations and DNA damaging in high concentrations. There was no evident dependence on concentration for quercetin and kaempferol. Probably, the DNA-protecting effect is associated with the affinity to DNA. Caffeine and theophylline are DNA binders; at the same time, they favor DNA repair. Although most alkaloids damage DNA, berberine can protect DNA against damage. Among the endogenous compounds, hormones belonging to the amine class, thyroid and steroid hormones appear to bind DNA and produce some DNA damage. Thus, natural compounds continue to reveal beneficial or adverse effects on genome integrity and provide a promising source of therapeutic activities.

Hypotensive effects of genistein: From chemistry to medicine

Genistein (4', 5, 7-trihydroxyisoflavone), a naturally occurring flavonoid characteristic of Leguminoseae plants, is a phyto-oestrogen exerting oestrogenic activity as both an agonist and an antagonist substance. A large body of evidence suggests that genistein possesses many physiological and pharmacological properties that make this molecule a potential agent for the prevention and treatment of a number of chronic diseases. Growing evidence suggests that genistein could act as a vasodilating, anti-thrombotic, and anti-atherosclerotic agent, exerting these effects through different mechanisms of action. This paper aims to review data from the literature assessing the beneficial effects of genistein on hypertension, one of the most important cardiovascular disease risk factors along with hyperglycemia and hyperlidipemia. In addition, we discuss the chemistry, main sources and bioavailability of genistein. Scientific findings support genistein's potential as a promising anti-hypertensive agent in different experimental models. However, clinical trials are very limited and more research will be required before genistein intake can be recommended as part of therapies targeting raised blood pressure.

Annexin A1 localization and its relevance to cancer

Annexin A1 (ANXA1) is a Ca(2+)-regulated phospholipid-binding protein involved in various cell processes. ANXA1 was initially widely studied in inflammation resolution, but its overexpression was later reported in a large number of cancers. Further in-depth investigations have revealed that this protein could have many roles in cancer progression and act at different levels (from cancer initiation to metastasis). This is partly due to the location of ANXA1 in different cell compartments. ANXA1 can be nuclear, cytoplasmic and/or membrane associated. This last location allows ANXA1 to be proteolytically cleaved and/or to become accessible to its cognate partners, the formyl-peptide receptors. Indeed, in some cancers, ANXA1 is found at the cell surface, where it stimulates formyl-peptide receptors to trigger oncogenic pathways. In the present review, we look at the different locations of ANXA1 and their association with the deregulated pathways often observed in cancers. We have specifically detailed the non-classic pathways of ANXA1 externalization, the significance of its cleavage and the role of the ANXA1-formyl-peptide receptor complex in cancer progression.