Knowledge of the chemical composition of propolis is crucial for understanding the characteristics of products of different origins, but also for quality control and regulatory purposes. To date, official monographs or official analyses that allow researchers to evaluate propolis in a proper way have not yet been released. This study focuses on the characterization of twenty-seven Italian propolis samples and the identification of chemical markers that define its geographical provenance. Total polyphenol (TP) and total flavonoid (TF) content, alongside the quantification of pinocembrin, chrysin, galangin, and caffeic acid phenethyl ester (CAPE), were identified as potential markers. Additionally, DPPH assays were conducted to evaluate the antiradical activity of propolis samples. Our findings demonstrated that TPs, TFs and pinocembrin differed in propolis of different origins, especially in samples from the islands. However, the quantification of the sum of chrysin and galangin and CAPE provided a clearer distinction of the geographical origin of the propolis samples. In contrast, the DPPH assay did not prove useful for this purpose, as most results were similar and, therefore, not significant. This study lays the groundwork for future research on propolis. These findings could contribute to the development of more refined methods for distinguishing propolis origins, enhancing the understanding, valuation and quality control of this natural product in various applications.

The knowledge in chemical composition of propolis is crucial for understanding the characteristics of products of different origin, but also for quality control and regulatory purposes. To date, offical monographs or official analyses that allow to evaluate propolis in a proper way have not yet been released. This study focuses on the characterization of twenty-seven Italian propolis and the identification of chemical markers that define its geographical provenance. Total polyphenol (TP) and total flavonoid (TF) content, alongside the quantification of pinocembrin, chrysin, galangin, and caffeic acid phenethyl ester (CAPE), were identified as as potential markers. Additionally, DPPH assays was conducted to evaluate antiradicalic activity of propolis samples. Our findings demonstrated that TP, TF and pinocembrin differed in propolis of different origin, especially in samples from the islands. However, the quantification of the sum of chrysin and galangin and CAP provided a clear distinction of the geographical origin of the propolis samples. In contrast, the DPPH assay did not prove useful for this purpose, as most results were similar and, therefore, not significant. This study lays the groundwork for future research on propolis. These findings could contribute to the development of more refined methods for distinguishing propolis origins, enhancing the understanding, valuation and quality control of this natural product in various applications.

Eph receptors, comprising A and B classes, interact with cell-bound ephrins generating bidirectional signaling. Although mainly related to carcinogenesis and organogenesis, the role of Eph/ephrin system in inflammation is growingly acknowledged. Recently, we showed that EphA/ephrin-A proteins can modulate the acute inflammatory responses induced by mesenteric ischemia/reperfusion, while beneficial effects were granted by EphB4, acting as EphB/ephrin-B antagonist, in a murine model of Crohn’s disease (CD). Accordingly, we now aim to evaluate the effects of UniPR1331, a pan-Eph/ephrin antagonist, in TNBS-induced colitis and to ascertain whether UniPR1331 effects can be attributed to A- or B-type signaling interference. The potential anti-inflammatory action of UniPR1331 was compared to those of the recombinant proteins EphA2, a purported EphA/ephrin-A antagonist, and of ephrin-A1-Fc and EphA2-Fc, supposedly activating forward and reverse EphA/ephrin-A signaling, in murine TNBS-induced colitis and in stimulated cultured mononuclear splenocytes. UniPR1331 antagonized the inflammatory responses both in vivo, mimicking EphB4 protection, and in vitro; EphA/ephrin-A proteins were inactive or only weakly effective. Our findings represent a further proof-of-concept that blockade of EphB/ephrin-B signaling is a promising pharmacological strategy for CD management and highlight UniPR1331 as a novel drug candidate, seemingly working through the modulation of immune responses.

Background/Objectives: IBDs are chronic relapsing inflammatory intestinal disorders whose precise etiology is still only poorly defined: critical for their pathogenesis is the CCL20/CCR6 axis, whose modulation by small molecules may represent an innovative therapeutic approach. The aim of the present work is to test the potential efficacy of two molecules, MR120, a small selective CCR6 antagonist, active in TNBS- and chronic DSS-induced murine models of intestinal inflammation, and its derivative MR452, a well-tolerated agent endowed with improved anti-chemotactic in vitro properties, in the adoptive transfer colitis model. To the best of our knowledge, this is the first attempt of using adoptive transfer colitis to test modulators of the CCL20/CCR6 axis. Methods and Results: The induction of colitis in immunocompromised mice receiving CD4⁺CD25⁻ T cells i.p. resulted in a moderate inflammation and was met with limited protective responses following daily subcutaneous administration of MR120 or MR452 for 8 weeks. Both compounds significantly reduced colonic myeloperoxidase activity, MR452 also lowered CCL20 levels in the gut, but they failed to prevent the increase in disease activity index, colon wall thickening, and macroscopic inflammation score. Conclusions: Our findings suggest that the pharmacological targeting of the CCL20/CCR6 axis in the adoptive transfer model has only a modest effect in ameliorating the IBD-like phenotype driven by the altered balance between Treg and Th17. The CCL20/CCR6 inhibitors MR120 and MR452 appear more clearly involved in the control of Th1 and Th2 adaptive immune responses, as it results from the beneficial effects displayed by MR120 against subacute TNBS- and chronic DSS-induced colitis.

Background/Objectives: IBDs are chronic relapsing inflammatory intestinal disorders whose precise etiology is still only poorly defined: critical for their pathogenesis is the CCL20/CCR6 axis, whose modulation by small molecules may represent an innovative therapeutic approach. The aim of the present work is to test the potential efficacy of two molecules, MR120, a small selective CCR6 antagonist, active in TNBS- and chronic DSS-induced murine models of intestinal inflammation, and its derivative MR452, a well-tolerated agent endowed with improved anti-chemotactic in vitro properties, in the adoptive transfer colitis model. To the best of our knowledge, this is the first attempt to use adoptive transfer colitis to test modulators of the CCL20/CCR6 axis. Methods and Results: The induction of colitis in immunocompromised mice receiving CD4⁺CD25⁻ T cells i.p. resulted in a moderate inflammation and was met with limited protective responses following daily subcutaneous administration of MR120 or MR452 for 8 weeks. Both compounds significantly reduced colonic myeloperoxidase activity, and MR452 also lowered CCL20 levels in the gut, but they failed to prevent the increase in the Disease Activity Index, colon wall thickening, and macroscopic inflammation score. Conclusions: Our findings suggest that, despite the beneficial effects played by MR120 against subacute TNBS- and chronic DSS-induced colitis, the pharmacological targeting of the CCL20/CCR6 axis in the adoptive transfer model has a negligible effect in ameliorating the IBD-like phenotype driven by the altered intestinal immune homeostasis and by the disrupted function of immune-suppressive Treg cells.