OBJECTIVES: This study presents a versatile, AI-guided workflow for the targeted isolation and characterization of prenylated flavonoids from Paulownia tomentosa (Thunb.) Steud. (Paulowniaceae). METHODS: The approach integrates established extraction and chromatography-based fractionation protocols with LC-UV-HRMS/MS analysis and supervised machine-learning (ML) custom-trained classification models, which predict prenylated flavonoids from LC-HRMS/MS spectra based on the recently developed Python package AnnoMe (v1.0). RESULTS: The workflow effectively reduced the chemical complexity of plant extracts and enabled efficient prioritization of fractions and compounds for targeted isolation. From the pre-fractionated plant extracts, 2687 features were detected, 42 were identified using reference standards, and 214 were annotated via spectra library matching (public and in-house). Furthermore, ML-trained classifiers predicted 1805 MS/MS spectra as derived from prenylated flavonoids. LC-UV-HRMS/MS data of the most abundant presumed prenyl-flavonoid candidates were manually inspected for coelution and annotated to provide dereplication. Based on this, one putative prenylated (C5) dihydroflavonol (1) and four geranylated (C10) flavanones (2-5) were selected and successfully isolated. Structural elucidation employed UV spectroscopy, HRMS, and 1D as well as 2D NMR spectroscopy. Compounds 1 and 5 were isolated from a natural source for the first time and were named 6-prenyl-4'-O-methyltaxifolin and 3',4'-O-dimethylpaulodiplacone A, respectively. CONCLUSIONS: This study highlights the combination of machine learning with analytical techniques to streamline natural product discovery via MS/MS and AI-guided pre-selection, efficient prioritization, and characterization of prenylated flavonoids, paving the way for a broader application in metabolomics and further exploration of prenylated constituents across diverse plant species.

• Keywords
• bioactive compounds, geranylated flavonoids, prenylated polyphenols, specialized metabolites, untargeted metabolomics,
• Publication type
• Journal Article MeSH

The aim of our study was to determine the PPARγ agonism and hypoglycemic activity of natural phenolics isolated from Paulownia tomentosa and Morus alba. We started with a molecular docking preselection, followed by in vitro cell culture assays, such as PPARγ luciferase reporter gene assay and PPARγ protein expression by Western blot analysis. The ability of the selected compounds to induce GLUT4 translocation in cell culture and lower blood glucose levels in chicken embryos was also determined. Among the thirty-six plant phenolic compounds, moracin M showed the highest hypoglycemic effect in an in ovo experiment (7.33 ± 2.37%), followed by mulberrofuran Y (3.84 ± 1.34%) and diplacone (3.69 ± 1.37%). Neither moracin M nor mulberrofuran Y showed a clear effect on the enhancement of GLUT4 translocation or agonism on PPARγ, while diplacone succeeded in both (3.62 ± 0.16% and 2.4-fold ± 0.2, respectively). Thus, we believe that the compounds moracin M, mulberrofuran Y, and diplacone are suitable for further experiments to elucidate their mechanisms of action.

• Keywords
• PPARγ, diabetes mellitus, hypoglycemic, natural products, plant phenolics,
• MeSH
• Phenols * chemistry   pharmacology   isolation & purification   MeSH
• Hypoglycemic Agents * chemistry   pharmacology   isolation & purification   MeSH
• Chick Embryo MeSH
• Humans MeSH
• Morus * chemistry   MeSH
• Mice MeSH
• PPAR gamma * agonists   metabolism   genetics   chemistry   MeSH
• Glucose Transporter Type 4 metabolism   genetics   MeSH
• Plant Extracts * chemistry   pharmacology   isolation & purification   MeSH
• Molecular Docking Simulation MeSH
• Animals MeSH
• Check Tag
• Chick Embryo MeSH
• Humans MeSH
• Mice MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Phenols * MeSH
• Hypoglycemic Agents * MeSH
• PPAR gamma * MeSH
• Glucose Transporter Type 4 MeSH
• Plant Extracts * MeSH

INTRODUCTION: Within oncology research, there is a high effort for new approaches to prevent and treat cancer as a life-threatening disease. Specific plant species that adapt to harsh conditions may possess unique properties that may be utilized in the management of cancer. HYPOTHESIS: Chokeberry fruit is rich in secondary metabolites with anti-cancer activities potentially useful in cancer prevention and treatment. AIMS OF THE STUDY AND METHODS: Based on mentioned hypothesis, the main goal of our study was to evaluate the antitumor effects of dietary administered Aronia melanocarpa L. fruit peels (in two concentrations of 0.3 and 3% [w/w]) in the therapeutic syngeneic 4T1 mouse adenocarcinoma model, the chemopreventive model of chemically induced mammary carcinogenesis in rats, a cell antioxidant assay, and robust in vitro analyses using MCF-7 and MDA-MB-231 cancer cells. RESULTS: The dominant metabolites in the A. melanocarpa fruit peel extract tested were phenolic derivatives classified as anthocyanins and procyanidins. In a therapeutic model, aronia significantly reduced the volume of 4T1 tumors at both higher and lower doses. In the same tumors, we noted a significant dose-dependent decrease in the mitotic activity index compared to the control. In the chemopreventive model, the expression of Bax was significantly increased by aronia at both doses. Additionally, aronia decreased Bcl-2 and VEGF levels, increasing the Bax/Bcl-2 ratio compared to the control group. The cytoplasmic expression of caspase-3 was significantly enhanced when aronia was administered at a higher dosage, in contrast to both the control group and the aronia group treated with a lower dosage. Furthermore, the higher dosage of aronia exhibited a significant reduction in the expression of the tumor stem cell marker CD133 compared to the control group. In addition, the examination of aronia`s epigenetic impact on tumor tissue through in vivo analyses revealed significant alterations in histone chemical modifications, specifically H3K4m3 and H3K9m3, miRNAs expression (miR155, miR210, and miR34a) and methylation status of tumor suppressor genes (PTEN and TIMP3). In vitro studies utilizing a methanolic extract of A.melanocarpa demonstrated significant anti-cancer properties in the MCF-7 and MDA-MB-231 cell lines. Various analyses, including Resazurin, cell cycle, annexin V/PI, caspase-3/7, Bcl-2, PARP, and mitochondrial membrane potential, were conducted in this regard. Additionally, the aronia extract enhanced the responsiveness to epirubicin in both cancer cell lines. CONCLUSION: This study is the first to analyze the antitumor effect of A. melanocarpa in selected models of experimental breast carcinoma in vivo and in vitro. The utilization of the antitumor effects of aronia in clinical practice is still minimal and requires precise and long-term clinical evaluations. Individualized cancer-type profiling and patient stratification are crucial for effectively implementing plant nutraceuticals within targeted anti-cancer strategies in clinical oncology.

• Keywords
• Aronia melanocarpa L., breast carcinoma, epigenetics, in vitro models, mechanism of action, rodent models,
• Publication type
• Journal Article MeSH

The review presents prenylated flavonoids as potential therapeutic agents for the treatment of topical skin infections and wounds, as they can restore the balance in the wound microenvironment. A thorough two-stage search of scientific papers published between 2000 and 2022 was conducted, with independent assessment of results by two reviewers. The main criteria were an MIC (minimum inhibitory concentration) of up to 32 µg/mL, a microdilution/macrodilution broth method according to CLSI (Clinical and Laboratory Standards Institute) or EUCAST (European Committee on Antimicrobial Susceptibility Testing), pathogens responsible for skin infections, and additional antioxidant, anti-inflammatory, and low cytotoxic effects. A total of 127 structurally diverse flavonoids showed promising antimicrobial activity against pathogens affecting wound healing, predominantly Staphylococcus aureus strains, but only artocarpin, diplacone, isobavachalcone, licochalcone A, sophoraflavanone G, and xanthohumol showed multiple activity, including antimicrobial, antioxidant, and anti-inflammatory along with low cytotoxicity important for wound healing. Although prenylated flavonoids appear to be promising in wound therapy of humans, and also animals, their activity was measured only in vitro and in vivo. Future studies are, therefore, needed to establish rational dosing according to MIC and MBC (minimum bactericidal concentration) values, test potential toxicity to human cells, measure healing kinetics, and consider formulation in smart drug release systems and/or delivery technologies to increase their bioavailability.

• Keywords
• MRSA, S. aureus, anti-inflammatory, antibacterial, antioxidant, cytotoxicity, mastitis, nanotechnology, prenylated flavonoids, skin, wound healing,
• MeSH
• Anti-Bacterial Agents pharmacology   MeSH
• Anti-Infective Agents * pharmacology   MeSH
• Antioxidants * pharmacology   MeSH
• Flavonoids pharmacology   MeSH
• Wound Healing MeSH
• Humans MeSH
• Microbial Sensitivity Tests MeSH
• Animals MeSH
• Check Tag
• Humans MeSH
• Animals MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Anti-Bacterial Agents MeSH
• Anti-Infective Agents * MeSH
• Antioxidants * MeSH
• Flavonoids MeSH

Background: Oxidative stress is a key factor in the pathophysiology of many diseases. This study aimed to verify the antioxidant activity of selected plant phenolics in cell-based assays and determine their direct or indirect effects. Methods: The cellular antioxidant assay (CAA) assay was employed for direct scavenging assays. In the indirect approach, the influence of each test substance on the gene and protein expression and activity of selected antioxidant enzymes was observed. One assay also dealt with activation of the Nrf2-ARE pathway. The overall effect of each compound was measured using a glucose oxidative stress protection assay. Results: Among the test compounds, acteoside showed the highest direct scavenging activity and no effect on the expression of antioxidant enzymes. It increased only the activity of catalase. Diplacone was less active in direct antioxidant assays but positively affected enzyme expression and catalase activity. Morusin showed no antioxidant activity in the CAA assay. Similarly, pomiferin had only mild antioxidant activity and proved rather cytotoxic. Conclusions: Of the four selected phenolics, only acteoside and diplacone demonstrated antioxidant effects in cell-based assays.

• Keywords
• CAA, Nrf2-ARE, antioxidants, catalase, glucose toxicity, plant phenolics, superoxide dismutase,
• MeSH
• Antioxidant Response Elements MeSH
• Antioxidants chemistry   pharmacology   MeSH
• Biomarkers MeSH
• Gene Expression MeSH
• NF-E2-Related Factor 2 genetics   metabolism   MeSH
• Phenols chemistry   pharmacology   MeSH
• Glucose MeSH
• Humans MeSH
• Molecular Structure MeSH
• Oxidative Stress MeSH
• Antineoplastic Agents chemistry   pharmacology   MeSH
• Plant Extracts chemistry   pharmacology   MeSH
• Superoxide Dismutase-1 genetics   metabolism   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Names of Substances
• Antioxidants MeSH
• Biomarkers MeSH
• NF-E2-Related Factor 2 MeSH
• Phenols MeSH
• Glucose MeSH
• NFE2L2 protein, human MeSH Browser
• Antineoplastic Agents MeSH
• Plant Extracts MeSH
• SOD1 protein, human MeSH Browser
• Superoxide Dismutase-1 MeSH

Multidrug resistance (MDR) is a common problem when fighting cancer with chemotherapy. P-glycoprotein (P-gp, or MDR1) is an active pump responsible for the efflux of xenobiotics out of the cell, including anti-cancer drugs. It is a validated target against MDR. No crystal structure of the human P-gp is available to date, and only recently several cryo-EM structures have been solved. In this paper, we present a comprehensive computational approach that includes constructing the full-length three-dimensional structure of the human P-gp and its refinement using molecular dynamics. We assessed its flexibility and conformational diversity, compiling a dynamical ensemble that was used to dock a set of lignan compounds, previously reported as active P-gp inhibitors, and disclose their binding modes. Based on the statistical analysis of the docking results, we selected a system for performing the structure-based virtual screening of new potential P-gp inhibitors. We tested the method on a library of 87 natural flavonoids described in the literature, and 10 of those were experimentally assayed. The results reproduced the theoretical predictions only partially due to various possible factors. However, at least two of the predicted natural flavonoids were demonstrated to be effective P-gp inhibitors. They were able to increase the accumulation of doxorubicin inside the human promyelocytic leukemia HL60/MDR cells overexpressing P-gp and potentiate the antiproliferative activity of this anti-cancer drug.

• Keywords
• P-glycoprotein, flavonoids, molecular docking, molecular dynamics, multidrug resistance, natural compounds, structure-based virtual screening,
• Publication type
• Journal Article MeSH