Flavonoids and their glycosides are abundant in many plant-based foods. The (de)glycosylation of flavonoids by retaining glycoside hydrolases has recently attracted much interest in basic and applied research, including the possibility of altering the glycosylation pattern of flavonoids. Research in this area is driven by significant differences in physicochemical, organoleptic, and bioactive properties between flavonoid aglycones and their glycosylated counterparts. While many flavonoid glycosides are present in nature at low levels, some occur in substantial quantities, making them readily available low-cost glycosyl donors for transglycosylations. Retaining glycosidases can be used to synthesize natural and novel glycosides, which serve as standards for bioactivity experiments and analyses, using flavonoid glycosides as glycosyl donors. Engineered glycosidases also prove valuable for the synthesis of flavonoid glycosides using chemically synthesized activated glycosyl donors. This review outlines the bioactivities of flavonoids and their glycosides and highlights the applications of retaining glycosidases in the context of flavonoid glycosides, acting as substrates, products, or glycosyl donors in deglycosylation or transglycosylation reactions.

• Keywords
• Glucosidase, Glycoside hydrolase, Glycosyl donor, Glycosynthase, Hydrolysis, Rutinosidase, Transglycosylation,
• MeSH
• Flavonoids * chemistry   MeSH
• Glycoside Hydrolases * metabolism   MeSH
• Glycosides chemistry   MeSH
• Glycosylation MeSH
• Catalysis MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Flavonoids * MeSH
• Glycoside Hydrolases * MeSH
• Glycosides 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

PURPOSE: The formation of new blood vessels from previous ones, angiogenesis, is critical in tissue repair, expansion or remodeling in physiological processes and in various pathologies including cancer. Despite that, the development of anti-angiogenic drugs has great potential as the treatment of cancer faces many problems such as development of the resistance to treatment or an improperly selected therapy approach. An evaluation of predictive markers in personalized medicine could significantly improve treatment outcomes in many patients. METHODS: This comprehensive review emphasizes the anticancer potential of flavonoids mediated by their anti-angiogenic efficacy evaluated in current preclinical and clinical cancer research. RESULTS AND CONCLUSION: Flavonoids are important groups of phytochemicals present in common diet. Flavonoids show significant anticancer effects. The anti-angiogenic effects of flavonoids are currently a widely discussed topic of preclinical cancer research. Flavonoids are able to regulate the process of tumor angiogenesis through modulation of signaling molecules such as VEGF, MMPs, ILs, HIF or others. However, the evaluation of the anti-angiogenic potential of flavonoids within the clinical studies is not frequently discussed and is still of significant scientific interest.

• Keywords
• Anti-cancer therapy, Cancer, Flavonoids, Neovascularity, Tumor angiogenesis, VEGF,
• MeSH
• Flavonoids therapeutic use   MeSH
• Angiogenesis Inhibitors therapeutic use   MeSH
• Interleukins genetics   MeSH
• Humans MeSH
• Matrix Metalloproteinases genetics   MeSH
• Neoplasms drug therapy   genetics   pathology   MeSH
• Neovascularization, Pathologic drug therapy   genetics   pathology   MeSH
• Signal Transduction drug effects   MeSH
• Vascular Endothelial Growth Factor A genetics   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Review MeSH
• Names of Substances
• Flavonoids MeSH
• Angiogenesis Inhibitors MeSH
• Interleukins MeSH
• Matrix Metalloproteinases MeSH
• Vascular Endothelial Growth Factor A MeSH

The stilbenoids, a group of naturally occurring phenolic compounds, are found in a variety of plants, including some berries that are used as food or for medicinal purposes. They are known to be beneficial for human health as anti-inflammatory, chemopreventive, and antioxidative agents. We have investigated a group of 19 stilbenoid substances in vitro using a cellular model of THP-1 macrophage-like cells and pyocyanin-induced oxidative stress to evaluate their antioxidant or pro-oxidant properties. Then we have determined any effects that they might have on the expression of the enzymes catalase, glutathione peroxidase, and heme oxygenase-1, and their effects on the activation of Nrf2. The experimental results showed that these stilbenoids could affect the formation of reactive oxygen species in a cellular model, producing either an antioxidative or pro-oxidative effect, depending on the structure pinostilbene (2) worked as a pro-oxidant and also decreased expression of catalase in the cell culture. Piceatannol (4) had shown reactive oxygen species (ROS) scavenging activity, whereas isorhapontigenin (18) had a mild direct antioxidant effect and activated Nrf2-antioxidant response element (ARE) system and elevated expression of Nrf2 and catalase. Their effects shown on cells in vitro warrant their further study in vivo.

• Keywords
• Nrf2, antioxidant, macrophages, pro-oxidant, pyocyanin, stilbenoid,
• MeSH
• Antioxidant Response Elements drug effects   MeSH
• Antioxidants chemistry   pharmacology   MeSH
• Hep G2 Cells MeSH
• NF-E2-Related Factor 2 genetics   MeSH
• Humans MeSH
• Lipid Peroxidation drug effects   MeSH
• Pyocyanine chemistry   MeSH
• Stilbenes chemistry   pharmacology   MeSH
• Thiobarbiturates chemistry   MeSH
• Check Tag
• Humans MeSH
• Publication type
• Journal Article MeSH
• Research Support, Non-U.S. Gov't MeSH
• Names of Substances
• Antioxidants MeSH
• NF-E2-Related Factor 2 MeSH
• NFE2L2 protein, human MeSH Browser
• Pyocyanine MeSH
• Stilbenes MeSH
• Thiobarbiturates MeSH
• thiobarbituric acid MeSH Browser