Spatial distribution of apoplastic antioxidative constituents in maize root

Bridging the buzz: In vivo EPR imaging unlocking the secrets of honey bee health

Honey bees play a pivotal role in shaping ecosystems and sustaining human health as both pollinators and producers of health-promoting products. However, honey bee colony mortality is on the rise globally, driven by various factors, including parasites, pesticides, habitat loss, poor nutrition, and climate change. This has far-reaching consequences for the environment, economy, and human welfare. While efforts to address these issues are underway, the current progress in electron paramagnetic resonance (EPR) instrumentation affords using the immense potential of this magnetic resonance technique to study small samples such as honey bees. This paper presents the pioneering 2D in vivo EPR imaging experiment on a honey bee, revealing the ongoing redox-status of bees' intestines. This way, by monitoring the spatio-temporal changes of the redox-active spin-probes' EPR signal, it is possible to gain access to valuable information on the course of ongoing bees' pathologies and the prospect of following-up on the efficiency of applied therapies. Employing a selection of diverse spin-probes could further reveal pH levels and oxygen concentrations in bee tissues, allowing a noninvasive assessment of bee physiology. This approach offers promising strategies for safeguarding pollinators and understanding their biology, fostering their well-being and ecological harmony.

Solanum dulcamara L. Berries: A Convenient Model System to Study Redox Processes in Relation to Fruit Ripening

The present study provides, for the first time, a physicochemical and biochemical characterization of the redox processes associated with the ripening of Solanum dulcamara L. (bittersweet) berries. Electron Paramagnetic Resonance Spectroscopy (EPRS) and Imaging (EPRI) measurements of reactive oxygen species (ROS) were performed in parallel with the tissue-specific metabolic profiling of major antioxidants and assessment of antioxidant enzymes activity. Fruit transition from the mature green (MG) to ripe red (RR) stage involved changes in the qualitative and quantitative content of antioxidants and the associated cellular oxidation and peroxidation processes. The skin of bittersweet berries, which was the major source of antioxidants, exhibited the highest antioxidant potential against DPPH radicals and nitroxyl spin probe 3CP. The efficient enzymatic antioxidant system played a critical protective role against the deleterious effects of progressive oxidative stress during ripening. Here, we present the EPRI methodology to assess the redox status of fruits and to discriminate between the redox states of different tissues. Interestingly, the intracellular reoxidation of cell-permeable nitroxide probe 3CP was observed for the first time in fruits or any other plant tissue, and its intensity is herein proposed as a reliable indicator of oxidative stress during ripening. The described noninvasive EPRI technique has the potential to have broader application in the study of redox processes associated with the development, senescence, and postharvest storage of fruits, as well as other circumstances in which oxidative stress is implicated.

Rich in Phenolics-Strong Antioxidant Fruit? Comparative Study of 25 Strawberry Cultivars

Phenolic compounds of 25 newly introduced strawberry cultivars were profiled using spectrophotometry, electron paramagnetic resonance (EPR) spectroscopy, and high-performance liquid chromatography-mass spectrometry. Total phenolic and anthocyanin content (TPC and TACY, respectively), as well as vitamin C, and concentrations of individual phenolic compounds in fruits were evaluated to identify the most promising cultivars according to their phenolic profile. The highest values of TPC, TACY, and vitamin C were recorded in 'Premy' (1.53 mg eq GA g^-1 FW), 'Sandra' (30.60 mg eq Pg-3-g 100 g^-1 FW), and 'Laetitia' (56.32 mg 100 g^-1 FW), respectively. The DPPH and •OH radicals scavenging activity of fruit methanolic extracts was estimated using EPR spectroscopy. All cultivars are almost uniformly effective in the scavenging of •OH radical, while 'Tea', 'Premy', and 'Joly' were marked as highly potent cultivars (over 70%) in terms of DPPH-antiradical activity. Specific peroxidase activities were the highest in 'Garda', 'Federica', and 'Rumba' (0.11, 0.08, and 0.06 U mg^-1 prot, respectively). 'Laetitia', 'Joly', 'Arianna', 'Tea', and 'Mila' cultivars were distinguished from others as the richest concerning almost all flavonoids and phenolic acids, including some other parameters of bioactivity. These cultivars could be recommended to consumers as functional fruit foods.