Obesity is a health concern associated with various metabolic disorders and chronic low-grade inflammation. Emerging evidence suggests that gut microbiota dysbiosis and oxidative stress play significant roles in the development and progression of obesity. However, the interplay between gut microbiota dysbiosis, oxidative stress, and obesity, particularly in the context of exercise interventions, remains poorly understood. This abstract aims to explore the interplay between these factors and provide insights into the potential mechanisms underlying exercise-mediated effects on gut microbiota, oxidative stress, and obesity.

Exercise interventions have been shown to exert beneficial effects on gut microbiota composition, promoting a diverse and balanced microbial community. These exercise-induced changes in the gut microbiota have been associated with reduced systemic inflammation and oxidative stress markers in obese individuals. Exercise may modulate gut microbiota composition directly through increased intestinal motility and changes in microbial metabolism. Additionally, exercise-induced improvements in metabolic health and reduction in adipose tissue inflammation may indirectly influence gut microbiota diversity and function. Furthermore, it is essential to identify appropriate exercise recommendations, given that endurance activities have proven to be significant for individuals. Consequently, our emphasis will be on endurance exercise. We will additionally consider whether Faecalibacterium prausnitzii, Akkermansia muciniphila, and Bifidobacterium adolescentis are associated with endurance exercise participation.

Exercise-induced improvements in gut microbiota can be attributed to increased intestinal motility, enhanced blood flow to the gut, and alterations in microbial metabolism. Exercise also reduces gut permeability, thereby preventing the translocation of harmful pathogens. These positive changes in gut microbiota composition have been associated with reduced inflammation, improved metabolic health, and enhanced immune function.

Understanding the intricate relationship between gut microbiota dysbiosis, oxidative stress, and obesity in the context of exercise interventions is crucial for developing effective strategies for obesity prevention and management.

Amid the global drive to identify green, and sustainable materials and natural antioxidants to meet the demands for biodegradable packaging materials in terms of yield, qualification, and application, citrus peels emerge as abundant, inexpensive, and often overlooked green sources suitable for innovative food packaging. In this study, citrus flavonoids (CF) and citrus pectin (CP) were obtained through sequential extraction technology from citrus by-products, followed by preliminary purification and characterization. The findings revealed that CP is an acidic heteropolysaccharide rich in arabinose and galacturonic acid, with hesperidin being the predominant flavonoid constituent of CF. Subsequently, we encapsulated CF into a matrix comprising soy protein isolate (SPI) and CP, creating innovative active films. These films were thoroughly assessed for their antioxidant, antimicrobial, physicochemical, morphological, optical, barrier, and mechanical properties. The results indicated a significant enhancement in the mechanical strength, heat resistance, and barrier properties of the composite films upon the addition of CP and CF. Moreover, the CF-loaded composite films exhibited remarkable antioxidant properties and demonstrated inhibitory effects against both Escherichia coli and Staphylococcus aureus. Employing these antimicrobial edible films for post-harvest preservation of red-grapes and pork revealed their effectiveness in extending the shelf life of both. Particularly, SPI/CP-CF films showed exceptional potential in prolonging the shelf life of red-grapes and pork, attributed to their reduced water vapor permeability and oxygen permeability values, along with their active antioxidant and antibacterial attributes. In conclusion, these composite films exhibit significant promise as multifunctional active packaging materials for fruit and pork preservation. Additionally, considering that citrus peels are by-products generated during food processing, transforming these readily available waste resources into value-added materials represents an innovative and sustainable approach, contributing to eco-friendliness.

Introduction:
The global prevalence of obesity continues to rise, with projections indicating that over half of the world’s population may be affected by 2035. Obesity is a multifactorial condition closely associated with chronic oxidative stress, resulting from an imbalance between pro-oxidant and antioxidant systems. This oxidative stress exacerbates metabolic dysfunction, interferes with appetite regulation, and promotes weight gain. Conventional weight loss strategies, including calorie restriction and increased physical activity, often prove challenging for individuals with obesity due to persistent hunger and increased food intake (hyperphagia). These issues are primarily driven by elevated orexigenic hormones and reduced anorexigenic signaling, making sustainable weight management difficult. This study aims to explore the therapeutic potential of natural compounds, specifically dietary polyphenols with antioxidant properties, to enhance the secretion of glucagon-like peptide-1 (GLP-1), an anorexigenic hormone that plays a critical role in appetite regulation.
Materials and Methods:
An in vitro screening of natural compounds was conducted using NCI-H716 enteroendocrine cells to identify polyphenols with significant GLP-1-stimulating effects. Two polyphenols showing the highest efficacy were selected for further evaluation in a diet-induced obesity mouse model. Mice received oral gavage administration of these polyphenols, and their food intake and metabolic markers, including cholesterol and triglycerides, were monitored.
Results:
The selected polyphenols significantly enhanced GLP-1 secretion in vitro in a dose-dependent manner. In the mouse model, these compounds effectively reduced food intake, improved cholesterol levels, and attenuated weight gain, suggesting their therapeutic potential.
Conclusion:
Dietary polyphenols with antioxidant and appetite-regulating properties show great potential as a natural strategy to address obesity by enhancing anorexigenic hormone secretion and improving metabolic markers such as cholesterol levels. With further research and clinical validation, these compounds could be developed into nutraceuticals or incorporated into dietary approaches to support sustainable weight management and overall metabolic health.

The main function of the placenta is to facilitate and regulate the mother-to-fetus transport of oxygen and nutrients. The placenta is also responsible, due to some enzymes present within it, for protecting the fetus against harmful xenobiotics. One of the protective mechanisms of the placenta is linked to the antioxidant enzyme glutathione S-transferase. Enzymes from this family can detoxify many endogenous compounds and break down xenobiotics through the conjugation of various substrates with reduced glutathione.

Organic sunscreens are expected to protect the skin, hair, and materials such as cosmetics or fabrics against the harmful effects of UV radiation. Unfortunately, many compounds from this group are known to cross biological barriers; they are found in the mother’s milk, umbilical cord blood, or placental tissues. Some organic sunscreens are able to cross the placenta and to interfere with fetal development; they are known or suspected to be endocrine disruptors or neurotoxins.

In this study, 16 organic sunscreens and over 100 products of sunscreen degradation in biotic and abiotic conditions were investigated in the context of their interactions with the enzyme gluthatione S-transferase present in the human placenta. Molecular docking analysis proved that several compounds from the studied group show stronger affinity for glutathione S-transferase that glutathione; it is therefore possible that they are able to reduce the enzyme’s antioxidant activity. It was established that sunscreens and their degradation products bind to glutathione S-transferase mainly by hydrogen bonds, but there are also van der Waals, pi-pi, pi-alkyl, and pi-sulfur interactions that contribute to the stability of enzyme—ligand complexes.

To conclude, due to the complexity of sunscreens’ degradation pathways and he abundance of both parent sunscreens and their degradation products in the environment, a relatively small group of popular cosmetic ingredients may be a source of a considerable number of stressors affecting individuals at different stages of development.

Polyphenols, known for their antioxidant properties, are plant secondary metabolites whose efficient extraction depends on factors such as solvent type, extraction conditions, and sample matrix. The present study compared different commonly used extraction conditions to recover polyphenols from different dried fruit and vegetable combinations (mainly citrus, berries, and beetroot) to identify a broadly applicable approach suitable for a range of samples. Selected extraction conditions compared cold maceration with a sonication-assisted approach, different temperature conditions (RT and 60°C) and different ethanol (acidified) concentrations (30 and 80%) as extraction solvent. The total polyphenol content (TPC) was determined using the commonly used Folin–Ciocalteu assay as well as Fast Blue assay as an alternative option, which has recently been proposed as a more accurate reflection of the actual polyphenol content.

The results show consistently higher TPC across different samples following extractions with 30% ethanol than 80% as the extraction solvent, indicating better suitability for polyphenol extraction. Furthermore, samples extracted at RT showed higher TPC compared to samples extracted at 60°C. Whilst sonication-assisted extraction slightly improved TPC recovery in some samples, it was generally less favourable due to the prolonged sample processing time. When comparing the Folin–Ciocalteu versus Fast Blue assay, both methods for determining TPCwere highly reproducible, although the Fast Blue assay showed markedly higher values for all samples. The accuracy of the polyphenol assay methods is currently confirmed with HPLC.

In summary, based on the overall best performance of 30% ethanol extraction at RT, this approach could be recommended across a range of different samples. The different performance of the two polyphenol assays requires further attention, and more sensitive approaches such as HPLC should be employed to confirm their accuracy and reliability.

Padina sp., an edible brown macroalgae found along Sri Lanka's coast, is known for its bioactive compounds, eco-friendliness, and therapeutic benefits. These compounds can reduce metal ions to form nanoparticles, acting as stabilizing and capping agents. Silver nanoparticles, renowned for their conductivity, stability, and disease-treating potential, were synthesized in this study using Padina sp. The objectives were to synthesize and characterize the nanoparticles and evaluate their antioxidant activity. Silver nanoparticles were synthesized by mixing crude methanol extract of Padina sp. with silver nitrate. Characterization was conducted using Ultraviolet–Visible (UV-Vis) spectroscopy, Dynamic Light Scattering (DLS), Zeta potential analysis, Scanning Electron Microscopy (SEM), Energy-Dispersive X-ray (EDX) analysis, X-ray Diffraction (XRD), Fourier-Transform Infrared (FTIR) spectroscopy, and Raman spectroscopy. Antioxidant activity was assessed using the 2,2-Diphenyl-1-picrylhydrazyl (DPPH) assay. Statistical data analysis was performed using Minitab, with the results expressed as the mean ± standard deviation (SD), and paired two-sample t-tests were used to assess significant differences (p < 0.05). A visible color change from pale yellow to reddish-brown within 48 hours confirmed the formation of silver nanoparticles. UV-Vis spectroscopy showed a surface plasmon resonance peak at 420 nm, confirming the presence of nanoparticles. The DLS analysis revealed an average particle size of 73.19 nm, and the zeta potential obtained, -21.5 mV, indicated stability. The SEM images depicted spherical nanoparticles with smooth surfaces and no aggregation, while the EDX analysis confirmed 20% silver content by weight. The XRD analysis showed a face-centered cubic structure, indicating crystallinity. FTIR and Raman spectroscopy identified proteins, phenolic compounds, and amines as stabilizing agents, with polyphenolic compounds and flavonoids acting as reducing agents. In the DPPH assay, the antioxidant activity of silver nanoparticles (IC50 = 271.17 ± 3.99 μg/ml) was significantly higher than that of the crude Padina sp. extract (IC50 = 307.69 ± 9.33 μg/ml). These findings suggest that green-synthesized silver nanoparticles from Padina sp. offer a promising therapeutic strategy for diseases linked to oxidative stress.

Arbutus unedo L. is a native species of the Mediterranean region, commonly known as strawberry tree [1]. Traditionally, this species has been used for medicinal purposes [2], and the berries are not usually directly consumed but instead used for the production of alcoholic beverages and jams [3]. Strawberry tree berries are noted for their impressive nutritional profile, being rich in different bioactive compounds [2], which underpins their various pharmacological properties [4], such as antioxidant activity, drawing the attention of food, nutraceutical, and cosmetic industries [5].
This study’s goal is to develop an eco-friendly extract from A. unedo L. berries using a green approach. Briefly, in October 2022, berries were collected from Natural Park of Montesinho and then processed using an ultrasound-assisted extraction (UAE), using water as solvent and with an extraction intensity of 30 W/m². The impact of extraction time (15–90 minutes) was assessed on the total phenolic content (TPC), in vitro antioxidant/antiradical activities, reactive oxygen species (ROS) scavenging capacity, phytochemical profile, and keratinocytes viability.
The results highlighted that the 60-min extract exhibited, overall, the highest values for the antioxidant/antiradical activities (ABTS = 30.36 mg AAE/g dw; DPPH = 43.83 mg TE/g dw; FRAP = 415.61 μmol FSE/g dw) and TPC (30.27 mg GAE/g dw). Concerning the ROS scavenging capacity, this extract's IC50 values for hypochlorous acid and superoxide radical were 19.78 and 90.51 μg/mL, respectively, and 0.19 μmol TE/mg dw for peroxyl radical. The analysis of the phytochemical profile highlighted significant levels of gallic acid, catechin, and its derivatives. Moreover, the keratinocyte viability was higher than 90% after exposure to the highest concentration tested (1000 μg/ml). These findings highlight the potential of UAE-extracted A. unedo L. fruit as a valuable source of bioactive compounds suitable for use as an active ingredient in different industries.

Acknowledgments: This research was funded by MTS/SAS/0077/2020—Honey+—New reasons to care honey from the Natural Park of Montesinho: A bioindicator of environmental quality & its therapeutic potential, and by the projects UIDB/50006/2020, UIDP/50006/2020, and LA/P/0008/2020, all supported by Fundação para a Ciência e a Tecnologia (FCT)/Ministério da Ciência, Tecnologia e Ensino Superior (MCTES). This work was also financed by national funds from FCT—Fundação para a Ciência e a Tecnologia, I.P., in the scope of the project UIDP/04378/2020 and UIDB/04378/2020 of the Research Unit on Applied Molecular Biosciences—UCIBIO and the project LA/P/0140/2020 of the Associate Laboratory Institute for Health and Bioeconomy—i4HB. Ana Margarida Silva is thankful for the Ph.D. grant (SFRH/BD/144994/2019) financed by POPH–QREN and subsidized by the European Science Foundation and Ministério da Ciência, Tecnologia e Ensino Superior. F. Rodrigues (2023.06819.CEECIND) and M. Moreira (2023.05993.CEECIND) are thankful for their contracts financed by FCT/MCTES.

References:
1. Macchioni, V., V. Santarelli, and K. Carbone, Phytochemical Profile, Antiradical Capacity and α-Glucosidase Inhibitory Potential of Wild Arbutus unedo L. Fruits from Central Italy: A Chemometric Approach. Plants (Basel), 2020. 9(12).
2. El Haouari, M., et al., An Insight into Phytochemical, Pharmacological, and Nutritional Properties of Arbutus unedo L. from Morocco. Evid Based Complement Alternat Med, 2021. 2021: p. 1794621.
3. Oliveira, I., et al., Volatile profile of Arbutus unedo L. fruits through ripening stage. Food Chemistry, 2011. 128: p. 667-673.
4. Ben Salem, I., et al., Exploring the nutraceutical potential and biological activities of Arbutus unedo L. (Ericaceae) fruits. Industrial Crops and Products, 2018. 122.
5. Martins, J., G. Pinto, and J. Canhoto, Biotechnology of the multipurpose tree species Arbutus unedo: a review. Journal of Forestry Research, 2021. 33.

The growth, development, and production of plants are severely hampered by abiotic conditions such as drought, salinity, high temperatures, and heavy metal toxicity. Reactive oxygen species (ROS) are produced in excess as a result of these stressors, which damages biomolecules and cellular structures oxidatively. Plants have developed complex antioxidant systems that include nonenzymatic antioxidants such as ascorbate, glutathione, carotenoids, and phenolic substances, as well as enzymatic antioxidants like superoxide dismutase (SOD), catalase (CAT), and peroxidases (POD). Secondary metabolites, such as flavonoids, alkaloids, and terpenoids, are essential for reducing oxidative stress and boosting plant resistance in addition to these antioxidant defenses. The complex interactions between secondary metabolism and antioxidant responses in plants under abiotic stress are examined in this review. Secondary metabolites' dual function as signaling molecules and ROS scavengers is examined, with a focus on how they support stress adaptation and redox equilibrium. Additionally, the way that ROS and antioxidants control the formation of secondary metabolites is investigated, providing insight into the dynamic feedback processes at play. Recent developments in molecular biology and omics technologies have demonstrated that transcription factors and signaling networks, including the MYB, bHLH, and WRKY families, as well as hormonal cross-talk involving abscisic acid, salicylic acid, and jasmonic acid, co-regulate antioxidant and secondary metabolic pathways. This study also emphasizes how biotechnological methods, such as genetic engineering and the use of exogenous elicitors, can be used to enhance plant stress tolerance by utilizing the integration of secondary metabolic pathways and antioxidants. Gaining insight into how these two systems work together offers encouraging opportunities to improve agricultural sustainability in the face of changing climate circumstances and create stress-resilient crops.

Brassica vegetables are known for their glucosinolate content. These secondary metabolites are responsible for the bitter taste present in these vegetables. Glucosinolates and their degradation products have been well documented for their powerful anti-cancer, anti-inflammatory and antioxidant properties and play a key role in reducing oxidative stress. This property is due not only to glucosinolates in their intact form, but also to their degradation products, such as isothiocyanates and indoles, which are generated during enzymatic and thermal processes. Cooking can significantly modify the concentration and composition of these compounds, influencing their bioavailability and bioactivity. Investigating the effects of various cooking techniques on glucosinolate content and bioavailability is vital to maximizing the potential health benefits of these extraordinary vegetables. Understanding the intricate relationship between cooking methods and glucosinolate preservation may help to optimize the health-promoting potential of cruciferous vegetables in dietary practices. Cooking induces significant changes in the chemical composition of foods, depending on the cooking method, temperature, and cooking time. In general, the literature agrees that cooking methods affect the nutritional quality of Brassica vegetables. Steaming and other gentle cooking techniques are recommended to preserve glucosinolates and their degradation products, while boiling should be minimized due to its detrimental effects on these compounds. This study aims to analyze and synthesize the existing information in the literature dealing with this topic, to select the main cooking methods used for Brassica vegetables, and to evaluate the impact of each cooking method on the stability, retention, and degradation of glucosinolates and their degradation products.

The rise of antibiotic-resistant bacteria presents a significant global health challenge, emphasizing the urgent need for alternative antimicrobial agents. This study investigates the antioxidant and antibacterial properties of several natural organic acids and flavonoids against common bacterial pathogens, including Escherichia coli (ATCC 25222), Pseudomonas aeruginosa (ATCC 27853), Staphylococcus aureus (ATCC 25923), Salmonella enterica (ATCC 13076), and Bacillus subtilis (ATCC 6633). To evaluate antibacterial activity, minimum inhibitory concentrations (MICs) and minimum bactericidal concentrations (MBCs) were determined through microdilution methods. Among the compounds tested, oxalic acid emerged as the most promising antibacterial agent, showing significant activity against Bacillus subtilis (MIC 0.087 μg/μl, MBC 0.35 μg/μl) and Escherichia coli (MIC 22.5 μg/μl, MBC 22.5 μg/μl). Additionally, oxalic acid exhibited potent antibacterial effects against Staphylococcus aureus (MIC 0.70 μg/μl, MBC 1.40 μg/μl) and Salmonella enterica (MIC 0.70 μg/μl, MBC 5.62 μg/μl). Succinic acid demonstrated moderate efficacy against Pseudomonas aeruginosa (MIC 0.18 μg/μl, MBC 0.73 μg/μl), while gallic acid proved particularly effective against Salmonella enterica (MIC 0.36 μg/μl, MBC 2.89 μg/μl). Other compounds tested, including quercetin, vanillin, ferulic acid, and ascorbic acid, showed varied antibacterial profiles.

In addition to antibacterial activity, the antioxidant properties of these compounds were evaluated, revealing a significant correlation between their antioxidant capacity and antimicrobial effects. This suggests that the antioxidant potential of these compounds may contribute to their antibacterial activity. Overall, the results highlight the potential of natural compounds as alternative antimicrobial agents, with a dual action as both antioxidants and bactericidal agents. These findings support the further exploration of natural products for developing new antimicrobial strategies to combat resistant bacterial infections.