The increasing demand for nutraceuticals in the circular economy era has driven the research toward studying bioactive compounds from renewable underexploited resources. In this regard, the exploration of brown algae has shown significant growth and maintains a great promise for the future. One possible explanation could be that brown algae are rich sources of nutritional compounds (polyunsaturated fatty acids, fiber, proteins, minerals, and vitamins) and unique metabolic compounds (phlorotannins, fucoxanthin, fucoidan) with promising biological activities that make them good candidates for nutraceutical applications with increased value-added. In this review, a deep description of bioactive compounds from brown algae is presented. In addition, recent advances in biological activities ascribed to these compounds through in vitro and in vivo assays are pointed out. Delivery strategies to overcome some drawbacks related to the direct application of algae-derived compounds (low solubility, thermal instability, bioavailability, unpleasant organoleptic properties) are also reviewed. Finally, current commercial and legal statuses of ingredients from brown algae are presented, considering future therapeutical and market perspectives as nutraceuticals.

Major depressive disorder is a widespread condition with antidepressants as the main pharmacological treatment. However, some patients experience concerning adverse reactions or have an inadequate response to treatment. Analytical chromatographic techniques, among other techniques, are valuable tools for investigating medication complications, including those associated with antidepressants. Nevertheless, there is a growing need to address the limitations associated with these techniques. In recent years, electrochemical (bio)sensors have garnered significant attention due to their lower cost, portability, and precision. Electrochemical (bio)sensors can be used for various applications related to depression, such as monitoring the levels of antidepressants in biological and in environmental samples. They can provide accurate and rapid results, which could facilitate personalized treatment and improve patient outcomes. This state-of-the-art literature review aims to explore the latest advancements in the electrochemical detection of antidepressants. The review focuses on two types of electrochemical sensors: Chemically modified sensors and enzyme-based biosensors. The referred papers are carefully categorized according to their respective sensor type. The review examines the differences between the two sensing methods, highlights their unique features and limitations, and provides an in-depth analysis of each sensor.

This study aimed to optimize the extraction conditions for a valuable source of antioxidants: seaweed. Therefore, ten seaweed samples were subjected to a solid–liquid extraction (SLE), where the extraction conditions (biomass (g): solvent (mL) ratio, temperature, and time) were optimized using response surface methodology (RSM). The seaweeds were also subjected to subcritical water extraction (SWE) (140 and 190 °C) and ultrasound-assisted extraction (UAE) (10 and 20 min). The antioxidant capacity of the extracts was determined through the ferric-reducing antioxidant power and the 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid). The total phenolic content revealed the significance of temperature and biomass; solvent ratio parameters in the extraction process with higher conditions generally promoting the release of phenolic compounds. Furthermore, applying RSM allowed for the identification of optimal conditions and the establishment of predictive models that can be valuable in industrial-scale extraction processes. The antioxidant potency composite index (APCI) shows that SWE at 190 °C stands out, with E. bicyclis reaching an APCI score of 46.27%. The AGREEprep evaluation showed that UAE is the most sustainable method, achieving the highest score (0.69). The results of this study contribute to the development of efficient and standardized extraction protocols for each seaweed species, allowing for the maximum yield of antioxidants.

As one of the most popular beverages in the world, coffee is a rich source of non-enzymatic bioactive compounds with antioxidant capacity. In this study, twelve commercial coffee beverages found in local Portuguese markets were assessed to determine their total phenolic and flavonoid contents, as well as their antioxidant capacity, by conventional optical procedures, namely, ferric reducing antioxidant power and DPPH-radical scavenging assay, and non-conventional procedures such as a homemade DNA-based biosensor against two reactive radicals: HO^• and H₂O₂. The innovative DNA-based biosensor comprised an adenine-rich oligonucleotide adsorbed onto a carbon paste electrode. This method detects the different peak intensities generated by square-wave voltammetry based on the partial damage to the adenine layer adsorbed on the electrode surface by the free radicals in the presence/absence of antioxidants. The DNA-based biosensor against H₂O₂ presented a higher DNA layer protection compared with HO^• in the presence of the reference gallic acid. Additionally, the phenolic profiles of the twelve coffee samples were assessed by HPLC-DAD, and the main contributors to the exhibited antioxidant capacity properties were caffeine, and chlorogenic, protocatechuic, neochlorogenic and gallic acids. The DNA-based sensor used provides reliable and fast measurements of antioxidant capacity, and is also cheap and easy to construct.

Background/Objectives: The CYP2C9 enzyme is involved in the metabolism of warfarin. The CYP2C9 gene harbors several single-nucleotide polymorphisms (SNPs), including CYP2C9*2 (rs1799853), which is known to affect warfarin’s therapeutic response. So, it is important to develop analytical tools capable of genotyping these SNPs to adjust warfarin’s therapeutic outcomes. In this work, an electrochemical DNA-based sensor was constructed and optimized for the detection of the CYP2C9*2 polymorphism. Methods: Using bioinformatic database platforms, two 71 base pair DNA target probes with the polymorphic variants A and G were chosen and designed. A DNA-based sensor was composed by mercaptohexanol and the CYP2C9*2 DNA capture probe in a self-assembled monolayer connected to screen-printed gold electrodes. Two independent hybridization events of the CYP2C9*2 allele were designed using complementary fluorescein-labeled DNA signaling to improve selectivity and avoid secondary structures. Three human samples with the homozygous variant (G/G) and non-variant (A/A) and heterozygous (G/A) genotypes were amplified by PCR and then applied to the developed genosensor. Results: Chronoamperometry measurements were performed for both polymorphic probes. A calibration curve in the 0.25 to 2.50 nM (LOD of 13 pM) and another in the 0.15 to 5.00 nM range (LOD of 22.6 pM) were obtained for the homozygous non-variant and variant probes, respectively. This innovative tool was capable of identifying the hybridization reaction between two complementary strands of immobilized DNA, representing a genotyping alternative to the classical PCR methodology. Conclusions: The developed electrochemical DNA-based sensor was able to discriminate two synthetic SNP target sequences (Target-A and Target-G) and detect, with specificity, the three patients’ genotypes (G/G, G/A, and A/A). This tool is therefore a promising, sensitive, and cost-effective analytical way to determine and discriminate an individual’s genotype and predict the appropriate warfarin dose.