Roles of Marine Macroalgae or Seaweeds and Their Bioactive Compounds in Combating Overweight, Obesity and Diabetes: A Comprehensive Review

Microalgae in the food-health nexus: Exploring species diversity, high-value bioproducts, health benefits, and sustainable market potential

Microalgae are valuable nutraceutical sources because of their nutrient-rich profiles and diverse bioactive compounds. This review provides a comprehensive analysis of marine and freshwater microalgae, emphasizing their species diversity, nutrient composition, and methods used for their extraction and processing. The health benefits of microalgal-based nutraceuticals have been explored, with evidence highlighting their role in managing diabetes, cancer, oxidative stress, inflammation, and obesity. Additionally, the sustainability and environmental benefits of marine and freshwater microalgal cultivation are discussed. The market potential for these nutraceuticals has been explored, underpinned by recent advancements in biotechnology, nanotechnology, and omics approaches. Despite their promising potential, challenges such as extraction efficiency, purification processes, and production scalability currently limit the widespread application of microalgae in nutraceuticals. However, recent advancements in biotechnology and omics approaches are driving innovations, addressing these limitations, and unlocking new possibilities. Furthermore, ongoing research and technological innovations suggest a bright future for the integration of marine microalgae into the nutraceutical industry, promoting both human health and environmental sustainability. This review also evaluates the growing market potential and economic viability of microalgal-based nutraceuticals, highlighting their growing demand and economic viability and providing a comprehensive understanding of the benefits, market potential, and technological advancements of marine and freshwater microalgae, fostering further innovation in this promising field.

Bioactive peptides PIISVYWK and FSVVPSPK improve glucose homeostasis by targeting DPP-IV and glucose transport in type 2 diabetic mice

Type 2 Diabetes Mellitus (T2DM) is a metabolic disorder characterized by chronic hyperglycemia, insulin resistance, and progressive β-cell dysfunction, often exacerbated by inflammation and oxidative stress. Effective management requires multi-targeted approaches, including modulation of glucose metabolism, suppression of inflammatory pathways, and pancreatic protection. This study investigates the antidiabetic and immunomodulatory potential of PIISVYWK (P1) and FSVVPSPK (P2), bioactive peptides from blue mussel, Mytilus edulis, in regulating these pathways. In vitro, P1 and P2 were assessed for their ability to inhibit α-glucosidase and DPP-IV activity in Caco-2 cells, alongside glucose uptake and transporter protein expression (SGLT-1 and GLUT2). In vivo, HFD/STZ-induced diabetic mice were administered P1 or P2 (1 mg/kg or 10 mg/kg) or metformin (200 mg/kg) for four weeks. Peptide treatment significantly improved glycemic control by inhibiting α-glucosidase and DPP-IV, increasing GLP-1 levels, and reducing intestinal glucose uptake. Additionally, P1 and P2 exhibited strong anti-inflammatory effects by suppressing NF-κB activation and reducing circulating IL-6, TNF-α, and IL-1β levels. Enhanced antioxidant enzyme activity (SOD, GPx, CAT) further mitigated oxidative stress, preventing pancreatic damage. Peptides also preserved β-cell function by enhancing insulin secretion and regulating glucagon levels. These findings suggest that P1 and P2 peptides exert antidiabetic effects through multi-targeted mechanisms, including immunomodulation, making them promising therapeutic candidates for T2DM management.

Bioactivities of Sargassum elegans, Bryopsis myosuroides, Callophyllis variegata seaweeds on diabetes and obesity-related biochemical parameters: A comparative in vitro study

Diabesity' is the occurrence of diabetes in the presence of obesity. Numerous reports have shown that seaweeds possess beneficial biological activities. This study assessed the effects of three seaweeds Bryopsis myosuroides (green), Callophyllis variegata (red), and Sargassum elegans (brown), on diabetes and obesity-related parameters in vitro. The antioxidant potential, carbohydrate and lipid digestive enzyme inhibitory activity, and glucose uptake activities of ethanolic and sulphated polysaccharides (SPs) rich extracts were evaluated. The SP-rich or ethanolic extracts of S. elegans showed the greater inhibition of 2,2-diphenyl-1-picrylhydrazyl (DPPH) (IC50 46.6 ± 1.00 g/mL), hydroxyl radical (OH) (IC50 353.70 ± 2.01 μg/mL), and nitric oxide (NO) (IC50 407.5 ± 0.95 μg/mL) compared to other seaweeds. Moreover, the SP-rich extract of S. elegans exhibited higher inhibition of α- glucosidase (IC50 123.8 ± 1.69 μg/mL), whereas B. myosuroides SP-rich extract had better α-amylase (IC50 55.7 ± 0.98 μg/mL) and pancreatic lipase inhibitory activities (IC50 481.1 ± 0.9 μg/mL) compared to other seaweeds. Liquid Chromatography Mass Spectroscopy (LC-MS) was used to identify the compounds present in the seaweed extracts. These include Taxifolin, Amentoflavone-7,4',4″'-Trimethyl Ether, Chrysophenol, and Glucotropaeolin, which have been previously reported to possess biological activities beneficial to human health. Although all three seaweeds evaluated in this study demonstrated antioxidant, digesting enzyme inhibitory and glucose uptake activity to different extents, S. elegans (brown) depicted the highest activity in most assays compared to the other seaweeds. However, further research is required to assess the effects of these seaweed extracts on diabetes and obesity via ex vivo and in vivo experimental animal models.

Actinomycetota From Macroalgae as Rich Source for Natural Products Discovery Revealed Through Culture-Dependent and -Independent Approaches

Actinomycetota are unrivalled producers of bioactive natural products, with strains living in association with macroalgae representing a prolific-yet largely unexplored-source of specialised chemicals. In this work, we have investigated the bioactive potential of Actinomycetota from macroalgae through culture-dependent and -independent approaches. A bioprospecting pipeline was applied to a collection of 380 actinobacterial strains, recovered from two macroalgae species collected in the Portuguese northern shore-Codium tomentosum and Chondrus crispus-in order to explore their ability to produce antibacterial, antifungal, anticancer and lipid-reducing compounds. Around 43% of the crude extracts showed activity in at least one of the screenings performed: 111 presented antimicrobial activity at 1 mg/mL, 83 significantly decreased cancer cells viability at 15 μg/mL and 5 reduced lipid content in zebrafish > 60% at 15 ug/mL. Dereplication of active extracts unveiled the presence of compounds that could explain most of the recorded results, but also unknown molecules in the metabolome of several strains, highlighting the opportunity for discovery. The bioactive potential of the actinobacterial community from the same macroalgae specimens, which served as the source for the aforementioned Actinomycetota collection, was also explored through metagenomics analysis, allowing to obtain a broader picture of its functional diversity and novelty. A total of 133 biosynthetic gene clusters recovered from metagenomic contigs and metagenome assembled genomes (MAGs). These were grouped into 91 gene cluster families, 83 of which shared less than 30% of similarity to database entries. Our findings provided by culture-dependent and -independent approaches underscore the potential held by actinomycetes from macroalgae as reservoirs for novel bioactive natural products.

Anti-Obesity Effects of Sulphated Polysaccharides Derived from Marine Macro Algae or Seaweeds: A Systematic Review and Meta-Analysis

Sulphated polysaccharides (SPs) are negatively charged compounds found in the cell wall of seaweeds or marine macro algae. These compounds exhibit a range of pharmacological activities, including anti-obesity effects. The aim of this systematic review as well as meta-analysis was to assess the potentials of seaweed-derived SPs to mitigate obesity through a systematic review and meta-analysis of animal model-based studies. A comprehensive summary of the included articles was conducted, focusing on the following obesity-related parameters: food intake, body weight gain, epididymal fat size, adipocyte size, liver weight, serum alanine transaminase (ALT) and aspartate transaminase (AST), insulin and tumour necrosis factor-α (TNF-α), and the lipid profile (total cholesterol, triglyceride, high-density lipoprotein cholesterol (HDL-c), and low-density lipoprotein cholesterol (LDL-c)). The systematic review demonstrated that seaweed-derived SPs exhibit ameliorative effects against obesity, as evidenced by reductions in food intake, body weight gain, epididymal fat and adipocyte size, liver weight, ALT and AST levels, serum insulin and TNF-α, LDL-c, total cholesterol, and triglycerides and an increase in HDL-c in obese rats administered with seaweed-derived SPs. However, the meta-analysis revealed statistically significant anti-obesity effects of seaweed-derived SPs for most, but not all the parameters tested. Further research in human subjects is necessary not only to ascertain the results of preclinical studies but also to provide conclusive evidence of the anti-obesity potential of SPs in humans.

Algal Active Ingredients and Their Involvement in Managing Diabetic Mellitus

Diabetes mellitus (DM) is becoming increasingly prominent, posing a serious threat to human health. Its prevalence is rising every year, and often affects young people. In the past few decades, research on marine algae has been recognized as a major field of drug discovery. Seaweed active substances, including algal polysaccharides, algal polyphenols, algal unsaturated fatty acids, and algal dietary fiber, have unique biological activities. This article reviews the effects and mechanisms of the types, structures, and compositions of seaweed on inhibiting glucose and lipid metabolism disorders, with a focus on the inhibitory effect of active substances on blood glucose reduction. The aim is to provide a basis for the development of seaweed active substance hypoglycemic drugs.

Marine Compounds and Age-Related Diseases: The Path from Pre-Clinical Research to Approved Drugs for the Treatment of Cardiovascular Diseases and Diabetes

Ageing represents a main risk factor for several pathologies. Among them, cardiovascular diseases (CVD) and type 2 diabetes mellitus (T2DM) are predominant in the elderly population and often require prolonged use of multiple drugs due to their chronic nature and the high proportion of co-morbidities. Hence, research is constantly looking for novel, effective molecules to treat CVD and T2DM with minimal side effects. Marine active compounds, holding a great diversity of chemical structures and biological properties, represent interesting therapeutic candidates to treat these age-related diseases. This review summarizes the current state of research on marine compounds for the treatment of CVD and T2DM, from pre-clinical studies to clinical investigations and approved drugs, highlighting the potential of marine compounds in the development of new therapies, together with the limitations in translating pre-clinical results into human application.

Codium fragile Suppressed Chronic PM2.5-Exposed Pulmonary Dysfunction via TLR/TGF-β Pathway in BALB/c Mice

This study investigated the ameliorating effect of the aqueous extract of Codium fragile on PM2.5-induced pulmonary dysfunction. The major compounds of Codium fragile were identified as palmitic acid, stearic acid, and oleamide using GC/MS2 and hexadecanamide, oleamide, and 13-docosenamide using UPLC-Q-TOF/MSE. Codium fragile improved pulmonary antioxidant system deficit by regulating SOD activities and reducing GSH levels and MDA contents. It suppressed pulmonary mitochondrial dysfunction by regulating ROS contents and mitochondrial membrane potential levels. It regulated the inflammatory protein levels of TLR4, MyD88, p-JNK, p-NF-κB, iNOS, Caspase-1, TNF-α, and IL-1β. In addition, it improved the apoptotic protein expression of BCl-2, BAX, and Caspase-3 and attenuated the fibrous protein expression of TGF-β1, p-Smad-2, p-Smad-3, MMP-1, and MMP-2. In conclusion, this study suggests that Codium fragile might be a potential material for functional food or pharmaceuticals to improve lung damage by regulating oxidative stress inflammation, cytotoxicity, and fibrosis via the TLR/TGF-β1 signaling pathway.

Algae-Derived Natural Products in Diabetes and Its Complications-Current Advances and Future Prospects

Diabetes poses a significant global health challenge, necessitating innovative therapeutic strategies. Natural products and their derivatives have emerged as promising candidates for diabetes management due to their diverse compositions and pharmacological effects. Algae, in particular, have garnered attention for their potential as a source of bioactive compounds with anti-diabetic properties. This review offers a comprehensive overview of algae-derived natural products for diabetes management, highlighting recent developments and future prospects. It underscores the pivotal role of natural products in diabetes care and delves into the diversity of algae, their bioactive constituents, and underlying mechanisms of efficacy. Noteworthy algal derivatives with substantial potential are briefly elucidated, along with their specific contributions to addressing distinct aspects of diabetes. The challenges and limitations inherent in utilizing algae for therapeutic interventions are examined, accompanied by strategic recommendations for optimizing their effectiveness. By addressing these considerations, this review aims to chart a course for future research in refining algae-based approaches. Leveraging the multifaceted pharmacological activities and chemical components of algae holds significant promise in the pursuit of novel antidiabetic treatments. Through continued research and the fine-tuning of algae-based interventions, the global diabetes burden could be mitigated, ultimately leading to enhanced patient outcomes.