Antidiabetic Potential of Marine Brown Algae-a Mini Review

Chnoospora minima: a Robust Candidate for Hyperglycemia Management, Unveiling Potent Inhibitory Compounds and Their Therapeutic Potential

The present study aimed to isolate a bioactive compound from Sri Lankan edible marine brown algae, Chnoospora minima, to manage diabetes. The de-polysaccharide crude methanolic extract was partitioned using hexane, chloroform, and ethyl acetate with increased polarity. The samples were subjected to determine the quantitative phytochemical analysis, antioxidants, and antidiabetic potentials. Further, the potent antidiabetic fraction was selected to isolate an active compound using bioactivity-guided fractionation. From the selected extract, the chloroform fraction exhibited comparatively high TPC (59.01 ± 1.86 mg GAE/g), TFC (5.14 ± 0.43 mg QE/g) and alkaloid content (2.79 ± 0.31 PE/g of extract). Crude methanol extract exhibited a potent DPPH activity (IC50: 0.48 ± 0.01 mg/mL) whereas the ethyl acetate fraction elicited a maximum ABTS activity (IC50: 0.064 ± 0.001 mg/mL) and a ferrous iron-chelating capacity (IC50: 0.019 mg/mL). Similarly, the chloroform fraction exhibited the highest FRAP (20.34 ± 1.72 mg TE/g) and ORAC (19.72 ± 2.92 mg TE/g) capacities. The potent inhibitory activity of α-amylase (IC50:3.17 ± 0.02 µg/mL) and α-glucosidase (IC50: 1.99 ± 0.01 µg/mL) enzymes and glucose diffusion was observed in the chloroform fraction. Similarly, the chloroform extract exhibited a potent BSA-glucose (IC50: 202.43 ± 5.71 µg/mL), BSA-MGO (IC50: 124.30 ± 2.85 µg/mL) antiglycation model and reversing activities (EC50BSAglucose: 98.99 ± 0.35 µg/mL; EC50BSA-MGO: 118.89 ± 1.58 µg/mL). Depending on the hypoglycemic activity, fucoxanthin was isolated as the active compound which showed a notable change in the functional group. Molecular docking studies were conducted on the compound, and binding energy was observed to be - 6.56 kcal/mol and - 4.83 kcal/mol for α-amylase and α-glucosidase enzymes, respectively, which confirmed the hypoglycemic effect of the isolated compounds. However, more studies are required to understand the mechanistic insights of these observations.

Revolutionizing Diabetes Care: The Role of Marine Bioactive Compounds and Microorganisms

Diabetes is a metabolic condition characterized by high blood glucose levels. Aquatic products like microalgae, bacteria, seagrasses, macroalgae, corals, and sponges have been investigated for potential anti-diabetic properties. We looked at polyphenols, peptides, pigments, and sterols, as well as other bioactive substances found in marine resources, to see if they could help treat or manage diabetes, in addition to describing the several treatment strategies that alter diabetes and its implications, such as inhibition of protein tyrosine phosphatases 1B (PTP1B), α-glucosidase, α-amylase, dipeptidyl peptidase IV (DPP-IV), aldose reductase, lipase, glycogen synthase kinase 3β (GSK-3β), and insulin resistance prevention, promotion of liver antioxidant capacity, natural killer cell stimulant, anti-inflammatory actions, increased AMP-activated protein kinase (AMPK) phosphorylation and sugar and metabolism of the lipid, reducing oxidative stress, and β-pancreatic cell prevention. This study highlights the revolutionary potential of marine bioactive compounds and microorganisms in transforming diabetes care. We believe in a future in which innovative, sustainable, and efficient therapeutic approaches will result in improved quality of life and better outcomes for people with diabetes mellitus by forging a new path for treatment, utilizing the power of the world's oceans, and capitalizing on the symbiotic relationship between humans and the marine ecosystem. This study area offers optimism and promising opportunities for transforming diabetes care.

Macroalgae-derived bioactive compounds for functional food and pharmaceutical applications-a critical review

The rising demand for global food resources, combined with an overreliance on land-based agroecosystems, poses a significant challenge for the sustainable production of food products. Macroalgae cultivation is a promising approach to mitigate impending global food insecurities due to several key factors: independence from terrestrial farming, rapid growth rates, unique biochemical makeup, and carbon capture potential. Furthermore, macroalgae are rich in vitamins, minerals, essential amino acids, polyunsaturated fatty acids and fiber, demonstrating significant potential as sustainable alternatives for enhancing dietary diversity and fulfilling nutritional requirements. This review provides an overview of the nutritional composition and functional properties of commercially cultivated macroalgae species, with emphasis on their viability as value additions to the functional food market. Furthermore, the review discusses the technological aspects of integrating macroalgae into food products, covering both innovative solutions and existing challenges. Macroalgae, beyond being nutritional powerhouses, contain a plethora of bioactive compounds with varied biological activities, including anti-diabetic, anti-cancer, cardioprotective, and neuroprotective properties, making them excellent candidates in developing novel pharmaceuticals. Thus, this review also summarizes the pharmaceutical applications of macroalgae, identifies research gaps and proposes potential strategies for incorporating macroalgae-derived bioactive compounds into therapeutic products.

Macromolecules from mushrooms, venoms, microorganisms, and plants for diabetes treatment - Progress or setback?

Diabetes is a substantial public health issue, while its prevalence continues to rise worldwide, affecting millions of persons between the ages of 20 and 80, the development of new therapeutic classes improving glycemic control and consequently micro and macrovascular complications are needed. Today, diabetes treatment is daily for life, and should not be interrupted. However, insulin secretagogues medications, and exogenous self-administration of insulin provide efficient antidiabetic effects, but their misuse leads to hypoglycemic complications besides other risks, hence the need to look for other natural products not to use solely but in concert with others types of medications. In this review, we will highlight briefly the pathophysiology of diabetes and its complications, then we will report the main bioactive macromolecules derived from various sources of natural products providing anti-diabetic properties. However, further researches need to be carried out to face the limitations hampering the development of effective natural drugs for diabetes treatment.

Marine Pharmacology in 2019-2021: Marine Compounds with Antibacterial, Antidiabetic, Antifungal, Anti-Inflammatory, Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems, and Other Miscellaneous Mechanisms of Action

The current 2019-2021 marine pharmacology literature review provides a continuation of previous reviews covering the period 1998 to 2018. Preclinical marine pharmacology research during 2019-2021 was published by researchers in 42 countries and contributed novel mechanism-of-action pharmacology for 171 structurally characterized marine compounds. The peer-reviewed marine natural product pharmacology literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral mechanism-of-action studies for 49 compounds, 87 compounds with antidiabetic and anti-inflammatory activities that also affected the immune and nervous system, while another group of 51 compounds demonstrated novel miscellaneous mechanisms of action, which upon further investigation, may contribute to several pharmacological classes. Thus, in 2019-2021, a very active preclinical marine natural product pharmacology pipeline provided novel mechanisms of action as well as new lead chemistry for the clinical marine pharmaceutical pipeline targeting the therapy of several disease categories.

Production and purification of fucoxanthins and β-carotenes from Halopteris scoparia and their effects on digestive enzymes and harmful bacteria

ABSTRACTAlgae constitute a significant part of marine biodiversity. They represent a renewable source of bioactive metabolites from drug development and therapeutic fields. Fucoxanthin and β-carotene from the brown macroalgae Halopteris scoparia, were extracted using conventional organic solvent extraction, then purified, to homogeneity, based on various chromatographic principles. Their effects on digestive enzymes and harmful bacteria were investigated. The capacities of both purified pigments to inhibit α-amylase and trypsin enzymes were evaluated. Purified fucoxanthin and β-carotene exhibited interesting α-amylase inhibition activities, with IC50 of 300 and 500 µg/mL, respectively. Moreover, trypsin inhibition activities were detected using purified these two pigments. The antibacterial potential of the purified pigments was evaluated. β-carotene showed to be a great antibacterial natural compound against gram-positive and gram-negative bacteria such as Listeria monocytogenes, Staphylococcus aureus and Salmonella enterica with Minimal Inhibitory Concentration (MIC) of about 0.225, 0.1125, 0.225 µg/mL, respectively. Those findings are in favor of the exploitation of H. scoparia pigments in therapeutic fields as an antidiabetic source directly by the inhibition of α-amylase and trypsin as well as antibacterial agents against gastrointestinal infections.

Protection of pancreatic beta cells against high glucose-induced toxicity by astaxanthin-s-allyl cysteine diester: alteration of oxidative stress and apoptotic-related protein expression

Purpose: High glucose (HG)-induced oxidative stress is associated with apoptosis in pancreatic β-cells. The protective effect of astaxanthin-s-allyl cysteine diester (AST-SAC) against HG-induced oxidative stress in pancreatic β-cells (βTC-tet cell line) in in vitro was studied.Materials and Methods: βTC-tet cell line was exposed to HG in the presence and absence of AST-SAC. Various parameters such as cell viability, reactive oxygen species generation, mitochondrial membrane potential, DNA fragmentation and expression of proteins involved in apoptosis [p53, B-cell lymphoma 2 (Bcl-2), Bcl-2 associated X (Bax), cytochrome c and caspase 3] were studied.Results: Pre-treatment of βTC-tet cells with AST-SAC (4, 8 and 12 μg/ml) in the presence of HG (25 mM) protected the viability of the cells in a dose-dependent manner. AST-SAC treatment mitigated the oxidative stress thereby preventing the mitochondrial dysfunction, DNA damage and apoptosis in βTC-tet cells against HG toxicity. Treatment with AST-SAC prevented the increased expression of p53 under HG conditions. Further, AST-SAC treatment maintained the level of pro-apoptotic (Bax, cleaved caspase-3 and cytochrome c) and anti-apoptotic (Bcl-2) proteins to that of the control level under HG exposed conditions in βTC-tet cells.Conclusion: Altogether, AST-SAC alleviated HG-induced oxidative damage and apoptosis in pancreatic β-cells by enhancing the antioxidant status and altering apoptotic-related protein expression.

Seaweeds as Nutraceutical Elements and Drugs for Diabetes Mellitus: Future Perspectives

Diabetes mellitus is a chronic metabolic condition marked by high blood glucose levels caused by inadequate insulin synthesis or poor insulin use. This condition affects millions of individuals worldwide and is linked to a variety of consequences, including cardiovascular disease, neuropathy, nephropathy, and retinopathy. Diabetes therapy now focuses on controlling blood glucose levels through lifestyle changes, oral medicines, and insulin injections. However, these therapies have limits and may not successfully prevent or treat diabetic problems. Several marine-derived chemicals have previously demonstrated promising findings as possible antidiabetic medicines in preclinical investigations. Peptides, polyphenols, and polysaccharides extracted from seaweeds, sponges, and other marine species are among them. As a result, marine natural products have the potential to be a rich source of innovative multitargeted medications for diabetes prevention and treatment, as well as associated complications. Future research should focus on the chemical variety of marine creatures as well as the mechanisms of action of marine-derived chemicals in order to find new antidiabetic medicines and maximize their therapeutic potential. Based on preclinical investigations, this review focuses on the next step for seaweed applications as potential multitargeted medicines for diabetes, highlighting the bioactivities of seaweeds in the prevention and treatment of this illness.

Fermentation of micro- and macroalgae as a way to produce value-added products

Fermentation of both microalgae and macroalgae is one of the most efficient methods of obtaining valuable value-added products due to the minimal environmental pollution and the availability of economic benefits, as algae do not require arable land and drift algae and algal bloom biomass are considered waste and must be recycled and their fermentation waste utilized. The compounds found in algae can be effectively used in the fuel, food, cosmetic, and pharmaceutical industries, depending on the type of fermentation used. Products such as methane and hydrogen can be produced by anaerobic digestion and dark fermentation of algae, and lactic acid and its polymers can be produced by lactic acid fermentation of algae. Article aims to provide an overview of the different types potential of micro- and macroalgae fermentation, the advantages and disadvantages of each type considered, and the economic feasibility of algal fermentation for the production of various value-added products.

Brown Seaweed Consumption as a Promising Strategy for Blood Glucose Management: A Comprehensive Meta-Analysis

Diabetes is a chronic condition that can lead to various complications; therefore, there is a need to emphasize prevention and management. Dietary interventions, such as the Mediterranean diet or calorie-restricted regimens, coupled with exercise-induced weight reduction, have been recommended for enhancing diabetes management. Seaweeds contain various functional components, such as polyphenols and fucoidan, which have been reported to exert multiple benefits, including blood glucose regulation, improved intestinal health, and enhanced of lipid profiles. The association between blood glucose and seaweed consumption has been established in previous research. We searched the PubMed, RISS, Google Scholar, ScienceDirect, and Cochrane Library databases to identify relevant studies after applying the selection/exclusion criteria, and 23 studies were ultimately included in this analysis. Comprehensive Meta-Analysis (CMA) software version 4.0 was used to assess statistical significance and heterogeneity. In this meta-analysis, postprandial blood glucose, glycated hemoglobin (HbA1c), and Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) levels demonstrated significant improvements in the seaweed group compared to the control group. Conversely, fasting blood glucose and insulin levels did not show significant associations with seaweed consumption. Subgroup analysis revealed that a high dose (1000 mg or more) was more beneficial than a low dose, and seaweeds such as Laminaria digitata, Undaria pinnatifida, Acophyllum nodosum, and Fucus vesiculosus were found to be more effective at improving blood glucose levels than control treatments. Therefore, based on our research, seaweed supplementation appears to be a promising strategy for reducing postprandial blood glucose, HbA1c, and HOMA-IR levels, thereby enabling better blood glucose management and leading to a decreased risk of type 2 diabetes.

Pro-Apoptotic Activity of Epi-Obtusane against Cervical Cancer: Nano Formulation, In Silico Molecular Docking, and Pharmacological Network Analysis

Cancer is a major disease that threatens human health all over the world. Intervention and prevention in premalignant processes are successful ways to prevent cancer from striking. On the other hand, the marine ecosystem is a treasure storehouse of promising bioactive metabolites. The use of such marine products can be optimized by selecting a suitable nanocarrier. Therefore, epi-obtusane, previously isolated from Aplysia oculifera, was investigated for its potential anticancer effects toward cervical cancer through a series of in vitro assays in HeLa cells using the MTT assay method. Additionally, the sesquiterpene was encapsulated within a liposomal formulation (size = 130.8 ± 50.3, PDI = 0.462, zeta potential -12.3 ± 2.3), and the antiproliferative potential of epi-obtusane was investigated against the human cervical cancer cell line HeLa before and after encapsulation with liposomes. Epi-obtusane exhibited a potent effect against the HeLa cell line, while the formulated molecule with liposomes increased the in vitro antiproliferative activity. Additionally, cell cycle arrest analysis, as well as the apoptosis assay, performed via FITC-Annexin-V/propidium iodide double staining (flow cytofluorimetry), were carried out. The pharmacological network enabled us to deliver further insights into the mechanism of epi-obtusane, suggesting that STAT3 might be targeted by the compound. Moreover, molecular docking showed a comparable binding score of the isolated compound towards the STAT3 SH2 domain. The targets possess an anticancer effect through the endometrial cancer pathway, regulation of DNA templated transcription, and nitric oxide synthase, as mentioned by the KEGG and ShinyGo 7.1 databases.

Algae Food Products as a Healthcare Solution

Diseases such as obesity; cardiovascular diseases such as high blood pressure, myocardial infarction and stroke; digestive diseases such as celiac disease; certain types of cancer and osteoporosis are related to food. On the other hand, as the world's population increases, the ability of the current food production system to produce food consistently is at risk. As a result, intensive agriculture has contributed to climate change and a major environmental impact. Research is, therefore, needed to find new sustainable food sources. One of the most promising sources of sustainable food raw materials is macroalgae. Algae are crucial to solving this nutritional deficiency because they are abundant in bioactive substances that have been shown to combat diseases such as hyperglycemia, diabetes, obesity, metabolic disorders, neurodegenerative diseases and cardiovascular diseases. Examples of these substances include polysaccharides such as alginate, fucoidan, agar and carrageenan; proteins such as phycobiliproteins; carotenoids such as β-carotene and fucoxanthin; phenolic compounds; vitamins and minerals. Seaweed is already considered a nutraceutical food since it has higher protein values than legumes and soy and is, therefore, becoming increasingly common. On the other hand, compounds such as polysaccharides extracted from seaweed are already used in the food industry as thickening agents and stabilizers to improve the quality of the final product and to extend its shelf life; they have also demonstrated antidiabetic effects. Among the other bioactive compounds present in macroalgae, phenolic compounds, pigments, carotenoids and fatty acids stand out due to their different bioactive properties, such as antidiabetics, antimicrobials and antioxidants, which are important in the treatment or control of diseases such as diabetes, cholesterol, hyperglycemia and cardiovascular diseases. That said, there have already been some studies in which macroalgae (red, green and brown) have been incorporated into certain foods, but studies on gluten-free products are still scarce, as only the potential use of macroalgae for this type of product is considered. Considering the aforementioned issues, this review aims to analyze how macroalgae can be incorporated into foods or used as a food supplement, as well as to describe the bioactive compounds they contain, which have beneficial properties for human health. In this way, the potential of macroalgae-based products in eminent diseases, such as celiac disease, or in more common diseases, such as diabetes and cholesterol complications, can be seen.

A novel anti-hyperglycemic sulfated pyruvylated polysaccharide from marine macroalga Hydropuntia edulis

Dipeptidyl peptidase is a crucial enzyme that regulates glucose metabolism by degrading incretins, such as glucagon-like-peptide-1, thereby reducing insulin secretion from the pancreatic β-cells. Consequently, dipeptidyl peptidase-IV inhibitors are an important remedial approach to moderate the hyperglycemic pathophysiology. A pyruvylated polysaccharide characterized as [→3)-4,6-O-(1-carboxyethylidene)-β-D-galp-(2SO3-)-(1→4)-3,6-α-L-AnGalp-(2OMe)-(1→], isolated from the marine macroalga Hydropuntia edulis, showed attenuation potential against dipeptidyl peptidase-IV (IC50 4.44 μM). The structure was elucidated using mass and one/two-dimensional nuclear magnetic resonance spectroscopic analyses of hydrolyzed polysaccharide besides glycosidic linkages obtained from partially methylated alditol acetate derivative. The isolated polysaccharide also revealed potential anti-carbolytic properties against α-amylase/α-glucosidase (IC50 45-47 μM). The results proved the candidacy of pyruvylated polysaccharide isolated from H. edulis as a potential therapeutic lead against hyperglycemia.

Study of the Phytochemical Composition, Antioxidant Properties, and In Vitro Anti-Diabetic Efficacy of Gracilaria bursa-pastoris Extracts

In this study, a comparison was made of the chemical makeup of different extracts obtained from Gracilaria bursa-pastoris, a type of red seaweed that was gathered from the Nador lagoon situated in the northern part of Morocco. Additionally, their anti-diabetic and antioxidant properties were investigated. The application of GC-MS technology to analyze the fatty acid content of the samples revealed that linoleic acid and eicosenoic acid were the most abundant unsaturated fatty acids across all samples, with palmitic acid and oleic acid following in frequency. The HPLC analysis indicated that ascorbic and kojic acids were the most prevalent phenolic compounds, while apigenin was the most common flavonoid molecule. The aqueous extract exhibited significant levels of polyphenols and flavonoids, registering values of 381.31 ± 0.33 mg GAE/g and 201.80 ± 0.21 mg QE/g, respectively. Furthermore, this particular extract demonstrated a remarkable ability to scavenge DPPH radicals, as evidenced by its IC₅₀ value of 0.17 ± 0.67 mg/mL. In addition, the methanolic extract was found to possess antioxidant properties, as evidenced by its ability to prevent β-carotene discoloration, with an IC₅₀ ranging from 0.062 ± 0.02 mg/mL to 0.070 ± 0.06 mg/mL. In vitro study showed that all extracts significantly inhibited the enzymatic activity of α-amylase and α-glucosidase. Finally, molecular docking models were applied to assess the interaction between the primary phytochemicals identified in G. bursa-pastoris extracts and the human pancreatic α-amylase and α-glucosidase enzymes. The findings suggest that these extracts contain bioactive substances capable of reducing enzyme activity more effectively than the commercially available drug acarbose.

Antioxidant and Antidiabetic Properties of Phlorotannins from Ascophyllum nodosum Seaweed Extracts

Seaweeds have gained considerable attention in recent years due to their potential health benefits and high contents of bioactive compounds. This review focuses on the exploration of seaweed's health-promoting properties, with particular emphasis on phlorotannins, a class of bioactive compounds known for their antioxidant and antidiabetic properties. Various novel and ecofriendly extraction methods, including solid-liquid extraction, ultrasound-assisted extraction, and microwave-assisted extraction are examined for their effectiveness in isolating phlorotannins. The chemical structure and isolation of phlorotannins are discussed, along with methods for their characterization, such as spectrophotometry, nuclear magnetic resonance, Fourier transform infrared spectroscopy, and chromatography. Special attention is given to the antioxidant activity of phlorotannins. The inhibitory capacities of polyphenols, specifically phlorotannins from Ascophyllum nodosum against digestive enzymes, such as α-amylase and α-glucosidase, are explored. The results suggest that polyphenols from Ascophyllum nodosum seaweed hold significant potential as enzyme inhibitors, although the inhibitory activity may vary depending on the extraction conditions and the specific enzyme involved. In conclusion, seaweed exhibits great potential as a functional food ingredient for promoting health and preventing chronic diseases. Overall, this review aims to condense a comprehensive collection of high-yield, low-cost, and ecofriendly extraction methods for obtaining phlorotannins with remarkable antioxidant and antidiabetic capacities.

Effects of an Extract of the Brown Seaweed Ascophylum nodosum on Postprandial Glycaemic Control in Healthy Subjects: A Randomized Controlled Study

The effects of the consumption of an extract of the brown seaweed Ascophyllum nodosum (BSW) on postprandial glucose and insulin responses to white bread were investigated in an acute, randomized, double-blind, three-arm, crossover, controlled trial in healthy, normoglycemic subjects. Sixteen subjects were administered either control white bread (50 g total digestible carbohydrates) or white bread with 500 mg or 1000 mg of BSW extract. Biochemical parameters were measured in venous blood over 3 h. Significant inter-individual variation in the glycaemic response to white bread was observed. Analysis of the responses of all subjects to either 500 mg or 1000 mg of BSW extract versus control revealed no significant effects of treatments. The variation in response to the control was used to classify individuals into glycaemic responders and non-responders. In the sub-cohort of 10 subjects with peak glucose levels after white bread above 1 mmol/L, we observed a significant decrease in maximum levels of plasma glucose after the intervention meal with 1000 mg of extract compared with the control. No adverse effects were reported. Further work is warranted to define all factors that determine "responders" to the effects of brown seaweed extracts and identify the cohort that would benefit the most from their consumption.

Utilization of Marine Seaweeds as a Promising Defense Against COVID-19: a Mini-review

COVID-19 is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which mainly affects the respiratory system. It has been declared as a "pandemic" in March 2020 by the World Health Organization due to the high spreading rate. SARS-CoV-2 binds with the angiotensin-converting enzyme 2 (ACE2) receptors on the cell surface which leads to the downregulation of ACE2 and upregulation of angiotensin-converting enzyme (ACE) receptors. The elevated level of cytokines and ACE receptors leads to the severity of SARS-CoV-2 infection. Due to the limited availability of vaccines and recurrent attacks of COVID-19 mainly in low-income countries, it is important to search for natural remedies to prevent or treat COVID-19 infection. Marine seaweeds are a rich source of bioactive compounds such as phlorotannins; fucoidan; carotenoids; omega-3 and omega-6 fatty acids; vitamins B₁₂, D, and C; and minerals including zinc and selenium that exhibit antioxidant, antiviral, and anti-inflammatory activities. Furthermore, bioactive compounds present in marine seaweeds have the ability to inhibit ACEs by inducing ACE2 which exhibits anti-inflammatory effects in COVID-19. Correspondingly, soluble dietary fibers present in seaweeds are served as prebiotics by generating short-chain fatty acids through fermentation. Hence, seaweeds can be utilized to reduce the gastrointestinal infections associated with SARS-CoV-2 infection.

Effect of Deployment and Harvest Date on Growth and High-Value Compounds of Farmed Alaria esculenta

Alaria esculenta is a brown seaweed farmed in many European countries for its biomass rich in useful bio compounds. This study aimed to identify the optimal growing season to maximise biomass production and quality. The seeded longlines of the brown seaweed were deployed in the southwest of Ireland in October and November 2019 and samples of the biomass were harvested in different dates, between March and June 2020. Biomass gain and composition, phenolic and flavonoid content (TPC and TFC) and biological activities (antioxidant and anti-hypertensive activities) of seaweed extracts prepared with Alcalase were evaluated. The biomass production was significantly higher for the line deployed in October (>20 kg·m-1). In May and June, an increasing amount of epiphytes was observed on the surface of A. esculenta. The protein content of A. esculenta varied between 11.2 and 11.76% and fat content was relatively low (1.8-2.3%). Regarding the fatty acids profile, A. esculenta was rich in polyunsaturated fatty acids (PUFA), especially in eicosapentaenoic acid (EPA). The samples analysed were very rich in Na, K, Mg, Fe, Mn, Cr and Ni. The content of Cd, Pb Hg was relatively low and below the maximum levels allowed. The highest TPC and TFC were obtained in extracts prepared with A. esculenta collected in March and levels of these compounds decreased with time. In general, the highest radical scavenging activities (ABTS and DPPH), as well as chelating activities (Fe2+ and Cu2+) were observed in early spring. Extracts from A. esculenta collected in March and April presented higher ACE inhibitory activity. The extracts from seaweeds harvested in March exhibited higher biological activity. It was concluded that an earlier deployment allows for maximising growth and harvest of biomass earlier when its quality is at the highest levels. The study also confirms the high content of useful bio compounds that can be extracted from A. esculenta and used in the nutraceutical and pharmaceutical industry.

Marine Algal Polyphenols as Skin Protective Agents: Current Status and Future Prospectives

The skin is the outermost anatomical barrier, which plays a vital role in the maintenance of internal homeostasis and protection against physical, chemical, and biological detractors. Direct contact with various stimuli leads to several physiological changes that are ultimately important for the growth of the cosmetic industry. Due to the consequences of using synthetic compounds in skincare and cosmeceutical-related industries, the pharmaceutical and scientific communities have recently shifted their focus to natural ingredients. The nutrient-rich value of algae, which are some of the most interesting organisms in marine ecosystems, has attracted attention. Secondary metabolites isolated from seaweeds are potential candidates for a wide range of economic applications, including food, pharmaceuticals, and cosmetics. An increasing number of studies have focused on polyphenol compounds owing to their promising biological activities against oxidation, inflammation, allergies, cancers, melanogenesis, aging, and wrinkles. This review summarizes the potential evidence of the beneficial properties and future perspectives of using marine macroalgae-derived polyphenolic compounds for advancing the cosmetic industry.

Antioxidant and Antidiabetic Activity of Algae

Currently, algae arouse a growing interest in the pharmaceutical and cosmetic area due to the fact that they have a great diversity of bioactive compounds with the potential for pharmacological and nutraceutical applications. Due to lifestyle modifications brought on by rapid urbanization, diabetes mellitus, a metabolic illness, is the third largest cause of death globally. The hunt for an efficient natural-based antidiabetic therapy is crucial to battling diabetes and the associated consequences due to the unfavorable side effects of currently available antidiabetic medications. Finding the possible advantages of algae for the control of diabetes is crucial for the creation of natural drugs. Many of algae's metabolic processes produce bioactive secondary metabolites, which give algae their diverse chemical and biological features. Numerous studies have demonstrated the antioxidant and antidiabetic benefits of algae, mostly by blocking carbohydrate hydrolyzing enzyme activity, such as α-amylase and α-glucosidase. Additionally, bioactive components from algae can lessen diabetic symptoms in vivo. Therefore, the current review concentrates on the role of various secondary bioactive substances found naturally in algae and their potential as antioxidants and antidiabetic materials, as well as the urgent need to apply these substances in the pharmaceutical industry.

A comprehensive review on algal nutraceuticals as prospective therapeutic agent for different diseases

Ongoing research in the food supplement sector provides insightful information regarding algae as a new-generation nutritional supplement and is also referred to as a superfood. Due to the diverse nutritional components, algae have documented numerous health benefits like fighting microbial diseases, hypertension, obesity, and diabetes. Therefore, algae-derived nutraceuticals account for a rapidly expanding market in the food supplements sector. The concept of algal prebiotics and their role in modulating gut microbiota have also been a chief contributor to this. This review evaluates the use of possible algal species and their specific bioactive compounds for the management of several chronic diseases. Proteins, peptides, polysaccharides, phenolics, and vitamins give an insight into the significance of algae in boosting the immune system and improving the body's nutritional makeup. In addition, phyco-compounds such as polysaccharides and polyphenols are also receiving a lot more interest in cosmeceutical applications for protecting skin from photodamage. The incorporation of algae in the diet for the management and prevention of chronic diseases like cancer, lung, and heart disease has been discussed in this review along with their action mechanism. This review provides a brief overview of several bioactive compounds present in micro and macroalgae and their therapeutic effect on lifestyle diseases, gastrointestinal diseases as well as neurodegenerative diseases.

Bioactivity Guided Study for the Isolation and Identification of Antidiabetic Compounds from Edible Seaweed-Ulva reticulata

Managing diabetes is challenging due to the complex physiology of the disease and the numerous complications associated with it. As part of the ongoing search for antidiabetic chemicals, marine algae have been demonstrated to be an excellent source due to their medicinal properties. In this study, Ulva reticulata extracts were investigated for their anti-diabetic effect by examining its inhibitory effects on α-amylase, α-glucosidase, and DPP-IV and antioxidant (DPPH) potential in vitro and its purified fraction using animal models. Among the various solvents used, the Methanolic extract of Ulva reticulata (MEUR) displayed the highest antidiabetic activity in both in vitro and in vivo; it showed no cytotoxicity and hence was subjected to bioassay-guided chromatographic separation. Among the seven isolated fractions (F1 to F7), the F4 (chloroform) fraction exhibited substantial total phenolic content (65.19 μg mL^-1) and total flavonoid content (20.33 μg mL^-1), which showed the promising inhibition against α-amylase (71.67%) and α-glucosidase (38.01%). Active fraction (F4) was further purified using column chromatography, subjected to thin-layer chromatography (TLC), and characterized by spectroscopy techniques. Upon structural elucidation, five distinct compounds, namely, Nonane, Hexadecanoic acid, 1-dodecanol, Cyclodecane methyl, and phenol, phenol, 3,5-bis(1,1-dimethylethyl) were identified. The antidiabetic mechanism of active fraction (F4) was further investigated using various in vitro and in vivo models. The results displayed that in in vitro both 1 and 24 h in vitro cultures, the active fraction (F4) at a concentration of 100 μg mL^-1 demonstrated maximum glucose-induced insulin secretion at 4 mM (0.357 and 0.582 μg mL^-1) and 20 mM (0.848 and 1.032 μg mL^-1). The active fraction (F4) reduces blood glucose levels in normoglycaemic animals and produces effects similar to that of standard acarbose. Active fraction (F4) also demonstrated outstanding hypoglycaemic activity in hyperglycemic animals at a dose of 10 mg/kg B.wt. In the STZ-induced diabetic rat model, the active fraction (F4) showed a (61%) reduction in blood glucose level when compared to the standard drug glibenclamide (68%). The results indicate that the marine algae Ulva reticulata is a promising candidate for managing diabetes by inhibiting carbohydrate metabolizing enzymes and promoting insulin secretion.

Biological Properties and Health-Promoting Functions of Laminarin: A Comprehensive Review of Preclinical and Clinical Studies

Marine algal species comprise of a large portion of polysaccharides which have shown multifunctional properties and health benefits for treating and preventing human diseases. Laminarin, or β-glucan, a storage polysaccharide from brown algae, has been reported to have potential pharmacological properties such as antioxidant, anti-tumor, anti-coagulant, anticancer, immunomodulatory, anti-obesity, anti-diabetic, anti-inflammatory, wound healing, and neuroprotective potential. It has been widely investigated as a functional material in biomedical applications as it is biodegradable, biocompatible, and is low toxic substances. The reported preclinical and clinical studies demonstrate the potential of laminarin as natural alternative agents in biomedical and industrial applications such as nutraceuticals, pharmaceuticals, functional food, drug development/delivery, and cosmeceuticals. This review summarizes the biological activities of laminarin, including mechanisms of action, impacts on human health, and reported health benefits. Additionally, this review also provides an overview of recent advances and identifies gaps and opportunities for further research in this field. It further emphasizes the molecular characteristics and biological activities of laminarin in both preclinical and clinical settings for the prevention of the diseases and as potential therapeutic interventions.

Integration of in vitro and in-silico analysis of Caulerpa racemosa against antioxidant, antidiabetic, and anticancer activities

Marine algae are found to be excellent in their nutritional and potential therapeutic properties. This study explores the antidiabetic and anticancer potential of fractionated polyphenolic extract of Caulerpa racemosa, green macroalgae. Crude polyphenolic extract (CPE) of C. racemosa and its fractions (n-hexane, ethyl acetate, chloroform, and distilled water) were tested for its total phenol and flavonoid contents and antioxidant potential. The ethyl acetate fraction was subjected to gas chromatography/mass spectrometry (GC/MS). The in vitro antidiabetic activity was assessed by alpha-amylase, glucosidase inhibition and anti-glycation assays. Also, in-silico studies were conducted to test the binding affinities between caulerpin with alpha-glucosidase enzyme and estrogen receptor (ER) active sites. Each fraction was tested for its in vitroin vitroanticancer activity by CellTiter-Glo and MTT cell proliferation assays. The total phenolic and flavonoid contents and the antioxidant potential of the crude extract were observed to be dose dependent. The GC/MS analysis of the ethyl acetate fraction yielded 47 peaks, whereas n-hexadecanoic acid and hexadecanoic acid methyl ester showed the highest compatibility percentages of 99% and 96%, respectively. The CPE exhibited a higher potential in both alpha-amylase inhibitory and anti-glycation activities. The ethyl acetate fraction was more effective against alpha-glucosidase inhibition. Molecular docking revealed a high binding affinity between the alpha-glucosidase enzyme and caulerpin and showed high binding affinity toward caulerpin, with H-bond interactions. The in vitro anticancer analyses revealed that chloroform fraction and CPE exhibited moderate activity on the KAIMRC1 cell line. Also, the CPE exhibited high specificity compared to the standard drug in anticancer studies. Our findings evidence the pharmacological potential of the CPE of C. racemosa, and bioactive compounds of the species may be utilized as lead molecules to develop anti-diabetic and anti-cancer drugs.

A Bioactive Substance Derived from Brown Seaweeds: Phlorotannins

Phlorotannins are a type of natural active substance extracted from brown algae, which belong to a type of important plant polyphenol. Phloroglucinol is the basic unit in its structure. Phlorotannins have a wide range of biological activities, such as antioxidant, antibacterial, antiviral, anti-tumor, anti-hypertensive, hypoglycemic, whitening, anti-allergic and anti-inflammatory, etc. Phlorotannins are mainly used in the fields of medicine, food and cosmetics. This paper reviews the research progress of extraction, separation technology and biological activity of phlorotannins, which will help the scientific community investigate the greater biological significance of phlorotannins.

An aqueous extract of the brown alga Eisenia bicyclis extends lifespan in a sex-specific manner by interfering with the Tor-FoxO axis

Food has a decisive influence on our health, to the extent where even lifespan can be directly affected by it. In the present work, we have examined the effects of an aqueous extract of the marine brown alga Eisenia bicyclis in terms of its potential to extend lifespan. For this purpose, we used the fruit fly Drosophila melanogaster as a model. The experiments showed that small amounts of Eisenia extract can extend lifespan by up to 40%. This effect is not only related to the median but also to the maximum lifespan. Interestingly, this life-extending effect is sex-specific, i.e. it occurs exclusively in females. Even under stressful nutritional conditions such as a high sugar diet, this effect is detectable. Mechanistic studies showed that this life-prolonging effect depends on a functional Tor and a functional FoxO signaling pathway. It can be concluded that components of the Eisenia extract prolong lifespan by interacting with the Tor-FoxO axis. This study may serve to stimulate further investigations, which on the one hand show such a life-prolonging effect also in other organisms and on the other hand identify the substances responsible for this effect. Finally, it may also encourage the increased use of arame as a health-promoting food supplement.

The Leaves of Cyclocarya paliurus: A Functional Tea with Preventive and Therapeutic Potential of Type 2 Diabetes

Type 2 diabetes mellitus (T2DM) has become a universal and chronic global public health concern and causes multiple complex complications. In order to meet the rapidly growing demand for T2DM treatment, increased research has been focused on hypoglycemic drugs. Cyclocarya paliurus (Batal.) Iljinsk is the only living species of the genus Cyclocarya Iljinskaja, whose leaves have been extensively used as a functional tea to treat obesity and diabetes in China. An enormous amount of very recent pharmacological research on the leaves of C. paliurus has demonstrated that they carry out numerous biological activities, such as hypoglycemic, anti-inflammatory, and intestinal microbiota regulation. Multiple in vitro and in vivo studies have also shown that the extracts of C. paliurus leaves are innocuous and safe. This study aims to provide an up-to-date review of the botany, traditional uses, phytochemistry, pharmacological effects against diabetes, toxicology, and clinical studies of C. paliurus leaves, in hopes of promoting a better understanding of their role in the prevention and treatment of T2DM.

Marine Health-Promoting Compounds: Recent Trends for Their Characterization and Human Applications

Seaweeds represent a rich source of biologically active compounds with several applications, especially in the food, cosmetics, and medical fields. The beneficial effects of marine compounds on health have been increasingly explored, making them an excellent choice for the design of functional foods. When studying marine compounds, several aspects must be considered: extraction, identification and quantification methods, purification steps, and processes to increase their stability. Advanced green techniques have been used to extract these valuable compounds, and chromatographic methods have been developed to identify and quantify them. However, apart from the beneficial effects of seaweeds for human health, these natural sources of bioactive compounds can also accumulate undesirable toxic elements with potential health risks. Applying purification techniques of extracts from seaweeds may mitigate the amount of excessive toxic components, ensuring healthy and safer products for commercialization. Furthermore, limitations such as stability and bioavailability problems, chemical degradation reactions during storage, and sensitivity to oxidation and photo-oxidation, need to be overcome using, for example, nanoencapsulation techniques. Here we summarize recent advances in all steps of marine products identification and purification and highlight selected human applications, including food and feed applications, cosmetic, human health, and fertilizers, among others.

Evaluation of Antidiabetic Activity of Sargassum tenerrimum in Streptozotocin-Induced Diabetic Mice

Diabetes mellitus has become the most predominant disease in most of the developing and developed countries. Diabetes could occur at any stage of life for which a change in sedentary life style is the possible solution. Despite the introduction of several medications, to curtail the side effects associated with diabetes mellitus, there is no medication or treatment for complete cure. Existing medications and treatments are targeted to mitigate the intensity of the disease which abruptly could result in organ failure. Rather than the available types of treatments, natural medication is reported to produce commendable results. Extracts of many medicinal plants and seaweeds have been documented to possess anti-diabetic properties. A brown alga, S. tenerrimum, found on the west coast of India, is chosen in this study to analyse the anti-diabetic property of its methanolic extract. This extract was used to treat streptozotocin-induced diabetic mice. An experimental design was framed based on acute toxicity studies to determine the change in blood glucose level, body weight, lipid profile, liver enzymes (SGPT and SGOT) and the renal function markers (urea and creatinine). After 15 days of treatment, an increase in body weight and HDL cholesterol was observed while the total cholesterol, VLDL, LDL, serum triglyceride, SGOT, SGPT, creatinine and urea decreased with 250 mg/Kg.bw of S. tenerrimum methanolic extract in Streptozotocin-induced diabetic mice group. This difference is significant (p<0.05) when compared with a healthy non-diabetic mice group and a treated diabetic mice group. This proves that the methanolic extract of S. tenerrimum possess anti-diabetic property. Further research could explore the active compounds that can be used in the formulation of herbal medicine for diabetes mellitus.

Dual Targeting of PTP1B and Aldose Reductase with Marine Drug Phosphoeleganin: A Promising Strategy for Treatment of Type 2 Diabetes

An in-depth study on the inhibitory mechanism on protein tyrosine phosphatase 1B (PTP1B) and aldose reductase (AR) enzymes, including analysis of the insulin signalling pathway, of phosphoeleganin, a marine-derived phosphorylated polyketide, was achieved. Phosphoeleganin was demonstrated to inhibit both enzymes, acting respectively as a pure non-competitive inhibitor of PTP1B and a mixed-type inhibitor of AR. In addition, in silico docking analyses to evaluate the interaction mode of phosphoeleganin with both enzymes were performed. Interestingly, this study showed that phosphoeleganin is the first example of a dual inhibitor polyketide extracted from a marine invertebrate, and it could be used as a versatile scaffold structure for the synthesis of new designed multiple ligands.

Pressurized Hot Liquid Extraction with 15% v/v Glycerol-Water as An Effective Environment-Friendly Process to Obtain Durvillaea incurvata and Lessonia spicata Phlorotannin Extracts with Antioxidant and Antihyperglycemic Potential

Brown seaweed phlorotannins have shown the potential to promote several health benefits. Durvillaea incurvata and Lessonia spicata-species that are widely distributed in central and southern Chile-were investigated to obtain phlorotannin extracts with antioxidant and antihyperglycemic potential. The use of an environmentally friendly and food-grade glycerol-based pressurized hot liquid extraction (PHLE) process (15% v/v glycerol water) was assessed for the first time to obtain phlorotannins. Multiple effects were analyzed, including the effect of the species, harvesting area (Las Cruces and Niebla), and anatomical part (holdfast, stipe, and frond) on the extracts' polyphenol content (TPC), antioxidant capacity (AC), and carbohydrate-hydrolyzing enzyme-α-glucosidase and α-amylase-inhibitory activity. Contaminants, such as mannitol, heavy metals (As, Cd, Pb, Hg, and Sn), and 5-hydroxymethylfurfural (HMF), were also determined. The anatomical part used demonstrated a significant impact on the extracts' TPC and AC, with holdfasts showing the highest values (TPC: 95 ± 24 mg phloroglucinol equivalents/g dry extract; DPPH: 400 ± 140 μmol Trolox equivalents/g dry extract; ORAC: 560 ± 130 μmol TE/g dry extract). Accordingly, holdfast extracts presented the most potent α-glucosidase inhibition, with D. incurvata from Niebla showing an activity equivalent to fifteen times that of acarbose. Only one frond and stipe extract showed significant α-glucosidase inhibitory capacity. No α-amylase inhibition was found in any extract. Although no HMF was detected, potentially hazardous cadmium levels (over the French limit) and substantial mannitol concentrations-reaching up to 50% of the extract dry weight-were found in most seaweed samples and extracts. Therefore, further purification steps are suggested if food or pharmaceutical applications are intended for the seaweed PHLE extracts obtained in this study.

Potential applications of alginate oligosaccharides for biomedicine - A mini review

Extensive research on marine algae, especially on their health-promoting properties, has been conducted. Various ingredients with potential biomedical applications have been discovered and extracted from marine algae. Alginate oligosaccharides are low molecular weight alginate polysaccharides present in cell walls of brown algae. They exhibit various health benefits such as anti-inflammatory, anti-microbial, anti-oxidant, anti-tumor and immunomodulation. Their low-toxicity, non-immunogenicity, and biodegradability make them an excellent material in biomedicine. Alginate oligosaccharides can be chemically or biochemically modified to enhance their biological activity and potential in pharmaceutical applications. This paper provides a brief overview on alginate oligosaccharides characteristics, modification patterns and highlights their vital health promoting properties.

Using polyphenols as a relevant therapy to diabetes and its complications, a review

Diabetes is currently a worldwide health concern. Hyperglycemia, hypertension, obesity, and oxidative stress are the major risk factors that inevitably lead to all the complications from diabetes. These complications severely impact the quality of life of patients, and they can be managed, reduced, or even reverted by several polyphenols, plant extracts and foods rich in these compounds. The goal of this review is to approach diabetes not as a single condition but rather an interconnected combination of risk factors and complications. This work shows that polyphenols have multi target action and effects and they have been systematically proven to be relevant in the reduction of each risk factor and improvement of associated complication.

Antidiabetic and antioxidant activity of phlorotannins extracted from the brown seaweed Cystoseira compressa in streptozotocin-induced diabetic rats

Diabetes mellitus is considered a set of diseases that lead to high glucose level due to the absolute or relative absence of insulin. The study investigated the antioxidant activity and antidiabetic effect of phlorotannins extracted from brown seaweed Cystoseira compressa. Phlorotannins were extracted from C. compressa. It was confirmed by 2,4 dimethoxy benzaldehyde assay (DMBA), ultraviolet spectra, Fourier transform infrared spectroscopy, and ultra performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS). The free radical scavenging activity of phlorotannins was estimated by total antioxidant capacity, 1,1-diphenyl-2-picrylhydrazyl radical-scavenging activity, and 2,2 azino-bis3-ethylbenthiazoline-6-sulfonic acid assays. Four groups of albino rats used in this study include control normal, control phlorotannins extract, diabetic by intraperitoneally administering of streptozotocin, and diabetic treatment with 60 mg/kg of phlorotannin extract after 4 weeks of diabetes induction. The main compound identified by UPLC-MS/MS in C. compressa extract belonged to the fuhalol. C. compressa extract showed high antioxidant properties. Phlorotannins significantly decreased serum glucose, liver malondialdehyde, and α-amylase, glucosidase activities. However, total antioxidant capacity, serum insulin, hepatic glutathione, and AMPKα2 expression in skeletal muscle were improved compared to the diabetic group. The histopathological examination showed that phlorotannins markedly reduced damage in β cells of pancreases. Phlorotannins from C. compressa have efficient antioxidant activity and the antidiabetic effect that may be utilized in human health.

Brown Algae Potential as a Functional Food against Hypercholesterolemia: Review

Brown algae have been part of the human diet for hundreds of years, however, in recent years, commercial and scientific interest in brown algae has increased due to the growing demand for healthier diet by the world population. Brown algae and its metabolites, such as carotenoids, polysaccharides, phlorotannins, and proteins, have been associated with multiple beneficial health effects for different diseases, such as cardiovascular diseases, one of the main causes of death in Europe. Since high blood cholesterol levels are one of the major cardiovascular risks, this review intends to provide an overview of current knowledge about the anti-hypercholesterolemic effect of different brown algae species and/or their isolated compounds.

Bioactive Properties of Marine Phenolics

Phenolic compounds from marine organisms are far less studied than those from terrestrial sources since their structural diversity and variability require powerful analytical tools. However, both their biological relevance and potential properties make them an attractive group deserving increasing scientific interest. The use of efficient extraction and, in some cases, purification techniques can provide novel bioactives useful for food, nutraceutical, cosmeceutical and pharmaceutical applications. The bioactivity of marine phenolics is the consequence of their enzyme inhibitory effect and antimicrobial, antiviral, anticancer, antidiabetic, antioxidant, or anti-inflammatory activities. This review presents a survey of the major types of phenolic compounds found in marine sources, as well as their reputed effect in relation to the occurrence of dietary and lifestyle-related diseases, notably type 2 diabetes mellitus, obesity, metabolic syndrome, cancer and Alzheimer's disease. In addition, the influence of marine phenolics on gut microbiota and other pathologies is also addressed.