Evaluation of phenolic contents and antioxidant activities of brown seaweeds belonging to Turbinaria spp. (Phaeophyta, Sargassaceae) collected from Gulf of Mannar

In vitro anticancer, antioxidant and antibacterial activities of crude extract prepared from Enteromorpha intestinalis habited in Jeddah, Saudi Arabia

The recent study purposes to evaluate the biological activities of Enteromorpha intestinalis gathered from Jeddah coastal area, Saudi Arabia, with respect to its phytochemical components. Our results indicated that the values ​​of moisture content, ash, total organic matter, total proteins, total lipids and total carbohydrates were 34.25 ± 5.6 %, 40.70 ± 2.3 %, 25.05 ± 1.73 %, 14.39 ± 0.8 %, 4.86 ± 6.9 % and 2.81 ± 1.4 %, respectively. The data also showed that the total phenols and flavonoids were 345.04 ± 1.50 and 320.67 ± 0.92 mg/g in the dried sample, respectively. Furthermore, four compounds were detected by HPLC at very low concentrations (quinic acid, ellagic acid, cinnamic acid, and phenanthrene) and flavonoids data confirmed the presence of apeginin, rudin, diosmin, and quercilin at high concentrations of 141.26, 11.42, 121.75, and 145.28. mg/g, respectively. The crude extract of Enteromorpha intestinalis exhibited cytotoxicity toward hepatocellular carcinoma cells (HepG-2 cell line) using an MTT assay with concentration range between 2 and 500 µg/mL for 48 h with IC50 = 40.02 ± 3.94 µg/mL. Evidently, the Enteromorpha intestinalis extract had Hepatoprotective activity with IC50 = 447.31 ± 14.59 μg/mL. The IC50 activity of a crude methanol extract of Enteromorpha intestinalis was compared with that of an antioxidant drug (Torolox). The value (98.82 ± 1.30 μg/mL) was recorded close to Torolox (62.4 ± 0.70 μg/mL). This extract also possessed moderate antibacterial activity with inhibition zones ranging between 10 mm against Pseudomonas aeruginosa to 16 mm against Escherichia coli. Green seaweed, along with other types of seaweed, has received significant attention in recent years. Despite their potential benefits, green seaweeds are underutilized in many parts of the world. Extensive studies on different green seaweed isolates and extracts are necessary.

Potential of the Ethyl Acetate Fraction of Padina boergesenii as a Natural UV Filter in Sunscreen Cream Formulation

Brown seaweeds, due to their wide range of bioactive compounds, have a high ability to inhibit free radicals and protect against ultraviolet rays. In the present study, the ethyl acetate fraction (EF) was isolated from the Padina boergesenii brown seaweed. Antioxidant activity (by the DPPH scavenging activity method) and cytotoxicity against UVB-induced cytotoxicity in HaCaT human keratinocytes were evaluated. Then, this fraction was used as a bio-filter in the formulation of sunscreen, and the physical properties and stability were investigated. The results showed that the EF could inhibit DPPH radical scavenging (54 ± 1%) and cell viability of HaCaT keratinocytes exposed to UVB irradiation (81.2 ± 0.1%). The results of the stability study of the cream formulated with EF showed that at temperatures 4 °C and 25 °C it has high stability; and at 40 °C on the 28th day, a slight decrease in its stability was observed. The pH and Sun Protection Factor of the cream formulated with EF were reported at 5.8 and 20.55, respectively. Also, the DPPH scavenging activity of the cream was not altered for 28 days of storage at temperatures of 4-40 °C. According to our results, it was proved that the sunscreen formulated with EF of P. boergesenii brown seaweed has promising properties and characteristics that can create a new opportunity for the development of cosmetics and skin care products.

Phytochemical and Potential Properties of Seaweeds and Their Recent Applications: A Review

Since ancient times, seaweeds have been employed as source of highly bioactive secondary metabolites that could act as key medicinal components. Furthermore, research into the biological activity of certain seaweed compounds has progressed significantly, with an emphasis on their composition and application for human and animal nutrition. Seaweeds have many uses: they are consumed as fodder, and have been used in medicines, cosmetics, energy, fertilizers, and industrial agar and alginate biosynthesis. The beneficial effects of seaweed are mostly due to the presence of minerals, vitamins, phenols, polysaccharides, and sterols, as well as several other bioactive compounds. These compounds seem to have antioxidant, anti-inflammatory, anti-cancer, antimicrobial, and anti-diabetic activities. Recent advances and limitations for seaweed bioactive as a nutraceutical in terms of bioavailability are explored in order to better comprehend their therapeutic development. To further understand the mechanism of action of seaweed chemicals, more research is needed as is an investigation into their potential usage in pharmaceutical companies and other applications, with the ultimate objective of developing sustainable and healthier products. The objective of this review is to collect information about the role of seaweeds on nutritional, pharmacological, industrial, and biochemical applications, as well as their impact on human health.

Spirornatas A-C from brown alga Turbinaria ornata: Anti-hypertensive spiroketals attenuate angiotensin-I converting enzyme

Bioactive compounds with angiotensin-I converting enzyme attenuation potential are deemed as therapeutic agents for hypertension owing to their capacity to suppress the conversion of angiotensin-I into the vasoconstrictor angiotensin-II. In an aim to develop natural angiotensin-I converting enzyme (ACE-I) inhibitors from marine algae, three 6, 6-spiroketals, spirornatas A-C were isolated from the organic extract of the spiny brown marine macroalga Turbinaria ornata (Turner) (family Sargassaceae). Spirornata A exhibited comparatively greater ACE-I attenuation potential (IC50 4.5 μM) than those displayed by other studied spiroketals (IC50 4.7-4.9 μM), and its activity was comparable to the ACE inhibitory agent captopril (IC50 4.3 μM). Greater antioxidant properties of spirornata A against oxidants (IC50 1.1-1.3 mM) also substantiated its potential attenuation property against ACE-I. Structure-activity correlation studies showed that electronic properties (topological polar surface area, 71) and balanced hydrophilic-lipophilic parameters (partition coefficient of logarithmic octanol-water ∼3.2) of spirornata A appeared to play pivotal roles in the inhibition of the targeted enzyme. Predicted drug-likeness and other physicochemical parameters appeared to attribute to the acceptable oral bioavailability of spiroketal derivatives. Additionally, the least binding energy of spirornata A with ACE-I (-10.5 kcal/mol) coupled with the maximum number of hydrogen-bonding interactions with allosteric sites of the zinc-dependent dicarboxypeptidyl peptidase could recognize its potential therapeutic application against hypertensive diseases.

The genus Turbinaria: chemical and pharmacological diversity

The Genus Turbinaria is still chemically and pharmacologically underexplored. These brown algae belong to the family Sargassaceae. Therapeutic potentials of pure compounds isolated from the Genus Turbinaria are extraordinarily promising as antiproliferative, antipyretic, anti-inflammatory immunostimulatory, anti-diabetic, anti-obesity, antiviral, antimicrobial, cardioprotective, hepatoprotective and hypolipidemic. Those activities are represented by diverse classes of compounds including sterols, amino acids, fatty acids, alcohols, halocarbons, hydrocarbons, carbohydrates, esters and cyclic tetrapyrrole compounds. This review focuses on the Genus Turbinaria during the period 1972 to 2019.

Nutritional Profile, Antioxidative and Antihyperglycemic Properties of Padina tetrastromatica from Tioman Island, Malaysia

Seaweeds are an important ingredient of functional foods recommended for daily food, due to their unique compositions and nutritional value. Padina tetrastromatica is a brown edible seaweed that is commonly found along the coastal regions of Peninsular Malaysia and consumed as food by some coastal communities. This study investigates the nutritional and antihyperglycaemic potential of P. tetrastromatica extracts, which is generally accepted as an important functional food. In our methodology, we induced diabetes intraperitoneally in experimental animals with a dose of 65 mg kg-1 body weight of streptozotocin. Oral treatment with 200 and 400 mg kg-1 of P. tetrastromatica ethanolic and ethyl acetate extracts were initiated, respectively, to experimental rats once daily for 18 days. Metformin was used as the positive control. Biochemical estimations and histopathological analysis were included in this study. Treatment with P. tetrastromatica extracts significantly lowered the plasma glucose levels in Streptozotocin-induced diabetic rats. In addition, P. tetrastromatica extract treatment also showed a significant reduction in serum alanine transaminase levels. However, no significant changes were observed in serum aspartate transaminase levels. The ethyl acetate extract of P. tetrastromatica at 400 mg kg-1 dose shows some nephroprotective effect, which is observed from the significant increase in the plasma albumin levels. Histopathological evaluation revealed no marked morphological changes in tissues of the isolated organs of the ethyl acetate extract-treated group, revealing the safe nature of P. tetrastromatica.

Protective Effect of Red Algae (Rhodophyta) Extracts on Essential Dietary Components of Heat-Treated Salmon

Salmon paste contains nutritious components such as essential fatty acids (EPA, DHA), vitamin E and astaxanthin, which can be protected with the addition of red algae extracts. Phenolic extracts were prepared with an ethanol: water mixture (1:1) from the red seaweeds Gracilaria chilensis, Gelidium chilense, Iridaea larga, Gigartina chamissoi, Gigartina skottsbergii and Gigartina radula, obtained from the Pacific Ocean. Most algae had a high content of protein (>7.2%), fiber (>55%) and β-glucans (>4.9%), all expressed on a dry weight basis. Total polyphenols (TP), total flavonoids (TF), antioxidant (DPPH, FRAP) and antibacterial power of the extracts were measured. In addition, the nutritional components of the algae were determined. Results showed that the content of TP in the six algae varied between 2.6 and 11.3 mg EAG/g dw and between 2.2 and 9.6 for TF. Also, the extracts of G. skottsbergii, G. chamissoi, G. radula and G. chilensis showed the highest antiradical activity (DPPH, FRAP). All samples exhibited a low production of primary oxidation products, and protection of the essential components and the endogenous antioxidants tocopherols and astaxanthin, particularly in the case of G. skottsbergii, G. chamissoi, G. radula and G. chilensis. Furthermore, all algae had inhibitory activity against the tested microorganisms, coincident with their antioxidant capacity. Results show that the extracts may have future applications in the development and preservation of essential dietary components of healthy foods.

Extraction of chlorophyll and carotenoids loaded into chitosan as potential targeted therapy and bio imaging agents for breast carcinoma

In the current study, the treatment efficacy of ECHCAH was evaluated in vitro studies using cell viability and flow cytometry in human TNBCs. The results here showed significant gradual reduction in growth of TNBCs (MDA-231cell lines) after their exposure to serial concentrations for hydrogel assembly (5 μg/mL to 25 μg/mL) for 24 and 48 h, representing (86 ± 1% to 45 ± 1.5% p < 0.001) and (79 ± 1.5% to 35 ± 2.5% p < 0.001) respectively. The flow cytometry showed significant increase in the present of late apoptotic and necrotic cells (64% ± 1.2 and 27% ± 0.3 p < 0.001) after 48 h incubation compared to untreated cells (1.13% ± 0.3 and 4% ± 0.2 p < 0.001) respectively. It can be summarized that ECHCA inside targeted hydrogel assemblies can inhibit proliferation of cancer cells.

Sulfated polysaccharide from Turbinaria ornata suppress lipopolysaccharide-induced inflammatory response in RAW 264.7 macrophages

BACKGROUND

Marine macroalgae known for its polysaccharides exhibit potent biomedical properties and its potential as an anti-inflammatory agent has increased in the recent past as inflammation is a major pathology noted in many chronic diseases.

PURPOSE

The present study investigates the anti-inflammatory potential of a sulfated polysaccharide (PS) isolated from the marine algae Turbinaria ornata collected from the Indian waters on LPS induced inflammation in RAW 264.7 macrophages.

STUDY DESIGN AND METHODS

PS isolated from the macroalgae was characterized using ESI(MS) and was screened for its antioxidant and anti-inflammatory potential in RAW 264.7 cells by assessing markers of oxidative stress, and inflammation.

RESULTS

LPS significantly increased the levels of LPO and LDH in RAW 264.7 cells which were significantly reduced in PS pre-treatment groups. Pretreatment significantly increased the antioxidants GSH and SOD and significantly reduced mRNA levels of IL6 and TNFα in vitro confirming its anti-inflammatory potential. NFκB and iNOS were significantly modulated by PS confirming the probable mode of action.

CONCLUSION

Altogether, it can be concluded that PS isolated from Turbinaria ornata collected from the Southeast Coast of India exhibits antioxidant and anti-inflammatory potential probably mediated by the sulfated polysaccharide containing glucopyranose and fucopyranose moieties.

Bioprospecting of seaweeds (Ulva lactuca and Stoechospermum marginatum): The compound characterization and functional applications in medicine-a comparative study

Seaweeds are considered to be one of the richest bio-reserves, comprising of numerous bioactive compounds with versatile properties and multiple activities. The present study examined the antibacterial activity of two types of seaweeds, Ulva lactuca (green) and Stoechospermum marginatum (brown) collected from Oman Coastal region against five multidrug-resistant bacteria. The aqueous extracts of the seaweeds showed better antibacterial activity compared to methanol extracts. The results of the antibacterial assay revealed the excellent inhibitory effects of U.lactuca with the maximum activity against E.coli(8 mm) followed by K.pneumonia(4 mm) and S.typhi(2 mm). S.marginatum formed a clear zone of inhibition only against E.coli(3 mm).The major phytochemical constituents identified in both the types of seaweeds were Alkaloids, Terpenoids, Saponins, Flavonoids, and Steroids. Fourier transform infrared spectroscopy (FTIR) results confirmed the presence of alcoholic/phenolic groups, and amide groups in the seaweed extracts. Gas chromatography-mass spectrometry (GC-MS) results evidenced the presence of bioactive compounds such as 5-Octadecenal, 1-Tricosanol, Neophytadiene, Lactaropallidin, Phytol, Fenretinide, Lucenin, Vincadifformine in U.lactuca. Additionally, U.lactuca displayed better antioxidant activity (33.05%) in the DPPH free radical scavenging activity test compared to the S.marginatum (21.51%). Thus, the green seaweed U.lactuca could be considered as a potential source of natural antioxidant and antibacterial agents for food and pharmaceutical products.

Unravelling the potential of seaweeds from the Black Sea coast of Romania as bioactive compounds sources. Part I: Cystoseira barbata (Stackhouse) C. Agardh

The Romanian coastlines of the Black Sea have abundant seaweed resources, but little effort has been done to investigate their biological potential. The aim of the present study was to assess the in vitro antioxidant and anti-proliferative effects of Cystoseira barbata (Stackhouse) C. Agardh (Sargassaceae), a brown alga inhabiting the Black Sea coast of Romania. The 70% acetone, methanol and water extracts of C. barbata were evaluated for their total phenolic content, antioxidant activity and anti-proliferative potential against human tumor cell lines (pulmonary A549, colon HT-29, mammary MCF-7) and the non-tumor mammary epithelial MCF-10A cell line. C. barbata 70% acetone extract (CBAE) displayed the highest antioxidant and cytotoxic activities. The mechanism of CBAE anti-proliferative activity involved initially increased intracellular ROS accumulation, followed by increased DNA content in the subG1 phase and DNA fragmentation leading to excessive apoptosis. Thus, our study provides a theoretical basis for the use of CBAE as a tumor preventive agent. Furthermore, UHPLC-DAD-QTOF-MS analysis of CBAE tentatively identified 18 phlorotannins as fucophlorethol and eckol derivatives, containing three up to seven phloroglucinol units. In conclusion, C. barbata represents a valuable source for the development of macroalgal-based products with putative use as nutraceuticals and pharmaceuticals.

Phenolic Content of Brown Algae (Pheophyceae) Species: Extraction, Identification, and Quantification

Over the last few decades, isolations and chemical characterizations of secondary metabolites with proved biological activities have been of interest for numerous research groups across the world. Phenolics, as one of the largest and most widely distributed group of phytochemicals, have gained special attention due to their pharmacological activity and array of health-promoting benefits. Reports on phenolic potentials of marine algae, especially brown algae (Pheophyceae) that are characterized by the presence of phlorotannins, are still scarce. The aim of this review paper is to provide an overview of current knowledge about phenolic potential of different brown algae species (74 species from 7 different orders). Studies on brown algae phenolics usually involve few species, thus the focus of this review is to provide information about the phenolic potential of reported algae species and to get an insight into some issues related to the applied extraction procedures and determination/quantification methods to facilitate the comparison of results from different studies. The information provided through this review should be useful for the design and interpretation of studies investigating the brown algae as a source of valuable phytochemicals.

OPTIMIZATION OF EXTRACTION PARAMETERS FOR FUCOXANTHIN, GALLIC ACID AND RUTIN FROM NITZSCHIA THERMALIS

Recently, microalgae have become important in their health, and cosmetic applications since they are viewed as new sources of carotenoids. Fucoxanthin is also a type of carotenoid. The anti-diabetic, anti-obesity, anti-cancer, and antioxidant properties of fucoxanthin have been widely reported. Since these valuable properties, they also represent a valuable resource of nutraceuticals for functional food applications. This study aims to determine the amount of fucoxanthin, gallic acid, and rutin in Nitzschia thermalis obtained from the Ege University Microalgae Culture Collection. The extraction parameters have been optimized using response surface methodology. The extraction temperature (25, 35, and 45°C), the extraction time (10, 20, and 30 min) and the biomass/solvent ratio (0.005, 0.001, and 0.015 g ml-1) have been assessed as response variables in the Box – Behnken design. The amount of fucoxanthin was determined by the C30 column at 450 nm, while both the amount of gallic acid and rutin were separated in the C18 column at 275 nm by HPLC-DAD. In the present study, the optimum extraction conditions providing the maximum amount of fucoxantin, gallic acid, and rutin were selected by applying the “desirability” function approach in response surface methodology. Finally, the temperature has been determined to be 27.30°C, the extraction time 10 minutes, and the biomass ratio 0.05 g ml-1. Under these conditions, the optimum fucoxanthin level has been determined as 5.8702 mg g-1, the gallic acid level as 0.0140 mg g-1, and the rutin level as 0.0496 mg g-1. The findings are in good agreement with international published values for fucoxanthin content. In addition, response surface methodology was shown to be an effective technique for optimising extraction conditions for maximum fucoxanthin yield. In conclusion, these findings may be applied in the development of extraction methodologies for value added microalgea products as well as can serve as a reference for the extraction of fucoxanthin having high gallic acid and rutin from other brown microalgae, and therefore it could potentially be applied in both pharmaceutical and food industries.

In Vivo Evaluation of the Antioxidant Activity and Protective Action of the Seaweed Gracilaria birdiae

The red seaweed Gracilaria birdiae (GB) is farmed and used as food in northeast Brazil. However, the economic potential of this seaweed has been explored little. To enable direct consumption and/or product diversification from GB, it is necessary to evaluate its effect in vivo. In this study, the food of mice was improved with the addition of GB. After 21 days, the consumption of seaweed reduced the weight gain and blood glucose levels in mice. In addition, it increased the trolox equivalent antioxidant capacity and glutathione reductase and catalase levels compared to those of the control group. In addition, some mice also received carbon tetrachloride (CCl4). In this case, histological, enzymatic, and antioxidant tests showed that the seaweed could protect animals from damage caused by this toxic agent. In addition, GB aqueous extract (AE) inhibited 50% of 3T3-L1 cell differentiation into adipocytes, whereas GB ethanolic extract was not effective. AE is composed mainly of sulfated polysaccharides. The results of the present study indicate that the alga GB protected the mice from CCl4-induced damage, indicating that the seaweed exhibits protective action in vivo. In addition, GB decreased the animal weight gain, which was mainly due to the action of the sulfated polysaccharides synthesized by this seaweed.

An emerging trend in functional foods for the prevention of cardiovascular disease and diabetes: Marine algal polyphenols

Marine macroalgae are gaining recognition among the scientific community as a significant source of functional food ingredients. Due to the harsh environments in which macroalgae survive, they produce unique bioactive compounds that are not found in terrestrial plants. Polyphenols are the predominant bioactive compound in brown algae and are accountable for the majority of its biological activity. Phlorotannins are a type of polyphenol that are unique to marine sources and have exhibited protective effects against hyperglycemia, hyperlipidemia, inflammation and oxidative stress, known risk factors for cardiovascular disease and diabetic complications, in cell culture, animal studies and some human studies. This review updates the information on marine polyphenols, with a particular focus on phlorotannins and their potential health benefits in relation to the prevention and treatment of risk factors for type 2 diabetes and cardiovascular diseases.

Valuable natural products from marine and freshwater macroalgae obtained from supercritical fluid extracts

The biologically active compounds (fatty acids, pigments, phenolics, and flavonoid content) were studied in supercritical fluid extracts from the biomass of marine (Ulva clathrata, Cladophora glomerata, Polysiphonia fucoides, and their multi-species mixture) and freshwater (C. glomerata) macroalgae. Different extraction techniques were used in order to compare differences in the biologically active compound composition of the macroalgal extracts. The results indicated that the saturated and unsaturated fatty acids ranged from C9:0 to C22:0. The analysis of differences in the composition of unsaturated to saturated fatty acids in extracts showed that palmitic acid (C16:0) and oleic acid (C18:1, n-9) reached the highest value not only in marine monospecies and multi-species biomass but also in the freshwater macroalga C. glomerata. When comparing the similarity between the concentration of fatty acids and the ratio of the concentration of unsaturated fatty acids to saturated in macroalgal extracts, we found small but not statistically significant variations in values between years (up to 10%). This is acceptable for applications as a stable raw material for industrial purposes. Significantly higher values of fatty acids, carotenoids, and chlorophylls were obtained in the case of SC-CO2 extraction. The active ingredients of polyphenols, possessing antioxidant activity ranged from approximately 2-4%. Moreover, flavonoids represented less than 10% of the total content of polyphenolic compounds. The extraction efficiency of polyphenols was higher from a mixture of marine algae for the ultrasound-assisted extraction compared to freshwater. All these findings show that marine and freshwater macroalgae, as a raw material, have the optimal biologically active compounds composition for cosmetics.

Malaysian brown seaweeds Sargassum siliquosum and Sargassum polycystum: Low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase inhibition activities

Two Malaysian brown seaweeds, Sargassum siliquosum and Sargassum polycystum were first extracted using methanol to get the crude extract (CE) and further fractionated to obtain fucoxanthin-rich fraction (FRF). Samples were evaluated for their phenolic, flavonoid, and fucoxanthin contents, as well as their inhibitory activities towards low density lipoprotein (LDL) oxidation, angiotensin converting enzyme (ACE), α-amylase, and α-glucosidase. In LDL oxidation assay, an increasing trend in antioxidant activity was observed as the concentration of FRF (0.04-0.2mg/mL) and CE (0.2-1.0mg/mL) increased, though not statistically significant. As for serum oxidation assay, significant decrease in antioxidant activity was observed as concentration of FRF increased, while CE showed no significant difference in inhibitory activity across the concentrations used. The IC50 values for ACE inhibitory activity of CE (0.03-0.42mg/mL) were lower than that of FRF (0.94-1.53mg/mL). When compared to reference drug Voglibose (IC50 value of 0.61mg/mL) in the effectiveness in inhibiting α-amylase, CE (0.58mg/mL) gave significantly lower IC50 values while FRF (0.68-0.71mg/mL) had significantly higher IC50 values. The α-glucosidase inhibitory activity of CE (IC50 value of 0.57-0.69mg/mL) and FRF (IC50 value of 0.50-0.53mg/mL) were comparable to that of reference drug (IC50 value of 0.54mg/mL). Results had shown the potential of S. siliquosum and S. polycystum in reducing cardiovascular diseases related risk factors following their inhibitory activities on ACE, α-amylase and α-glucosidase. In addition, it is likelihood that FRF possessed antioxidant activity at low concentration level.

Structural characterization and evaluation of mosquito-larvicidal property of silver nanoparticles synthesized from the seaweed, Turbinaria ornata (Turner) J. Agardh 1848

The silver nanoparticles synthesized from Turbinaria ornata (To-AgNPs) showed spherical with crystalline nature (20-32 nm) was evaluated against fourth instar larvae of three mosquitoes. The maximum activity of To-AgNPs was recorded on Aedes aegypti followed by Anopheles stephensi and Culex quinquefasciatus with the following lethal concentration values (μg/ml): LC50 of 0.738, 1.134, and 1.494; and LC90 of 3.342, 17.982, and 22.475, respectively. The obtained respective values (μg/ml) vis-a-vis aqueous extract (To-AE) were: 2.767 and 40.577; 4.347 and 158.399, and 7.351 and 278.994. The findings revealed that To-AgNPs could form a base for the development of an eco-friendly, low-cost pesticide.

Anti-stress activity of Sargassum polycystum extracts using a cold restraint stress model

Anti-stress effects of polyphenol extracts of Sargassum polycystum were evaluated. Polyphenol extracts of S. polycystum and diazepam were compared for anti-stress activities using a cold restraint animal stress model. S. polycystum extracts were administered orally at dosages of 150 and 450 mg/kg. Diazepam, an anti-stress agent, was used as a standard drug at 0.18 mg/kg p.o. Both dosages of S. polycystum extracts showed good anti-stress effects. Due to cold restraint stress there was an imbalance in levels of biochemical parameters, including glucose, triglycerides, cholesterol, alkaline phosphatase (ALP), alanine aminotransferase (ALT), and aspartate amino transferase (AST), which were near normalized following adminstration of S. polycystum extracts. Polyphenol extracts of S. polycystum at oral dosages of 150 and 450 mg/kg exerted anti-stress effects.

Looking Beyond the Terrestrial: The Potential of Seaweed Derived Bioactives to Treat Non-Communicable Diseases

Seaweeds are a large and diverse group of marine organisms that are commonly found in the maritime regions of the world. They are an excellent source of biologically active secondary metabolites and have been shown to exhibit a wide range of therapeutic properties, including anti-cancer, anti-oxidant, anti-inflammatory and anti-diabetic activities. Several Asian cultures have a strong tradition of using different varieties of seaweed extensively in cooking as well as in herbal medicines preparations. As such, seaweeds have been used to treat a wide variety of health conditions such as cancer, digestive problems, and renal disorders. Today, increasing numbers of people are adopting a "westernised lifestyle" characterised by low levels of physical exercise and excessive calorific and saturated fat intake. This has led to an increase in numbers of chronic Non-communicable diseases (NCDs) such as cancer, cardiovascular disease, and diabetes mellitus, being reported. Recently, NCDs have replaced communicable infectious diseases as the number one cause of human mortality. Current medical treatments for NCDs rely mainly on drugs that have been obtained from the terrestrial regions of the world, with the oceans and seas remaining largely an untapped reservoir for exploration. This review focuses on the potential of using seaweed derived bioactives including polysaccharides, antioxidants and fatty acids, amongst others, to treat chronic NCDs such as cancer, cardiovascular disease and diabetes mellitus.

Antioxidant activities and phenolic contents of three red seaweeds (Division: Rhodophyta) harvested from the Gulf of Mannar of Peninsular India

The antioxidant activities of methanol extract and its solvent fractions (n-hexane, dichloromethane and ethyl acetate) of three red seaweeds (Hypnea musciformis, H. valentiae, and Jania rubens) collected from the Gulf of Mannar of South eastern coast of India were evaluated, using different in vitro systems, viz., DPPH, ABTS, HO radical scavenging activities, H2O2 scavenging ability, Fe(2+) ion chelating ability and reducing potential. Folin-Ciocalteu method was used to determine the total phenolic content of the extracts/fractions, and the results were expressed as mg of gallic acid equivalent (GAE)/g of the seaweed extracts/fractions. Thiobarbituric acid-reactive substances (TBARS) inhibition assay was employed to assess the ability of the seaweed extracts/fractions to inhibit lipid oxidation. Ethyl acetate (EtOAc) fractions of H. musciformis exhibited significantly higher total phenolic content (205.5 mg GAE/g), DPPH· scavenging activity (IC50 0.6 mg/mL), ABTS(.+) scavenging activity (IC50 0.51 μg/mL), Fe(2+) chelating ability (IC50 0.70 mg/mL), H2O2 scavenging activity (IC50 0.39 mg/mL), reducing ability (Abs700 nm 1.46) and lipid peroxidation inhibitory ability (2.71 MDAEC/kg) (P < 0.05) compared to its n-hexane, DCM fractions, crude MeOH extract and MeOH extracts/fractions of H. valentiae and J. rubens. DCM fraction of J. rubens showed significantly higher hydroxyl radical scavenging activity (IC50 0.55 mg/mL) compared with H. musciformis and H. valentiae (P < 0.05). This study indicated the potential use of red seaweeds, in particular, H. musciformis as candidate species to be used as food supplement for increasing the shelf-life of food industry, and candidates in combating carcinogenesis and inflammatory diseases.