Metabolite Profiling, Biological and Molecular Analyses Validate the Nutraceutical Potential of Green Seaweed Acrosiphoniaorientalis for Human Health.

Seaweeds have proven to be nutrient-dense and are rich in antioxidants, like phenolics, flavonoids, and other essential metabolites that help to provide their medicinal benefits. Non-targeted metabolite profiling of the tropical green seaweed Acrosiphonia orientalis showed the presence of numerous groups of contents, including sugars, essential amino acids, and fatty acids. Targeted metabolite profiling using HPLC identified 17 amino acids. The extract exhibited a very low half-maximal effective concentration (EC50) dosage for HeLa and Huh-7 cell lines, indicating a high likelihood of anticancer properties. A significant positive correlation was found between biological activities, such as antioxidation, scavenging, and reducing power with the phenolic and flavonoid contents. The extract revealed augmentation of proliferation in selected cervical cells, as it upregulated p53 1.3-fold, and downregulated important cancerous genes such as Cas-3 and DNMT 12- and 8-fold, respectively. An approximate 55-fold downregulation was observed in selected hepatic cell lines. Microarray analysis of hepatic cells indicated 0.27% and 0.07% upregulation of coding and non-coding genes, respectively, and 0.41% and 0.13% downregulation of coding and non-coding genes, respectively. As a consequence, it can be said that A. orientalis has possible medicinal use, such as anticancer activity, and therefore may be an intriguing food component that has potential as a regular dietary supplement.

Differential Physio-Biochemical and Metabolic Responses of Peanut (Arachis hypogaea L.) under Multiple Abiotic Stress Conditions.

The frequency and severity of extreme climatic conditions such as drought, salinity, cold, and heat are increasing due to climate change. Moreover, in the field, plants are affected by multiple abiotic stresses simultaneously or sequentially. Thus, it is imperative to compare the effects of stress combinations on crop plants relative to individual stresses. This study investigated the differential regulation of physio-biochemical and metabolomics parameters in peanut (Arachis hypogaea L.) under individual (salt, drought, cold, and heat) and combined stress treatments using multivariate correlation analysis. The results showed that combined heat, salt, and drought stress compounds the stress effect of individual stresses. Combined stresses that included heat had the highest electrolyte leakage and lowest relative water content. Lipid peroxidation and chlorophyll contents did not significantly change under combined stresses. Biochemical parameters, such as free amino acids, polyphenol, starch, and sugars, significantly changed under combined stresses compared to individual stresses. Free amino acids increased under combined stresses that included heat; starch, sugars, and polyphenols increased under combined stresses that included drought; proline concentration increased under combined stresses that included salt. Metabolomics data that were obtained under different individual and combined stresses can be used to identify molecular phenotypes that are involved in the acclimation response of plants under changing abiotic stress conditions. Peanut metabolomics identified 160 metabolites, including amino acids, sugars, sugar alcohols, organic acids, fatty acids, sugar acids, and other organic compounds. Pathway enrichment analysis revealed that abiotic stresses significantly affected amino acid, amino sugar, and sugar metabolism. The stress treatments affected the metabolites that were associated with the tricarboxylic acid (TCA) and urea cycles and associated amino acid biosynthesis pathway intermediates. Principal component analysis (PCA), partial least squares-discriminant analysis (PLS-DA), and heatmap analysis identified potential marker metabolites (pinitol, malic acid, and xylopyranose) that were associated with abiotic stress combinations, which could be used in breeding efforts to develop peanut cultivars that are resilient to climate change. The study will also facilitate researchers to explore different stress indicators to identify resistant cultivars for future crop improvement programs.

Antioxidant, Scavenging, Reducing, and Anti-Proliferative Activities of Selected Tropical Brown Seaweeds Confirm the Nutraceutical Potential of Spatoglossum asperum.

Brown seaweeds have shown high potential of bioactivity and provide health benefits as an important functional food ingredient. Therefore, four abundantly growing tropical brown seaweeds-Iyengaria stellata, Spatoglossum asperum, Sargassum linearifolium, and Stoechospermum polypodioides-were collected from the Saurashtra Coast of the Arabian Sea. They were analyzed for metabolite profiling, biochemical activities (including total antioxidant, reducing, scavenging, and anti-proliferative characteristics), and total phenolic and flavonoid contents. A concentration-dependent antioxidant, reducing, and scavenging activities were observed for all four brown seaweeds. The S. asperum and I. stellata extracts showed maximum total antioxidant activity. S. asperum also showed high scavenging and reducing activities compared to other studied brown seaweeds. Further, S. asperum contained high total phenolic and flavonoid content compared to other brown seaweeds collected from the same coast. A multivariate correlation study confirmed a positive correlation between total phenolic and flavonoid contents, and biochemical activities (total antioxidant, scavenging and reducing) for all brown seaweeds. About 35% anti-proliferative activity was observed with S. asperum extract on Huh7 cells; in contrast S. polypodioide showed about 44% proliferation inhibition of Huh7 cells. Similarly, 26% proliferation inhibition of HeLa cells was observed with S. asperum extract. Overall, S. asperum possesses high total flavonoid and phenolic amounts, and showed potential antioxidant, scavenging and reducing characteristics. The study confirmed the nutraceutical potential of S. asperum and that it could be a promising functional food ingredient.

Anti-proliferative and ROS-inhibitory activities reveal the anticancer potential of Caulerpa species.

Seaweeds are considered a promising functional food and safe for human consumption as they have significant health benefits. Five abundant tropical seaweeds, Caulerpa racemosa var. macrophysa, Caulerpa scalpelliformis, Grateloupia indica, Sargassum linearifolium, and Spatoglossum asperum rich in metabolites, phenolic, and flavonoid compounds, were analyzed for the anti-proliferative and ROS inhibitory activities including transcript expression of cancer-linked key genes and apoptosis. C. racemosa var. macrophysa showed the maximum effective activities with a lower dose of extract, about 130 ± 30 and 23 ± 1 µg ml-1 EC50 dose for HeLa and Huh-7, respectively, followed by C. scalpelliformis, showing EC50 dose about 200 ± 10 and 140 ± 30 µg ml-1, respectively. Similarly, about 56% and 54% ROS inhibition were determined with Caulerpa spp. for HeLa and Huh-7 cells, respectively. Results indicated that tropical green seaweed Caulerpa spp. (C. racemosa var. macrophysa and C. scalpelliformis) have substantial potential of ROS inhibition. Further, it was observed that different cancer-linked marker proteins encoding genes were deferentially expressed with seaweed extracts in different cell lines. Overall, it is concluded that Caulerpa spp. are rich in antioxidant and anti-proliferative activities. Caulerpa spp. have potential to be explored further for cancer preventive properties or functional food or nutraceuticals applications.

Physicochemical, scavenging and anti-proliferative analyses of polysaccharides extracted from psyllium (Plantago ovata Forssk) husk and seeds.

Polysaccharides extracted from seeds and husk of psyllium were characterized for different physicochemical characteristics, and bioactivities. Extracted polysaccharides are comprised of d-xylose, l-arabinose, d-glucose, d-galactose, and l-rhamnose. Crude husk-polysaccharide was crystalline, whereas rest was amorphous in nature. Husk-polysaccharide was structurally stable, and purified fractions were thermostable. Crude polysaccharides were irregular in shape with non-porous smooth-surface, however purified husk-polysaccharides showed some porosity, and fibrous nature. Husk-polysaccharide showed higher viscosity compared to seed-polysaccharide, but viscosity decreased with the purification. Crude polysaccharides contained hydrogel-like behavior compared to corresponding purified fractions. The purified fractions of seed-polysaccharide showed the utmost antioxidant and scavenging activities with a half-maximal effective concentration of 347.40 ±â€¯1.79 and 362.72 ±â€¯2.75 µg, respectively. Crude seed-polysaccharide showed about 34% anti-proliferation on Huh-7, whereas its purified fractions showed 42% anti-proliferation on HeLa cell line. The study confirms that psyllium polysaccharides are potential natural antioxidant and anti-carcinogenic agent; however a detailed study is needed to explore psyllium for nutraceutical applications.

Nutraceutical Potential of Seaweed Polysaccharides: Structure, Bioactivity, Safety, and Toxicity.

In recent years, marine organisms including seaweeds have been highlighted as potential sources of useful metabolites and bioactive compounds, with vast biological and physiological activities. Seaweeds have long been used as a food source, for medicinal purposes, and as dietary supplements in various Asian countries, and their potential benefits have recently attracted the attention of many Western and European countries. Their commercial value depends on their applications in the food, nutraceutical, and pharmaceutical industries. Seaweeds are considered a potential source of nutraceuticals or functional foods, and analysis of taste-oriented motives has revealed that seaweeds are preferentially selected over other types of marine foods by seafood consumers and people with high levels of health, education, and living status. It is a general perception that health conscious people prefer environmentally friendly food sources, and present an opportunity to focus on seaweed-based foods, which have significant nutritional benefits to humans. Among the various bioactive constituents, seaweed polysaccharides have been proven to possess various beneficial properties including anticoagulant, anti-inflammatory, antioxidant, anticarcinogenic, and antiviral activities. The diversity and composition of seaweed polysaccharides play vital roles in these biological activities. Seaweeds are a rich source of sulfated polysaccharides, which are responsible for much of the bioactivity, as they can interact with various textures and cellular proteins. A number of toxicological assays and clinical trials suggest that the ingestion of seaweeds as functional foods should be considered worldwide to improve immune responses. In this review, different polysaccharides from seaweeds and their compositions and potential nutraceutical applications are discussed.

Physicochemical characterization, antioxidant and anti-proliferative activities of a polysaccharide extracted from psyllium (P. ovata) leaves.

Psyllium leaves polysaccharides were physicochemically characterized and evaluated for antioxidant, free-radical scavenging and anticancer activities. The polysaccharide comprised of arabinose, rhamnose, xylose, galactose, and glucose. FTIR and NMR study exhibited the presence of key functional groups whereas morphological study revealed that crude polysaccharides are aggregates of irregular shape, non-porous, and smooth surface, while the purified products are porous and fibrous in nature. Extracted polysaccharides were thermally stable and exhibited the characteristic diffraction curve with a higher viscosity and size distribution. Biochemical analyses demonstrated the higher antioxidant and scavenging activities. In vitro anticancer assay showed the maximum inhibitory effect about 33% on Huh7 and about 30% on HeLa cell lines. The study confirmed the presence of high antioxidant and free-radical scavenging activities with a potential anticancer activity. The polysaccharide could be developed as a potential natural antioxidant and anticancer agents after comprehensive studies on experimental animal models.

Metabolites Unravel Nutraceutical Potential of Edible Seaweeds: An Emerging Source of Functional Food.

Functional foods are nutritional compounds which also provide health and medicinal benefits. Daily food intake has much impact on the quality of life, and therefore inclusion of functional foods is now essential to our diet. Nutraceuticals are neither food nor drug but are added to food to provide extra nutritional and physiological properties. Though nutraceutical compounds provide minimal actions, their regular involvement in the diet can provide major and long-term health benefits. Global demand for additional and sustainable biomass for the production of important metabolites with nutraceutical potential has resulted in renewed interest in seaweeds. Seaweeds have been consumed from ancient times in Asian areas, and in recent times they have been demonstrated to possess many medicinal effects. Seaweeds are considered a rich source of various nutritional ingredients and metabolites that have pharmaceutical properties. It has been observed that total protein, from terrestrial plants such as soybean and wheat, produces an allergic response on consumption. Therefore, seaweed proteins can be considered a promising source for food industries. Overall, seaweeds are a rich source of PUFAs, metabolites, proteins, sulfated polysaccharides, vitamins, and minerals, which are all responsible for different bioactivities; they are therefore considered a promising functional food (nutraceutical). In this review we discuss the nutraceutical potential of seaweeds regarding different metabolites (primary and secondary), variation in composition, probable biological applications, limitations, research gaps, and future prospects.

Halophytes: Potential Resources for Salt Stress Tolerance Genes and Promoters.

Halophytes have demonstrated their capability to thrive under extremely saline conditions and thus considered as one of the best germplasm for saline agriculture. Salinity is a worldwide problem, and the salt-affected areas are increasing day-by-day because of scanty rainfall, poor irrigation system, salt ingression, water contamination, and other environmental factors. The salinity stress tolerance mechanism is a very complex phenomenon, and some pathways are coordinately linked for imparting salinity tolerance. Though a number of salt responsive genes have been reported from the halophytes, there is always a quest for promising stress-responsive genes that can modulate plant physiology according to the salt stress. Halophytes such as Aeluropus, Mesembryanthemum, Suaeda, Atriplex, Thellungiella, Cakile, and Salicornia serve as a potential candidate for the salt-responsive genes and promoters. Several known genes like antiporters (NHX, SOS, HKT, VTPase), ion channels (Cl-, Ca2+, aquaporins), antioxidant encoding genes (APX, CAT, GST, BADH, SOD) and some novel genes such as USP, SDR1, SRP etc. were isolated from halophytes and explored for developing stress tolerance in the crop plants (glycophytes). It is evidenced that stress triggers salt sensors that lead to the activation of stress tolerance mechanisms which involve multiple signaling proteins, up- or down-regulation of several genes, and finally the distinctive or collective effects of stress-responsive genes. In this review, halophytes are discussed as an excellent platform for salt responsive genes which can be utilized for developing salinity tolerance in crop plants through genetic engineering.