Microwave-assisted extraction and pharmacological evaluation of polysaccharides from Posidonia oceanica

A critical review on pharmacological properties of sulfated polysaccharides from marine macroalgae

The marine ecosystem contains an assorted range of organisms, among which macroalgae stands out marine resources as an invaluable reservoir of structurally diverse bioactive compounds. Marine macroalgae are considered as primary consumers have gained more attention for their bioactive components. Sulfated polysaccharides (SPs) are complex polymers found in macroalgae that play a crucial role in their cell wall composition. This review consolidates high-tech methodologies employed in the extraction of macroalgal SPs, offering a valuable resource for researchers focuses in the pharmacological relevance of marine macromolecules. The pharmacological activities of SPs, focusing on their therapeutic action by encompassing diverse study models are summarized. Furthermore, in silico docking studies facilitates a comprehensive understanding of SPs interactions with their binding sites providing a valuable insight for future endeavors. The biological properties of algal SPs, along with a brief reference to mode of action based on different targets are presented. This review utilizes up-to-date research discoveries across various study models to elucidate the biological functions of SPs, focusing on their molecular-level mechanisms and offering insights for prospective investigations. Besides, the significance of SPs from seaweeds is highlighted, showcasing their potential beneficial applications in promoting human health. With promising biomedical prospects, this review explores the extensive uses and experimental evidence supporting the important roles of SPs in various fields.

Chemical characterization and pharmacological properties of polysaccharides from Allium roseum leaves: In vitro and in vivo assays

Allium roseum is amongst the most important wild medicinal plants. It is known for its diverse biological properties, including antioxidant, antibacterial and antidiabetic activities. In this work, the polysaccharides (PARLs) were ultrasonically extracted from Allium roesum leaves then purified and analyzed by several techniques. Chemical composition and GC-MS analysis showed that the obtained polysaccharides were composed mainly of glucose (40.20 %), mannose (25.30 %), fructose (10.60 %) and galacturonic acid (15.11 %). Moreover, PARLs exhibited a potent antioxidant effect with higher capacities up to 69.61 % and 71.72 % for DPPH and ABTS free radicals, respectively. Furthermore, PARLs significantly modulated inflammatory response by reducing TNF-α, IL-6, and IL-8 pro-inflammatory mediators and promoting the anti-inflammatory IL-10 mediator in LPS stimulated THP-1 derived macrophages. The in-vivo tests proved that the extract was able to decrease carrageenan-induced rat paw swelling by around 68.15 % after 4 h of treatment. PARLs, significantly reduced the growth of U87 (glioblastoma) and IGROV-1 cancer cells with IC50 values of about 4.27 and 7.89 mg/mL respectively. This research clearly shows that Allium roseum polysaccharides can be used as natural antioxidants with anti-inflammatory and anticancer properties.

Structural Characterization of Polysaccharides from Coriandrum sativum Seeds: Hepatoprotective Effect against Cadmium Toxicity In Vivo

Coriandrum sativum is one of the most widespread curative plants in the world, being vastly cultivated in arid and semi-arid regions as one of the oldest spice plants. The present study explored the extraction of polysaccharides from Coriandrum sativum seeds and the evaluation of their antioxidant potential and hepatoprotective effects in vivo. The polysaccharide from coriander seeds was extracted, and the structural characterization was performed by FT-IR, UV-vis, DSC, NMR (1D and 2D), GC-MS, and SEC analysis. The polysaccharide extracted from Coriandrum sativum (CPS) seeds was characterized to evaluate its antioxidant and hepatoprotective capacities in rats. Results showed that CPS was composed of arabinose, rhamnose, xylose, mannose, fructose, galactose, and glucose in molar percentages of 6.2%, 3.6%, 8.8%, 17.7%, 5.2%, 32.9%, and 25.6%, respectively. Further, CPS significantly hindered cadmium-induced oxidation damage and exercised a protective effect against Cd hepatocytotoxicity, with a considerable reduction in MDA production and interesting CAT and SOD enzyme levels. Results suggest that CPS might be employed as a natural antioxidant source.

Chemical Composition, Biomolecular Analysis, and Nuclear Magnetic Resonance Spectroscopic Fingerprinting of Posidonia oceanica and Ascophyllum nodosum Extracts

A detailed analysis of the elemental and molecular composition of Posidonia oceanica (PO) and Ascophyllum nodosum (AN) is presented. In particular, an in-depth study of the molecular identification via NMR spectroscopy of aqueous and organic extracts of PO and AN was carried out, exploiting 2D COSY and pseudo-2D DOSY data to aid in the assignment of peaks in complex 1D proton NMR spectra. Many metabolites were identified, such as carbohydrates, amino acids, organic acids, fatty acids, and polyphenols, with NMR complementing the characterization of the two species by standard elemental analysis, HPLC analysis, and colorimetric testing. For PO, different parts of the live plant (roots, rhizomes, and leaves) were analysed, as well as the residues of the dead plant which typically deposit along the coasts. The combination of the various studies made it possible to recognize bioactive compounds naturally present in the two plant species and, in particular, in the PO residues, opening the door for their possible recycling and use in, for example, fertilizer. Furthermore, NMR is proven to be a powerful tool for the metabolomic study of plant species as it allows for the direct identification of specific biomarkers as well as providing a molecular fingerprint of the plant variety.

Plant/algal polysaccharides extracted by microwave: A review on hypoglycemic, hypolipidemic, prebiotic, and immune-stimulatory effect

Microwave-assisted extraction (MAE) is an emerging technology to obtain polysaccharides with an extensive spectrum of biological characteristics. In this study, the hypoglycemic, hypolipidemic, prebiotic, and immunomodulatory (e.g., antiinflammatory, anticoagulant, and phagocytic) effects of algal- and plant-derived polysaccharides rich in glucose, galactose, and mannose using MAE were comprehensively discussed. The in vitro and in vivo results showed that these bioactive macromolecules with the low digestibility rate could effectively alleviate the fatty acid-induced lipotoxicity, acute hemolysis, and dyslipidemia status. The optimally extracted glucomannan- and glucogalactan-containing polysaccharides revealed significant antidiabetic effects through inhibiting α-amylase and α-glucosidase, improving dynamic insulin sensitivity and secretion, and promoting pancreatic β-cell proliferation. These bioactive macromolecules as prebiotics not only improve the digestibility in gastrointestinal tract but also reduce the survival rate of pathogens and tumor cells by activating macrophages and producing pro-inflammatory biomarkers and cytokines. They can effectively prevent gastrointestinal disorders and microbial infections without any toxicity.

HPLC-ESI-QTOF-MS/MS profiling and therapeutic effects of Schinus terebinthifolius and Schinus molle fruits: investigation of their antioxidant, antidiabetic, anti-inflammatory and antinociceptive properties

The aim of the current work was to study the phytochemical variability among Schinus terebinthifolius (STE) and Schinus molle (SME) fruit extracts. The in vitro antioxidant, antihemolytic, antidiabetic, and macromolecule damage protective activities, as well as, the in vivo anti-inflammatory and antinociceptive capacities were assessed. Using the HPLC-ESI-QTOF/MS analysis, the chemical profile of fruit extract varied between S. terebinthifolius (30 compounds) and S. molle (16 compounds). The major compound was masazino-flavanone (5774.98 and 1177.65 μg/g sample for STE and SME, respectively). The investigations highlighted significant antioxidant proprieties when using ABTS radical (IC₅₀; 0.12 and 0.14 mg/ml for STE and SME, respectively), superoxide (IC₅₀; 0.17 and 0.22 mg/ml for STE and SME, respectively) and hydrogen peroxide (IC₅₀; 014 and 0.17 mg/ml for STE and SME, respectively). In addition, STE and SME proved preventive effects against H₂O₂-induced hemolysis (IC₅₀; 0.22 and 0.14 mg/ml for STE and SME, respectively). The in vitro antidiabetic effect revealed that STE and SME exhibited important inhibitory effects against α-amylase (IC₅₀; 0.13 and 0.19 mg/ml for STE and SME, respectively) and α-glycosidase (IC₅₀; 0.21 and 0.18 mg/ml for STE and SME, respectively) when compared with acarbose. Furthermore, the extracts showed potent inhibitory activity against AAPH-induced plasmid DNA damage, and protein oxidation. In vivo study revealed that STE and SME presented interesting antinociceptive and anti-inflammatory capacities. All observed effects highlighted the potential application of Schinus fruit extract in food and pharmaceutical industries against ROS-induced damage.

Anti-inflammatory properties of the marine plant Posidonia oceanica (L.) Delile

ETHNOPHARMACOLOGICAL RELEVANCE

Posidonia oceanica (L.) Delile is an endemic seagrass of the Mediterranean Sea whose use has been documented as a traditional herbal remedy for diabetes and hypertension. Our recently described Posidonia oceanica leaves extract is a phytocomplex endowed with interesting bioactivities, including the inibitory property on human cancer cell migration.

AIM OF THE STUDY

The aim of this study was to investigate the anti-inflammatory effects of P. oceanica extract underlying its mechanism of action.

MATERIALS AND METHODS

We explored the anti-inflammatory effects of P. oceanica extract on RAW264.7 murine macrophages activated by LPS. We investigated the reactive oxygen species (ROS) and nitric oxide (NO) production and the expression of inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). Then, we examined P. oceanica extract role on the regulation of NF-κB signaling pathway.

RESULTS

P. oceanica phytocomplex exhibited a strong ability to inhibit oxidative stress by affecting the production of both ROS and NO and to reduce iNOS and COX-2 levels. In addition, it was evidenced its anti-inflammatory role via inhibiting NF-κB signaling pathway through modulation of ERK1/2 and Akt intracellular cascades.

CONCLUSIONS

Our results recognize an anti-inflammatory role of P. oceanica phytocomplex particularly emphasizing its cell safe mechanism of action. In conclusion, the marine plant P. oceanica may be of great interest for scientific research as a source of promising molecules for designing alternative strategies to the conventional treatment of inflammatory diseases.

Novel Antioxidant, Anti-α-Amylase, Anti-Inflammatory and Antinociceptive Water-Soluble Polysaccharides from the Aerial Part of Nitraria retusa

In this paper, water-soluble polysaccharides (named as NRLP) were extracted from Nitraria retusa leaves. The main structural features of NRLP were determined by High-pressure size exclusion chromatography, Fourier transform infrared and Gas Chromatography/Mass Spectrometry-Electronic Impact analysis. The in vitro and in vivo biological potential of NRLP were evaluated by measuring its antioxidant (•OH and DPPH• scavenging, total antioxidant capacity), anti-α-amylase as well as anti-inflammatory and antinociceptive activities in a mice model. NRLP was composed of Rha (33.7%), Gal (18.1%), GalA (15.0%), Glc (13.3%), Ara (13.3%), Xyl (3.8%), and GlcA (2.8%) and showed a Molecular Weight (Mw) of 23.0 kDa and a polydispersity index (PDI) of 1.66. The investigations highlighted a significant antioxidant activity (IC50 = 2.4-2.6 mg/mL) and an inhibition activity against α-amylase (IC50 = 4.55 mg/mL) in a dose-dependent manner. Further, NRLP revealed interesting anti-edematous effects and antinociceptive activities (both > 70%). These results open up new pharmacological prospects for the water-soluble polysaccharides extracted from Nitraria retusa leaves.

In-Depth Characterization of Bioactive Extracts from Posidonia oceanica Waste Biomass

Posidonia oceanica waste biomass has been valorised to produce extracts by means of different methodologies and their bioactive properties have been evaluated. Water-based extracts were produced using ultrasound-assisted and hot water methods and classified according to their ethanol-affinity (E1: ethanol soluble; E2: non-soluble). Moreover, a conventional protocol with organic solvents was applied, yielding E3 extracts. Compositional and structural characterization confirmed that while E1 and E3 extracts were mainly composed of minerals and lipids, respectively, E2 extracts were a mixture of minerals, proteins and carbohydrates. All the extracts showed remarkably high antioxidant capacity, which was not only related to phenolic compounds but also to the presence of proteins and polysaccharides. All E2 and E3 extracts inhibited the growth of several foodborne fungi, while only E3 extracts decreased substantially the infectivity of feline calicivirus and murine norovirus. These results show the potential of P. oceanica waste biomass for the production of bioactive extracts.