Physico-chemical characterization and pharmacological activities of sulfated polysaccharide from sea urchin, Paracentrotus lividus

Visnagin alleviates rheumatoid arthritis via its potential inhibitory impact on malate dehydrogenase enzyme: in silico, in vitro, and in vivo studies

Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disorder. The present study aimed to evaluate the in silico, in vitro, and in vivo inhibitory effect of visnagin on malate dehydrogenase activity and elucidate its inflammatory efficacy when combined with methotrexate in the RA rat model. The molecular docking, ADMET simulations, MDH activity, expression, and X-ray imaging were detected. Moreover, CRP, RF, (anti-CCP) antibody, (TNF-α), (IL-6), (IL-17), and (IL-10) were evaluated. The expression levels of MMP3 and FOXP3 genes and CD4, CD25, and CD127 protein levels were assessed. Histological assessment of ankle joints was evaluated. The results revealed that visnagin showed reversible competitive inhibition on MDH with inhibitory constant (Ki) equal to 141 mM with theoretical IC50 equal to 1202.7 mM, LD50 equal to 155.39 mg/kg, and LD25 equal to 77.69 mg/kg. In vivo studies indicated that visnagin exhibited anti-inflammatory effects through decreasing MDH1 activity and expression and induced proliferation of anti-inflammatory CD4+CD25+FOXP3 regulatory T cells with increasing the anti-inflammatory cytokine IL-10 levels. Moreover, visnagin reduced the levels of inflammatory cytokines and the immuno-markers. Our findings elucidate that visnagin exhibits an anti-inflammatory impact against RA through its ability to inhibit the MDH1 enzyme, improve methotrexate efficacy, and reduce oxidative stress.

Hyaluronic acid from bluefin tuna by-product: Structural analysis and pharmacological activities

The fishing and aquaculture industries generate a huge amount of waste during processing and preservation operations, especially those of tuna. Recovering these by-products is a major economic and environmental challenge for manufacturers seeking to produce new active biomolecules of interest. A new hyaluronic acid was extracted from bluefin tuna's vitreous humour to assess its antioxidant and pharmacological activities. The characterization by infrared spectroscopy (FT-IR), nuclear magnetic resonance ((1D1H) and 2D (1H COSY, 1H/13C HSQC)) and size exclusion chromatography (SEC/MALS/DRI/VD) revealed that the extracted polysaccharide was a hyaluronic acid with high uronic acid content (55.8 %) and a weight average molecular weight of 888 kDa. This polymer possesses significant anti-radical activity and ferrous chelating capacity. In addition, pharmacological evaluation of its anti-inflammatory and analgesic potential, using preclinical models, in comparison with reference drugs (Dexamethasone, diclofenac, and acetylsalicylate of lysine), revealed promising anti-inflammatory activity as well as interesting peripheral and central antinociceptive activity. Therefore, our new hyaluronic acid compound may therefore serve as a potential drug candidate for the treatment of pain sensation and inflammation of various pathological origins.

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.

Anti-Inflammatory Effects of Compounds from Echinoderms

Chronic inflammation can extensively burden a healthcare system. Several synthetic anti-inflammatory drugs are currently available in clinical practice, but each has its own side effect profile. The planet is gifted with vast and diverse oceans, which provide a treasure of bioactive compounds, the chemical structures of which may provide valuable pharmaceutical agents. Marine organisms contain a variety of bioactive compounds, some of which have anti-inflammatory activity and have received considerable attention from the scientific community for the development of anti-inflammatory drugs. This review describes such bioactive compounds, as well as crude extracts (published during 2010-2022) from echinoderms: namely, sea cucumbers, sea urchins, and starfish. Moreover, we also include their chemical structures, evaluation models, and anti-inflammatory activities, including the molecular mechanism(s) of these compounds. This paper also highlights the potential applications of those marine-derived compounds in the pharmaceutical industry to develop leads for the clinical pipeline. In conclusion, this review can serve as a well-documented reference for the research progress on the development of potential anti-inflammatory drugs from echinoderms against various chronic inflammatory conditions.

Recent advances in utilization of pectins in biomedical applications: a review focusing on molecular structure-directing health-promoting properties

The numerous health benefits of pectins justify their inclusion in human diets and biomedical products. This review provides an overview of pectin extraction and modification methods, their physico-chemical characteristics, health-promoting properties, and pharmaceutical/biomedical applications. Pectins, as readily available and versatile biomolecules, can be tailored to possess specific functionalities for food, pharmaceutical and biomedical applications, through judicious selection of appropriate extraction and modification technologies/processes based on green chemistry principles. Pectin's structural and physicochemical characteristics dictate their effects on digestion and bioavailability of nutrients, as well as health-promoting properties including anticancer, immunomodulatory, anti-inflammatory, intestinal microflora-regulating, immune barrier-strengthening, hypercholesterolemia-/arteriosclerosis-preventing, anti-diabetic, anti-obesity, antitussive, analgesic, anticoagulant, and wound healing effects. HG, RG-I, RG-II, molecular weight, side chain pattern, and degrees of methylation, acetylation, amidation and branching are critical structural elements responsible for optimizing these health benefits. The physicochemical characteristics, health functionalities, biocompatibility and biodegradability of pectins enable the construction of pectin-based composites with distinct properties for targeted applications in bioactive/drug delivery, edible films/coatings, nano-/micro-encapsulation, wound dressings and biological tissue engineering. Achieving beneficial synergies among the green extraction and modification processes during pectin production, and between pectin and other composite components in biomedical products, should be key foci for future research.

In vitro characterization of bioactive compounds extracted from sea urchin (Stomopneustes variolaris) using green and conventional techniques

This study investigated the in vitro bioactivities of extracts obtained from viscera, spines, shells, and gonads of Stomopneustes variolaris using subcritical water extraction (SWE) at 110 °C, 150 °C, 190 °C, and 230 °C and Soxhlet extraction. The highest amounts of phenolics (22.68 ± 0.05 mg GAE/g), flavonoids (27.11 ± 0.10 mg RE/g), and proteins (40.25 ± 0.84 mg BSA/g) were recorded from gonads at 230 °C, whereas maximum sugar content (23.38 ± 1.30 mg glucose/g) was in viscera at 150 °C. Gonads at 230 °C exhibited the highest DPPH activity (78.68 ± 0.18%), whereas viscera at 150 °C exhibited the highest ABTS⁺ (98.92 ± 1.27%) and protein denaturation inhibition activity (37.13 ± 9.94%). Viscera at 110 °C claimed the highest amylase inhibition (42.46 ± 0.83%), and spines at 150 °C had the highest anticancer activity (IC₅₀ = 767.47 μg/mL). SWE achieved superior results in bioactive compound recovery and detected higher levels of bioactivities (p < 0.05). Results suggest processing sea urchin extracts via SWE has potential application to the food and pharmaceutical industries.

Isolation, Characterization, and Antioxidant Activity Evaluation of a Fucoidan from an Enzymatic Digest of the Edible Seaweed, Hizikia fusiforme

The previous study suggested that the sulfated polysaccharides from Hizikia fusiforme (HFPS) possess strong antioxidant activity. The purpose of this study is to isolate fucoidan from HFPS and to investigate its antioxidant activity. A fucoidan (HFPS-F4) with a molecular weight of 102.67 kDa was isolated from HFPS. HFPS-F4 contains 99.01% of fucoidan (71.79 ± 0.56% of carbohydrate and 27.22 ± 0.05% of sulfate content). The fucoidan increased the viability of H₂O₂-treated Vero cells by 5.41, 11.17, and 16.32% at the concentration of 12.5, 25, and 50 μg/mL, respectively. Further results demonstrated that this effect act diminishing apoptosis by scavenging intracellular reactive oxygen species (ROS) via increasing the expression of the endogenous antioxidant enzymes, which was induced by elevating total nuclear factor (erythroid-derived 2)-like 2 (Nrf2) levels. In addition, the in vivo test results displayed that the pretreatment of fucoidan improved the survival rates and decreased heart-beating rate, ROS, cell death, and lipid peroxidation in H₂O₂-stimulated zebrafish. Taken together, these results demonstrated that fucoidan isolated from HFPS has strong in vitro and in vivo antioxidant activities and it could be utilized in pharmaceutical, nutraceutical, and cosmeceutical industries.

Fatty Acids from Paracentrotus lividus Sea Urchin Shells Obtained via Rapid Solid Liquid Dynamic Extraction (RSLDE)

Sea urchins (Echinodermata, Echinoidea) are good a source of bioactive compounds belonging to different classes of natural substances. The edible Mediterranean sea urchin Paracentrotus lividus is a renowned animal model for study in different fields of biology, but it is intensively harvested for high commercial value due to the delicacy of its gonads. Most studies have focused on the composition and the nutritional value of P. lividus gonads (the edible part), but little interest has been taken in the other body parts, such as the shells and spines, which are generally considered waste material. The purpose of this study was to obtain an extract from sea urchin shells, with a green methodology of extraction, and to characterize the lipophilic components for potential applications. The shells of P. lividus were extracted via a very well performing technology based on rapid solid liquid dynamic extraction (RSLDE) implemented via an automated device (Naviglio Extractor®). The obtained extract shows the presence of fatty acids and their esters (methyl, ethyl and 1-glycerol esters). Gas chromatography-mass spectrometry (GC-MS) measurements were used to determine fatty acid abundance in the chromatographic fractions of the extract. Arachidonic acid (ARA), 5,8,11,14,17-eicosapentanoic acid (EPA), and 11-eicosenoic acids and their esters are the most abundant components. The presence of many polyunsaturated fatty acids (PUFA) in the extract, even in low percentages allows a future application in nutrition or medical use.

Fucoidan isolated from Padina commersonii inhibit LPS-induced inflammation in macrophages blocking TLR/NF-κB signal pathway

Brown seaweeds are well-known source of bioactive compounds, which are producing a variety of secondary metabolites with promising bioactive properties. Traditionally, seaweeds used as ingredients in medicine for many centuries in Asian countries. However, the protective mechanisms of many metabolites found in seaweeds are remains to be determined. Thus, applications of seaweeds are limited because of poor understanding of their structural features and mechanisms responsible for their bioactive properties. In the present study, anti-inflammatory properties of fucoidan isolated from the brown seaweed Padina commersonii (PCF) was evaluated against LPS-activated RAW 264.7 macrophages. PCF was characterized using NMR, FT-IR, and HPAE-PAD spectrum (for mono sugar composition). It was observed that PCF is rich in fucose and sulfate as well as a similar structure to the commercial fucoidan. Western blots and RT-qPCR analysis were used to determine the protective effects of PCF after LPS challenge using RAW 264.7 macrophages. According to the results, PCF significantly down-regulated LPS-activated mRNA and protein expression levels of TLR2, TLR4, and MyD88 which are known inducers/activators of NF-κB transcriptional factors. The results, obtained from this study demonstrated PCF has a potential to inhibit LPS-induced inflammatory responses via blocking TLR/MyD88/ NF-κB signal transduction.

Isolation and purification of fucoidan fraction in Turbinaria ornata from the Maldives; Inflammation inhibitory potential under LPS stimulated conditions in in-vitro and in-vivo models

Fucoidan, referred to as fucose containing sulfated polysaccharides (FCSP), is a polymer from brown algae cell wall that is reported to exhibit potential anti-inflammatory activity. In the present study, the fucoidans are extracted from Turbinaria ornata (TO) from the Maldives. The method involves enzyme assisted extraction and is modified in order to improve the effectiveness and purity of final product. Purified fucoidan fraction was identified as F10, and its chemical properties were verified via FTIR, 1H NMR and monosaccharide analysis. Selected inflammatory mediators were studied to evaluate the anti-inflammatory potential using RAW 264.7 macrophages. F10 successfully inhibited NO production (IC50 = 30.83 ± 1.02 μg mL-1). F10 dose-dependently down-regulated iNOS, COX-2, and pro-inflammatory cytokines including PGE2 levels. The in vivo experiments were assisted by zebrafish embryo model. This exhibited reduction in ROS, NO expression levels. To our knowledge, this is the first report to illustrate potential anti-inflammatory activity of FCSPs' extracted from the brown algae T. ornata. Concisely, the results suggest that fucoidan purified from T. ornata increases the macrophage cellular and zebrafish embryo resistance against LPS-induced inflammation. Based on the observations, the fucoidans are promising candidates to be used in the pharmaceutical and cosmeceutical sectors.

Anti-inflammatory activity and gastroprotective effect of Hertia cheirifolia L. roots extract

ETHNOPHARMACOLOGICAL RELEVANCE

Hertia cheirifolia L. is used traditionally to treat rheumatic pains and known as a medicinal plant having several pharmaceutical and biological activities. The present study evaluated in vivo the anti-inflammatory and gastroprotective effects of the methanolic extract from H. cheirifolia L.

MATERIALS AND METHODS

Reverse phase high-performance liquid chromatography (RP-HPLC) was performed to identify various chemical components of the plant extract. Anti-inflammatory and gastroprotective activities were assessed on carrageenan-induced paw edema and HCl/ethanol-induced gastric lesions in rats, respectively.

RESULTS

(RP-HPLC) analysis indicated that coumarin is the abundant component in the extract (53.80%). Intraperitoneal administration of the methanolic extract at different doses showed interesting activities in rats in a dose-dependent manner. At 100 mg/kg, this extract showed the highest acute anti-inflammatory activity and an important inhibition of gastric lesions with inhibition percentage of 79.41% and 88.53%, respectively.

CONCLUSION

Altogether, the results of this study reveal the anti-inflammatory and gastroprotective effects of H. cheirifolia extract and promote the traditional use of this plant in the treatment of different pain and inflammatory diseases.

In silicoassessment and structural characterization of antioxidant peptides from major yolk protein of sea urchinStrongylocentrotus nudus

Sea urchin gonads have been demonstrated to contain major yolk protein (MYP), which can be hydrolyzed by enzymes to release biologically active peptides.

The efficacy of sulfated polysaccharides from Padina tetrastromatica in modulating the immune functions of RAW 264.7 cells

Immunomodulation is a collective term of immunostimulation and immunosuppression. Immunotherapy by means of immunomodulation is gaining additional significance as the frequency of mutant microbes as well as cancer cases are increasing in the present time. A wide population of marine vegetation has contributed to the traditional and modern therapeutic regimens owing to the abundance of bioactive molecules. Among the seaweed born macromolecules, the sulfated polysaccharides (SPS) from marine macro algae were reported to exhibit excellent biological activities in addition to their structural and nutritional roles. Interestingly, SPS from the marine brown algae Padina tetrastromatica is not yet explored for their immunomodulatory potential. In the present study, SPS were extracted by ethanol precipitation, purified using DEAE cellulose column chromatography, and named as Ethanolic Sulfated Polysaccharide-Column Purified (ESPs-CP). The study includes, evaluation of macrophage proliferation, prostaglandin and nitric oxide production, COX-2, 5-LOX, and iNOS estimation and gene expression studies in RAW 264.7 cells. ESPs-CP strongly stimulated macrophage proliferation and production of prostaglandin and nitric oxide. They also increased COX-2, 5-LOX, and iNOS concentration in macrophages, which was comparable to that of LPS stimulated macrophages. Increase of prostaglandin and NO production may be due to increased expression of COX-2 and iNOS as observed in gene expression studies. The mRNA expression of pro- inflammatory cytokines such as IL-6, IL-1β, TNF-α and anti-inflammatory cytokines IL-10 and TGF-β were also enhanced by ESPs-CP. The evaluations signify the possibilities of SPS as potent immunostimulators during immune deficiencies.