Polysaccharide from Caulerpa lentillifera: extraction optimization with response surface methodology, structure and antioxidant activities

Structural characteristics of sulfated xylogalactomannan isolated from Caulerpa okamurae and its anticoagulant activity

Due to wonderful taste, rich nutrition and biological functions, many marine green algae in the genus Caulerpa have been recently developed as candidates for green caviar. A novel water-soluble sulfated xylogalactomannan CO-0-1 was obtained from the green algae Caulerpa okamurae. CO-0-1 was mainly composed of mannose (Man), galactose (Gal), and xylose (Xyl) at the ratio of 4.4:4.0:1.4 with the molecular weight at 470 kDa and the sulfate content at 12.78 %. The sulfated xylogalactomannan had Man at the backbone with →4)-β-D-Manp-(1→ and →2)-β-D-Manp-(1→ as the main chain and branches at O-3 position. The side chains contained →3)-β-D-Galp-(1→ and minor →2)-β-D-Xylp(1→. The sulfate groups only distributed at the side chains and at O-6 position of →3)-β-D-Galp-(1→ and O-4 position of (1→2)-β-D-Xylp. The anticoagulant activity indicated that CO-0-1 displayed intrinsic anticoagulant and specific anti-thrombin activities. The investigation expanded the utilization and development scene and scope of the green algae Caulerpa okamurae.

Anti-Vasculogenic, Antioxidant, and Anti-Inflammatory Activities of Sulfated Polysaccharide Derived from Codium tomentosum: Pharmacokinetic Assay

The purpose of this paper was to investigate the anti-inflammatory and anti-angiogenic activities of sulfated polysaccharide from C. tomentosum (PCT) using carrageenan (CARR)-induced paw edema in a rat model and anti-vasculogenic activity on a chorioallantoic membrane assay (CAM) model. Based on in vitro tests of anti-radical, total antioxidant, and reducing power activities, PCT presents a real interest via its antioxidant activity and ability to scavenge radical species. The in vivo pharmacological tests suggest that PCT possesses anti-inflammatory action by reducing paw edema and leukocyte migration, maintaining the redox equilibrium, and stabilizing the cellular level of several pro-/antioxidant system markers. It could significantly decrease the malondialdehyde levels and increase superoxide dismutase, glutathione peroxidase, and glutathione activities in local paw edema and erythrocytes during the acute inflammatory reaction of CARR. PCT pretreatment was effective against DNA alterations in the blood lymphocytes of inflamed rats and reduced the hematological alteration by restoring blood parameters to normal levels. The anti-angiogenic activity results revealed that CAM neovascularization, defined as the formation of new vessel numbers and branching patterns, was decreased by PCT in a dose-dependent manner, which supported the in silico bioavailability and pharmacokinetic findings. These results indicated the therapeutic effects of polysaccharides from C. tomentosum and their possible use as anti-proliferative molecules based on their antioxidant, anti-inflammatory, and anti-angiogenic activities.

Subcritical water extraction of polysaccharides from Gastrodiae Rhizoma: optimization, characterization and in vitro hepatoprotective activity

Subcritical water extraction (SWE) is an efficient and eco-friendly technology that rapidly extracts valuable compounds from natural materials. In this study, response surface methodology (RSM) was utilized to determine the optimal extraction conditions for Gastrodiae Rhizoma using SWE (GRP-S). The optimum conditions were found to be 161 °C extraction temperature, 41 min extraction time, and a solid-to-liquid ratio of 1.55 mg/mL. Under these optimal conditions, the experimental yield of GRP-S was 66.32% ± 0.10% (n = 3), demonstrating a significant increase compared to hot water reflux extraction (HWE) in the extraction yield of polysaccharides. Characterization studies employing SEM, FT-IR, and HPAEC-PAD confirmed the differences between GRP-S and GRP-H (GRP obtained by HWE). Furthermore, both GRP-S and GRP-H exhibited a significant ability to protect HepG2 cells from ethanol-induced damage, with GRP-S showcasing a superior effect. The widespread adoption of SWE technology can lead to high GRP content in extracts and promote the green and sustainable development of natural products extraction processes.

Caulerspiros A and B, a new pair of α-tocopheroid isomers from the green alga Caulerpa racemosa var. turbinata

Caulerspiros A (1) and B (2), a new pair of α-tocopheroid isomers, with five known compounds (3-7) were isolated from the green alga Caulerpa racemosa var. turbinata. Their structures were elucidated by the method of comprehensive spectroscopy. The absolute configurations of 1 and 2 were established by the methods of ECD calculation and comparing with the previously reported literature. Compounds 1 and 2 represented the rare examples of α-tocopherol derivatives possessing a core unit of 1-oxaspiro[4.4]non 7-en-6-one. Additionally, the antibacterial activities of these seven compounds were also evaluated. However, none of them showed antibacterial activities with MIC values > 128 μg/ml.

Sulfated polysaccharides from Caulerpa lentillifera: Optimizing the process of extraction, structural characteristics, antioxidant capabilities, and anti-glycation properties

The polysaccharides found in Caulerpa lentillifera (sea grape algae) are potentially an important bioactive resource. This study makes use of RSM (response surface methodology) to determine the optimal conditions for the extraction of valuable SGP (sea grape polysaccharides). The findings indicated that a water/raw material ratio of 10:1 mL/g, temperature of 90 °C, and extraction time of 45 min would maximize the yield, with experimentation achieving a yield of 21.576 %. After undergoing purification through DEAE-52 cellulose and Sephacryl S-100 column chromatography, three distinct fractions were obtained, namely SGP11, SGP21, and SGP31, each possessing average molecular weights of 38.24 kDa, 30.13 kDa, and 30.65 kDa, respectively. Following characterization, the fractions were shown to comprise glucose, galacturonic acid, xylose, and mannose, while the sulfate content was in the range of 12.2-21.8 %. Using Fourier transform infrared spectroscopy (FT-IR) it was possible to confirm with absolute certainty the sulfate polysaccharide attributes of SGP11, SGP21, and SGP31. NMR (nuclear magnetic resonance) findings made it clear that SGP11 exhibited α-glycosidic configurations, while the configurations of SGP21 and SGP31 were instead β-glycosidic. The in vitro antioxidant assays which were conducted revealed that each of the fractions was able to demonstrate detectable scavenging activity against 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical cations. All fractions were also found to exhibit the capacity to scavenge NO radicals in a dose-dependent manner. SGP11, SGP21, and SGP31 were also able to display cellular antioxidant activity (CAA) against the human adenocarcinoma colon (Caco-2) cell line when oxidative damage was induced. The concentration levels were found to govern the extent of such activity. Moreover, purified SGP were found to exert strong inhibitory effects upon glycation, with the responses dependent upon dosage, thus confirming the potential for SGP to find a role as a natural resource for the production of polysaccharide-based antioxidant drugs, or products to promote improved health.

Anticoagulant Property of a Sulfated Polysaccharide with Unique Structural Characteristics from the Green Alga Chaetomorpha aerea

Sulfated polysaccharides from marine algae have attracted a great amount of attentions for the development of marine drugs due to their unique structural features, and they are great potential sources of naturally occurring anticoagulant agents. The genus Chaetomorpha is one of the largest genera in green algae and has a worldwide distribution. In the present study, a homogeneous polysaccharide from Chaetomorpha aerea, designated as PCA, was obtained by alkali extraction, anion-exchange and size-exclusion chromatography. Based on the results of chemical and spectroscopic analyses, PCA was a sulfated galactoarabinan which was mainly constituted of a backbone of →4)-β-l-Arap-(1→ unit, partially sulfated at C-3 of →4)-β-l-Arap-(1→ and C-4 of →6)-α-d-Galp-(1→. The side chains consisting of →6)-α-d-Galp-(1→ and →5)-α-l-Araf-(1→ residues were in C-2 of →4)-β-l-Arap-(1→ unit. PCA had a strong anticoagulant activity in vitro as evaluated by the assays of activated partial thromboplastin time, thrombin time and fibrinogen level. The obvious anticoagulant activity in vivo of PCA was also found. PCA significantly inhibited the activities of the intrinsic coagulation factors XII, XI, IX and VIII, and exhibited weak inhibition effects on the common coagulation factors II and X. The anticoagulant mechanism of PCA was attributed to strong thrombin inhibition potentiated by heparin cofactor II or antithrombin III, and it also possessed an apparent inhibition effect on coagulation factor Xa mediated by antithrombin III. The investigation demonstrated that PCA could be a promising anticoagulant agent for health promotion and the treatment of thrombotic diseases.

Preparation, characterization, antioxidant and antianemia activities of Poria cocos polysaccharide iron (III) complex

As a new natural antioxidant with high safety and non-toxic side effects, polysaccharide can also be used as a critical macromolecular carrier to form a stable iron complex with Fe³⁺. Our previous study has extracted and purified the homogeneous polysaccharide (PCP1C) from Poria cocos. In this study, the PCP1C-iron (III) complex was synthesized by co-thermal synthesis with PCP1C and ferric trichloride. The chelating capacity, iron releasing capacity, and qualitative identification of complex were evaluated. The complex was characterized by scanning electron microscope-energy dispersive spectrometer (SEM-EDS) analysis, particle size distribution, and fourier transform infrared (FTIR) spectroscopy. The antioxidant and iron supplement effects of the complex were also studied in vitro and in the iron deficiency anemia (IDA) rat model. The results showed that the iron content in the PCP1C-iron (III) complex was 28.14% with no free iron, and the iron release rate was 95.3%. The structure analysis showed that the iron core of the PCP1C-iron (III) complex existed in the form of β-FeOOH and the surface of the complex become smooth and particle size increased, which indicated the high iron content of polysaccharide iron and slow release. Furthermore, we found that the PCP1C iron (III) complex had positive scavenging effect on DPPH, ABTS, MDA, and hydroxyl radical in vitro study and significantly increased the levels of red blood cell (RBC), Hemoglobin (Hb), and red blood cell specific volume (HCT) in IDA rat model. Therefore, our results suggested that the PCP1C-iron (III) complex is expected to develop into a new comprehensive iron supplement and antioxidant.

Extraction, physicochemical properties, and antioxidant activity of natural melanin from Auricularia heimuer fermentation

Introduction

Natural melanin from Auricularia heimuer have numerous beneficial biological properties, which were used as a safe and healthy colorant in several industries.

Methods

In this study, single-factor experiments, Box-Behnken design (BBD), and response surface methodology (RSM) were employed to investigate the effects of alkali-soluble pH, acid precipitation pH, and microwave time on the extraction yield of Auricularia heimuer melanin (AHM) from fermentation. Ultraviolet-visible spectrum (UV-Vis), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscope (SEM), and high-performance liquid chromatography (HPLC) were used to analyze the extracted AHM. The solubility, stability, and antioxidant activities of AHM were also measured.

Results

The results showed that alkali-soluble pH, acid precipitation pH, and microwave time significantly affected the AHM yield, with the following optimized microwave-assisted extraction conditions: alkali-soluble pH of 12.3, acid precipitation pH of 3.1, and microwave time of 53 min, resulting in an AHM extraction yield of 0.4042%. AHM exhibited a strong absorption at 210 nm, similar to melanin from other sources. FT-IR spectroscopy also revealed that AHM exhibited the three characteristic absorption peaks of natural melanin. The HPLC chromatogram profile of AHM showed a single symmetrical elution peak with a 2.435 min retention time. AHM was highly soluble in alkali solution, insoluble in distilled water and organic solvents, and demonstrated strong DPPH, OH, and ABTS free radical scavenging activities.

Discussion

This study provides technical support to optimize AHM extraction for use in the medical and food industries.

Preparation, Characterization, and Anti-Adhesive Activity of Sulfate Polysaccharide from Caulerpa lentillifera against Helicobacter pylori

In the gastric mucosa, chronic inflammation due to Helicobacter pylori infection promotes gastrocarcinogenesis. Polysaccharides of Caulerpa lentillifera are well-characterized by broad antimicrobial activity and anti-inflammatory potentials. The present study was undertaken to investigate whether the low molecular sulfate polysaccharides of C. lentillifera (CLCP) exhibit any anti-adhesive activity against H. pylori. After a hot water extraction and purification process, two purified polysaccharide fractions (CLCP-1 and CLCP2) were studied based on structural characterization and bioactivity determination. The results implied that except for the molar ratio, CLCP-1 and CLCP-2 contain high sulfate, mannose, galactose, xylose, glucose levels, and low protein levels. The molecular weight and Fourier transform infrared spectroscopy (FT-IR) assays confirmed that CLCP-1 and CLCP-2 are sulfate polysaccharides with an average molecular weight (Mw) of 963.15 and 648.42 kDa, respectively. In addition, CLCP-1 and CLCP-2 exhibited stronger antibacterial activity against H. pylori. CLCP-1 and CLCP-2 could significantly promote macrophage proliferation and decrease the production of nitric oxide (NO) through downregulated expression of inducible nitric oxide synthase (iNOS). Meanwhile, CLCP-1 and CLCP-2 in this study showed efficiently protected gastric adenocarcinoma (AGS) cells against H. pylori with the inhibition of the IL-8/NF-κB axis. These findings suggested the effect of Caulerpa lentillifera polysaccharides on H. pylori adhesion, a potential supply of nutrients for eradication therapy through the reduction of cell count and inflammation.

A new polysaccharide from Caulerpa chemnitzia induces molecular shifts of immunomodulation on macrophages RAW264.7

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CCP showed significant immunomodulatory effects.

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CCP raising the level of NO, TNF-α, and IL-6 of macrophages RAW264.7.

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Investigation on the metabolites and genes changes in CCP-induced RAW264.7.

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Potential immunostimulatory mechanism of CCP on RAW264.7 was elucidated.

Investigation on Caulerpa chemnitzia polysaccharides led to the finding of a new polysaccharide (CCP). The basic components of CCP were the total sugar (59.18% ± 0.57%), the uronic acids (36.75% ± 0.28%) and the sulfate (42.50% ± 0.42%), in total content. The physicochemical analysis revealed that CCP was a heteropolysaccharide with a molecular weight of 321.6 KDa, and composed of arabinose, fucose, glucose, mannose, galactose, xylose, fructose, ribose, glucuronic acid and galacturonic acid. The immunomodulatory assay showed that CCP played an important role in activating cell viability, the nitric oxide product and cytokines (IL-6 and TNF-α) secretion. Furthermore, the transcript-metabolic analysis displayed a total of 7692 differentially expressed genes (DEGs) and 95 differentially accumulated metabolites (DAMs), and revealed that CCP may play an immunomodulatory effect by activating NF-κB signaling pathway and arachidonic acid metabolism pathway. These findings will provide a basic understanding to further investigation of Caulerpa polysaccharides.

Structural characterization and SARS-CoV-2 inhibitory activity of a sulfated polysaccharide from Caulerpa lentillifera

Caulerpa lentillifera (Bryopsidophyceae, Chlorophyta) is an edible seaweed attracting great attention for its expansion of farming scale and increasing consumption in these years. In the present study, a sulfated polysaccharide (CLSP-2) was isolated and separated from C. lentillifera, and its chemical structure was elucidated by a series of chemical and spectroscopic methods. Among these methods, mild acid hydrolysis and photocatalytic degradation were applied to release mono- and oligo-saccharide fragments which were further identified by HPLC-MSⁿ analysis, affording the information of the sugar sequences and the sulfate substitution in CLSP-2. Results indicated that the backbone of CLSP-2 was constructed of →6)-β-Manp-(1→ with sulfated branches at C2, which were comprised of prevalent →3)-β-Galp4S-(1→, →3)-β-Galp2,4S-(1→, and minor Xyl. In addition, the virus neutralization assay revealed that CLSP-2 could effectively protect HeLa cells against SARS-CoV-2 infection with an IC₅₀ of 48.48 μg/mL. Hence, the present study suggests CLSP-2 as a promising agent against SARS-CoV-2.

Characterization and analysis of the antidiabetic activities of sulphated polysaccharide extract from Caulerpa lentillifera

Caulerpa lentillifera is a type of green seaweed that is cultivated in tropical and subtropical areas. The objectives of this study were to determine the characteristics of the sulfated polysaccharides from C. lentillifera and evaluate its antidiabetic activity. In the initial process of this study, samples were macerated with ethanol (1:10). Then, the maceration residue was extracted with an accumulator at 75 °C for three hours. The crude extract yield was 4.16% based on weight seaweed. Ion chromatography purification with DEAE-Sepharose resin provided a yield of 14.8% of crude extract. The monomer analysis of C. lentillifera from the crude extract and purified extract revealed that galactose monomers were dominant and glucose was a minor component. The total carbohydrate and sulfate contents of purified C. lentillifera were higher than those of crude C. lentillifera. Bioactivity tests revealed that purified polysaccharides had higher antidiabetic activity against α-glucosidase enzyme than crude ones with IC50 values of 134.81± 2.0 µg/mL. Purified sulfated polysaccharides of C. lentillifera could potentially be used as an antidiabetic medication.

Valeric Acid Suppresses Liver Cancer Development by Acting as a Novel HDAC Inhibitor

Liver cancer is the fastest growing cause of cancer deaths in the United States due to its aggressiveness and lack of effective therapies. The current preclinical study examines valeric acid (pentanoic acid [C₅H₁₀O₂]), one of the main compounds of valerian root extract, for its therapeutic use in liver cancer treatment. Anticancer efficacy of valeric acid was tested in a series of in vitro assays and orthotopic xenograft mouse models. The molecular target of valeric acid was also predicted, followed by functional confirmation. Valeric acid has a broad spectrum of anticancer activity with specifically high cytotoxicity for liver cancer in cell proliferation, colony formation, wound healing, cell invasion, and 3D spheroid formation assays. Mouse models further demonstrate that systematic administration of lipid-based nanoparticle-encapsulated valeric acid significantly reduces the tumor burden and improves survival rate. Histone deacetylase (HDAC)-inhibiting functions of valeric acid are also revealed by a structural target prediction tool and HDAC activity assay. Further transcriptional profiling and network analyses illustrate that valeric acid affects several cancer-related pathways that may induce apoptosis. In summary, we demonstrate for the first time that valeric acid suppresses liver cancer development by acting as a potential novel HDAC inhibitor, which warrants further investigation on its therapeutic implications.

An Analysis of the Nutritional and Health Values of Caulerpa racemosa (Forsskål) and Ulva fasciata (Delile)-Two Chlorophyta Collected from the Philippines

Polysaccharides, lipids and amino acid profiles were investigated to understand the nutritional value of Caulerpa racemosa and Ulva fasciata from the Philippines. The results revealed that both species contain high amounts of proteins (8.8-19.9% for C. racemosa and 8.0-11.1% for U. fasciata). The portions of the total amino acids that were essential amino acids (EAAs) (45.28 ± 0.12% for C. racemosa and 42.17 ± 0.12% for U. fasciata) out were comparable to FAO/WHO requirements. Leucine, valine, isoleucine, and lysine are the dominant EAAs in C. racemosa, while leucine, valine, lysine, and phenylalanine are those in U. fasciata. The fatty acid profiles are dominated by monounsaturated fatty acids and polyunsaturated fatty acids in C. racemosa (56.2%), while saturated fatty acids (72.1%) are dominant in U. fasciata. High C18/C20 polyunsaturated fatty acid ratios were recorded in both species. Mineral contents for both seaweeds were within levels considered safe for functional foods. Total pigment content of C. racemosa (140.84 mg/g dw) was almost 20 times higher than that of U. fasciata (7.54 mg/g dw). Hot water extract (HWE) from C. racemosa showed in vitro antiherpetic activity without cytotoxicity. Nutritional characteristics confirmed that C. racemosa could be potentially used as a nutritious and functional food items for human consumption.

Modulation of the 5-HT3A receptor current by desacylbaldrinal

The serotonin (5-hydroxytryptamine) type 3 receptor is an important target in the control of digestive dysfunction such as anorexia and bulimia, and 5-HT₃ receptor antagonists are effective against eating disorder and the early-phase chemotherapy and radiotherapy evoked vomiting. Our previous research of Valeriana jatamansi revealed the presence of iridoids, which showed potent antitumor activities. Here, we explored the effects of 10π aromatic iridoid desacylbaldrinal isolated from V. jatamansi on the 5-HT₃ receptor current. We performed whole cell recordings of 5-HT₃A receptor currents in the presence of the compound. The result indicated that desacylbaldrinal inhibited the 5-HT-mediated 5-HT₃A receptor current.