Sulfated polysaccharide from the green marine algae Caulerpa racemosa reduces experimental pain in the rat temporomandibular joint

The molecular mechanism of polysaccharides in combating major depressive disorder: A comprehensive review

Major depressive disorder (MDD) is a complex psychiatric condition with diverse etiological factors. Typical pathological features include decreased cerebral cortex, subcortical structures, and grey matter volumes, as well as monoamine transmitter dysregulation. Although medications exist to treat MDD, unmet needs persist due to limited efficacy, induced side effects, and relapse upon drug withdrawal. Polysaccharides offer promising new therapies for MDD, demonstrating antidepressant effects with minimal side effects and multiple targets. These include neurotransmitter, neurotrophin, neuroinflammation, hypothalamic-pituitary-adrenal axis, mitochondrial function, oxidative stress, and intestinal flora regulation. This review explores the latest advancements in understanding the pharmacological actions and mechanisms of polysaccharides in treating major depression. We discuss the impact of polysaccharides' diverse structures and properties on their pharmacological actions, aiming to inspire new research directions and facilitate the discovery of novel anti-depressive drugs.

Extraction of bioactive polysaccharide from Ulva prolifera biomass waste toward potential biomedical application

Ulva prolifera macroalgae blooming caused by water eutrophication seriously affects the marine ecological environment. Exploring an efficient approach to turning algae biomass waste into high-value-added products is significant. The present work aimed to demonstrate the feasibility of the bioactive polysaccharide extraction from Ulva prolifera and to evaluate its potential biomedical application. A short autoclave process was proposed and optimized using the response surface methodology to extract Ulva polysaccharides (UP) with high molar mass. Our results indicated that UP with high molar mass (9.17 × 10⁵ g/mol) and competitive radical scavenging activity (up to 53.4 %) could be effectively extracted with the assistance of Na₂CO₃ (1.3 %, wt.) at a solid-liquid ratio of 1/10 in 26 min. The obtained UP mainly composes of galactose (9.4 %), glucose (73.1 %), xylose (9.6 %), and mannose (4.7 %). The biocompatibility of the UP and its potential application as a bioactive ingredient in 3D cell culture has been evaluated and confirmed by confocal laser scanning microscopy and fluorescence microscope imaging inspection. This work demonstrated the feasibility of extracting bioactive sulfated polysaccharides with potential applications in biomedicine from biomass waste. Meanwhile, this work also provided an alternative solution to deal with the environmental challenges incurred by algae blooming worldwide.

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.

Biological and Molecular Docking Evaluation of a Benzylisothiocyanate Semisynthetic Derivative From Moringa oleifera in a Pre-clinical Study of Temporomandibular Joint Pain

Objective

Moringa oleifera possesses multiple biological effects and the 4-[(4′-O-acetyl-α-L- rhamnosyloxy) benzyl] isothiocyanate accounts for them. Based on the original isothiocyanate molecule we obtained a semisynthetic derivative, named 4-[(2′,3′,4′-O-triacetyl-α-L-rhamnosyloxy) N-benzyl] hydrazine carbothioamide (MC-H) which was safe and effective in a temporomandibular joint (TMJ) inflammatory hypernociception in rats. Therefore, considering that there is still a gap in the knowledge concerning the mechanisms of action through which the MC-H effects are mediated, this study aimed to investigate the involvement of the adhesion molecules (ICAM-1, CD55), the pathways heme oxygenase-1 (HO-1) and NO/cGMP/PKG/K⁺_ATP, and the central opioid receptors in the efficacy of the MC-H in a pre-clinical study of TMJ pain.

Methods

Molecular docking studies were performed to test the binding performance of MC-H against the ten targets of interest (ICAM-1, CD55, HO-1, iNOS, soluble cGMP, cGMP-dependent protein kinase (PKG), K⁺_ATP channel, mu (μ), kappa (κ), and delta (δ) opioid receptors). In in vivo studies, male Wistar rats were treated with MC-H 1 μg/kg before TMJ formalin injection and nociception was evaluated. Periarticular tissues were removed to assess ICAM-1 and CD55 protein levels by Western blotting. To investigate the role of HO-1 and NO/cGMP/PKG/K⁺_ATP pathways, the inhibitors ZnPP-IX, aminoguanidine, ODQ, KT5823, or glibenclamide were used. To study the involvement of opioid receptors, rats were pre-treated (15 min) with an intrathecal injection of non-selective inhibitor naloxone or with CTOP, naltrindole, or norbinaltorphimine.

Results

All interactions presented acceptable binding energy values (below −6.0 kcal/mol) which suggest MC-H might strongly bind to its molecular targets. MC-H reduced the protein levels of ICAM-1 and CD55 in periarticular tissues. ZnPP-IX, naloxone, CTOP, and naltrindole reversed the antinociceptive effect of MC-H.

Conclusion

MC-H demonstrated antinociceptive and anti-inflammatory effects peripherally by the activation of the HO-1 pathway, as well as through inhibition of the protein levels of adhesion molecules, and centrally by μ and δ opioid receptors.

Applications of algae to obtain healthier meat products: A critical review on nutrients, acceptability and quality

Meat constitutes one the main protein sources worldwide. However, ethical and health concerns have limited its consumption over the last years. To overcome this negative impact, new ingredients from natural sources are being applied to meat products to obtain healthier proteinaceous meat products. Algae is a good source of unsaturated fatty acids, proteins, essential amino acids, and vitamins, which can nutritionally enrich several foods. On this basis, algae have been applied to meat products as a functional ingredient to obtain healthier meat-based products. This paper mainly reviews the bioactive compounds in algae and their application in meat products. The bioactive ingredients present in algae can give meat products functional properties such as antioxidant, neuroprotective, antigenotoxic, resulting in healthier foods. At the same time, algae addition to foods can also contribute to delay microbial spoilage extending shelf-life. Additionally, other algae-based applications such as for packaging materials for meat products are being explored. However, consumers' acceptance for new products (particularly in Western countries), namely those containing algae, not only depends on their knowledge, but also on their eating habits. Therefore, it is necessary to further explore the nutritional properties of algae-containing meat products to overcome the gap between new meat products and traditional products, so that healthier algae-containing meat can occupy a significant place in the market.

Isolation of Enteromorpha species and analyzing its crude extract for the determination of in vitro antioxidant and antibacterial activities

The extract of green algae (Enteromorpha species) was prepared by the cold extraction technique. The prepared algal extract exhibits a high antioxidant potential due to the presence of sulfated polysaccharides (SPs). The extract of Enteromorpha species was analyzed to identify the presence of significant biochemical composition. The extract of Enteromorpha species was evaluated to assess the DPPH-free radical scavenging activity, total antioxidant activity by phosphomolybdenum assay, in vitro anti-bacterial by agar diffusion method, and cell viability by MTT assay. It was found that the extract of Enteromorpha species contains the various chemical composition such as carbohydrates (0.13 g/ml), xylose (0.0819 g/ml), sulfate (0.0153 g/ml), and proteins (0.0363 g/ml). Phytochemicals such as flavonoids and phenolic compounds were found in the extract. The antioxidant potential of the crude extract was investigated by the total antioxidant assay (400 µl/ml) and DPPH-free radical scavenging assay (5 µl/ml). The prepared green algal extract produced the highest inhibitory zone up to 18 mm, 13 mm, and 18 mm at 200 µl/ml concentrations against Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli, respectively. The above results revealed that the extract of Enteromorpha species exhibited strong antioxidant and anti-bacterial activities due to the presence of sulfated polysaccharides.

Relationship between cervical angle and temporomandibular disorders in young and middle-aged population

OBJECTIVE

To verify temporomandibular disorders (TMDs) and cervical angles in a young and middle-aged population.

METHODS

Ninety participants were included, 45 of whom had TMDs. The participants were diagnosed according to the Research Diagnostic Criteria for TMDs. Lateral cervical radiographs were taken, and relevant cervical angles were measured. The general characteristics of the TMD group and control group were analyzed using chi-square analysis, and the relationship between cervical angles and TMDs was evaluated using the unpaired t-test.

RESULTS

The decrease in C2-C7 Cobb and increase in the posterior occipitocervical angle (POCA) were associated with the incidence of TMDs (p < 0.0001).

CONCLUSION

This study revealed that the cervical angle was related to TMDs. People with a long-time habit of head bending posture had a decrease in C2-C7 Cobb and an increase in the POCA. This group of people was more likely to develop TMDs.

Fast and accurate protocol for histology and immunohistochemistry reactions in temporomandibular joint of rats

OBJECTIVE

Propose a standard, fast and accurate protocol for the processing of the temporomandibular joint (TMJ) of adults' rats for histology and immunohistochemistry reactions.

DESIGN

Wistar male rats were perfused with paraformaldehyde (4 %). The heads were fixed in formaldehyde 10 % solution for 48 h. After that, the heads were sectioned in a sagittal plane and fixed for plus 48 h. Decalcification was performed using 20 % formic acid for 96 h and delimitation of TMJ area was done. Detailed methodology to a standard extraction and processing of TMJ to histological sections is described. Different buffers, equipment, temperature and time were tested to optimize immunostaining. Morphological preservation and antigenicity were evaluated by hematoxylin and eosin staining and immunohistochemistry reaction.

RESULTS

The current findings demonstrated that TMJ fixed in 10 % formaldehyde and decalcified in 20 % formic acid optimized decalcification processing time with preservation of cell morphology. Antigen retrieval with citrate buffer in pressure cooker (2 min at 100 °C and 5 min at room temperature) demonstrated the best protocol to preservation of the structures of TMJ.

CONCLUSIONS

This work demonstrates in detail a methodology of a fast and accurate TMJ processing for histology and immunohistochemistry reactions that guarantee tissue integrity and quality of staining.

A Systematic Review of Rat Models With Temporomandibular Osteoarthritis Suitable for the Study of Emerging Prolonged Intra-Articular Drug Delivery Systems

PURPOSE

Development of minimally invasive therapies for temporomandibular joint osteoarthritis (TMJOA) has focused on drug intra-articular injections to avoid the systemic adverse effects experienced when these substances are administered orally. Therefore, we performed a systematic review to answer the question "Which method of induction of a TMJOA-related pain model in rats leads to prolonged painful symptoms, allowing the best assessment of a sustained drug delivery system?"

MATERIALS AND METHODS

Following the PRISMA guidelines, we searched MEDLINE for papers published from 1994 to July 2020 on a TMJ arthritis model using rats. We identified the means of pain induction and of nociception assessment. We assessed protocol bias using an adaptation of the QUADAS-2 tool. Animal selection, the reference standard method of pain assessment, applicability of a statistical assessment, and flow and timing were assessed.

RESULTS

Of the 59 full papers we reviewed, 41 performed no pain assessment after the first 7 days following induction of the TMJ-related pain model. We eventually identified 18 long-term TMJOA-related pain models. Pain was induced by injection of toxic substances, most commonly Freund's complete adjuvant (50 μg per 50 μl), formalin at various concentrations, or monosodium iodoacetate (0,5 mg per 50 μl), into the TMJ, or by physical methods. Few studies reported data on pain after 21 days of follow-up. Heterogeneity of induction methods, pain assessment methods, and flow and timing biases precluded a meta-analysis.

CONCLUSIONS

Given that pain is 1 of the main symptoms of TMJOA, experimental study protocols should include long-term pain assessment.

Therapeutic Agents for the Treatment of Temporomandibular Joint Disorders: Progress and Perspective

Temporomandibular joint disorders (TMD) are a common health condition caused by the structural or functional disorders of masticatory muscles and the temporomandibular joint (TMJ). Abnormal mandibular movement in TMD patients may cause pain, chronic inflammation, and other discomfort, which could be relieved by a variety of drugs through various delivery systems. In this study, we summarized commonly used therapeutic agents in the management of TMD as well as novel bioactive molecules in preclinical stage and clinical trials. The emerging therapy strategies such as novel intra-TMJ delivery systems and implants based on tissue engineering are also discussed. This comprehensive review will strengthen our understanding of pharmacological approaches for TMD therapy.

Antidiabetic and Nephroprotective Effects of Polysaccharide Extract from the Seaweed Caulerpa racemosa in High Fructose-Streptozotocin Induced Diabetic Nephropathy

BACKGROUND

Nephropathy is a frontline complication of diabetes mellitus (DM) associated with impaired redox-inflammatory networks. The study investigated the antidiabetic and nephroprotective potentials of PCR against diabetic nephropathy (DN) in rats.

METHODS

DN was induced in rats using a combination of a high fructose solution for 4 weeks and an intraperitoneal injection of streptozotocin (35 mg/kg). Diabetic rats were treated with PCR (100 and 400 mg/kg body weight) for 8 weeks. Serum biochemical parameters as well as renal oxidative stress parameters, proinflammatory cytokines, Western blot and histopathological analyses were evaluated.

RESULTS

There were significant increases in fasting blood glucose, urinary albumin, serum creatinine, blood urea nitrogen (BUN), total cholesterol (TC), triglycerides (TG), and low-density lipoproteins (LDL-C) levels in diabetic rats compared to the non-diabetic control rats. DM-induced DN prominently depressed renal superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) activities, whereas renal malondialdehyde (MDA) level was markedly increased. Furthermore, renal inflammatory cytokines, IL-1β, IL-6, TNF-α and TGF-β, were considerably elevated compared to non-diabetic control rats. Additionally, DN rats showed a significant increase in renal fibrosis, as evidenced by increased expression of TGF-β1, collagen-1, fibronectin and alpha-smooth muscle actin (α-SMA) in the kidneys. Histopathological lesions were consistent with tubule thickening and glomerular hypertrophy. Conversely, PCR treatment exerted significant attenuation of hyperglycemia, dyslipidemia and renal oxidative stress indicators. The increased renal levels of IL-1β, IL-6, TNF-α and TGF-β were also notably reversed dose-dependently with alleviation of nephropathic histology. Furthermore, PCR reduced the expression of α-SMA, fibronectin, collagen-1 and TGF-β1 in the renal tissues.

CONCLUSION

Our results suggest that PCR displayed antidiabetic and nephroprotective effects against DN by impeding oxidative stress and inflammation. As such, PCR has potentials as a food supplement for alleviating renal dysfunction caused by diabetes.

Bioinformatic Characterization of Sulfotransferase Provides New Insights for the Exploitation of Sulfated Polysaccharides in Caulerpa

Caulerpa is an unusual algal genus from Caulerpaceae (Chlorophyta, Bryopsidales). Species from this family produce a wide range of metabolites suitable for biotechnology applications. Among these, sulfated polysaccharides (SPs) are often highly desirable for pharmaceutical and nutraceutical applications. Here, we provide a classification of sulfotransferases from Caulerpa; these important enzymes catalyze the nodal step for the biosynthesis of SPs. For this, we performed phylogenetic, genomic, expression analyses and prediction of the protein structure on sulfotransferases from Caulerpa. Sequences, domains and structures of sulfotransferases generally shared common characteristics with other plants and algae. However, we found an extensive duplication of sulfotransferase gene family, which is unique among the green algae. Expression analysis revealed specific transcript abundance in the pinnae and rachis of the alga. The unique genomic features could be utilized for the production of complex SPs, which require multiple and specific sulfation reactions. The expansion of this gene family in Caulerpaceae would have resulted in a number of proteins characterizing the unique SPs found in these algae. We provide a putative biosynthetic pathway of SPs, indicating the unique characteristics of this pathway in Caulerpa species. These data may help in the future selection of Caulerpa species for both commercial applications and genetic studies to improve the synthesis of valuable products from Caulerpa.

Diversity of Sulfated Polysaccharides From Cell Walls of Coenocytic Green Algae and Their Structural Relationships in View of Green Algal Evolution

Seaweeds biosynthesize sulfated polysaccharides as key components of their cell walls. These polysaccharides are potentially interesting as biologically active compounds. Green macroalgae of the class Ulvophyceae comprise sulfated polysaccharides with great structural differences regarding the monosaccharide constituents, linearity of their backbones, and presence of other acidic substituents in their structure, including uronic acid residues and pyruvic acid. These structures have been thoroughly studied in the Ulvales and Ulotrichales, but only more recently have they been investigated with some detail in ulvophytes with giant multinucleate (coenocytic) cells, including the siphonous Bryopsidales and Dasycladales, and the siphonocladous Cladophorales. An early classification of these structurally heterogeneous polysaccharides was based on the presence of uronic acid residues in these molecules. In agreement with this classification based on chemical structures, sulfated polysaccharides of the orders Bryopsidales and Cladophorales fall in the same group, in which this acidic component is absent, or only present in very low quantities. The cell walls of Dasycladales have been less studied, and it remains unclear if they comprise sulfated polysaccharides of both types. Although in the Bryopsidales and Cladophorales the most important sulfated polysaccharides are arabinans and galactans (or arabinogalactans), their major structures are very different. The Bryopsidales produce sulfated pyruvylated 3-linked β-d-galactans, in most cases, with ramifications on C6. For some species, linear sulfated pyranosic β-l-arabinans have been described. In the Cladophorales, also sulfated pyranosic β-l-arabinans have been found, but 4-linked and highly substituted with side chains. These differences are consistent with recent molecular phylogenetic analyses, which indicate that the Bryopsidales and Cladophorales are distantly related. In addition, some of the Bryopsidales also biosynthesize other sulfated polysaccharides, i.e., sulfated mannans and sulfated rhamnans. The presence of sulfate groups as a distinctive characteristic of these biopolymers has been related to their adaptation to the marine environment. However, it has been shown that some freshwater algae from the Cladophorales also produce sulfated polysaccharides. In this review, structures of sulfated polysaccharides from bryopsidalean, dasycladalean, and cladophoralean green algae studied until now are described and analyzed based on current phylogenetic understanding, with the aim of unveiling the important knowledge gaps that still exist.