Isolation, structure elucidation, and immunostimulatory activity of polysaccharide fractions from Boswellia carterii frankincense resin

Characterization of Unfractionated Polysaccharides in Brown Seaweed by Methylation-GC-MS-Based Linkage Analysis

This study introduces a novel approach to analyze glycosidic linkages in unfractionated polysaccharides from alcohol-insoluble residues (AIRs) of five brown seaweed species. GC-MS analysis of partially methylated alditol acetates (PMAAs) enables monitoring and comparison of structural variations across different species, harvest years, and tissues with and without blanching treatments. The method detects a wide array of fucose linkages, highlighting the structural diversity in glycosidic linkages and sulfation position in fucose-containing sulfated polysaccharides. Additionally, this technique enhances cellulose quantitation, overcoming the limitations of traditional monosaccharide composition analysis that typically underestimates cellulose abundance due to incomplete hydrolysis of crystalline cellulose. The introduction of a weak methanolysis-sodium borodeuteride reduction pretreatment allows for the detection and quantitation of uronic acid linkages in alginates.

Cytochemical localization and synthesis mechanism of the glucomannan in pseudobulbs of Bletilla striata Reichb. f

The dried pseudobulbs of Bletilla striata, an important traditional Chinese medicine named BaiJi, have an extraordinary polysaccharide content and excellent prospects for medicinal effects. However, the distribution and molecular mechanism underlying biosynthesis are poorly understood. In this study, chemical and immunologic analyses were performed in representative tissues of B. striata, and the results showed that what are conventionally termed Bletilla striata polysaccharides (BSPs) are water-soluble polysaccharides deposited only in pseudobulbs. The structural component of BSPs is glucomannan, with a mannose:glucose mass ratio of ~3:2. BSPs are present in the parenchyma of the pseudobulbs in cells known as glucomannan idioblasts and distributed in the cytoplasm within cellular membranes, but are not contained in the vacuole. Comparative transcriptomics and bioinformatics analyses mapped the pathway from sucrose to BSP and identified BsGPI, BsmanA, and BsCSLAs as the key genes of BSP biosynthesis, suggesting that the functional differentiation of the cellulose synthase-like family A (CSLA) may be critical for the flow of glucomannan to the BSP or cell wall. Subsequently, virus-mediated gene silencing showed that silencing of two CSLAs (Bs03G11846 and Bs03G11849) led to a decrease in BSP content, and yeast two-hybrid and luciferase complementation experiments confirmed that four CSLAs (Bs03G11846, Bs03G11847, Bs03G11848, and Bs03G11849) can form homo- or heterodimers, suggesting that multiple CSLAs may form a large complex that functions in BSP synthesis. Our results provide cytological evidence of BSP and describe the isolation and characterization of candidate genes involved in BSP synthesis, laying a solid foundation for further research on its regulation mechanisms and the genetic engineering breeding of B. striata.

Methylation-GC-MS/FID-Based Glycosidic Linkage Analysis of Unfractionated Polysaccharides in Red Seaweeds

Glycosidic linkage analysis was conducted on the unfractionated polysaccharides in alcohol-insoluble residues (AIRs) prepared from six red seaweeds (Gracilariopsis sp., Prionitis sp., Mastocarpus papillatus, Callophyllis sp., Mazzaella splendens, and Palmaria palmata) using GC-MS/FID analysis of partially methylated alditol acetates (PMAAs). The cell walls of P. palmata primarily contained mixed-linkage xylans and small amounts of sulfated galactans and cellulose. In contrast, the unfractionated polysaccharides of the other five species were rich in galactans displaying diverse 3,6-anhydro-galactose and galactose linkages with varied sulfation patterns. Different levels of cellulose were also observed. This glycosidic linkage method offers advantages for cellulose analysis over traditional monosaccharide analysis that is known for underrepresenting glucose in crystalline cellulose. Relative linkage compositions calculated from GC-MS and GC-FID measurements showed that anhydro sugar linkages generated more responses in the latter detection method. This improved linkage workflow presents a useful tool for studying polysaccharide structural variations across red seaweed species. Furthermore, for the first time, relative linkage compositions from GC-MS and GC-FID measurements, along with normalized FID and total ion current (TIC) chromatograms without peak assignments, were analyzed using principal component analysis (PCA) as a proof-of-concept demonstration of the technique's potential to differentiate various red seaweed species.

Phytochemical study of Boswellia dalzielii oleo-gum resin and evaluation of its biological properties

Boswellia dalzielii is a resin-producing tree endemic to West and Central Africa, used by local populations for various medicinal purposes. In this study, B. dalzielii gum resin was analyzed by GC-MS and UHPLC-MS to identify and quantify volatile and non-volatile compounds. Its main volatile constituents were α-pinene (54.9%), followed by α-thujene (4.4%) and α-phellandren-8-ol (4.0%). Pentacyclic triterpenoids such as β-boswellic acids and their derivatives were quantified by UHPLC-MS and their content was shown to reach around 22% of the gum resin. Since some of the volatile and non-volatile compounds identified in this work are known to possess biological effects, the bioactivities of B. dalzielii ethanolic extract, essential oil, as well as fractions of the oil and extract were evaluated. Some of these samples exhibited interesting anti-inflammatory properties, and their antioxidant, anti-ageing and skin-bleaching activities were also tested.

Structural Characterization, Simulated Digestion and Anti-Aging Activities of an Acidic Polysaccharide from Salvia Miltiorrhiza

An acidic polysaccharide (SMP) with a molecular weight (Mw) of 1.28 × 10⁶ Da was isolated from Salvia miltiorrhiza. The monosaccharide composition in molar percentages was rhamnose (Rha): galacturonic acid (GalA): galactose (Gal): arabinose (Ara) = 6.15: 55.98: 21.27: 16.69. The results of simulated digestion in vitro showed that SMP was not degraded in saliva, gastric juice or intestinal juice. The Y maze test and new object recognition test showed that SMP could improve the working memory impairment of aging mice. SMP could also increase the activity of superoxide dismutase (SOD) and catalase (CAT) in serum and brain tissue, decrease the content of malondialdehyde (MDA), decrease the levels of interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) in brain tissue, and increase the content of short-chain fatty acids (SCFA) in the intestine. In addition, SMP could also regulate the intestinal flora structure, including increasing the relative abundance of Firmicutes and Bacteroidetes and decreasing the relative abundance of Proteobacteria. This work lays a foundation for the development of functional foods related to Salvia miltiorrhiza.

Ameliorative effect of buckwheat polysaccharides on colitis via regulation of the gut microbiota

Plant polysaccharides act as prebiotics by modulating gut microbiota. However, the functional characteristics of buckwheat Fagopyrum tataricum polysaccharides (FTP) and F. esculentum polysaccharides (FEP) on colitis prevention are not valid. This study evaluated the ameliorative effects of FTP and FEP against TNBS-induced colitis via gut microbiota modulation in rats. The characterizations of FTP and FEP were analyzed, including FTIR, TGA, DSC, and monosaccharide composition. In addition, the pathological features of colon length and symptoms in TNBS-induced colitis were improved via the intragastric preadministration of FTP and FEP. The results showed that prefeeding with FTP and FEP decreased inflammatory cytokines (IL-6, IL-1β, and TNF-α), β-glucuronidase, and mucinase, as well as increasing superoxide dismutase, catalase, and glutathione peroxidase levels, in TNBS-induced rats. A decrease in inflammatory signaling-associated proteins (NF-κB, MAPK, COX-2, and iNOS) improved the treatment of TNBS-induced colitis by buckwheat polysaccharides. Moreover, prefeeding with buckwheat polysaccharides increased the Firmicutes/Bacteroidetes ratio and short-chain fatty acid (SCFA) production and decreased the abundance of inflammation-related bacteria (Oscillospiraceae and Oscillibacter). In conclusion, FTP and FEP strongly improved TNBS-induced colitis through antioxidant, anti-inflammatory, and microbiota modulation properties, especially in the high-dose FEP group. Buckwheat polysaccharides have the potential for utilization in functional ingredients or food development.

Rhinacanthus nasutus and okara polysaccharides attenuate colitis via inhibiting inflammation and modulating the gut microbiota

Plant polysaccharides have prebiotic properties for gut microbiota and immune modulation. This study aimed to investigate the prevention abilities of edible Rhinacanthus nasutus polysaccharide (RNP) and okara polysaccharide (OP) in Sprague-Dawley rats with acetic acid-induced colitis. The characterizations of RNP and OP were analyzed, including Fourier transform infrared, thermogravimetric analysis, differential scanning calorimetry, and monosaccharide composition. The prebiotic properties of RNP and OP were determined in vitro. In addition, the pathological features of colon length and inflammatory cytokine levels in acetic acid-induced colitis were improved by intragastric preadministration of RNP and OP for 3 weeks. There was no nephrotoxicity or hepatotoxicity in rats via histopathological assessment after RNP and OP intake. Moreover, the abundance of short-chain fatty acids-producing bacteria (Lachnospiraceae, Lactobacilli, and Prevotellaceae) were increased after RNP supplementation. In conclusion, intragastric gavage of RNP and OP significantly modulated the gut microbiota and immune response, consequently alleviating the symptoms of colitis. This novel finding provides an alternative strategy and potential application of these two polysaccharides for colitis prevention and treatment.

Effects of Frankincense Compounds on Infection, Inflammation, and Oral Health

Boswellia trees, found throughout the Middle East and parts of Africa and Asia, are the source of frankincense oil. Since antiquity, frankincense has been traded as a precious commodity, but it has also been used for the treatment of chronic disease, inflammation, oral health, and microbial infection. More recently, the bioactive components of Boswellia trees have been identified and characterized for their effects on cancer, microbial infection (especially infection by oral pathogens), and inflammation. Most studies have focused on cell lines, but more recent research has also investigated effects in animal models of disease. As natural products are considered to be safer than synthetic drugs, there is growing interest in further developing the use of substances such as frankincense oil for therapeutic treatment.

Tracing analgesic constituents from crude and vinegar-processed resin of Boswellia carterii by integrating ultra-performance liquid chromatography tandem mass spectrometry based determination, analgesic evaluation in mice and grey relationship analysis

The analgesic effect of resin of Boswellia carterii is well-known, however, the constituents which contribute to the analgesic effect remain elusive. The current study intergrates ultrasonic assisted extraction, quantitative determination, analgesic evaluation in rats and grey relationship analysis for tracing analgesic constituents from resin of Boswellia carterii. First, a robust and precise ultra-performance liquid chromatography tandem mass spectrometry approach with multiple reaction monitoring mode was developed for simultaneous quantification of seven major constituents in crude and vinegar-processed resin of Boswellia carterii. Glycyrrhetinic acid was chosen as the internal standard. The approach showed good linearity. The intra-day and inter-day precisions of each constituent were all within 3.0%. The recoveries of each constituent were in the range of 96.4 to 102.7%. The approach was then applied to determining the seven constituents in ten batches of crude and vinegar-processed resin of Boswellia carterii. Second, the analgesic effects of crude and vinegar-processed resin of Boswellia carterii were assessed in mice. Third, chemometrics methods, grey relationship analysis and partial least squares regression were employed for clarifying the relationship between the contents of seven constituents and their analgesic effect. 11-Keto-β-boswellic acid, 3-acetyl-β-boswellic acid, 3-acetyl-α-boswellic acid, 3-acetyl-11-keto-β-boswellic acid and β-sitosterol were identified to be the key analgesic constituents of Boswellia carterii.

In situ exopolysaccharides produced by Lactobacillus helveticus MB2-1 and its effect on gel properties of Sayram ketteki yoghurt

In order to study the mechanism of high viscosity of Sayram ketteki yoghurt, the growth, acidification properties, in situ exopolysaccharides (EPS) production of Lactobacillus helveticus MB2-1 in milk medium were investigated. The microstructure of the yoghurt was analyzed. The characteristics of in situ EPS produced by this strain in yoghurt were studied by high-performance liquid chromatography (HPLC), Fourier-transform infrared spectroscopy (FT-IR), ultraviolet-visible (UV-vis) analysis. The amount of in situ EPS produced could be up to 689.47 mg/L. The micrographs of Sayram ketteki yoghurt demonstrated that the in situ EPS secreted by ropy L. helveticus MB2-1 were closely connected with proteins, effectively filling the three-dimensional network structure of casein clusters, thereby resulting in high viscosity of yoghurt. Besides, the molecular weight of in situ EPS was 9.34 × 10⁴ Da, and the in situ EPS was determined to be a new heteropolysaccharide, containing fucose, which made it unique. Moreover, the set yoghurts added with in situ EPS were demonstrated fine effects on the texture improvement. These results illustrated that L. helveticus MB2-1 could be set as a good starter and the in situ EPS could be considered as a probiotic stabilizer substitute for fermented dairy products.

Five terpenoids from the gum resin of Boswellia carterii and their cytotoxicity

One undescribed tetracyclic triterpene (boswellicarin A), four undescribed pentacyclic triterpenes (boswellicarterins A-C) and one undescribed prenylaromadendrane-type diterpene (boscarterin A) were isolated from the gum resin of Boswellia carterii Birdw. (Burseraceae). Their structures were elucidated from NMR and HRESIMS spectroscopic data and ECD spectra. Boswellicarterins A-C and boscarterin A displayed weak and selective cytotoxicity against three human cancer cells (HepG2, A549 and MCF-7) by MTT assay.

Antibacterial Activity of Boswellia sacra Flueck. Oleoresin Extract against Porphyromonas gingivalis Periodontal Pathogen

Boswellia sacra Flueck. oleoresin extract (frankincense) has traditionally been used in the treatment of different diseases, but there are no sufficient studies on its potential activity against periodontal pathogens. Therefore, antibacterial and antibiofilm activity of frankincense extract against Porphyromonas gingivalis clinical isolates were studied. The phytochemical composition of the volatile components of the extract was identified by GC-MS analysis revealing 49 compounds as trans-nerolidyl formate, cycloartenol acetate, ursenoic acid 3-oxomethyl ester, bisabolene epoxide, and kaur-16-ene. It decreased the growth and increased the leakage of nucleotides in 58.3% and 33.3% of isolates, respectively. Additionally, it reduced the extracellular polysaccharide production and the cell surface hydrophobicity in 41.67% and 50% of the isolates, respectively. Crystal violet assay revealed inhibition of biofilm formation by the tested isolates. Light microscope and scanning electron microscope were used to examine the biofilms and they confirmed the reduction of biofilm formation by frankincense extract. Downregulation of the genes linked to biofilm formation (fimA, hagA, and hagB) was observed using qRT-PCR after treatment with the frankincense extract. This study suggested that the frankincense extract could exhibit antibacterial and antibiofilm activity against P. gingivalis isolates. Thus, the frankincense extract could be used as a treatment approach for periodontitis.

Boswellia serrata Resin Extract in Diets of Nile Tilapia, Oreochromis niloticus: Effects on the Growth, Health, Immune Response, and Disease Resistance to Staphylococcus aureus

Simple Summary

The current study evaluated the effects of Boswellia serrata resin extract (BSRE) as a feed additive on the growth performance, immune response, antioxidant status, and disease resistance of Nile tilapia, Oreochromis niloticus. Fish were fed on four basal diets complemented with four levels of BSRE 0, 5, 10, or 15 g kg⁻¹. The results of this study proposed that BSRE addition can enhance the antioxidant activity, immune status, and disease resistance of O. niloticus to S. aureus infection. The level of 5 g kg⁻¹ BSRE can improve fish growth without causing harmful effects on fish health. Higher levels of BSRE are not recommended as they badly affected the histoarchitecture of many vital organs.

Abstract

The influences of Boswellia serrata resin extract (BSRE) as a feed additive on the growth performance, immune response, antioxidant status, and disease resistance of Nile tilapia, Oreochromis niloticus L. were assessed. One hundred-forty four fingerlings (initial weight: 21.82 ± 0.48 g) were randomly allotted into four groups with three replicates where they were fed on one of four treatments with four levels of Boswellia serrata resin extract 0, 5, 10, or 15 g kg⁻¹, BSRE0, BSRE5, BSRE10, BSRE15, respectively for eight weeks. After the end of the feeding trial, the fish were challenged with Staphylococcus aureus, and mortalities were noted. The final body weight, total body weight gain, and the total feed intake were quadratically increased in BSRE5 treatment (p < 0.01). The protein productive efficiency (PPE) was linearly and quadratically increased in all BSRE supplemented treatments (p < 0.01). Dietary addition of BSRE raised the fish crude protein content and reduced the fat content in a level-dependent manner (p < 0.01). The ash content was raised in the BSRE15 group (p < 0.01). Dietary BSRE supplementation decreased the serum levels of glucose, total cholesterol, triglycerides, and nitric oxide. It increased the serum levels of total protein, albumin, total globulins, α1 globulin, α2 globulin, ß globulin, ɣ globulin, Catalase, and SOD (superoxide dismutase) activity, GSH (reduced glutathione), lysozyme activity, and MPO (myeloperoxidase) in a level-dependent manner (p < 0.05). The BSRE15 diet increased the serum level of ALT (alanine aminotransferase) and decreased creatinine serum level (p < 0.05). Dietary BSRE supplementation increased the relative percentage of survival % (RPS) of S. aureus challenged fish. The histoarchitecture of the gills and kidney was normal in the BSRE5 treatment and moderately changed in BSRE10 and BSRE15 treatments. The splenic lymphoid elements were more prevalent, and the melano-macrophage centers (MMC) were mild to somewhat activated in BSRE supplemented treatments. Dietary BSRE supplementation improved the intestinal histomorphology. It can be concluded that BSRE addition can enhance the antioxidant activity, immune status, and disease resistance of O. niloticus to S. aureus infection. The level of 5 g kg⁻¹ BSRE can improve fish growth without causing harmful effects on fish health. The highest levels of BSRE are not recommended as they badly affected the histoarchitecture of many vital organs.

Panax quinquefolius (North American Ginseng) Polysaccharides as Immunomodulators: Current Research Status and Future Directions

Panax quinquefolius (North American ginseng, NAG) is a popular medicinal plant used widely in traditional medicine. NAG products are currently available in various forms such as roots, extracts, nutraceuticals, dietary supplements, energy drinks, etc. NAG polysaccharides are recognized as one of the major bioactive ingredients. However, most NAG reviews are focused on ginsenosides with little information on polysaccharides. NAG polysaccharides have demonstrated a therapeutic activity in numerous studies, in which many of the bioactivities involve regulation of the immune response. The purpose of this review is to summarize the structural features and the immunomodulatory properties of crude, partially purified, and pure polysaccharides isolated from NAG. Receptors of the innate immune system that potentially bind to NAG polysaccharides and the respective signal transduction pathways initiated by these compounds are discussed. Major challenges, recent innovations, and future directions in NAG polysaccharide research are also summarized.

An acidic polysaccharide (AGC3) isolated from North American ginseng (Panax quinquefolius) suspension culture as a potential immunomodulatory nutraceutical

Polysaccharides isolated from Panax quinquefolius roots are widely used as nutraceuticals due to their immunomodulatory properties. Despite their popularity, several challenges exist in isolating ginseng root polysaccharides such as batch-to-batch structural inconsistencies and bacterial endotoxin contamination. A plant tissue culture-based platform offers a potential solution to isolate natural polysaccharide fractions with consistent chemical characteristics and reduced endotoxin content. In this study, an acidic polysaccharide fraction (AGC3) with immunomodulatory properties was isolated from Panax quinquefolius suspension cultures. The heterogeneous fraction (molecular weight: 4.81 and 32.14 kDa), purified by anion exchange chromatography, was predominantly composed of galactose (>60%) along with the presence of rhamnose, arabinose, glucose, glucuronic acid and galacturonic acid. The major glycosidic linkages were found to be t-Galp (47.7%), 4-Galp (15.6%), 2,4-Rhap (8.1%), 6-Galp (8.1%) and 4-GalAp (6.8%). Structural analyses indicated the presence of a pectic rhamnogalacturonan I polysaccharide in AGC3. AGC3 significantly (p < 0.05) stimulated RAW 264.7 murine macrophage cells and primary murine splenocytes by enhancing the production of several immunomodulatory mediators such as IL-6, TNF-α, GM-CSF and MCP-1. The results also indicated the putative roles of NF-κB (p65/RelA) and MAPK (p38) signaling pathways in the immunostimulatory response. Additionally, AGC3 induced murine splenocyte proliferation, another major indicator of immunostimulation. Overall, AGC3 has the potential to be used as an immunostimulatory nutraceutical.

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American ginseng suspension culture as source of natural bioactive polysaccharides.

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Acidic polysaccharide, AGC3 displayed potent immunostimulatory properties.

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Putative mechanism of action includes NF-κB (p65/RelA) and MAPK (p38) pathways.

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AGC3 predominantly composed of RGI-type pectins.

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Potential nutraceutical that can be used as an exogenous immunomodulator.