Structural characterization of a galactan from Ophiopogon japonicus and anti-pancreatic cancer activity of its acetylated derivative

Anticancer and anti-angiogenic activities of mannooligosaccharides extracted from coconut meal on colorectal carcinoma cells in vitro

Colorectal carcinoma (CRC) is one of the most common malignancies, though there are no effective therapeutic regimens at present. This study aimed to investigate the inhibitory effects of mannooligosaccharides extracted from coconut meal (CMOSs) on the proliferation and migration of human colorectal cancer HCT116 cells in vitro. The results showed that CMOSs exhibited significant inhibitory activity against HCT116 cell proliferation in a concentration-dependent manner with less cytotoxic effects on the Vero normal cells. CMOSs displayed the ability to increase the activation of caspase-8, -9, and -3/7, as well as the generation of reactive oxygen species (ROS). Moreover, CMOSs suppressed HCT116 cell migration in vitro. Interestingly, treatment of human microvascular endothelial cells (HMVECs) with CMOSs resulted in the inhibition of cell proliferation, cell migration, and capillary-like tube formation, suggesting its anti-vascular angiogenesis. In summary, the results of this study indicate that CMOSs could be a valuable therapeutic candidate for CRC treatment.

Structural and interfacial properties of acetylated Millettia speciosa Champ polysaccharide and stability evaluation of the resultant O/W emulsion containing β-carotene

The aim of this study was to investigate the effects of acetylation modification on the structural, interfacial and emulsifying properties of Millettia speciosa Champ polysaccharide (MSCP). Besides, the influence of acetylation modification on the encapsulation properties of polysaccharide-based emulsion was also explored. Results indicated that modification resulted in a prominent reduction in molecular weight of MSCP and the interfacial layer thickness formed by acetylated MSCP (AC-MSCP) was also decreased, but the adsorption rate and ability of AC-MSCP to reduce interfacial tension were improved. AC-MSCP formulated emulsion possessed smaller droplet size (6.8 μm) and exhibited better physical stability under stressful conditions. The chemical stability of β-carotene was also profoundly enhanced by AC-MSCP fabricated emulsion. Moreover, AC-MSCP improved lipids digestion extent, thus facilitating the formation of micelle and increasing bioaccessibility of β-carotene. This study provided insights for rational modification of polysaccharide-based emulsifier and designing delivery system for chemically labile hydrophobic bioactive components.

Structural characteristics of steamed Polygonatum cyrtonema polysaccharide and its bioactivity on colitis via improving the intestinal barrier and modifying the gut microbiota

Steamed Polygonatum cyrtonema has been commonly used clinically for its gaining effect, whose main active ingredient is a polysaccharide. A water-soluble polysaccharide named PSP-W-1 was isolated from steamed Polygonatum cyrtonema. PSP-W-1 was characterized as a galactan having a backbone consisting predominately of 1,4-β-linked Galp branched at the C-6 position by T-β-linked Galp with a molecular weight of 14.4 kDa. PSP-W-1 could inhibit the overproduction of inflammatory factors and inflammatory mediators (iNOS, IL-6, COX-2) in dextran sodium sulfate-induced colitis mice. Oral administration of PSP-W-1 dramatically alleviated colonic pathological damage, repaired the intestinal barrier (occludin and ZO-1) and regulated the intestinal microbiota by increasing the abundance of norank_f_Muribaculaceae, Lactobacillus and norank_f_norank_o_Clostridia UCG-014, while decreasing the abundance of Bacteroides and Escherichia-Shigella to alleviate colitis symptoms. Overall, our findings suggest that PSP-W-1 might be a therapeutic option for both the prevention and treatment of colitis.

Structure and Binding Properties to Blood Co-Factors of the Least Sulfated Galactan Found in the Cell Wall of the Red Alga Botryocladia occidentalis

Three different populations of sulfated polysaccharides can be found in the cell wall of the red alga Botryocladia occidentalis. In a previous work, the structures of the two more sulfated polysaccharides were revised. In this work, NMR-based structural analysis was performed on the least sulfated polysaccharide and its chemically modified derivatives. Results have revealed the presence of both 4-linked α- and 3-linked β-galactose units having the following chemical features: more than half of the total galactose units are not sulfated, the α-units occur primarily as 3,6-anhydrogalactose units either 2-O-methylated or 2-O-sulfated, and the β-galactose units can be 4-O-sulfated or 2,4-O-disulfated. SPR-based results indicated weaker binding of the least sulfated galactan to thrombin, factor Xa, and antithrombin, but stronger binding to heparin cofactor II than unfractionated heparin. This report together with our previous publication completes the structural characterization of the three polysaccharides found in the cell wall of the red alga B. occidentalis and correlates the impact of their composing chemical groups with the levels of interaction with the blood co-factors.

The traditional use, structure, and immunostimulatory activity of bioactive polysaccharides from traditional Chinese root medicines: A review

As research on traditional Chinese medicine (TCM) has expanded, our understanding of the role it can have in controlling the immune system has increased. Polysaccharides from medicinal plants exhibit numerous beneficial therapeutic properties, presumably owing to their modulation of innate immunity and macrophage function. Numerous studies have demonstrated the multiple ways whereby certain polysaccharides can affect the immune system. In addition to stimulating immune cells, such as T cells, B lymphocytes, macrophages, and natural killer cells, polysaccharides stimulate complements and increase cytokine secretion. The biological functions of polysaccharides are directly correlated with their structures. This paper summarizes the sources, TCM uses, extraction and purification methods, structural characterization, in vitro and in vivo immune activities, and underlying molecular mechanisms of TCM root polysaccharides. Moreover, the structure-activity relationships of TCM root polysaccharides are emphasized and discussed. This review can provide a scientific basis for the research and industrial utilization of TCM root polysaccharides.

Characterisation of an anticomplement polysaccharide BP-S1 from seeds of Brucea javanica

Bioactivity-guided purification obtained polysaccharide BP-S1 from seeds of Brucea javanica. The results showed that BP-S1 was a homogenous polysaccharide with molecular weight of 45.7 kDa, mainly composed of arabinose and glucose in the ratio of 1.0:1.0 and the backbone of BP-S1 was deduced to be →3,4)-α-Glup-(1→ with branches of →2)-α-Arap-(1→and α-Arap-(1→, and the possible repetitive units were speculated according to result of methylation and 2D-NMR. Moreover, BP-S1 is a periodic rope-like structure. Functional analysis revealed that BP-S1 inhibited complement activation on the classic and alternative pathways with values of CH50 0.073 ± 0.012 mg/mL and AP50 0.097 ± 0.004 mg/mL, respectively. In mechanism study, using complement component depleted-sera methods indicated that BP-S1 selectively interacted with C3 and C4 components.

A novel branched galacturonan from Gardenia jasminoides alleviates liver fibrosis linked to TLR4/NF-κB signaling

Gardenia jasminoides (GJ) is a classic edible medicine in China of which the fruit has been proved to alleviate liver damage. We hypothesized whether polysaccharide in the fruit could have comparable bioactivity. To address this, a novel polysaccharide GJE0.2-2, is purified from the fruit of Gardenia jasminoides. Indeed, GJE0.2-2 may attenuate CCl₄-induced liver fibrosis in mice and impede the expression of critical fibrogenesis associated molecules such as α-SMA, FN1, and Collagen I induced by TGF-β in human hepatic stellate LX-2 cells. Mechanism studies suggest that this bioactivity may be implicated in TLR4/NF-κB signaling pathway via directly binding to TLR4. The structure characterization shows that the backbone of this polysaccharide is mainly composed of galacturonic acid with minor rhamnose, branched with galactose and arabinose, galacturonic acid, and esterified hexenuronic acid (HexpA). These findings provide evidence for a novel pectin-linked polysaccharide-based new drug candidate development for liver fibrosis therapy.

Ophiopogon japonicus and its active compounds: A review of potential anticancer effects and underlying mechanisms

BACKGROUND

Ophiopogon japonicus (Thunb.) Ker Gawl., a well-known Chinese herb, has been used in traditional Chinese medicine for thousands of years. Extensive in vitro and in vivo studies have shown that O. japonicus and its active compounds exhibit potential anticancer effects in a variety of cancer cells in vitro and suppress tumor growth and metastasis without causing serious toxicity in vivo.

PURPOSE

This review aims to systemically summarize and discuss the anticancer effects and the underlying mechanisms of O. japonicus extracts and its active compounds.

METHODS

The review is prepared following the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses. Various scientific databases including Web of Science, PubMed, Scopus, and Chinese National Knowledge Infrastructure were searched using the keywords: Ophiopogon japonicus, tumor, cancer, carcinoma, content, pharmacokinetics, and toxicity.

RESULTS

O. japonicus extracts and the active compounds, such as ruscogenin-1-O-[β-d-glucopyranosyl(1→2)][β-d-xylopyranosyl(1→3)]-β-d-fucopyranoside (DT-13), ophiopogonin B, and ophiopogonin D, exert potential anticancer effects, including the induction of cell cycle arrest, activation of apoptosis and autophagy, and inhibition of metastasis and angiogenesis. In addition, the mechanisms underlying these effects, as well as the pharmacokinetics, toxicity and clinical utility of O. japonicus extracts and active compounds are discussed. Furthermore, this review highlights the research and application prospects of these compounds in immunotherapy and combination chemotherapy.

CONCLUSIONS

The traditional herb O. japonicus and its phytochemicals could be safe and reliable anticancer drug candidates, alone or in combination with chemotherapeutic drugs. We hope that this review, which highlights the anticancer properties of O. japonicus, will contribute to drug optimization, therapeutic development, and future studies on cancer therapies based on this medicinal plant.

Naturally and chemically acetylated polysaccharides: Structural characteristics, synthesis, activities, and applications in the delivery system: A review

Acetylated polysaccharides refer to polysaccharides containing acetyl groups on sugar units. In the past, the acetylation modification of wall polysaccharides has been a hot research topic for scientists. However, in recent years, many studies have reported that acetylation-modified plant, animal, and microbial polysaccharide show great potential in delivery systems. From the latest perspective, this review systematically presents the different sources of naturally acetylated polysaccharides, the regularity of their modification, the chemical preparation of acetylation modifications, the biological activities and functions of acetylated polysaccharides, and the application in the delivery system. In nature, acetylated polysaccharides are extensively distributed in plants, microorganism, and animals. The level of acetylation modification, the distribution of chains, and the locations of acetylation modification sites differ between species. An increasing number of acetylated polysaccharides were prepared in the aqueous medium, which is safe, environment friendly, and low-cost. In addition to being necessary for plant growth and development, acetylated polysaccharides have immunomodulatory, antioxidant, and anticancer properties. The above-mentioned multiple sources, multifunctional and multi-active acetylated polysaccharides, make them an increasingly important part of delivery systems. We conclude by discussing the future directions for research and development and the potential uses for acetylated polysaccharides.

Acetylated polysaccharides: Synthesis, physicochemical properties, bioactivities, and food applications

Polysaccharides are biomacromolecular widely applied in the food industry, as gelling agents, thickeners and health supplements. As hydrophobic groups, acetyls provide amphiphilicity to polysaccharides with numerous hydroxyl groups, which greatly expand the presence of polysaccharides in organic organisms and various chemical environments. Acetylation could result in diverseness and promotion of the structure of polysaccharides, which improve the physicochemical properties and biological activities. High efficient and environmentally friendly access to acetylated derivatives of different polysaccharides is being explored. This review discusses and summarizes acetylated polysaccharides in terms of synthetic methods, physicochemical properties and biological activities and emphasizes the structure-effect relationships introduced by acetyl groups to reveal the potential mechanism of acetylated polysaccharides. Acetyls with different contents and substitution sites could change the molecular weight, monosaccharide composition and spatial architecture of polysaccharides, resulting in differences among properties such as water solubility, emulsification and crystallinity. Coupled with acetyls, polysaccharides have increased antioxidant, immunomodulatory, antitumor, and pro-prebiotic capacities. In addition, their possible applications have also been discussed in green food materials, bioactive ingredient carriers and functional food products, indicating that acetylated polysaccharides hold a clear vision in food health and industrial development.

Quality Evaluation of Ophiopogon japonicus from Two Authentic Geographical Origins in China Based on Physicochemical and Pharmacological Properties of Their Polysaccharides

Ophiopogon japonicus is widely used as a tonic herb in China. According to the origins, MaiDong of Chinese materia medica can be classified as Zhe MaiDong (Ophiopogon japonicus in Zhejiang), Chuan MaiDong (Ophiopogon japonicus in Sichuan), Duanting Shan MaiDong (Liriope muscari), and Hubei MaiDong (Liriope spicata). In terms of quality control, polysaccharides-based evaluations have not yet been conducted. In this study, microwave-assisted extraction (MAE) was used for the preparation of polysaccharides from 29 batches of MaiDong. HPSEC-MALLS-RID and HPAEC-PAD were employed to investigate their molecular parameters and compositional monosaccharides, respectively. The ability to scavenge ABTS radicals and immune promotion abilities, in terms of nitric oxide releasing and phagocytosis on RAW 264.7 macrophages, were also compared. The results showed that polysaccharides in different MaiDong varied in molecular parameters. All polysaccharides mainly contained fructose and glucose with small amounts of arabinose, mannose, galactose, and xylose. For polysaccharides of Zhe MaiDong and Chuan MaiDong, the molar ratio of Fru to Glc was roughly 15:1 and 14:1, respectively. Zhe MaiDong exhibited better antioxidant and immune promotion activity, and so did that of fibrous roots. The pharmacological activity, however, did not account for the variation in growth years. Finally, indicators for quality control based on multivariate statistical analysis included: yield, antioxidant activity, the content of fructose, and RI signal. It was concluded that MaiDong’s fibrous roots had similar components to the root, and their quality was not significantly affected by growth age. This may provide some guidance for the cultivation and use of MaiDong.

Extraction, purification, structure, modification, and biological activity of traditional Chinese medicine polysaccharides: A review

Traditional Chinese medicines (TCM), as the unique natural resource, are rich in polysaccharides, polyphenols, proteins, amino acid, fats, vitamins, and other components. Hence, TCM have high medical and nutritional values. Polysaccharides are one of the most important active components in TCM. Growing reports have indicated that TCM polysaccharides (TCMPs) have various biological activities, such as antioxidant, anti-aging, immunomodulatory, hypoglycemic, hypolipidemic, anti-tumor, anti-inflammatory, and other activities. Hence, the research progresses and future prospects of TCMPs must be systematically reviewed to promote their better understanding. The aim of this review is to provide comprehensive and systematic recombinant information on the extraction, purification, structure, chemical modification, biological activities, and potential mechanism of TCMPs to support their therapeutic effects and health functions. The findings provide new valuable insights and theoretical basis for future research and development of TCMPs.

Enhanced Growth Inhibition and Apoptosis Induction in Human Colon Carcinoma HT-29 Cells of Soluble Longan Polysaccharides with a Covalent Chemical Selenylation

The selenylated polysaccharides chemically belong to the organic Se-conjugated macromolecules and have recently been attracting more and more attention due to their potential to promote body health or prevent cancers. Longan (Dimocarpus longan L.), as a subtropical fruit, contains soluble and non-digestible polysaccharides that are regarded with health care functions in the body. In this study, the longan polysaccharides (LP) were obtained via enzyme-assisted water extraction, and then chemically selenylated using a reaction system composed of HNO₃–Na₂SeO₃ to yield two selenylated products, namely, SeLP1 and SeLP2, with Se contents of 1.46 and 4.79 g/kg, respectively. The anti-cancer effects of the three polysaccharide samples (LP, SeLP1, and SeLP2) were thus investigated using the human colon cancer HT-29 cells as the cell model. The results showed that SeLP1 and SeLP2 were more able than LP to inhibit cell growth, alter cell morphology, cause mitochondrial membrane potential loss, increase intracellular reactive oxygen and [Ca²⁺]_i levels, and induce apoptosis via regulating the eight apoptosis-related genes and proteins including Bax, caspases-3/-8/-9, CHOP, cytochrome c, DR5, and Bcl-2. It was thereby proven that the selenylated polysaccharides could induce cell apoptosis via activating the death receptor, mitochondrial-dependent, and ER stress pathways. Collectively, both SeLP1 and SeLP2 showed higher activities than LP in HT-29 cells, while SeLP2 was consistently more active than SeLP1 in exerting these assessed anti-cancer effects on the cells. In conclusion, this chemical selenylation covalently introduced Se into the polysaccharide molecules and caused an enhancement in their anti-cancer functions in the cells, while higher selenylation extent was beneficial to the activity enhancement of the selenylated products.

Preparation, structure and activity of polysaccharide phosphate esters

Polysaccharides have anti-virus, anti-cancer, anti-oxidation, immune regulation, hypoglycemia and other biological activities. Because of their safety, fewer side effects and other advantages, polysaccharides are considered as ideal raw materials in food and drugs. The biological activity of polysaccharides can be improved by structural modification (such as sulfation, carboxymethylation, phosphorylation, etc.), and even new biological activity can be generated. In this review, the recent advances in the phosphorylation of polysaccharides were reviewed from the perspectives of modification methods, structures, biological activities and structure-activity relationships.

Traditional Chinese medicine may be further explored as candidate drugs for pancreatic cancer: A review

Pancreatic cancer is a disease with a high mortality rate. Although survival rates for different types of cancers have improved in recent years, the five-year survival rate of pancreatic cancer stands at 8%. Moreover, the current first-line therapy, gemcitabine, results in low remission rates and is associated with drug resistance problems. Alternative treatments for pancreatic cancer such as surgery, chemotherapy and radiation therapy provide marginal remission and survival rates. This calls for the search of more effective drugs or treatments. Traditional Chinese medicine contains numerous bioactive ingredients some of which show activity against pancreatic cancer. In this review, we summarize the mechanisms of five types of traditional Chinese medicine monomers. In so-doing, we provide new potential drug candidates for the treatment of pancreatic cancer.

A novel pectin from Polygala tenuifolia blocks Aβ42 aggregation and production by enhancing insulin-degradation enzyme and neprilysin

More and more evidences show that pectin polysaccharide may have impact on Aβ_42, one important molecule implicated in Alzhemer's disease pathology. We speculate special structural motif of pectin might have better bioactivity on Aβ₄₂. To address this hypothesis, we reported structure and impact of a novel pectin RP02-1 with the molecular weight of 116.0 kDa from roots of Polygala tenuifolia on Aβ₄₂ aggregation and production and the underlying mechanism. Its structure is characterized as a backbone of alternate 1, 2, 4-linked α-Rhap and 1, 4-linked α-GalpA, with branches of terminal (T) -, 1, 3-,1, 4-, 1, 6- and 1, 3, 6-linked β-Galp, T-, 1, 5- and 1, 3, 5-linked α-Araf substituted at C-4 of 1, 2, 4-linked α-Rhap. Bioactivity study shows that this pectin may significantly block the aggregation of Aβ₄₂. We further show that RP02-1 suppresses Aβ₄₂ production with no apparent cytotoxicity in both CHO/APPBACE1 and HEK293-APPsw cells. Mechanism study demonstrates that RP02-1 may enhance the expression of insulin-degradation enzyme (IDE) and neprilysin (NEP), which are the main enzymes involved in Aβ degradation. These results suggest that RP02-1 may be a candidate leading compound for anti-Alzheimer's disease new drug development by attenuating Aβ₄₂ production and inhibiting Aβ₄₂ aggregation.

Extraction Optimization, Structural Characterization, and Antioxidant Activities of Polysaccharides from Cassia Seed (Cassia obtusifolia)

In order to explore Cassia seed polysaccharides (CSPs) as natural antioxidants for application in the functional-food industry, microwave-assisted extraction (MAE) was optimized for the extraction of CSPs by using a response surface methodology. Furthermore, the chemical structures and antioxidant activities of CSPs extracted by MAE and hot water extraction were investigated and compared. The maximum extraction yield of CSPs extracted by MAE (8.02 ± 0.19%) was obtained at the optimized extraction parameters as follows: microwave power (415 W), extraction time (7.0 min), and ratio of water to raw material (51 mL/g). Additionally, the contents of the uronic acids, molecular weight, ratio of constituent monosaccharides, intrinsic viscosities, and degrees of esterification of CSPs were significantly affected by the MAE method. Moreover, CSPs exhibited remarkable 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) ABTS, 2,2-diphenyl-1-(2,4,6-trinitrophenyl) hydrazyl DPPH, nitric oxide, and hydroxyl radical scavenging activities as well as reducing power. The high antioxidant activities observed in CSPs extracted by MAE could be partially attributed to its low molecular weights and high content of unmethylated galacturonic acid. Results indicate that the MAE method could be an efficient technique for the extraction of CSPs with high antioxidant activity, and CSPs could be further explored as functional food ingredients.