Antioxidant, antitumor and immunomodulatory activities of water-soluble polysaccharides in Abrus cantoniensis

Abrus cantoniensis Hance: Ethnopharmacology, phytochemistry and pharmacology of a promising traditional Chinese medicine

ETHNOPHARMACOLOGICAL RELEVANCE

Abrus cantoniensis Hance (ACH), known as Jigucao (Chinese: ) has been used in ethnopharmacology for a long history with therapeutic effects for clearing heat, soothing the liver, especially in treating acute and chronic hepatitis which was very effective. In southern China, such as Guangdong and Guangxi, people often use ACH in soup or herbal tea as dietetic therapy.

AIM OF THE REVIEW

This paper aims to review ACH's ethnopharmacology, phytochemistry, and pharmacological activity systematically, at the same time, we also hope to provide more research avenues between traditional uses and pharmacological properties.

MATERIAL AND METHODS

Through PubMed, Wan Fang Database, CNKI, Web of Science, EBSCO Database, and Google Scholar search for relevant literature in both Chinese and English, the keywords "Abrus cantoniensis, Abrus cantoniensis Hance, Jigucao, pharmacology, chemical constituents, clinical application, network pharmacology" were used alone or combination.

RESULTS

Traditionally, ACH was believed to have the effect of soothing the liver, clearing heat, and detoxifying, often used to treat diseases of the liver and inflammation. Modern pharmacological research indicates that ACH has liver protection, anti-inflammation, anti-oxidant, immunomodulation, anti-tumor effects and so on. Whether it was a single chemical compound or an extract from ACH, studies have found that it has abundant pharmacological activities, these were the fundamental sources of traditional uses, like liver protection and anti-inflammation.

CONCLUSIONS

A systematic review found that modern phytochemistry and pharmacodynamic research reports on ACH are closely related to its traditional uses, especially its hepatoprotective and anti-inflammatory effects. Modern research has also further explored and expanded the effects of ACH, such as its anti-tumor effect. And all these efforts are gradually filling the gap between traditional uses and modern pharmacology. In general, the current research on the pharmacodynamic mechanism of ACH still needs further in-depth research, and the strategies adopted must also be further strengthened.

Natural resourced polysaccharides: Preparation, purification, structural elucidation, structure-activity relationships and regulating intestinal flora, a system review

Natural resourced polysaccharides (NRPs), as metabolites synthesized during activity of organisms, widely present in animal cell membranes or plant and microbial cell walls. NRPs have garnered extensive attention in the fields of medicine, foods, and farming owing to their distinct bioactivities and structural diversity. Despite the burgeoning growth in NRPs research, the available literature focuses primarily on a review of specific polysaccharides, necessitating an urgent need for a comprehensive summary of NRPs to offer readers a whole landscape of current advancements in NRPs research. Based on this, this article comprehensively reviews the latest research progress regarding preparation, purification, structure elucidation, structure-activity relationships and regulation of intestinal flora of NRPs in electronic databases, such as PubMed, Wiley, ScienceDirect and Web of Science from last 5 years. This review analyzes the effects of various extraction techniques on NRPs and also delves into the intrinsic correlation between the biological activity and structure of NRPs, highlighting that chemical modification can enhance their structural diversity and confer novel or improved biological functions. Moreover, this article extensively explores the application of NRP in promoting intestinal microecology balance, underscoring its significant potential as a probiotic initiator. This review lays a solid theoretical foundation for the future research and development of NRPs.

Effect of ultrasound assisted H2O2/Vc treatment on the hyperbranched Lignosus rhinocerotis polysaccharide: Structures, hydrophobic microdomains, and antitumor activity

The effect of ultrasonic intensity (28.14, 70.35, and 112.56 W/cm2) on Lignosus rhinocerotis polysaccharide (LRP) degraded by ultrasound assisted H2O2/Vc system (U-H/V) was investigated. U-H/V broke the molecular chain of LRP and improved the conformational flexibility, decreasing the molecular weight, intrinsic viscosity ([η]) and particle size. The functional groups and hyperbranched structure of LRP were almost stable after U-H/V treatment, however, the triple helix structure of LRP was partially disrupted. With increasing ultrasonic intensity, the critical aggregation concentration increased from 0.59 mg/mL to 1.57 mg/mL, and the hydrophobic microdomains reduced. Furthermore, the LRP treated with U-H/V significantly inhibited HepG2 cell proliferation by inducing apoptosis. The increase in antitumor activity of LRP was closely associated with the reduction of molecular weight, [η], particle size and hydrophobic microdomains. These results revealed that U-H/V treatment facilitates the degradation of LRP and provides a better insight into the structure-antitumor activity relationship of LRP.

Network pharmacology and experimental validation of effects of total saponins extracted from Abrus cantoniensis Hance on acetaminophen-induced liver injury

ETHNOPHARMACOLOGICAL RELEVANCE

Abrus cantoniensis Hance (AC), an abrus cantoniensis herb, is a Chinese medicinal herb used for the treatment of hepatitis. Total saponins extracted from AC (ACS) are a compound of triterpenoid saponins, which have protective properties against both chemical and immunological liver injuries. Nevertheless, ACS has not been proven to have an influence on drug-induced liver injury (DILI).

AIM OF THE STUDY

This study used network pharmacology and experiments to investigate the effects of ACS on acetaminophen (APAP)-induced liver injury.

MATERIALS AND METHODS

The targets associated with ACS and DILI were obtained from online databases. Cytoscape software was utilized to construct a "compound-target" network. In addition, Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were used to analyze the related signaling pathways impacted by ACS. AutoDock Vina was utilized to evaluate the binding affinity between bioactive compounds and the key targets. To validate the findings of network pharmacology, in vitro and in vivo experiments were conducted. Cell viability assay, transaminase activity detection, immunofluorescence assay, immunohistochemistry staining, RT-qPCR, and western blotting were utilized to explore the effects of ACS.

RESULTS

25 active compounds and 217 targets of ACS were screened, of which 94 common targets were considered as potential targets for ACS treating APAP-induced liver injury. GO and KEGG analyses showed that the effects of ACS exert their effects on liver injury through suppressing inflammatory response, oxidative stress, and apoptosis. Molecular docking results demonstrated that core active compounds of ACS were successfully docked to core targets such as CASP3, BCL2L1, MAPK8, MAPK14, PTGS2, and NOS2. In vitro experiments showed that ACS effectively attenuated APAP-induced damage through suppressing transaminase activity and attenuating apoptosis. Furthermore, in vivo studies demonstrated that ACS alleviated pathological changes in APAP-treated mice and attenuated inflammatory response. Additionally, ACS downregulated the expression of iNOS, COX2, and Caspase-3, and upregulated the expression of Bcl-2. ACS also suppressed the MAPK signaling pathway.

CONCLUSIONS

This study demonstrated that ACS is a hepatoprotective drug through the combination of network pharmacology and in vitro and in vivo experiments. The findings reveal that ACS effectively attenuate APAP-induced oxidative stress, apoptosis, and inflammation through inhibiting the MAPK signaling pathway. Consequently, this research offers novel evidence supporting the potential preventive efficacy of ACS.

From Tea to Health: Exploring Abrus mollis for Liver Protection and Unraveling Its Potential Mechanisms

Abrus mollis Hance is a characteristic medicinal herb which is used in Guangdong and Guangxi provinces of China for making soup, medicinal meals, and herbal tea to treat dampheat jaundice and rib discomfort. Current phytochemical study on A. mollis led to the isolation of four new flavones, mollisone A-D (1-4), and thirty two known compounds (5-36). Their structures were characterized by an extensive analysis of spectroscopic data including IR, UV, HR-ESI-MS, and 1D and 2D NMR, as well as electronic circular dichroism calculation. In addition, in order to initially understand their biological activities for traditional applications, in vitro antioxidant and hepatoprotective tests were carried out, whose results illustrated that 25 compounds had significant free radical scavenging ability, and compounds 13 and 16 exhibited protective activities on D-GalN-induced LO2 cell damage than the positive control. Moreover, network pharmacological analysis revealed that the hepatoprotective activity of A. mollis involved multitargets and multipathways such as PI3K/Akt, MAPK, and JAK-STAT pathways and various biological processes such as positive regulation of phosphorylation and regulation of kinase activity. These results suggested that this species could serve as a potential hepatoprotective agent for functional food or medicinal use.

Structural Characterization of an Alcohol-Soluble Polysaccharide from Bletilla striata and Antitumor Activities in Vivo and in Vitro

In general, Bletilla striata polysaccharides were mostly water-soluble. However, the structural property, immunomodulatory effects and antitumor activities of alcohol-soluble Bletilla striata polysaccharide were rarely reported. In this study, an alcohol-soluble Bletilla striata polysaccharide was firstly extracted, investigated the structural property and evaluated the antitumor activity in vivo and in vitro. Results showed that BSAP was a low molecular weight polysaccharide (2.29×10⁴  Da) and consisted of glucose, xylose and mannose (molar ratio: 2.39 : 1.00 : 0.21). Animal experiments results suggested that BSAP could effectively inhibit the expansion of H22 solid tumors, protect thymus and spleen, improve macrophages, lymphocytes and NK cells activities and enhance lymphocyte subsets proportion, presenting a better immunological enhancement effect in vivo. Additionally, the results of cell experiments showed that BSAP had obvious antitumor effect in vitro, including inhibiting the proliferation of H22 cells and inducing the apoptosis of tumor cells. These results would provide theoretical basis and new ideas for the further development and utilization of BSAP in the biomedical field.

Abrusamide H Impairs the Secretion of the Cytokines in RAW264.7 Cells and the Inflammatory Infiltration in Tail Transection-Induced Zebrafish

Abrus mollis Hance (Leguminosae) has a variety of biological activities, including anti-inflammatory, antioxidant, antibacterial, antiviral, and antitumor activities. However, the specific substances responsible for the anti-inflammatory effects are unknown. Abrusamide H (BJBS) is a truxillic acid derivative obtained from the leaves of Abrus mollis Hance and has potential anti-inflammatory effects. In this study, we aimed to estimate the potential effect and mechanism of BJBS in inflammation by establishing lipopolysaccharide (LPS)-stimulated RAW264.7 cells in vitro and an injured zebrafish tail fin in vivo. The RAW264.7 cells were treated with different concentrations of BJBS after LPS stimulation. The production of nitric oxide (NO) was detected by Griess reaction, and reactive oxygen species (ROS) were detected by an ROS assay kit. The levels of proinflammatory cytokines, including interleukin 6 (IL-6), tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and interleukin 18 (IL-18) were measured by ELISA. Results showed that BJBS at all concentrations inhibited the proliferation of RAW264.7 macrophages after LPS stimulation by cell counting kit-8 and the production of NO and ROS. In the BJBS treatment group, the levels of IL-6, TNF-α, IL-1β, and IL-18 decreased in a concentration-dependent manner. The results in vivo showed that no significant difference in the survival of zebrafish between the BJBS and blank groups and BJBS inhibited the migration and aggregation of zebrafish neutrophils in a dose-dependent manner in inflammation induced by tail transection-induced inflammation. In conclusion, BJBS inhibited the production of NO and ROS, decreased the levels of secreted IL-6, TNF-α, IL-1β, and IL-18, and reduced the migration and aggregation of zebrafish neutrophils.

Analysis of the chemical composition of natural carbohydrates - An overview of methods

Natural carbohydrates are gaining importance over a wide spectrum of human activity due to their versatile functionalities. The properties of carbohydrates are currently used in many branches of industry and new possibilities of their utilization, like in medicine or materials science, are demonstrated systematically. The attractive properties of carbohydrates result from their chemical structure and ability to form macromolecules and derivatives. Each application of carbohydrate requires a knowledge of their chemical composition, which due to the number and differentiation of monosaccharides and their spatial forms is often challenging. This review presents an overview on sample preparation and the methods used for the determination of the fine chemical structure of natural carbohydrates. Most popular and reliable colorimetric, chromatographic and spectroscopic methods are presented with an emphasis on their pros and cons.

Subcritical Water Enhanced with Deep Eutectic Solvent for Extracting Polysaccharides from Lentinus edodes and Their Antioxidant Activities

In the present study, subcritical water extraction (SWE) assisted with deep eutectic solvent (DES) is used to extract Lentinus edodes polysaccharides (LEP). In addition, the antioxidant activity of the polysaccharide samples was also investigated. Based on a single factor test and response surface test, the optimal extraction factors were a liquid-solid solvent of 40:1 mL/g, extraction temperature of 147.23 °C, water content of 39.76% and extraction time of 17.58 min. Under these extraction conditions, the yield of LEP was 6.26 ± 0.08%. Compared with the SWE and hot water extraction (HWE), it improved by 19.24% and 17.01%, respectively. In addition, the results of monosaccharide composition, molecular weight, FT-IR, UV and SEM confirmed that the extracts had the features of polysaccharides. Interestingly, the polysaccharides obtained with the SWE assisted with the DES procedure showed a higher DPPH scavenging activity, hydroxyl radical scavenging activity and hydrogen peroxide scavenging activity, which indicated that the polysaccharides with this method had a stronger antioxidant activity. These findings demonstrated that the SWE-assisted DES is a strong method to obtain polysaccharides from Lentinus edodes for food, biopharmaceutical and other industrial production.

A natural selenium polysaccharide from Pleurotus ostreatus: Structural elucidation, anti-gastric cancer and anti-colon cancer activity in vitro

The development and application of new natural selenium polysaccharides with relatively clear structure and excellent activity have become hot and difficult issues. This study used GC-MS and 2D NMR to characterize the detailed chain structure information of selenium polysaccharide (Se-POP-3) from Selenium-enriched Pleurotus ostreatus, and then explored its anti-gastric cancer and anti-colon cancer effects in vitro. Results showed that the main chain of Se-POP-3 was →[3)-β-D-Glcp-(1]₂ → 6)-β-D-Glcp-(1 → 3,6)-β-D-Glcp-(1 → 3)-β-D-Glcp-(1→, and the branch was α-D-Glcp-(1 → [4)-α-D-Glcp-(1]₄→, which was connected to the main chain through the O-3 bond of →3,6)-β-D-Glcp-(1 → glycosidic bond. In addition, Se-POP-3 could reduce viability, induce apoptosis, inhibit migration and invasion, destroy the Bax/Bcl-2 ratio, and inhibit the epithelial-to-mesenchymal transition of MGC-803 and HCT-116 cells in vitro. Moreover, this study also showed that within the concentration range set in this study, Se-POP-3 had no significant effect on the growth of normal cells (NCM460 cells). This study can provide a theoretical basis for the potential application of Se-POP-3 as an anti-gastrointestinal cancer drug or functional food.

Medicinal Plants and Isolated Molecules Demonstrating Immunomodulation Activity as Potential Alternative Therapies for Viral Diseases Including COVID-19

Plants have been extensively studied since ancient times and numerous important chemical constituents with tremendous therapeutic potential are identified. Attacks of microorganisms including viruses and bacteria can be counteracted with an efficient immune system and therefore, stimulation of body's defense mechanism against infections has been proven to be an effective approach. Polysaccharides, terpenoids, flavonoids, alkaloids, glycosides, and lactones are the important phytochemicals, reported to be primarily responsible for immunomodulation activity of the plants. These phytochemicals may act as lead molecules for the development of safe and effective immunomodulators as potential remedies for the prevention and cure of viral diseases. Natural products are known to primarily modulate the immune system in nonspecific ways. A number of plant-based principles have been identified and isolated with potential immunomodulation activity which justify their use in traditional folklore medicine and can form the basis of further specified research. The aim of the current review is to describe and highlight the immunomodulation potential of certain plants along with their bioactive chemical constituents. Relevant literatures of recent years were searched from commonly employed scientific databases on the basis of their ethnopharmacological use. Most of the plants displaying considerable immunomodulation activity are summarized along with their possible mechanisms. These discussions shall hopefully elicit the attention of researchers and encourage further studies on these plant-based immunomodulation products as potential therapy for the management of infectious diseases, including viral ones such as COVID-19.

A novel polysaccharide from Castanea mollissima Blume: Preparation, characteristics and antitumor activities in vitro and in vivo

A new water-soluble polysaccharide, CMP90, with a molecular weight of 23.9 kDa was isolated from Castanea mollissima Blume and the preliminary structural characteristics and antitumor effects of CMP90 in vitro and in vivo were investigated in the research. CMP90 consists of arabinose, galactose, glucose, xylose and mannose (molar ratio: 0.08:0.11:5.14:0.12:0.08) with α- and β-anomeric units. The results of in vitro experiments indicated that CMP90 exhibited a significant inhibitory effect on the proliferation of HL-60 cells with typical apoptotic characteristics by inducing cell cycle arrested at G1/M phase. Additionally, the results in vivo suggested CMP90 was able to inhibit the growth of S180 solid tumors via protecting immune organs, improving the levels of serum cytokines (TNF-α, IL-2 and IFN-γ), enhancing the activities of immune cells (macrophages, lymphocytes and NK cells) and inducing cell apoptosis or death. Taken together, these combined data clearly indicated that CMP90 may be used as a potential candidate agent for cancer therapy.

Alcohol-soluble polysaccharide from Astragalus membranaceus: Preparation, characteristics and antitumor activity

The alcohol-soluble polysaccharide (ASP) was extracted from Astragalus membranaceus, and their preliminary structural characteristics and in vivo antitumor activity were investigated in this study. The contents of total sugar, protein and uronic acid in ASP was 92.04%, 0.51% and 1.42%, respectively. FTIR and IC results indicated that ASP (about 2.1 × 10³ Da) was a neutral polysaccharide composed of arabinose, galactose, glucose and mannose (molar ratio: 1.00:0.98:3.01:1.52) with pyranose ring and α-type glycosidic linkages. Besides, ASP could significantly inhibit the growth of H22 heptoma cells in vivo via improving the levels of serum cytokines (TNF-α, IL-2 and IFN-γ) and activities of immune cells (macrophages, lymphocytes and NK cells), thereby inducing tumor cell apoptosis and attenuating their accessional damages. These results suggested that ASP may serve as a novel potential antitumor agent in the future.

Structure characterization and biological activities of a pectic polysaccharide from cupule of Castanea henryi

A pectic polysaccharide (CHIP3) was fractionated from the natural cupule of Castanea henryi. It contained mannose (10.70%), rhamnose (8.70%), galacturonic acid (38.21%), galactose (13.75%) and arabinose (28.63%) with a molecular weight of 2.44 × 10⁴ g/mol by multi-laser light scattering. The structure was elucidated by using FT-IR spectroscopy, methylation analysis and NMR analysis. Results showed that the backbone of CHIP3 consisted of 1, 4-α-linked d-GalpA residues containing the non-methyl-esterified carboxyl groups, interspersed with a few 1,2-α-l-Rhap units. Its side chains were attached by two branches to O-4 of Rhap with 1,4-β-linked d-Galp units and 1,5-α-l-linked Araf units bearing 3,5-substituted α-l-linked Araf residues as branching points. AFM data revealed it existed as a flexible chain in 0.1 M NaNO₃ aqueous solution. Furthermore, CHIP3 was demonstrated to have notable antioxidant activity of FRAP, ABTS⁺ radical scavenging and reducing power. Cytotoxicity assay showed it displayed inhibitory activity against HepG2 cells with IC₅₀ values of 242.6 μg/mL.

The preparation of three selenium-containing Cordyceps militaris polysaccharides: Characterization and anti-tumor activities

In the present work, three fractions of selenized Cordyceps militaris polysaccharides (SeCPS) named SeCPS- I, SeCPS- II and SeCPS- III were isolated and purified by ultra-filtration. Their selenium content were measured as 541.3, 863.7 and 623.3μg/g respectively by a graphite furnace atomic absorption spectroscopy. The monosaccharide comformation analysis showed that they were mainly consisted of D-Mannose, D-Glucose, and D-Galactose in mole ratios of 1:7.63:0.83, 1:1.34:0.31 and 1:3.77:0.41 respectively. Their structure characteristics were compared by IFR and NMR spectroscopy. Scanning electron microscopy (SEM) and Congo red (CR) spectrophotometric method were used to investigate their morphological characteristics and conformational transition. SeCPS-II showed the strongest anti-tumor effects judging from the result of in vitro anti-tumor assays against two tumor cell lines (hepatocellular carcinoma HepG-2 cells and lung adenocarcinom A549 cells).