Aloe arborescens Polysaccharides: In Vitro Immunomodulation and Potential Cytotoxic Activity

An Aloe-Based Composition Constituting Polysaccharides and Polyphenols Protected Mice against D-Galactose-Induced Immunosenescence

A decline in immune response, exhibited in the form of immunosenescence and inflammaging, is an age-associated disturbance of the immune system known to predispose the elderly to a greater susceptibility to infection and poor vaccine response. Polysaccharides and polyphenols from botanicals are known for their immune modulation effects. Here we evaluated a standardized mushroom-based composition, UP360, from Aloe barbadensis, Poria cocos, and Rosmarinus officinalis, as a natural nutritional supplement for a balanced immune response in an accelerated aging mouse model. Immunosenescence was induced by continual subcutaneous injection of D-galactose (D-gal) at a dose of 500 mg/kg/day to CD-1 mice. UP360 was administered at oral doses of 200 and 400 mg/kg to the mice starting on the 5th week of D-gal injection. The study lasted for a total of 9 weeks. All mice were given a quadrivalent influenza vaccine at 3 µg/animal via intramuscular injection 14 days before the end of the study. A group of D-gal-treated mice treated at 400 mg/kg/day UP360 was kept without vaccination. Whole blood, serum, spleen homogenate, and thymus tissues were used for analysis. UP360 was found to improve the immune response as evidenced by stimulation of innate and adaptive immune responses, increase antioxidant capacity as reflected by augmented SOD and Nrf2, and preserve vital immune organs, such as the thymus, from aging-associated damage. The findings depicted in this report show the effect of the composition in activating and maintaining homeostasis of the immune system both during active infections and as a preventive measure to help prime the immune system. These data warrant further clinical study to explore the potential application of the mushroom-based composition as an adjunct nutritional supplement for a balanced immune response.

Middle Eastern Plants with Potent Cytotoxic Effect Against Lung Cancer Cells

Cancer is one of the leading causes of increasing global mortality with uprising health concerns and threats. Unfortunately, conventional chemotherapy has substantial side effects, limiting its relevance and prompting a quest for safe and efficient alternatives. For thousands of years, plants have provided a rich reservoir for curing a variety of ailments, including cancer. According to the World Health Organization, medicinal plants would be the best source of medications. However, only 25% of drugs in the present pharmacopoeia are derived from plants. Hence, further research into different plants is required to better understand their efficacy. Twenty extracts of widely distributed Middle Eastern plants were screened for the cytotoxic effect against lung cancer cell lines (A549). Eleven plants showed IC50 below 25 μg/mL, consequently, the bioactive extracts were further fractionated by graded precipitation using absolute ethanol. All fraction A (FA; crude polysaccharides precipitate) showed potent IC50, 0.2-5.5 μg/mL except the FA of Brassica juncea, Silybum marianum, and Phaseolus vulgaris, whereas FB fractions (filtrate) of Anastatica hierochuntica, Plantago ovate, Tussilago farfara, and Cucurbita moschata had lower efficacy than other fractions with IC50 values in the range of 0.1-7.7 μg/mL. The fractions of FA Taraxacum officinale and FB Ziziphus spina possess the most potent cytotoxic activity with IC50, 0.2 and 0.1 μg/mL, respectively. Moreover, cell cycle analysis of both fractions revealed an arrest at G1/S-phase and activation of apoptosis rather than necrosis as the mode of cell death. Therefore, T. officinale and Z. spina fractions may pave the way to manage lung carcinoma as an alternative and complementary food regimen.

Vertex-Based Resolvability Parameters for Identification of Certain Chemical Structures

Chemical graph theory explores chemical phenomena and entities through the conceptual framework of graph theory. In chemical graph theory, molecular structures are represented by chemical graphs, where edges and vertices correspond to bonds and atoms, respectively. Chemical graphs serve as fundamental data types in cheminformatics for illustrating chemical structures. The computable properties of graphs form the basis for quantitative structure-property and structure-activity predictions, which are central to cheminformatics. These graphs capture the physical characteristics of molecules and can be further reduced to graph-theoretical indices or descriptors. One extensively studied distance-based graph descriptor is the resolving set Z, which enables the distinction of every pair of distinct vertices in a connected simple graph. Resolving sets were specifically employed in pharmaceutical research to find patterns shared by several different drugs. Since very early times, medicinal drugs have played a significant part in human civilization. In this article, we investigate minimum resolving sets for certain significant drug molecular structures, namely, suramin (S86) and acemannan (A116).

Microbiota-derived short chain fatty acids in fermented Kidachi Aloe promote antimicrobial, anticancer, and immunomodulatory activities

BACKGROUND

Fermented Aloe leaf juice is a commonly used food supplement in Japan. In a previous study, fermentation of A. arborescence juice was performed and the presence of short-chain fatty acids (SCFAs) was confirmed and quantified. Samples were collected before and after the fermentation process to be subjected, in the present study, to DNA extraction, 16S rRNA gene (V3-V4 regions) amplification, and sequencing by the next-generation Illumina MiSeq sequencer. Our work aims to analyze the sequences to assess the bacterial diversity in the juice before and after fermentation, identify the beneficial microbes responsible for the production of SCFAs, and evaluate some of the biological activities of the fermented juice.

RESULTS

Data revealed the richness and diversity of the bacterial community in the fermented juice compared to the unfermented control. Relative abundance of bacterial phyla showed that the majority of the microbial community in the test samples corresponded to Pseudomonadota (unfermented; 10.4%, fermented; 76.36%), followed by Bacillota (unfermented; 4.71%, fermented; 17.13%) and then Bacteroidota (unfermented; 0.57%, fermented; 1.64%). For the fermented sample, 84% of Bacillota were lactobacilli. A hierarchically clustered heatmap revealed that Lactobacillus was the most abundant genus in both samples suggesting its involvement in the production of SCFAs. To assess potential health benefits, the anticancer efficacy of the fermented product of A. arborescens was investigated against colorectal cancer (IC50 = 3.5 µg/ml) and liver cancer (IC50 = 6.367 µg/ml) compared to the normal peripheral blood mononuclear cells (PBMCs). Flow cytometric analysis of the cell cycle pattern revealed remarkable population arrest in G0 and G1, however, the highest percentages were mainly in the G1 phase for Hep-G2 (40.1%) and HCT-116 (53.2%) cell lines. This effect was accompanied by early apoptotic profiles of HCT-116 (36.9%) and late apoptosis for Hep-G2 (17.3%). Furthermore, immunomodulatory properties demonstrated a significantly (p < 0.001) reduced percentage of induced TNF-α while enhancing IFN-γ dramatically. For antimicrobial activities, marked broad-spectrum activities were recorded against some bacterial and fungal pathogens (17-37 mm inhibition zone diameter range).

CONCLUSION

Therefore, this study affords the basis of bacterial community composition in fermented A. arborescens juice as well as its potential biological benefits.

The therapeutic mechanism of Chebulae Fructus in the treatment of immunosuppression in Chinese yellow quail on the basis of network pharmacology

Introduction

Chebulae Fructus (Terminalia chebula Retz.) is a well-known traditional Chinese medicine (TCM), one of the family Combretaceae, whose immature fruit is called Fructus Chebulae Immaturus or Zangqingguo. This present study aimed at detecting the target and therapeutic mechanism of Chebulae Fructus against immunosuppression through network analysis and experimental validation.

Methods

Effective components and potential targets of Chebulae Fructus were Search and filtered through the Chinese herbal medicine pharmacology data and analysis platform. A variety of known disease target databases were employed to screen the therapeutic target proteins against immunosuppression and thus constructing a protein-protein interaction network. Hub genes and key pathways in this study were identified by continuous project enrichment analysis. Further, the core targets and therapeutic mechanism of Chebulae Fructus against immunosuppression in Chinese yellow quail through animal experiment.

Results

Seventy-five identifiable major candidate targets of Chebulae Fructus were found and thus constructing a drug-compound-target-disease network. Targets derived from gene enrichment analysis play pivotal roles in lipid and atherosclerosis, fluid shear stress and atherosclerosis, and the hepatitis B pathway. Height of plicate and areas of lymphoid follicle were both increased and the expression of GATA-3 and T-bet was upregulated in Chinese yellow quail fed with Chebulae Fructus in animal experiment.

Conclusion

Chebulae Fructus may be a helpful Chinese medicine with immunosuppressive effect and prospective applications in future. Further research is also needed to understand the mechanisms of immunosuppression and the mechanism of action of immunomodulators.

Antioxidant capacity, flavor and physicochemical properties of FH06 functional beverage fermented by lactic acid bacteria: a promising method to improve antioxidant activity and flavor of plant functional beverage

The ability of natural plants to treat chronic diseases is closely related to their antioxidant function. Lactic acid bacteria (LAB) fermentation is an effective way to improve the nutritional value, biological activity and flavor of food. This study investigated the pH, titratable acidity, total polysaccharide, total flavone, total saponin, total polyphenol, and antioxidant activity of the FH06 beverage before and after probiotic fermentation. Results: After fermentation, FH06 had lower contents of total polysaccharides, total flavonoids, total saponins and total polyphenols but higher titratable acidity. The antioxidant activity was tested by total antioxidant capacity (FRAP method) and DPPH· scavenging ability. The FRAP value significantly increased after fermentation (P < 0.05), and the maximum increase was observed for Lactobacillus fermentum grx08 at 25.87%. For DPPH· scavenging ability, the value of all fermentations decreased, and L. fermentum grx08 had the smallest reduction at 2.21% (P < 0.05). The results of GC-MS and sensory analysis showed that fermentation eliminated bad flavors, such as grass, cassia and bitterness, and highlighted the fruit aroma and soft sour taste. Conclusion: The FRAP value and sensory flavor of FH06 fermentation by L. fermentum grx08 were significantly improved, indicating its great potential as a functional food with both strong antioxidant activity and good flavor.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1186/s13765-022-00762-2.

The pathogenesis of liver cancer and the therapeutic potential of bioactive substances

Liver cancer is the third most common cause of cancer-related deaths in the world and has become an urgent problem for global public health. Bioactive substances are widely used for the treatment of liver cancer due to their widespread availability and reduced side effects. This review summarizes the main pathogenic factors involved in the development of liver cancer, including metabolic fatty liver disease, viral infection, and alcoholic cirrhosis, and focuses on the mechanism of action of bioactive components such as polysaccharides, alkaloids, phenols, peptides, and active bacteria/fungi. In addition, we also summarize transformation methods, combined therapy and modification of bioactive substances to improve the treatment efficiency against liver cancer, highlighting new ideas in this field.

Phytochemical Composition, Antioxidant, Antibacterial, and Enzyme Inhibitory Activities of Various Organic Extracts from Apocynum hendersonii (Hook.f.) Woodson

Apocynum hendersonii is a traditional medicinal plant used primarily as tea. It has a potential health benefit from its rich bioactive substances. This study investigated the reactivity of solvents of different polarities (ethanol, ethyl acetate, n-hexane, methanol, and water) extracts of the A. hendersonii leaf. The phytochemical composition of the extracts was evaluated using a Fourier Transform Infrared spectrophotometer (FT-IR), Gas Chromatography-Mass Spectrometry (GC-MS), UHPLC-MS, and Higher Performance Liquid Chromatography (HPLC). The result revealed the presence of medicinally important bioactive constituents, including phenols, flavonoids, and polysaccharides. Methanol extracts exhibited the highest flavonoid contents (20.11 ± 0.85 mg QE/g DW) and the second-highest in terms of phenolic (9.25 ± 0.03 mg GAE/g DW) and polysaccharide (119.66 ± 2.65 mg GE/g DW). It also had the highest antioxidant capacity with 60.30 ± 0.52% and 4.60 ± 0.02 µmol Fe²⁺ per g DW based on a 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay and ferric reducing antioxidant power (FRAP), respectively. Ethanol extract displayed the maximum antibacterial action against Gram-negative and Gram-positive bacteria and the highest inhibition activity against the enzymes tyrosinase and acetylcholinesterase, followed by methanol extract. The principal component analysis revealed a positive correlation between the constituents, bioactivities, and extracts. The overall result showed A. hendersonii as a rich natural source of antimicrobial and antioxidant bioactive compounds and may be used for future applications in pharmaceuticals and food industries.

In Vitro Anti-Obesity Effect of Shenheling Extract (SHLE) Fermented with Lactobacillus fermentum grx08

Obesity is a common global problem. There are many fat-reducing herbal prescriptions in traditional Chinese medicine that have been proven to be safe and functional during long-term application. Microbial fermentation can improve the efficacy of herbal medicine and improve the unsavory flavor. In this study, Shenheling extract (SHLE) composed of six medicine food homology materials was used as the research object. The purpose of this study was to evaluate the effects of Lactobacillusfermentum grx08 fermentation on the antiobesity efficacy and flavor of SHLE. We found that L. fermentum grx08 grew well in SHLE. After 72 h of fermentation, the total polysaccharides, total flavonoids, total polyphenols and total saponins of SHLE decreased, but the lipase inhibitory activity and total antioxidant capacity (FRAP) were significantly increased (p < 0.01). There were no significant differences in the α-glucosidase inhibition rate and DPPH· clearance rate before or after fermentation (p > 0.05). In addition, the fermentation reduces the unpleasant flavors of SHLE such as bitterness and grassy and cassia flavors. This study demonstrates that SHLE fermented by L. fermentum grx08 improved some anti-obesity functions and improved the unpleasant flavor.

Aloe arborescens: In Vitro Screening of Genotoxicity, Effective Inhibition of Enzyme Characteristics for Disease Etiology, and Microbiological Activity

The present study assessed the genotoxicity, the possibility of inhibiting selected enzymes, and the microbial activity of lyophilisate from 3-year-old A. arborescens leaves obtained from controlled crops. The lyophilisate from 3-year-old A. arborescens leaves was standardized for aloin A and aloenin A content. Moreover, concentrations of polyphenolic compounds and phenolic acids were determined. The first stage of the research was to determine genotoxicity using the comet test, which confirmed the safety of A. arborescens. Assays of enzymatic inhibition were performed for hyaluronidase (IC50 = 713.24 ± 41.79 µg/mL), α-glucosidase (IC50 = 598.35 ± 12.58 µg/mL), acetylcholinesterase and butyrylcholinesterase (1.16 vs. 0.34 µM of eserine/g d.m., respectively). The next stage of the research was to determine the ability of the healing properties using the scratch test, which showed a positive response using the extract. Microbial activity was evaluated and obtained against Gram-negative and Gram-positive bacteria and yeasts. We concluded that A. arborescens leaf gel meets the important conditions for plant raw materials to obtain semi-solid forms of herbal medicinal products.

The Immunomodulatory Effects of Phellodendri Cortex Polysaccharides on Cyclophosphamide-Induced Immunosuppression in Mice

Cyclophosphamide is a commonly used anticancer drug, and immunosuppression is one of the most common side effects. How to recover the immunological function is important for cyclophosphamide-treated patients. In the present study, Phellodendri Cortex polysaccharides (CPP) could enhance the proliferation of mouse spleen lymphocytes in vitro. The immunoregulatory function of CPP was then investigated in cyclophosphamide-induced immunosuppressed mice. In CPP-treated groups, mice were orally treated with CPP at doses of 1, 0.5, and 0.25 g/kg bodyweight from 1 to 11 d, respectively. The cyclophosphamide was administrated in CPP and cyclophosphamide groups from 12 to 14 d. In the cyclophosphamide and normal control groups, the mice received equal volume of saline from 1 to 14 d. The results showed that CPP (1 g/kg) could significantly increase the bodyweight of mice, even during cyclophosphamide treatment. The organ coefficients of the spleen and thymus were recovered by CPP treatment. CPP upregulated the contents of cytokines (IL-2, IL-6, IFN-γ, and TNF-α) in serum, which were downregulated by cyclophosphamide. The mRNA levels of these cytokines were also elevated by CPP treatment in the spleen. Cyclophosphamide upregulated the expressions of NF-κB p65, TLR4, and MyD88, suggesting that the NF-κB signaling pathway was activated by cyclophosphamide. After CPP treatment, it was recovered to normal level. These results indicated that CPP alleviated the cyclophosphamide-induced immunosuppression.

Antioxidant activities of sulfated Codonopsis polysaccharides in acute oxidative stress

This study aimed to explore the protective effect of sulfated Codonopsis polysaccharides (SCP) on acute oxidative stress. SCP was modified by chlorosulfonic acid-pyridine method from Codonopsis polysaccharides (CP), which had 34.48% of sulfate content determined by ultrasonic-acidic barium chromate spectrophotometry. The analysis of Fourier transform-infrared spectroscopy (FT-IR) appeared an absorption peak of SCP at 811.91 cm^-1 , which related to C-O-SO₃ . In vitro test, the antioxidant activities of CP and SCP was induced by H₂ O₂ in RAW264.7 cells, results indicated that SCP and CP could significantly enhance the activity of superoxide dismutase (SOD), glutathione peroxidase (GDH-Px) and catalase (CAT), and nitric oxide (NO) and decrease the level of malondialdehyde (MDA), reactive oxygen species (ROS), and inducible nitric oxide synthase (iNOS) secreted by RAW264.7 cells compared with modeling group (p < .05). The flow cytometry results also revealed that SCP and CP could markedly inhibit the apoptosis of macrophage induced by acute oxidative stress. In vivo test, 50% ethanol was used to induce mice acute oxidative stress, results indicated that the blood biochemical parameters in mice were restored to normal levels following administration of SCP and CP, andalanineamino transferase (ALT), aspartate transaminase (AST), total protein (TP), albumin (ALB), glucose (GLU), and creatinine (UREA) had significant differences compared with modeling group (p < .05). Quantitative real-time PCR analysis revealed that SCP and CP could promote the expression of Keap1 and Nrf2. In summary, both SCP and CP had protective effects against acute oxidative stress. PRACTICAL APPLICATIONS: Oxidative stress is a kind of stress injury, which can cause a variety of diseases and accelerate physical aging. Codonopsis has many active components, among which Codonopsis polysaccharide has antioxidant effect. Recent studies have found that Codonopsis polysaccharides could be modified by sulfate molecules to obtain higher antioxidant activity. The modified Codonopsis polysaccharides could significantly promote the production of antioxidant enzymes (SOD, CAT, GDH-Px) and reduce the content of oxidative stress marks (ROS, MDA). Moreover, its antioxidant mechanism may be related to the Keap1 /Nrf2 signaling pathway. Therefore, SCP was an effective antioxidant, and could be used as a potential health food with antioxidant and anti-aging effects.

Analysis of the Composition of Lyophilisates Obtained from Aloe arborescens Gel of Leaves of Different Ages from Controlled Crops

The aim of the study is to evaluate the composition of lyophilisates obtained from Aloe arborescens leaf gel at the age of one to four years. The leaves were obtained from controlled crops, which allowed to exclude environmental factors as variables. It was confirmed that the lyophilisates obtained from different years of Aloe arborescens leaf gel varied in chromatographic analyses in terms of aloin A and aloenin A content (high-performance liquid chromatography with diode-array detection HPLC-DAD, high-performance liquid chromatography with tandem mass spectrometric detection HPLC-MS/MS). Similarly, while testing the phenolic acids and the sum of polyphenols content, differences in their levels in leaf gel lyophilisates from plants of individual years were observed (spectrophotometric method UV-VIS). The lyophilisate composition analysis showed that the one-year-old leaves were characterized by the highest content of aloin A and aloenin A. While the content of polyphenols, including phenolic acids, was higher in the leaves of older plants. The antioxidant potential of the tested lyophilisates was assessed simultaneously. Regardless of the research model used (CUPRAC, DPPH, ABTS), an antioxidant effect was noted for Aloe arborescens leaves.

In vivo immuno - and angiomodulatory effects of Aloe arborescens folii recentis extractum siccum (AAES) in mice

Introduction

AAES is a powdered form of Biostymina, herbal medicinal product of Phytopharm Klęka S.A., a water extract of Aloe arborescens Mill. leaves. Aloe arborescens Mill. (woody aloe, tree-like aloe) is known to have several traditional medicinal properties including anti-inflammatory, immunomodulatory, antiviral and antimicrobial activity.

Objective

The aim of this work was to study the in vivo effect of AAES on cellular (leukocyte-induced cutaneous angiogenesis, LIA test, and proliferative response to PHA) and humoral (anti-SRBC antibody response) immunity in mice.

Methods

Balb/c mice were fed AAES from 0.5 to 75 mg/kg body mass for seven days before grafting their splenocytes intradermally to F1 (Balb/cxC3H) recipients (LIA test). Neovascular reaction was evaluated 72 h later in dissection microscope. Spleen cell cultures were incubated with 0.5, 1 and 2 μg/ml of PHA. After 48 h of incubation, tritiated thymidine was added. After further 24 h, cells were harvested (Skatron) and incorporation of tritiated thymidine was measured using Beta-scintillation counter. Balb/c mice were fed for 7 days with AAES, then immunized intraperitoneally with 5% SRBC suspension and 7 days later the antibody response was measured with hemagglutination test.

Results

Neovascular reaction was significantly higher in groups grafted with splenocytes collected from all AAES fed donors than from the controls. The proliferation of splenocytes taken from mice fed AAES at doses ranging from 0.5 mg/kg to 7.5 mg/kg was stimulated in all cultures. Suppression of proliferation was observed in cell cultures derived from mice fed with higher doses of AAES. Stimulation of anti-SRBC antibody production was seen in mice fed both 2.5 and 7.5 mg/kg dose of AAES.

Conclusion

Powdered form of Biostymina (AAES) might be useful in the treatment of patients with ischaemia of tissues and organs (myocardial infarction, stroke, necrosis) and in deficiency in the production of immune cells and growth factors (infections, chronic wound healing, ulceration and bone fusion).

Exploring the multifocal role of phytochemicals as immunomodulators

A well-functioning immune system of the host body plays pivotal role in the maintenance of ordinary physiological and immunological functions as well as internal environment. Balanced immunity enhances defense mechanism against infection, diseases and unwanted pathogens to avoid hypersensitivity reactions and immune related diseases. The ideal immune responses are the results of corrective interaction between the innate immune cells and acquired components of the immune system. Recently, the interest towards the immune system increased as significant target of toxicity due to exposure of chemicals, drugs and environmental pollutants. Numerous factors are involved in altering the immune responses of the host such as sex, age, stress, malnutrition, alcohol, genetic variability, life styles, environmental-pollutants and chemotherapy exposure. Immunomodulation is any modification of immune responses, often involved induction, amplification, attenuation or inhibition of immune responses. Several synthetic or traditional medicines are available in the market which promptly have many serious adverse effects and create pathogenic resistance. Phytochemicals are naturally occurring molecules, which significantly play an imperative role in modulating favorable immune responses. The present review emphasizes on the risk factors associated with alterations in immune responses, and immunomodulatory activity of phytochemicals specifically, glycosides, alkaloids, phenolic acids, flavonoids, saponins, tannins and sterols and sterolins.

Enhancement of the Anti-Skin Wrinkling Effects of Aloe arborescens Miller Extracts Associated with Lactic Acid Fermentation

This work clearly shows that Aloe arborescens but not gels from Aloe vera, a common juice-type product of Aloe, exerted anti-skin wrinkling effects, and these effects were greatly enhanced by lactic acid fermentation with Lactobacillus plantarum. Treatment with the extract from the fermentation process (FE) at a dose of 0.5% highly activated human fibroblast cells by up to 175%, whereas 140% activation and 105% activation were observed with the extract obtained using conventional water extraction (WE) and the gel from A. vera (GE), respectively. The treatment of human fibroblasts with FE at a dose of 0.5% increased collagen production by up to 170% and inhibited MMP-1 synthesis to 48%, which is likely due to its high antioxidant activity because the WE and GE showed markedly lower effects compared with those of the FE. Interestingly, the FE exhibited a profile dominated by relatively low-molecular-weight (MW) polysaccharides: 20% of the total polysaccharides in the FE were in the MW weight range of 600 to 900, whereas 95% of the total polysaccharides in the GE were in the MW range of 200,000 to 300,000. This result suggests that the larger polysaccharide molecules in the extract might be broken down during lactic acid fermentation, and the easy penetration of the small molecules in the extract into fibroblast cells thus results in improved anti-skin wrinkling effects. This conclusion is also supported by the finding that the FE and WE, but not the GE, contained similar amounts of barbaloin, a strong antioxidant eluted from A. arborescens through the fermentation process. Therefore, this study strongly indicates that the enhanced anti-skin wrinkling effects of the FE are most likely due to synergistic effects between the barbaloin and the low-MW polysaccharides retained after the fermentation process.

Structural Characterization and In Vitro Cytokines Modulation Effect of New Acetylated Galactomannans from Aloe arborescens

Three new galactomannan components designed as AANP-1, AANP-3, and AAAP-7 were isolated from previously purified Aloe arborescence polysaccharide fractions, using ion-exchange, gel filtration, and preparative chromatographic techniques. Based on Fourier transform-infrared, one-dimensional and two-dimensional nuclear magnetic resonance spectroscopy, the main backbone of AANP-1 elucidated as (1 → 4)-linked_α-d-deoxyGalp, (1 → 4) d-Manp, and β-d-2-glup. The sugar residue sequence of AANP-3 was (1 → 4)-linked β-d-NHAC-GAlp with β-d-AcManp side chain that attached to O-4 position. The AAAP-7 repeated units were (1 → 4) d-Manp linked with (1 → 4) d-Galp interspersed with (1 → 3)-α-Manp. The results of high performance size-exclusion chromatography indicated that the approximate molecular weights of AANP-1, AANP-3, and AAAP-7 were 4.2, 2.4, and 2.5 kDa, respectively. The cytokine modulation assay revealed that the isolated components promoted a remarkable release of interleukin (IL)-12 and tumor necrosis factor alpha in comparison with the negative control group, whereas potent significant induction of IL-2 and interferon gamma was detected more than the positive control phytohemagglutinin (P < .05). This is the first report for isolation galactomannans from Aloe arborescence. Moreover, this finding could provide new insights for exploring the biological modifier mechanism in correlation with the knowledge of structural configuration.

Structural Elucidation of Immunomodulators, Acetylated Heteroglycan and Galactosamine, Isolated from Aloe arborescens Leaves

Plant polysaccharides gained extended scientific attention for their immunomodulatory effect. However, few scientific studies structurally defined polysaccharides in relation to their biological modifier response. Therefore, the study explored the effect of structurally identified isolated macromolecules from Aloe arborescens against cytokine modulation (interferon [IFN-γ], interleukins [IL-2 and IL-12], and tumor necrosis factor [TNF-α]) in vitro. The structures were elucidated by GC, GPC, FT-IR spectroscopy, 1D NMR, COSY, HMBC, and HSQC. Two acetylated glucomannans (AANP4 and AAAP6), one deoxy-glucogalactan (AANP5), and one deoxy-N-acetyl-[1-4]-galactosamine (AANP2) were isolated. The results showed significant induction for all cytokines and the most potent component was AAAP6; acetylated phenolic glucomannan with a (1 → 3)-linked glucose-mannose and (1 → 4)-linked mannose backbone, which stimulated IL-12 by more than 10-fold compared with phytohemagglutinin (positive control). In conclusion, A. arborescens polysaccharides could be a landmark for development of effective immunotherapeutics against cancer and chronic inflammatory conditions.

Extraction, Purification, Structural Characteristics, Biological Activities and Pharmacological Applications of Acemannan, a Polysaccharide from Aloe vera: A Review

Aloe vera is a medicinal plant species of the genus Aloe with a long history of usage around the world. Acemannan, considered one of the main bioactive polysaccharides of Aloe vera, possesses immunoregulation, anti-cancer, anti-oxidation, wound healing and bone proliferation promotion, neuroprotection, and intestinal health promotion activities, among others. In this review, recent advancements in the extraction, purification, structural characteristics and biological activities of acemannan from Aloe vera were summarized. Among these advancements, the structural characteristics of purified polysaccharides were reviewed in detail. Meanwhile, the biological activities of acemannan from Aloe vera determined by in vivo, in vitro and clinical experiments are summarized, and possible mechanisms of these bioactivities were discussed. Moreover, the latest research progress on the use of acemannan in dentistry and wound healing was also summarized in details. The structure-activity relationships of acemannan and its medical applications were discussed. Finally, new perspectives for future research work on acemannan were proposed. In conclusion, this review summarizes the extraction, purification, structural characteristics, biological activities and pharmacological applications of acemannan, and provides information for the industrial production and possible applications in dentistry and wound healing in the future.