Characterization of polysaccharides from Tetrastigma hemsleyanum Diels et Gilg Roots and their effects on antioxidant activity and H2O2-induced oxidative damage in RAW 264.7 cells

Molecular mechanisms of Tetrastigma hemsleyanum Diels&Gilg against lung squamous cell carcinoma: From computational biology and experimental validation

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum （T. hemsleyanum）, valued in traditional medicine for its potential to boost immunity and combat tumors, contains uncharacterized active compounds and mechanisms. This represents a significant gap in our understanding of its ethnopharmacological relevance.

AIM OF THE STUDY

To involve the mechanism of anti-lung cancer effect of T. hemsleyanum by means of experiment and bioinformatics analysis.

MATERIALS AND METHODS

The anticancer mechanism of T. hemsleyanum against lung squamous carcinoma (LUSC) in zebrafish was investigated. The LUSC model was established by injecting NCI-H2170 cells in the zebrafish and evaluating its anti-tumor efficacy. Next, component targets and key genes were obtained by molecular complex detection (MCODE) analysis and protein-protein interaction (PPI) network analysis. Component analysis of T. hemsleyanum was performed by UPLC-Q-TOF-MS. Molecular docking was used to simulate the binding activities of key potential active components to core targets were simulated using. Prognostic and pan-cancer analyses were then performed to validate the signaling pathways involved in the prognostic genes using gene set enrichment analysis (GSEA). Subsequently, Molecular dynamics simulations were then performed for key active components and core targets. Finally, cellular experiments were used to verify the expression of glutamate metabotropic receptor 3 (GRM3) and glutamate metabotropic receptor 7 (GRM7) in the anticancer effect exerted of T. hemsleyanum.

RESULTS

We experimentally confirmed the inhibitory effect of T. hemsleyanum on LUSC by transplantation of NCI-H2170 cells into zebrafish. There are 20 main compounds in T. hemsleyanum, such as procyanidin B1, catechin, quercetin, and kaempferol, etc. A total of 186 component targets of T. hemsleyanum and sixteen hub genes were screened by PPI network and MCODE analyses. Molecular docking and molecular dynamics simulation results showed that Gingerglycolipid B and Rutin had higher affinity with GRM3 and GRM7, respectively. Prognostic analysis, Pan-cancer analysis and verification experiment also confirmed that GRM3 and GRM7 were targets for T. hemsleyanum to exert anti-tumor effects and to participate in immune and mutation processes. In vitro experiments suggested that the inhibitory effect of T. hemsleyanum on cancer cells was correlated with GRM3 and GRM7.

CONCLUSION

In vivo, in vitro and in silico results confirmed the potential anticancer effects against LUSC of T. hemsleyanum, which further consolidated the claim of its traditional uses.

Revealing quality chemicals of Tetrastigma hemsleyanum roots in different geographical origins using untargeted metabolomics and random-forest based spectrum-effect analysis

Tetrastigma hemsleyanum root is a popular functional food in China, and the price varies based on the origin of the product. The link between the origin, metabolic profile, and bioactivity of T. hemsleyanum must be investigated. This study compares the metabolic profiles of 254 samples collected from eight different areas with 49 potential key chemical markers using plant metabolomics. The metabolic pathways of the five critical flavonoid metabolites were annotated and enriched using the Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway. Moreover, a random forest model aiding the spectrum-effect relationship analysis was developed for the first time indicating catechin and darendoside B as potential quality markers of antioxidant activity. The findings of this study provide a comprehensive understanding of the chemical composition and bioactive compounds of T. hemsleyanum as well as valuable information on the evaluation of the quality of various samples and products in the market.

Optimization of tetrastigma hemsleyanum extraction process based on GA-BPNN model and analysis of its antioxidant effect

Tetrastigma hemsleyanum (Tetrastigma hemsleyanum Diels et Gilg) is a valuable traditional Chinese medicine with various applications. In this study, we aimed to optimize the extraction process for the total extraction yield of five flavonoid components, namely kaempferol, quercetin, rutin, kaempferol-3-O-rutinoside, and astragalin from the Tetrastigma hemsleyanum root (THR), and explore its potential molecular mechanisms in treating oxidative diseases as well as antioxidant activity. To achieve these objectives, we employed the genetic algorithm-back propagation neural network (GA-BPNN), the Box-Behnken design (BBD) with 4-factors and 3-levels to establish the optimal ethanol extraction process for the total extraction yield of the 5 components. Using public databases, the "component core targets-disease core target genes" networks were built, as well as molecular docking. Furthermore, DPPH was used to examine the antioxidant activity of the extracts obtained from THR under the optimal extraction process. The experimental value of the total extraction yield of the 5 components achieved a maximum of 788.12 mg/kg when the ethanol concentration was 73%, the solid-liquid ratio was 26 g/mL, and the ultrasonic duration was 30 min, and the ultrasonic temperature was 76 °C. When docked with protein molecules such as 6Y8I, quercetin, and other components received moderate to high scores. When the total concentration of the 5 components was 3.033 μg/mL, the DPPH radical scavenging rate was 89.81%. Compared with the BBD method, the GA-BPNN method is more efficient and reliable for optimizing the extraction process of active ingredients in THR because of its good data-fitting ability.

Immunoregulatory effects of Tetrastigma hemsleyanum polysaccharide via TLR4-mediated NF-κB and MAPK signaling pathways in Raw264.7 macrophages

Polysaccharide of Tetrastigma hemsleyanum (THP) exert antioxidant, antibacterial, lipid-lowering, and anti-inflammatory properties, especially some evidences have highlighted the efficiency of it as an anti-tumor agent. However, as a biological macromolecule with bidirectional immune regulation, the immunological enhancement effects of THP on macrophages and its underlying mechanisms are still largely unknown. In the present study, THP was prepared and characterized, and then the effect of THP on Raw264.7 cell activation was investigated. Structural characteristics of THP showed that the average molecular weight was 370.26 kDa, and the main monosaccharide composition was galactose, glucuronic acid, mannose, and glucose at a ratio of 31.56: 25.15: 19.44: 12.60, with high viscosity causing by relative high uronic acid. For immunomodulatory activity investigation, THP promoted the production of NO, IL-6 and TNF-α, as well as the expression of IL-1β, MCP-1, iNOS and COX-2, which were almost completely inhibited by TLR4 antagonist. Further study showed that THP could activate NF-κB and MAPK signaling pathways, and thus enhanced the phagocytic activity of Raw264.7 macrophages. In conclusion, the present study provided evidences that THP could be served as a new immunomodulator in both functional foods and the pharmaceutical field.

Purification, structural characterization and immunological activity of Sibiraea laexigata (L.) Maxim polysaccharide

Sibiraea laexigata (L.) Maxim (SLM) has been used as an herbal tea for treating stomach discomfort and indigestion for a long time in china. Polysaccharides have been identified as one of the major bioactive compounds in the SLM. In the present paper, ultrasonic-assisted enzymatic extraction (UAEE) method was employed in polysaccharides extraction derived from SLM using polyethylene glycol (PEG) as extraction solvent, two SLM polysaccharides (SLMPs) fractions (SLMPs-1-1 and SLMPs-2-1) were purified by DEAE Cellulose-52 and Sephadex G-100 chromatography in sequence. Then, the preliminarily structure of the two factions were characterized by chemical composition analysis, molecular weight measurement, UVS, HPLC-PMP, FT-IR, nuclear magnetic resonance (NMR) spectra analysis and SEM. The results showed that SLMPs-1-1 and SLMPs-2-1 with different molecular weights of 1.03 and 1.02 kDa, mainly composed of glucose (46.76 and 46.79%), respectively. The results of structural characterization from FT-IR, 1H NMR, and SEM revealed that SLMPs-1-1 and SLMPs-2-1 contained the typical pyranoid polysaccharide with α-glycosidic bond and β-glycosidic bond. Furthermore, it was found that SLMPs-1-1 could increase the levels of tumor necrosis factor-α (TNF-α) and interleukin-2 (IL-2), and alleviated the immune organs tissue damage of cyclophosphamide (Cy)-treated mice. RT-qPCR and Western-Blot analysis showed that SLMPs-1-1 could significantly up-regulated the levels of NF-κB, TLR4, which revealed that SLMPs-1-1 could participate in immunosuppressive protection of Cy-treated mice. These findings suggested that the potential of SLMPs-1-1 as an alternative immunostimulator could be used in food and pharmaceutical industries.

Quality Evaluation of Tetrastigmae Radix from Two Different Habitats Based on Simultaneous Determination of Multiple Bioactive Constituents Combined with Multivariate Statistical Analysis

Tetrastigmae Radix, also known as Sanyeqing (SYQ) in Chinese, is an important traditional Chinese medicine with a long history. Tetrastigma hemsleyanum Diels et Gilg mainly grows in the south of the Yangtze River and is widely distributed. The content of bioactive constituents in SYQ varies greatly in different habitats, and there are obvious differences in the content of bioactive constituents between southwestern SYQ (WS) and southeastern SYQ (ES). To distinguish and evaluate the quality of ES and WS, an analytical method based on ultrafast performance liquid chromatography coupled with triple quadrupole-linear ion trap mass spectrometry (UFLC-QTRAP-MS/MS) was established for the simultaneous determination of 60 constituents including 25 flavonoids, 9 phenolic acids, 15 amino acids, and 11 nucleosides in 47 samples from ES and WS. In addition, orthogonal partial least squares discriminant analysis (OPLS-DA), t-test, and gray correlation analysis (GRA) were used to discriminate and evaluate the ES and WS samples based on the contents of 60 constituents. The results showed that there were significant differences in the bioactive constituents between ES and WS, and ES was superior to WS in terms of quality evaluation. This study not only provides basic information for differentiating ES and WS but also provides a new perspective for the comprehensive evaluation and quality control of SYQ from two different habitats.

Genus Tetrastigma: A review of its folk uses, phytochemistry and pharmacology

The genus Tetrastigma belongs to the Vitaceae family and contains over 100 species. This paper reviewed folk uses, chemical constituents, pharmacological activities, and clinical applications of the medicinal plants in the genus Tetrastigma. In addition, the paper also discussed the current problems for the further studies. Up to now, more than 240 compounds were reported from the genus Tetrastigma, covering 74 flavonoids, 14 terpenoids, 19 steroids, 21 phenylpropanoids, 14 alkaloids and others constituents. Among them, flavonoids are the major and the characteristic chemical constituents in this genus. Modern pharmacological studies and clinical practice showed that the extracts and chemical constituents of Tetrastigma species possessed wide pharmacological activities including antitumor, antioxidative, hepatoprotective, antiviral, anti-inflammatory, and analgesic activities. The information summarized in this paper provides valuable clues for new drug discovery and an incentive to expand the research of genus Tetrastigma.

Extraction optimization, physicochemical characterization, and antioxidant activity of polysaccharides from Rhodosorus sp. SCSIO-45730

Microalgal polysaccharides have been reported in many studies due to their uniqueness, biocompatibility, and high value, and Rhodosorus sp. SCSIO-45730 was an excellent source of polysaccharides and β-glucans. However, the polysaccharides from the red unicellular alga Rhodosorus sp. SCSIO-45730 have barely been studied. In this work, hot water extraction of Rhodosorus sp. SCSIO-45730 polysaccharides (RSP) was optimized using response surface methodology (RSM) based on Box-Behnken design (BBD). The maximum RSP yield (9.29%) was achieved under the optimum extraction conditions: liquid-solid ratio of 50.00 mL g^-1; extraction temperature of 84 °C; extraction time of 2 h; and extraction times of 5 times. The results of physicochemical characterization showed that RSP had high sulfate and uronic acid with content of 19.58% and 11.57%, respectively, rough layered structure, and mainly contained glucose, galactose, xylose, and galacturonic acid with mass percentages of 34.08%, 28.70%, 12.46%, and 12.10%. Furthermore, four kinds of antioxidant assays were carried out, and the results indicated that RSP had strong scavenging activities on ABTS and hydroxyl radical and moderate scavenging activities on DPPH and ferrous chelating ability. These results indicated that RSP showed potential as a promising source of antioxidants applied in food, pharmaceutical, and cosmetics industry.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10811-021-02646-2.

A natural anti-obesity reagent derived from sea buckthorn polysaccharides: Structure characterization and anti-obesity evaluation in vivo

Sea buckthorn polysaccharide (SBP) has received increasing attention for its various bioactive functions. In this study, a novel polysaccharide SBP-1 was initially separated from crude SBP and further purified to obtain its main fraction SBP-1-A with a Mw of 9944 Da, consisting of Rha, Ara, Gal, Glc, and GalA. The structure of SBP-1-A was characterized based on FT-IR, GC-MS, and 1D/2D NMR, and its backbone was composed of a repeated unit of → 3,4)-β-l-Rhap-(1 → 4)-α-d-GalAp-(1 → 4)-α-d-GalAp-(1 → with branches at C-4 position comprised of α-l-Araf, β-d-Galp, β-d-Glcp, α-d-Glcp. Besides, the anti-obesity effects of SBP-1 on high-fat diet mice were evaluated, indicating it could restrain the body weight gain and lipids accumulation by promoting the expression of PGC1α, UCP-1, and PRDM16 to activate the brown adipocyte and improve the thermogenesis. In summary, the results offered new supports for the structural information of SBP and its feasibility to be used as a natural anti-obesity reagent.

Structural characterization and immunoregulatory activity of polysaccharides from Dendrobium officinale leaves

In this study, two kinds of polysaccharides from leaves of Dendrobium officinale, namely DLP-1 and DLP-2, were obtained by hot water extraction, ethanol sedimentation, and chromatographic separation using DEAE-52 cellulose and Sephadex G-100 columns. They were composed of different monosaccharides and the content of monosaccharides varied significantly while DLP-1 (M_w 1.38 × 10⁶  Da) was mainly composed of mannose (71.69%) and glucose (22.89%), and DLP-2 (M_w 1.93 × 10⁶  Da) was constituted by rhamnose (35.05%), arabinose (24.12%), and galactose (25.65%). A triple-helical conformation was exhibited by both of them. The scanning electron microscope image of DLP-1 showed an irregular and large lamellar shape, as well as a smooth surface and a porous interior, illustrating they had an amorphous structure. In contrast, DLP-2 revealed a rough, loose, and uneven surface consisting of large sponge-like particles. Nuclear magnetic resonance analysis showed that (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and (1→4)-2-O-acetyl-β-D-Manp were the main linkage types of DLP-1, whereas DLP-2 was constituted by a large amount of (1→4)-β-D-Manp, (1→4)-β-D-Glcp, and other residues. Besides, DLP-1 and DLP-2 stimulated the proliferation and phagocytic capacities of RAW 264.7 cells and improved the production of nitric oxide, interleukin-6, TNF-α, and IL-1β. These results proved that both DLP-1 and DLP-2 possessed excellent immunoregulatory bioactivities and could be functional food or adjuvant drug. PRACTICAL APPLICATIONS: The leaf of Dendrobium officinale is a by-product with huge biomass. The lack of systematic research on its chemical composition and pharmacologic effect, leading to a great waste of resources. In order to maximize the value of D. officinale, this study aimed to investigate the structural characteristics and immunologic effects of two polysaccharide fractions (DLP-1 and DLP-2) from D. officinale leaves, showing that DLP-1 and DLP-2 in D. officinale leaves could be used as anti-inflammatory agents to avoid wasting.

Recent Developments in Inonotus obliquus (Chaga mushroom) Polysaccharides: Isolation, Structural Characteristics, Biological Activities and Application

Inonotus obliquus (Chaga mushroom) is a kind of medicine and health food widely used by folk in China, Russia, Korea, and some occidental countries. Among the extracts from Inonotus obliquus, Inonotus obliquus polysaccharide (IOPS) is supposed to be one of the major bioactive components in Inonotus obliquus, which possesses antitumor, antioxidant, anti-virus, hypoglycemic, and hypolipidemic activities. In this review, the current advancements on extraction, purification, structural characteristics, and biological activities of IOPS were summarized. This review can provide significant insight into the IOPS bioactivities as their in vitro and in vivo data were summarized, and some possible mechanisms were listed. Furthermore, applications of IOPS were reviewed and discussed; IOPS might be a potential candidate for the treatment of cancers and type 2 diabetes. Besides, new perspectives for the future work of IOPS were also proposed.