Characterization and antitumor activities of a water-soluble polysaccharide from Ampelopsis megalophylla

Hypolipidemic effect and gut microbiota regulation of Gypenoside aglycones in rats fed a high-fat diet

ETHNOPHARMACOLOGICAL RELEVANCE

Gynostemma pentaphyllum (Thunb.) Makino has traditional applications in Chinese medicine to treat lipid abnormalities. Gypenosides (GPs), the main bioactive components of Gynostemma pentaphyllum, have been reported to exert hypolipidemic effects through multiple mechanisms. The lipid-lowering effects of GPs may be attributed to the aglycone portion resulting from hydrolysis of GPs by the gut microbiota. However, to date, there have been no reports on whether gypenoside aglycones (Agl), the primary bioactive constituents, can ameliorate hyperlipidemia by modulating the gut microbiota.

AIM OF THE STUDY

This study explored the potential therapeutic effects of gypenoside aglycone (Agl) in a rat model of high-fat diet (HFD)-induced hyperlipidemia.

METHODS

A hyperlipidemic rat model was established by feeding rats with a high-fat diet. Agl was administered orally, and serum lipid levels were analyzed. Molecular techniques, including RT-polymerase chain reaction (PCR) and fecal microbiota sequencing, were used to investigate the effects of Agl on lipid metabolism and gut microbiota composition.

RESULTS

Agl administration significantly reduced serum levels of total cholesterol (TC), triglycerides (TG), and low-density lipoprotein cholesterol (LDL-C) and mitigated hepatic damage induced by HFD. Molecular investigations have revealed the modulation of key lipid metabolism genes and proteins by Agl. Notably, Agl treatment enriched the gut microbiota with beneficial genera, including Lactobacillus, Akkermansia, and Blautia and promoted specific shifts in Lactobacillus murinus, Firmicutes bacterium CAG:424, and Allobaculum stercoricanis.

CONCLUSION

This comprehensive study established Agl as a promising candidate for the treatment of hyperlipidemia. It also exhibits remarkable hypolipidemic and hepatoprotective properties. The modulation of lipid metabolism-related genes, along with the restoration of gut microbiota balance, provides mechanistic insights. Thus, Agl has great potential for clinical applications in hyperlipidemia management.

Exploring the antioxidant potential of nekemias species extracts on edible oils: In vitro assessment and lipid oxidation inhibition

Synthetic antioxidants have long been used to protect edible oils from oxidation. However, concerns about their potential health risks and environmental impact have led to a growing interest in natural antioxidants. In this study, we explore the antioxidant properties of extracts from four Nekemias plant species: Nekemias grossedentata (AGR), Nekemias megalophylla (AME), Nekemias chaffanjonii (ACH), and Nekemias cantoniensis (ACA) by obtaining the values for different tests. We investigate their bioactive compound content and evaluate their antioxidant capabilities on six edible oils categorized into three lipid systems based on their fatty acid compositions: oleic acid, linoleic acid, and linolenic acid. Our findings demonstrate that AGR and AME extracts, rich in bioactive compounds, exhibit strong antioxidant activities in vitro, effectively inhibiting lipid oxidation, especially in oleic acid-rich oils like camellia oil. The antioxidant effects of these extracts are comparable to synthetic antioxidants such as TBHQ and superior to natural antioxidant Tea Polyphenols (TP). While the extracts also show antioxidant potential in linoleic and linolenic acid systems, the stability of their effects in these oils is lower than in oleic acid system. These results suggest that Nekemias species extracts have the potential to serve as natural additives for extending the shelf life of edible oils, contributing to the exploration of natural antioxidants.

The effects of Astragalus polysaccharides, tragacanthin, and bassorin on methotrexate-resistant acute lymphoblastic leukemia

Background and purpose

One strategy to overcome methotrexate (MTX) resistance in acute lymphoblastic leukemia is suppressing MDR1 expression. It has been proved Astragalus polysaccharides (APS) exert their anticancer effect by reversing drug resistance. Due to the structural similarity of tragacanthin and bassorin with APS, we aimed to investigate the effects of the aforementioned polysaccharides on the expression of the MDR1 gene in the MTX-treated CCRF-CEM cells.

Experimental approach

Cytotoxicity of APS, bassorin, and tragacanthin on CCRF-CEM, CCRF-CEM/MTX (cells treated with MTX at IC50), and CCRF-CEM/R cells (CCRF-CEM cells resistant to MTX) was evaluated by MTT assay. The effect of all three compounds on MDR1 expression was evaluated using RT-PCR.

Findings/Results

All the concentrations of tragacanthin, bassorin, and APS (except at 0.8-100 μg/mL in CCRF-CEM) decreased the viability of all the cells compared to the negative control group; and against the positive control (MTX-treated cells), only bassorin at 20-100 μg/mL in CCRF-CEM/R and tragacanthin at 50 and 100 μg/mL in CCRF-CEM/MTX and at 2-100 μg/mL in CCRF-CEM/R decreased cell viability. Tragacanthin diminished MDR1 expression in CCRF-CEM/MTX and CCRF-CEM/R cells, which MTX had already induced.

Conclusion and implication

According to the results of this study, tragacanthin was a potent cytotoxic agent against CCRF-CEM cells and enhanced the chemosensitivity of CCRF-CEM/MTX and CCRF-CEM/R cells to MTX by down-regulation of MDR1 gene expression. Therefore, it could be a promising compound against cancer. Other possible mechanisms of action of tragacanthin should be evaluated and further in vitro and in vivo investigations are required.

The complete mitochondrial genome of Aorianigripes (Coleoptera, Eumolpidae, Eumolpinae) and its phylogenetic status

Aorianigripes (Baly, 1860) is one of the main pests of grapes, mainly damaging leaves, petioles and shoots and seriously affecting plant growth and development. Recently, this pest was found to damage the leaves of Ampelopsisgrossedentata, Ampelopsismegalophylla, Ampelopsischaffanjonii and Ampelopsiscantoniensis. However, the phylogenetic relationships of A.nigripes and other related family members are unclear. In this study, we sequenced and analysed the complete mitogenome of A.nigripes for the first time. The mitogenome of A.nigripes is circular and 17,306 bp in size, consisting of 13 protein-coding genes (PCGs), 22 transfer RNA genes (tRNAs) and two ribosomal RNA genes (rRNAs). The base composition of the A.nigripes mitogenome is 41.70% A, 33.76% T, 9.01% G and 15.53% C. The phylogenetic analysis showed that A.nigripes was clustered together with Basileptafulvipes and Colasposomadauricum.

Immunomodulatory effects of the polysaccharide from Sinonovacula constricta on RAW264.7 macrophage cells

This study aimed to evaluate the immunomodulatory effect of the polysaccharide from Sinonovacula constricta (SCP‐1‐1) in RAW264.7 cells. SCP‐1‐1 with a molecular weight of 440.0 kDa consisted of glucose and mannose. The immunomodulatory assay results showed that SCP‐1‐1 could significantly enhance phagocytic ability, NO production, and some cytokines (TNF‐α, IL‐6, and IL‐1β) secretion of RAW264.7 cell in a dose‐dependent manner. Western blot analysis results demonstrated that SCP‐1‐1 could regulate the expression levels of the key proteins in the signaling pathways of RAW264.7 cell and might associated with NF‐κβ and PI3K signaling pathway. These findings could contribute to elucidate the immunomodulatory activities of the polysaccharide from Sinonovacula constricta.

Extraction and Hypolipidemic Activity of Low Molecular Weight Polysaccharides Isolated from Rosa Laevigata Fruits

Three novel low molecular weight polysaccharides (RLP-1a, RLP-2a, and RLP-3a) with 9004, 8761, and 7571 Da were first obtained by purifying the crude polysaccharides from the fruits of a traditional Chinese medicinal herb Rosae Laevigatae. The conditions for polysaccharides from the R. Laevigatae fruit (RLP) extraction were optimized by the response surface methodology, and the optimal conditions were as follows: extraction temperature, 93°C; extraction time, 2.8 h; water to raw material ratio, 22; extraction frequency, 3. Structural characterization showed that RLP-1a consisted of rhamnose, arabinose, xylose, glucose, and galactose with the ratio of 3.14 : 8.21 : 1 : 1.37 : 4.90, whereas RLP-2a was composed of rhamnose, mannose, glucose, and galactose with the ratio of 1.70 : 1 : 93.59 : 2.73, and RLP-3a was composed of rhamnose, arabinose, xylose, mannose, glucose, and galactose with the ratio of 6.04 : 26.51 : 2.05 : 1 : 3.17 : 31.77. The NMR analyses revealed that RLP-1a, RLP-2a, and RLP-3a contained 6, 4, and 6 types of glycosidic linkages, respectively. RLP-1a and RLP-3a exhibited distinct antioxidant abilities on the superoxide anions, 1,1-diphenyl-2-picrylhydrazyl (DPPH), and hydroxyl radicals in vitro. RLPs could decrease the serum lipid levels, elevate the serum high-density lipoprotein cholesterol levels, enhance the antioxidant enzymes levels, and upregulate of FADS2, ACOX3, and SCD-1 which involved in the lipid metabolic processes and oxidative stress in the high-fat diet-induced rats. These results suggested that RLPs ameliorated the high-fat diet- (HFD-) induced lipid metabolism disturbance in the rat liver through the peroxisome proliferator-activated receptor (PPAR) signaling pathway. Low molecular weight polysaccharides of RLP could be served as a novel potential functional food for improving hyperlipidemia and liver oxidative stress responses.

Total flavone extract from Ampelopsis megalophylla induces apoptosis in the MCF‑7 cell line

Ampelopsis megalophylla has been found to demonstrate anticancer activities in human cancer cells; however, the effect of total flavone extract (TFE), commonly used in Traditional Chinese Medicine, remains unclear. Furthermore, there is limited information on its effects on breast cancer cell lines. The present study aimed to investigate the inhibitory effects of TFE in different human cancer cell lines. In addition, the underlying mechanisms and the signaling pathways involved were also investigated by determining tumor cell morphological changes, and differences in the cell cycle, apoptosis, mitochondrial transmembrane potential, and related protein expression levels in a breast cancer cell line. It was found that TFE inhibited proliferation in seven cancer cell lines (HeLa, A549, MCF-7, HepG2, A2780, SW620 and MDA-MB-231 and demonstrated a strong inhibitory effect on MCF-7 cell proliferation. Cell morphological changes were also observed and arrested at the G₂/M phase following treatment with TFE at different concentrations. In addition, TFE disrupted the mitochondrial membrane potential and upregulated the expression level of apoptotic proteins, including caspase-3, -8 and -9, the Bax/Bcl-2 ratio, and Apaf-1 in time-dependent manner. These results indicated that TFE induced apoptosis of the MCF-7 cells via a mitochondrial-mediated apoptotic pathway. In conclusion, TFE is potentially effective in treating breast cancer.

Antipyretic and antitumor effects of a purified polysaccharide from aerial parts of Tetrastigma hemsleyanum

ETHNOPHARMACOLOGICAL RELEVANCE

Tetrastigma hemsleyanum Diels et Gilg (Sanyeqing) is traditionally used as a folk medicine for the treatments of inflammation, high fever, hepatitis and cancer, and can improve the immune function of the patient. It belongs to the family of Vitaceae, and is mainly distributed in southeast China (Yunnan province) and can be found in India (Andaman Islands), Myanmar, Thailand, Vietnam, Malaysia and Indonesia in the valleys with 1100-1300 m above the sea level.

AIM OF THE STUDY

The present study aimed to characterize the chemical properties of a purified polysaccharide extracted from the aerial part of Tetrastigma hemsleyanum (SYQP) and investigate its antipyretic and antitumor effects in mice models.

MATERIALS AND METHODS

Water-soluble crude polysaccharides from the aerial parts of Tetrastigma hemsleyanum were extracted and fractionated by DEAE and gel permeation chromatography. Homogeneity, molecular weight, monosaccharide composition, and FTIR analysis were performed to characterize the SYQP. Antipyretic effect of SYQP was examined using Brewer's yeast induced hyperthermia test. Antitumor effect was investigated using H22 tumor bearing mice. The serum cytokines were determined to evaluated the biological activities of SYQP.

RESULTS

SYQP was composed of galacturonic acid (GalA), glucose (Glc), mannose (Man), arabinose (Ara), galactose (Gal), and rhamnose (Rha) with a molar ratio of 11.3:7.1:2.5:1.0:0.9:0.5 and it had an average molecular weight of 66.2 kDa. The oral administration of SYQP at 200 and 400 mg/kg could markedly suppress the hyperthermia of mice induced by Brewer's yeast and decrease the production of cytokines especially prostaglandin E2 (PGE2) in the serum of mice. SYQP inhibited the growth of H22 tumor in mice with inhibitory rate of 39.9% at the administration dose of 200 mg/kg and increased the production of cytokines such as tumor necrosis factor-alpha (TNF-a) and interferon γ (IFN-γ). Experimental results showed that the preventive administration of SYQP before lipopolysaccharide (LPS) reduced the high cytokine levels such as IL-6, IL-10 and IFN-γ, indicating that SYQP might act as a competitor with LPS to interact with toll like receptor 4 (TLR4), which further regulated the secretion of cytokines.

CONCLUSION

The anti-inflammatory and antitumor activities of SYQP might be related to its regulation of host immune function by controlling the secretion of cytokines.

Comparative Transcriptome Analysis of Ampelopsis megalophylla for Identifying Genes Involved in Flavonoid Biosynthesis and Accumulation during Different Seasons

Ampelopsis megalophylla is an important species used in Chinese folk medicine. Flavonoids, the most important active components of plants, greatly determine the quality of A. megalophylla. However, biosynthesis of flavonoids at the molecular and genetic levels in A. megalophylla is not well understood. In this study, we performed chemical analysis and transcriptome analysis of A. megalophylla in different seasons (i.e., May, August, and October). Accumulation of flavonoids was higher in May than in the other two months. Genes involved in the flavonoid biosynthesis pathway, such as chalcone synthase, anthocyanidin synthase, flavanone 3-hydroxylase, flavonoid-3′,5′-hydroxylase, caffeoyl-CoA O-methyltransferase, dihydroflavonol 4-reductase, 4-coumarate-CoA ligase, phenylalanine ammonia-lyase, cinnamate 4-hydroxylase, flavonoid 3′-monooxygenase, shikimate O-hydroxycinnamoyltransferase, and leucoanthocyanidin reductase, were identified based on transcriptome data. Fifty ATP binding cassette (ABC) transporter, nine SNARE, forty-nine GST, and eighty-four glycosyltransferases unigenes related to flavonoid transport and biomodification were also found. Moreover, seventy-eight cytochrome P450s and multiple transcription factors (five MYB, two bHLH, and three WD40 family genes) may be associated with the regulation of the flavonoid biosynthesis process. These results provide insights into the molecular processes of flavonoid biosynthesis in A. megalophylla and offer a significant resource for the application of genetic engineering in developing varieties with improved quality.

Cytotoxicity of two water-soluble polysaccharides from Codonopsis pilosula Nannf. var. modesta (Nannf.) L.T.Shen against human hepatocellular carcinoma HepG2 cells and its mechanism

Two water-soluble polysaccharides named CPP1a and CPP1c were isolated from C. pilosula Nannf. var. modesta L.T.Shen by hot-water extraction and purified by graded alcohol precipitation and DEAE-52 cellulose column. The structure of CPP1c with higher yield has been characterized while its antitumor activities has not been elucidated. In this study, we firstly analyzed the chemical structure of CPP1a. The results of instrumental analysis combined with chemical analysis showed that CPP1a was composed of →1)- β‑l‑Rhap‑(4→, →1)- β‑Arap‑(5→, →1)- β‑d‑GalpA‑(4→, →1)- β‑d‑Galp‑(6→, terminal‑β‑d‑Glcp in a molar ratio of 1:12:1:10:3 and its relative and absolute molecular weight were 1.01 × 10⁵ Da and 1.03 × 10⁵ Da respectively. Further, the cytotoxicity assay indicated that CPP1a and CPP1c were more sensitive to HepG2 cells than cervical carcinoma Hela cells and gastric carcinoma MKN45 cells. Both of CPP1a and CPP1c could influence cell morphology, inhibit the migration and induce apoptosis by affecting the G2/M phase of HepG2 cells. Preliminary mechanism studies confirmed that CPP1a and CPP1c could induce apoptosis through up-regulating the ratio of Bax/Bcl-2 and activating caspase-3. According to previous research, we might speculate that the reason for the stronger cytotoxicity and pro-apoptotic effect of CPP1c than that of CPP1a can be attributed to its high uronic acid content.

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.

iTRAQ-Based Quantitative Proteomic Analysis of the Inhibitory Effects of Polysaccharides from Viscum coloratum (Kom.) Nakai on HepG2 Cells

Viscum coloratum (Kom.) Nakai is one of active medicinal plants, and its active components, especially polysaccharides, have been shown to exhibit bioactivity. In this study, we examined the effects of three polysaccharide fractions from Viscum coloratum (Kom.) Nakai on HepG2 cell growth in a dose-dependent manner by using a CCK-8 assay kit. Flow cytometry analysis showed that VCP2 treatment delayed the cell cycle in the G1 phase and induced apoptosis in HepG2 cells, a result possibly due to the increased expression of p21Wafl/Cip1 and Cyclin D and the decreased expression of Cyclin E and CDK4. The increased expression of Bad, Smac and Caspase-3 and the decreased expression of Bcl-XL and XIAP may be some of the reasons for the induction of apoptosis in VCP2-treated HepG2 cells. Through iTRAQ and 2D-LC-MSMS, 113 and 198 differentially expressed proteins were identified in normal and VCP2-treated HepG2 and Caco2 cells. The mRNA and protein levels of Histone H3.1, Cytoskeletal 9 and Vitronectin agreed with iTRAQ proteomic results. GO, pathways and the PPI of differentially expressed proteins were further analyzed. These findings broaden the understanding of the anti-tumor mechanisms of mistletoe polysaccharides and provide new clues for screening proteins that are responsive to polysaccharides.

Extraction, characterization, and biological activity of polysaccharides from Sophora flavescens Ait

Four water-soluble polysaccharides, designated as SF1, SF2, SF3 and SF4, were efficiently extracted from the roots of Sophora flavescens by mechanochemistry under the conditions of rotational speed of 400rpm, grinding time of 10min, powder to ball weight ratio of 1:20, and Na₂CO₃ loading of 7wt%. The results obtained indicated that all of these four acid heteropolysaccharides are composed of rhamnose, arabinose, xylose, mannose, glucose and galactose, with the average molecular weights of 400.9, 98.6, 99.3, 42.7kDa, respectively. In vitro, SF4 showed the most significant scavenging activity on superoxide radical, ABTS, and DPPH radical, while SF3 had the most significant scavenging activity on hydroxyl radical. Immunological tests demonstrated that SF1, SF2, SF3 and SF4 significantly stimulated nitric oxide production without cytotoxicity in macrophages and promoted splenocyte proliferation. These data suggest that the four polysaccharides fractions have the potential as novel natural sources of antioxidative and immunopotentiating agents.

The Effects of Different Purifying Methods on the Chemical Properties, in Vitro Anti-Tumor and Immunomodulatory Activities of Abrus cantoniensis Polysaccharide Fractions

Abrus cantoniensis (Hance) is a popular Chinese vegetable consumed as a beverage, soup or folk medicine. To fully exploit the potential of the polysaccharide in Abrus cantoniensis, nine polysaccharide fractions of Abrus cantoniensis were isolated and purified (AP-AOH30-1, AP-AOH30-2, AP-AOH80-1, AP-AOH80-2, AP-ACl-1, AP-ACl-2, AP-ACl-3, AP-H and AP-L). Fourier-transform infrared spectroscopy (FT-IR) and gas chromatography (GC) were used to characterize these Abrus polysaccharides fractions (APF). In vitro anti-tumor and immunomodulatory activities were also investigated and compared using the rank-sum ratio (RSR) method. Results demonstrated significant differences in the structure and bioactivities among APF, which were associated to the process used for their purification. Among the APF, AP-ACl-3 yield was 613.5 mg/kg of product and consisted of rhamnose (9.8%), arabinose (8.9%), fructose (3.0%), galactose (9.9%), glucose (4.3%), galacturonic acid (3.0%) and glucuronic acid (61.1%) with a molecular weight of 4.4 × 10⁴ Da. Furthermore, AP-ACl-3 exhibited considerable bioactivities significantly preventing the migration of MCF-7 cells and stimulating lymphocyte proliferation along with nitric oxide (NO) production of peritoneal macrophages. AP-ACl-3 could be explored as a novel potential anti-tumor and immunomodulatory agent.

Isolation and antitumor efficacy evaluation of a polysaccharide from Nostoc commune Vauch

A polysaccharide from Nostoc commune Vauch. (NVPS) was characterized and its antitumor efficacy was elucidated.