Distinct prebiotic effects of polysaccharide fractions from Polygonatum kingianum on gut microbiota.

This study investigated the physicochemical properties, digestive stability, and in vitro fermentation behavior of Polygonatum kingianum polysaccharide (PKP) fractions (PKP60, PKP70, PKP80) obtained through graded ethanol precipitation. High-performance gel permeation chromatography revealed significant molecular weight differences among the fractions, while reverse-phase high-performance liquid chromatography indicated consistent monosaccharide types with variations in their proportions. Uronic acid analysis confirmed that all polysaccharide fractions met the criteria for neutral polysaccharides. Congo red staining confirmed the presence of a triple-helix structure in all PKP fractions. Comprehensive analysis demonstrated that these fractions remained stable during in vitro digestion, as evidenced by consistent molecular weights and total carbohydrate content, with no significant production of free monosaccharides or reducing sugars. All PKP fractions were fermented by gut microbiota, resulting in the production of short-chain fatty acids. Beta diversity and structural analyses of gut microbiota revealed distinct modulatory effects associated with each PKP fraction. The PKP fractions promoted probiotic growth, especially PKP70, which significantly enhanced Bifidobacterium proliferation, indicating strong prebiotic potential. These findings underscore the importance of isolation and purification methods in determining the functionality and gut microbiota-modulating effects of plant-derived polysaccharides, emphasizing the need for in-depth research that extends beyond merely evaluating their source.

Chemical structures and immunomodulatory activities of polysaccharides from Polygonatum kingianum.

The physicochemical properties of the polysaccharides in Polygonatum kingianum, a Chinese medicinal herb used for both medicine and food, have not been fully studied. This study isolated three polysaccharides (PKP-1, PKP-2, and PKP-3) from the dry rhizomes of P. kingianum, with an average molecular weight of approximately 3137 Da, 5341 Da and 3755 Da, respectively. Structural analysis showed that all the three polysaccharides are fructans with ß-D-Fruf-(2→, →6)-ß-D-Fruf-(2→, →1)-ß-D-Fruf-(2→, →1,6)-ß-D-Fruf-(2→ and →6)-α-D-Glcp-(1→ glycosidic bond type. Notably, PKP-2 contains both acetyl groups and trace amounts of mannose residues. Scanning electron microscopy indicated that each polysaccharide possesses unique surface morphology. Thermal analysis showed that the three polysaccharides have good thermal stability. Rheological studies further revealed that all the three polysaccharides are typical shear thinning fluids. In vitro experiments showed that PKP-1 and PKP-2 significantly promote the secretion of NO and cytokines (TNF-α, IL-6) in macrophages by activating the NF-κB signaling pathway, thereby demonstrating potential immunomodulatory activity. These findings lay a theoretical foundation for the potential application of Polygonatum polysaccharides in the food industry.

Elucidating the interaction of rhizosphere microorganisms and environmental factors influencing the quality of Polygonatum kingianum Coll. et Hemsl.

Polygonatum kingianum Collett & Hemsl., is one of the most important traditional Chinese medicines in China. The purpose of this study is to investigate the relationship between herb quality and microbial-soil variables, while also examining the composition and structure of the rhizosphere microbial community in Polygonatum kingianum, the ultimate goal is to provide a scientific approach to enhancing the quality of P. kingianum. Illumina NovaSeq technology unlocks comprehensive genetic variation and biological functionality through high-throughput sequencing. And in this study it was used to analyze the rhizosphere microbial communities in the soils of five P. kingianum planting areas. Conventional techniques were used to measure the organic elements, pH, and organic matter content. The active ingredient content of P. kingianum was identified by High Performance Liquid Chromatography (HPLC) and Colorimetry. A total of 12,715 bacterial and 5487 fungal Operational Taxonomic Units (OTU) were obtained and taxonomically categorized into 81 and 7 different phyla. Proteobacteria, Bacteroidetes, and Acidobacteriae were the dominant bacterial phyla Ascomycota and Basidiomycota were the dominat fungal phyla. The key predictors for bacterial community structure included hydrolysable nitrogen and available potassium, while for altering fungal community structure, soil organic carbon content (OCC), total nitrogen content (TNC), and total potassium content (TPOC) were the main influencing factors. Bryobacter and Candidatus Solibacter may indirectly increase the polysaccharide content of P. kingianum, and can be developed as potential Plant Growth Promoting Rhizobacteria (PGPR). This study has confirmed the differences in the soil and microorganisms of different origins of P. kingianum, and their close association with its active ingredients. And it also broadens the idea of studying the link between plants and microorganisms.

Research on the anti-oxidant and anti-aging effects of Polygonatum kingianum saponins in Caenorhabditis elegans.

Oxidative stress and its impact on aging are critical areas of research. Natural anti-oxidants, such as saponins found in Polygonatum sibiricum, hold promise as potential clinical interventions against aging. In this study, we utilized the nematode model organism, Caenorhabditis elegans, to investigate the pharmacological effects of Polygonatum sibiricum saponins (PKS) on antioxidation and anti-aging. The results demonstrated a significant anti-aging biological activity associated with PKS. Through experiments involving lifespan and stress, lipofuscin, q-PCR, and ROS measurement, we found that PKS effectively mitigated aging-related processes. Furthermore, the mechanism underlying these anti-aging effects was linked to the SKN-1 signaling pathway. PKS increased the nuclear localization of the SKN-1 transcription factor, leading to the up-regulation of downstream anti-oxidant genes, such as gst-4 and sod-3, and a substantial reduction in intracellular ROS levels within the nematode. In conclusion, our study sheds light on the anti-oxidant and anti-aging properties of PKS in C. elegans. This research not only contributes to understanding the biological mechanisms involved but also highlights the potential therapeutic applications of these natural compounds in combating aging-related processes.

Combined Metabolomics and Transcriptomics Analysis of the Distribution of Flavonoids in the Fibrous Root and Taproot of Polygonatum kingianum Coll.et Hemsl.

Polygonati rhizoma, known for its distinct yellow rhizomes, is a common therapeutic and culinary plant in Far East Asia. The hue of medicinal plants is closely tied to the flavonoid biosynthesis and content levels. In this research, the fibrous root and taproot of Polygonatum kingianum Coll.et Hemsl. were studied to explore the secondary metabolite expression and flavonoid biosynthesis mechanisms using transcriptomics and metabolomics. Metabolic analysis identified that the differentially accumulated metabolites (DAMs) in the fibrous root and taproot were predominantly flavonoids, steroids, alkaloids, and phenolic acids. Overall, 200 flavonoids were identified in P. kingianum Coll.et Hemsl., with 170 exhibiting variances between the fibrous root and taproot. The transcriptome analysis revealed that a total of 289 unigenes encoding 32 enzymes were annotated into four flavonoid biosynthesis pathways, which include phenylpropanoid biosynthesis pathway, flavonoid biosynthesis pathway, isoflavonoid biosynthesis pathway, and flavone and flavonol biosynthesis pathway. The integration of transcriptomic and metabolomic data elucidated that the 76 differentially expressed genes (DEGs) encoding 13 enzyme genes (HCT, CCOMT, C4H, C3'H, CHI, PGT1, FLS, F3'H, CHS, ANR, DFR, F3'5'H, and LAR) and 15 DAMs preferred to be regulated in the flavonoid biosynthesis pathway. The expression of 10 DEGs was validated by qRT-PCR, agreeing with the same results by RNA-Seq. These findings shed light into the biosynthesis of secondary metabolites in P. kingianum Coll.et Hemsl., offering valuable information for the sustainable utilization and enhancement of this plant species.

First Report of Polygonatum kingianum Leaf Spot Caused by Alternaria alternata in Kunming, China.

Polygonatum kingianum Coll. et Hemsl., a Polygonatum species in the Asparagaceae family, plays an important role in Chinese herbal medicine (Zhao et al. 2018). P. kingianum is widely planted in the Southwestern China. In September 2023, we observed a leaf spot of P. kingianum with disease incidence of 100%, and disease index reached 60 in commercial plantings in Kunming, Yunnan province, China (24.3610°N, 102.3740°E). In the initial stage of infection, symptoms manifested as a small circular brown spot. As the spots gradually expanded, they formed oval to irregular shaped lesions with grayish-white or dark-brown borders. Progressively the entire leaf withered and died. For identification of the causal agent of the leaf spot, leaf sections (5×5 mm2) were cut from the margin of the lesion and soaked in 75% ethanol for 10 s, 1% sodium hypochlorite for 3 min, washed with sterile distilled water, dried on sterilized tissue paper and placed on potato dextrose agar (PDA). The Petri dishes were then incubated at 28℃ for 3 days with a 12-h photoperiod. A predominant fungus was isolated from 95% of the samples. Three monosporic isolates were screened using a single-spore isolation method. After 4 days of incubation the colonies were white, after 7 days turned yellow-white. Conidia were black-brown, oblong or fusiform, with 3-7 transverse septa and 0-3 longitudinal septa, with dimensions of 19.5 to 49.5 × 8.7 to 17.6 µm (n = 30). Total genomic DNA of these three isolates was extracted from mycelia by the cetyltrimethylammonium bromide (CTAB) protocol. The nucleotide sequences of the elongation factor 1-alpha (EF1α), nuclear ribosomal internal transcribed spacer (ITS), 28S nuclear ribosomal large subunit rRNA gene (LSU), 18S nuclear ribosomal small subunit rRNA gene (SSU), and the second largest subunit of nuclear DNA-directed RNA polymerase II (RPB2) gene regions were amplified using the primer pairs EF1-728F/EF1-986R (Carbone and Kohn 1999), ITS1/ITS4 (White et al. 1990), LR0R/LR5 (Schoch et al. 2012), NS1/NS4 (Schoch et al. 2012), and fRPB2-5F/fRPB2-7Cr (Liu et al. 1999), respectively. Amplicons were cloned in a pMDTM19-T vector (code no. 6013, Takara, Kusatsu, Japan) and bidirectionally sequenced. All three isolates had identical nucleotide sequences. Sequences from one isolate (PkF03) were deposited in GenBank. BLASTn analyses showed that sequences of EF1α (GenBank accession no. PP695240), ITS (PP694046), LSU (PP683406), SSU (PP683407), and RPB2 (PP695241) of isolate PkF03 were 99.6 (KP125134), 100 (KP124358), 100 (KP124510), 99.9 (KP124980), and 100% (KP124826), respectively, identical with Alternaria alternata (Fr.) Keissl. strain CBS 118815. Based on the nucleotide sequences of EF1α, ITS, LSU, SSU, and RPB2, a maximum likelihood phylogenetic tree was constructed using MEGAX with Tamura-Nei model. Isolate PkF03 was grouped in the same clade as A. alternata. According to the morphology and sequence analyses isolate PkF03 was identified as A. alternata (Woudenberg et al. 2013). To determine pathogenicity of isolate PkF03, a spore suspension (106 spores/mL) was sprayed on 1-year-old healthy leaves of P. kingianum. The control leaves were sprayed with sterile water. All plants were incubated at 28℃, 70% relative humidity, and a 12-h photoperiod. The pathogenicity tests were repeated three times with six plants in each treatment. Fifteen days post-inoculation, the inoculated leaves showed brown-yellow lesions, whereas the control leaves remained symptomless. A. alternata was reisolated from infected leaves. To our knowledge, this is the first report of A. alternata causing leaf spot on P. kingianum in Kunming, China. The results provide a scientific basis for prevention and control of the disease.

The complete chloroplast genomes of Polygonatum hunanense, P. verticillatum, and P. caulialatum and their phylogenetic positions.

Polygonatum hunanense H.H. Liu & B.Z. Wang (2021) and P. verticillatum (L.) All. (1875) have been widely used as foods and as folk medicines in China and India, and P. caulialatum S. R. Yi (2021) has recently been described as a new medical plant in China. There is at present a lack of genome information regarding the species. Hence, this study reports the complete chloroplast genomes of the three species. The genomes of P. hunanense, P. verticillatum, and P. caulialatum were 155,583 bp, 155,650 bp, and 155,352 bp in length, respectively. They contained large single-copy (LSC) regions of 84,412 bp, 84,404 bp, and 84,285 bp, small single-copy (SSC) regions of 18,427 bp, 18,416 bp, and 18,463 bp, and a pair of inverted repeats of 26,372 bp, 26,415 bp, and 26,302 bp, respectively. The chloroplast genomes of P. hunanense, P. verticillatum, and P. caulialatum had 133 (103 unique) genes, consisting of 87 protein-coding genes, 38 ribosomal ribonucleic acid (RNA) genes, and eight transfer RNA genes, respectively. A maximum-likelihood phylogenetic tree showed that P. kingianum Coll. et Hemsl. var. grandifolium D.M. Liu & W.Z. Zeng (1991) was closer to P. cyrtonema Hua (1892) rather than to P. kingianum Coll. et Hemsl. (1890), further supporting its status as a unique species of the genus. Moreover, P. verticillatum was separated from the easily confused herb P. cirrhifolium (Wall.) Royle (1839), while P. caulialatum was closest to P. humile Fisch. ex Maxim. (1859). This research provides a foundation for further study of these herbs.

Transcriptome-wide identification of ARF gene family in medicinal plant Polygonatum kingianum and expression analysis of PkARF members in different tissues.

BACKGROUND: Polygonatum kingianum holds significant importance in Traditional Chinese Medicine due to its medicinal properties, characterized by its diverse chemical constituents including polysaccharides, terpenoids, flavonoids, phenols, and phenylpropanoids. The Auxin Response Factor (ARF) is a pivotal transcription factor known for its regulatory role in both primary and secondary metabolite synthesis. However, our understanding of the ARF gene family in P. kingianum remains limited. METHODS AND RESULTS: We employed RNA-Seq to sequence three distinct tissues (leaf, root, and stem) of P. kingianum. The analysis revealed a total of 31,558 differentially expressed genes (DEGs), with 43 species of transcription factors annotated among them. Analyses via gene ontology and the Kyoto Encyclopedia of Genes and Genomes demonstrated that these DEGs were predominantly enriched in metabolic pathways and secondary metabolite biosynthesis. The proposed temporal expression analysis categorized the DEGs into nine clusters, suggesting the same expression trends that may be coordinated in multiple biological processes across the three tissues. Additionally, we conducted screening and expression pattern analysis of the ARF gene family, identifying 12 significantly expressed PkARF genes in P. kingianum roots. This discovery lays the groundwork for investigations into the role of PkARF genes in root growth, development, and secondary metabolism regulation. CONCLUSION: The obtained data and insights serve as a focal point for further research studies, centred on genetic manipulation of growth and secondary metabolism in P. kingianum. Furthermore, these findings contribute to the understanding of functional genomics in P. kingianum, offering valuable genetic resources.

Polygonatum kingianum Polysaccharides Enhance the Preventive Efficacy of Heat-Inactivated Limosilactobacillus reuteri WX-94 against High-Fat-High-Sucrose-Induced Liver Injury and Gut Dysbacteriosis.

Limosilactobacillus reuteri (L. reuteri) is an efficacious probiotic that could reduce inflammation and prevent metabolic disorders. Here, we innovatively found that Polygonatum kingianum polysaccharides (PKP) promoted proliferation and increased stability of L. reuteri WX-94 (a probiotic strain showing anti-inflammation potentials) in simulated digestive fluids in vitro. PKP was composed of galactose, glucose, mannose, and arabinose. The cell-free supernatant extracted from L. reuteri cultured with PKP increased ABTS•+, DPPH•, and FRAP scavenging capacities compared with the supernatant of the medium without PKP and increased metabolites with health-promoting activities, e.g., 3-phenyllactic acid, indole-3-lactic acid, indole-3-carbinol, and propionic acid. Moreover, PKP enhanced alleviating effects of heat-inactivated L. reuteri on high-fat-high-sucrose-induced liver injury in rats via reducing inflammation and regulating expressions of protein and genes involved in fatty acid metabolism (such as HIF1-α, FAßO, CPT1, and AMPK) and fatty acid profiles in liver. Such benefits correlated with its prominent effects on enriching Lactobacillus and short-chain fatty acids while reducing Dubosiella, Fusicatenilacter, Helicobacter, and Oscillospira. Our work provides novel insights into the probiotic property of PKP and emphasizes the great potential of the inactivated L. reuteri cultured with PKP in contracting unhealthy diet-induced liver dysfunctions and gut dysbacteriosis.

Chemical composition and antioxidant activity of Polygonatum kingianum processed by the traditional method of "Nine Cycles of Steaming and Sun-Drying".

Polygonatum kingianum Coll. et (Hemsl) is a famous Chinese traditional food and medicine analogous plant. The rhizome of P. kingianum showed a decrease in levels of alkaloids, amino acids and derivatives, terpenoids, and an increase in organic acid and saccharides when it was processed by the traditional method of "Nine Cycles of Steaming and Sun-Drying". The relative content of 341 metabolites were increased (fold change, FC > 2; variable importance in projection, VIP > 1 and P-value, P < 0.05); while 456 metabolites were decreased (FC < 0.5, VIP > 1, and P < 0.05). The changes in chemical components result in a decrease in numb taste and an increase in sweetness. The increased antioxidant activity was observed in the processed samples. Together, this work has advanced the mechanism of reducing numb taste and enhancing antioxidant activity in the resource plants, such as P. kingianum, processed by the traditional method.

Investigation of natural deep eutectic solvent for the extraction of crude polysaccharide from Polygonatum kingianum and influence of metal elements on its immunomodulatory effects.

In this study, natural deep eutectic solvent (NADES) was used to extract Polygonatum kingianum crude polysaccharide (PKCP) and response surface methodology (RSM) was designed to optimize the extraction procedure. The immunomodulatory effect of PKCP and the influence of metal elements on its immunomodulatory effect were further discussed. The optimum conditions for PKCP extraction were obtained by RSM optimization: NADES were synthesized with a 1:2 choline chloride-glycerol molar ratio, then extracted at a liquid-solid ratio of 16.6 mL g-1 and water content of 31.2 % for 60 min at 60 °C. This method was used for the extraction of PKCP, and the extraction efficiency was 29.69 %, which was 2.5 times greater than the conventional method of water extraction. In the concentration range of 200-800 µg mL-1, PKCP could activate macrophages, promoting NO secretion and mRNA expression of interleukin-6 (IL-6) and inducible nitric oxide synthase (iNOS) in a dose-dependent way. NO secretion and cytokine expression were not affected when the metal elements were spiked to the equivalent of the metal elements contained in Polygonatum kingianum. When the content of metal elements was higher, the secretion of NO and the gene expression of iNOS were both decreased, which may affect the immunomodulatory effect of Polygonatum kingianum.

'Nine Steaming Nine Sun-drying' processing enhanced properties of Polygonatum kingianum against inflammation, oxidative stress and hyperglycemia.

BACKGROUND: Polygonatum kingianum Coll. & Hemsl (PK), a prominent medicine and food homology plant, has been consumed as a decoction from boiling water for thousands of years. 'Nine Steaming Nine Sun-drying' processing has been considered an effective method for enriching tonic properties, but studies investigating such impacts on PK and underlying mechanisms are extremely rare. RESULTS: We first demonstrated substantial improvements in the anti-oxidative, anti-inflammatory and anti-hyperglycemia effects of the Nine Steaming Nine Sun-drying processed PK water extracts compared with crude PK in cell models (i.e., HepG2 and Raw 264.7 cells). We then integrated foodomics and network pharmacology analysis to uncover the key compounds responsible for the improved benefits. A total of 551 metabolites of PK extracts were identified, including polyphenols, flavonoids, alkaloids, and organic acids. During processing, 204 metabolites were enhanced, and 32 metabolites were recognized as key constituents of processed PK responsible for the improved health-promoting activities, which may affect PI3K-Akt-, MAPK-, and HIF-1 pathways. We further confirmed the high affinity between identified key constituents of processed PK and their predicted acting targets using molecular docking. CONCLUSION: Our results provide novel insights into bioactive compounds of processed PK, elaborating the rationality of processing from the perspective of tonic effects. Consuming processed PK could be an efficacious strategy to combat the high prevalence of metabolic diseases that currently affect millions of people worldwide. © 2023 Society of Chemical Industry.

Comparative analysis of the medicinal plant Polygonatum kingianum (Asparagaceae) with related verticillate leaf types of the Polygonatum species based on chloroplast genomes.

Background: Polygonatum kingianum has been widely used as a traditional Chinese medicine as well as a healthy food. Because of its highly variable morphology, this medicinal plant is often difficult to distinguish from other related verticillate leaf types of the Polygonatum species. The contaminants in P. kingianum products not only decrease the products' quality but also threaten consumer safety, seriously inhibiting the industrial application of P. kingianum. Methods: Nine complete chloroplast (cp) genomes of six verticillate leaf types of the Polygonatum species were de novo assembled and systematically analyzed. Results: The total lengths of newly sequenced cp genomes ranged from 155,437 to 155,977 bp, including 86/87 protein-coding, 38 tRNA, and 8 rRNA genes, which all exhibited well-conserved genomic structures and gene orders. The differences in the IR/SC (inverted repeats/single-copy) boundary regions and simple sequence repeats were detected among the verticillate leaf types of the Polygonatum cp genomes. Comparative cp genomes analyses revealed that a higher similarity was conserved in the IR regions than in the SC regions. In addition, 11 divergent hotspot regions were selected, providing potential molecular markers for the identification of the Polygonatum species with verticillate leaf types. Phylogenetic analysis indicated that, as a super barcode, plastids realized a fast and efficient identification that clearly characterized the relationships within the verticillate leaf types of the Polygonatum species. In brief, our results not only enrich the data on the cp genomes of the genus Polygonatum but also provide references for the P. kingianum germplasm resource protection, herbal cultivation, and drug production. Conclusion: This study not only accurately identifies P. kingianum species, but also provides valuable information for the development of molecular markers and phylogenetic analyses of the Polygonatum species with verticillate leaf types.

Genomic characterization and seed transmission of a novel unclassified partitivirus infecting Polygonatum kingianum Coll. et Hemsl.

This study identified a novel virus in the family Partitiviridae infecting Polygonatum kingianum Coll. et Hemsl, which is tentatively named polygonatum kingianum cryptic virus 1 (PKCV1). PKCV1 genome has two RNA segments: dsRNA1 (1926 bp) has an open reading frame (ORF) encoding an RNA-dependent RNA polymerase (RdRp) of 581 amino acids (aa), and dsRNA2 (1721 bp) has an ORF encoding a capsid protein (CP) of 495 aa. The RdRp of PKCV1 shares 20.70-82.50% aa identity with known partitiviruses, and the CP of PKCV1 shares 10.70-70.80% aa identity with known partitiviruses. Moreover, PKCV1 phylogenetically clustered with unclassified members of the Partitiviridae family. Additionally, PKCV1 is common in P. kingianum planting regions and has a high infection rate in P. kingianum seeds.

Untargeted GC-MS and FT-NIR study of the effect of 14 processing methods on the volatile components of Polygonatum kingianum.

Introduction: Polygonatum kingianum is a traditional medicinal plant, and processing has significantly impacts its quality. Methods: Therefore, untargeted gas chromatography-mass spectrometry (GC-MS) and Fourier transform-near-infrared spectroscopy (FT-NIR) were used to analyze the 14 processing methods commonly used in the Chinese market.It is dedicated to analyzing the causes of major volatile metabolite changes and identifying signature volatile components for each processing method. Results: The untargeted GC-MS technique identified a total of 333 metabolites. The relative content accounted for sugars (43%), acids (20%), amino acids (18%), nucleotides (6%), and esters (3%). The multiple steaming and roasting samples contained more sugars, nucleotides, esters and flavonoids but fewer amino acids. The sugars are predominantly monosaccharides or small molecular sugars, mainly due to polysaccharides depolymerization. The heat treatment reduces the amino acid content significantly, and the multiple steaming and roasting methods are not conducive to accumulating amino acids. The multiple steaming and roasting samples showed significant differences, as seen from principal component analysis (PCA) and hierarchical cluster analysis (HCA) based on GC-MS and FT-NIR. The partial least squares discriminant analysis (PLS-DA) based on FT-NIR can achieve 96.43% identification rate for the processed samples. Discussion: This study can provide some references and options for consumers, producers, and researchers.

Protective effect and mechanism of Polygonatum kingianum against hypoxia-induced injury.

Background: Hypoxia is an essential cause of fatigue and aging, and is associated with the occurrence and development of many diseases. Polygonatum kingianum (PK) is a deficiency-nourishing Chinese herbal medicine utilized as both medicine and food, and it has long been used to ameliorate human conditions associated with fatigue and aging over 2000 years in China. PK is an important genuine-medicinal-materials cultivated in Yunnan, China, and is used by the Bai, Wa, and Zhuang nationalities as a traditional medicine for enhancing immunity, anti-fatigue, and anti-aging, while the preventive effect of PK on hypoxia-induced injury and the underlying mechanism are indefinite. Aim of the study: The present study aimed to evaluate the anti-hypoxia efficacy and understand the corresponding mechanism of PK water extract. Materials and methods: The main active ingredients and targets of PK were predicted using network pharmacology, and the anti-hypoxia activities of Gracillin and Liquiritigenin were verified by in vitro experiments. The pharmacodynamic experiments were conducted to evaluate the major signal pathways of PK for detecting anti-hypoxia activity. Results: Fifty active ingredients and 371 potential targets were screened by network pharmacology, then, we confirmed that Gracillin and Liquiritigenin were the main active components of PK to exert anti-hypoxia effect in vitro. The pharmacodynamic experiments revealed that PK enhanced the extension rate of the survival time (ERST) and regulated the targets-related biochemical parameters of rats under hypoxia, showing significant anti-hypoxia effects on rats. Conclusion: The network pharmacology results suggested that PK exerts its anti-hypoxia effect through a multi-component and multi-target manner. Simultaneously, we also observed that Gracillin (saponins) and Liquiritigenin (flavonoids) are the main active components of PK to play a role in anti-hypoxia. The anti-hypoxia effect of PK could be associated with scavenging excess free radicals, maintaining the activities of antioxidant enzymes, and inhibiting oxidative stress due to lipid peroxidation. These findings provide insight into the Polygonatum kingianum as promising medicines or healthcare products for preventing and treating hypoxia.

Effect of fermentation modification on the physicochemical characteristics and anti-aging related activities of Polygonatum kingianum polysaccharides.

In order to fully investigate the anti-aging value of the plants polysaccharides, the fermentation method was applied to modify the Polygonatum kingianum polysaccharides (PKPS), and the ultra-filtration was used to further segment the hydrolyzed polysaccharides. It was found that the fermentation induced an increase in the in vitro anti-aging-related activities of PKPS including antioxidant, hypoglycemic and hypolipidemic activity, and cellular aging-delaying ability. In particular, the low Mw fraction PS2-4 (10-50 kDa) separated from the fermented polysaccharide exhibited superior anti-aging activity on experimental animals. PS2-4 extended the Caenorhabditis elegans lifespan by 20.70 %, with an increased effect of 10.09 % compared to the original polysaccharide; it was also more effective than the original one in improving movement ability and reducing lipofuscin accumulation of worms. This fraction was screened as the optimal anti-aging active polysaccharide. After fermentation, the main molecular weight distribution of PKPS changed from 50-650 kDa to 2-100 kDa, and the chemical composition and monosaccharide composition also changed; the initial rough and porous microtopography turned into smooth state. These alterations in physicochemical characteristics suggest that fermentation exerted an influence on the structure of PKPS, which contributed to the enhanced anti-aging activity, indicating that fermentation was promising in the structural modification of polysaccharides.

Effects of Polygonatum Kingianum Coll.et Hemsl on Oxidative Stress and Expression of Nrf2/HO-1 Signaling Pathyway in Diabetes Rats with Skin Lesions / 世界科学技术-中医药现代化

Objective To investigate the effects of Polygonatum kingianum on wound healing and nuclear factor-erythroid 2-related factor 2(Nrf2)/heme oxygenase-1(HO-1)signaling pathway in diabetic skin injury rats.Methods Diabetic rat models were established and 48 rats were randomly divided into model group,sitagliptin group(10 mg·kg-1),Polygonatum kingianum water extract low dose group(2 g·kg-1),Polygonatum kingianum water extract high dose group(8 g·kg-1)and Polygonatum Kingianum alcohol extract low and high dose group(2 g·kg-1 and 8 g·kg-1).8 in each group;Another control group was set up.After 4 weeks of intragastric administration,all rats established back skin wounds,and continued to be administered for 14 days after operation.At the end of the experiment,the rats were killed,and blood glucose,glycosylated hemoglobin(GHb),plasma levels of H2O2,MDA,SOD,GSH and wound margin skin tissue T-AOC,SOD,MDA levels were measured.The relative expression of Nrf2 and HO-1 mRNA in wound margin skin tissue was measured by fluorescence quantitative method.Results Compared with the model group,the levels of SOD and GSH in plasma and the relative expressions of Nrf2 and HO-1 mRNA in wound margin skin tissue in the low and high dose groups of ethanol extract of Polygonatum kingianum,and the low and high dose groups of water extract of Polygonatum kingianum were increased(P<0.01,P<0.001).The levels of glycosylated hemoglobin(GHb)in plasma and MDA in wound margin tissue were decreased(P<0.05,P<0.01,P<0.001).The level of T-AOC in the high dose group was increased(P<0.01).The SOD level of skin tissue in the low dose group of Polygonatum kingianum water extract was increased(P<0.01),and the level of H2O2 in the low dose group was decreased(P<0.01).Conclusion Polygonatum canaliculatum can up-regulate Nrf2/HO-1 signaling pathway,regulate excessive oxidative stress,and promote wound healing.

Effect and mechanisms of Polygonatum kingianum (polygonati rhizome) on wound healing in diabetic rats.

ETHNOPHARMACOLOGICAL RELEVANCE: Diabetic dermatopathy is one of the most serious and common complications of diabetes. It has been found that high glucose can lead to abnormal glycometabolism. The skin microenvironment pollution caused by the increase in glucose and the oxidative stress mediated by the deposition of advanced glycation end products can lead to invisible skin injury, and the interaction between them is the key factor that makes the skin wounds of diabetic rats difficult to heal. Therefore, the main task of promoting healing is to reduce blood glucose levels and relieve the deposition of advanced glycation end products. Polygonatum kingianum Collett & Hemsl (PK) of Asparagaceae is planted in Yunnan, China, and is used by the Bai, Hani and Wa nationalities as a traditional medicine for preventing and treating diabetes. AIM OF THE STUDY: To study the effects of PK extract on skin wound healing in diabetic rats and to explore the regulatory mechanism of PK on wound microenvironment pollution, the antioxidative stress signaling pathway and latent injury of wound skin tissue. METHODS: First, wounds were prepared after diabetic rats were given PK extract by gavage for 4 weeks, and then gavage was continued for 2 weeks to observe and calculate the wound healing rate. A scanning electron microscope was used to observe the pathomorphological changes in the skin tissue at the edge of the wound. Western blotting was used to detect protein expression. Immunohistochemistry was used to detect the expression of CD34, AGEs, bFGF and VEGF. The Nrf2/HO-1 signaling pathway in skin tissue was detected by fluorescence quantitative PCR. Serum biochemical indicators and inflammatory cytokine levels were detected by a kit. RESULTS: After PK treatment, the wound healing rate increased significantly (P < 0.001), the infiltration of inflammatory cells in skin tissue of DM lesion rats decreased, the number of new blood vessels increased, and the epidermis and dermis thickened. The content of glucose, AGEs, RAGE protein and RAGE mRNA in skin decreased significantly (P < 0.05, P < 0.01, P < 0.001), while the expression of Nrf2 mRNA, HO-1 mRNA, CD34, bFGF and VEGF increased significantly (P < 0.05, P < 0.01, P < 0.001). The levels of SOD, GSH, MMP-9 and MMP-2 in skin decreased (P < 0.05, P < 0.01, P < 0.001), but the level of TIMP-2 increased (P < 0.001). GSP, GHb and ICAM-1 in plasma decreased (P < 0.05, P < 0.01, P < 0.001), while T-AOC, SOD and FINS increased (P < 0.05, P < 0.01). The levels of MDA, TNF-, IL-6, IL-2 and IFN-γ in plasma and wound skin tissue decreased (P < 0.05, P < 0.01, P < 0.001). CONCLUSION: PK can reduce the infiltration of inflammatory cells and glucose content in the skin tissue at the edge of the wound, reduce inflammatory factors in skin and plasma, and increase angiogenesis, thus improving the wound healing rate. PK can alleviate the microenvironment pollution caused by AGEs and glucose metabolism disorder in diabetic rats and induce antioxidant activity through the Nrf 2/HO-1 signaling pathway, thus reducing oxidative damage and offsetting endogenous skin damage and hidden damage.

[Relative molecular mass distribution and monosaccharide composition of polysaccharides in Polygonatum kingianum var.grandifolium].

Polygonatum kingianum var.grandifolium, different from most Polygonatum species in biological characteristics, sprouts and blooms in spring and autumn, respectively, and it is evergreen in winter.It is difficult to learn from the patterns of other Polygonatum plants because the chemical composition in P.kingianum var.grandifolium changes with phenology, which consequently restricts the production of high-quality medicinal and eatable substances.Samples of P.kingianum var.grandifolium in different months and ages collected from Xiushan, Chongqing were analyzed for polysaccharide content, polysaccharide relative molecular mass, and mono-saccharide composition by anthrone-sulfuric acid colorimetric assay, high-performance gel-permeation chromatography, and trimethylsilane(TMS) derivatization prior to GC-MS.The results showed that the polysaccharide content and composition in the rhizome of P.kingianum var.grandifolium were closely related to the growth period.New shoot sprouting promoted the accumulation of polysaccharides, and flowering and fruiting consumed polysaccharides.The highest polysaccharide content was found in April, reaching 134.04 mg·g~(-1).Polysaccharides in P.kingianum var.grandifolium were divided into five fractions according to the weight-average M_W, i.e., P1(2.02×10~7), P2(5.09×10~6), P3(1.37×10~6), P4(4.73×10~5), and P5(5.11×10~3), and P5 had the highest content.In terms of monosaccharide composition, polysaccharides were mainly composed of fructose, glucose, galactose, mannose, xylose, and arabinose with the average molar ratio of 1.31∶1.00∶0.90∶0.53∶0.22∶0.21.The results of the study provide a scientific basis for the precise harvesting and resource utilization of P.kingianum var.grandifolium.