Species identification of polygonati rhizoma in China by both morphological and molecular marker methods

Laser-Induced Breakdown Spectroscopy-Visible and Near-Infrared Spectroscopy Fusion Based on Deep Learning Network for Identification of Adulterated Polygonati Rhizoma

The geographical origin of foods greatly influences their quality and price, leading to adulteration between high-priced and low-priced regions in the market. The rapid detection of such adulteration is crucial for food safety and fair competition. To detect the adulteration of Polygonati Rhizoma from different regions, we proposed LIBS-VNIR fusion based on the deep learning network (LVDLNet), which combines laser-induced breakdown spectroscopy (LIBS) containing element information with visible and near-infrared spectroscopy (VNIR) containing molecular information. The LVDLNet model achieved accuracy of 98.75%, macro-F measure of 98.50%, macro-precision of 98.78%, and macro-recall of 98.75%. The model, which increased these metrics from about 87% for LIBS and about 93% for VNIR to more than 98%, significantly improved the identification ability. Furthermore, tests on different adulterated source samples confirmed the model's robustness, with all metrics improving from about 87% for LIBS and 86% for VNIR to above 96%. Compared to conventional machine learning algorithms, LVDLNet also demonstrated its superior performance. The results indicated that the LVDLNet model can effectively integrate element information and molecular information to identify the adulterated Polygonati Rhizoma. This work shows that the scheme is a potent tool for food identification applications.

Genetic diversity and population structure of Polygonatum cyrtonema Hua in China using SSR markers

Polygonatum cyrtonema Hua is a perennial herbaceous plant of the Polygonatum genus, belonging to the Liliaceae family, with significant medicinal and nutritional value. In China, this species is a traditional medicinal and edible herb with a long history of application and is widely appreciated by the people. However, as the demand for medicinal herbs continues to grow, excessive harvesting has led to the depletion of wild resources and the risk of genetic erosion. In addition, the chaotic cultivation of varieties and the lack of high quality germplasm resources have led to inconsistent quality of medical materials. Therefore, it is urgent to conduct genetic diversity evaluation of this species and establish a sound conservation plan. This study assessed the genetic diversity and population structure of 96 samples collected from seven regions in China using the simple sequence repeat (SSR) molecular marker technology. In this study, a total of 60 alleles (Na) were detected across the 10 polymorphic SSR markers used, with an average of 6.0 alleles generated per locus. The values of polymorphic information content (PIC) values ranged from 0.3396 to 0.8794, with an average value of 0.6430. The average value of the effective number of alleles (Ne) was 2.761, and the average value of the Shannon's information index (I) was 1.196. The population structure analysis indicates that the Polygonatum cyrtonema Hua germplasm can be classified into three subpopulations (JZ, QY, JD) at the molecular level, which corresponds to the previous subgroups identified based on individual plant phenotypic traits. Analysis of Molecular Variance (AMOVA) showed that 74% of the genetic variation was between individuals within populations in different regions. The phylogenetic analysis of the 96 germplasm samples divided them into three main populations. The QY and JD subpopulations are largely clustered together, which could be attributed to their mountainous distribution and the local climate environment. The genetic differentiation coefficient (Fst) value was low at 0.065, indicating relatively low population differentiation. The ratio of the genetic differentiation coefficient (Fst) between the JZ population and the other two populations (QY and JD) is much higher than the ratio between the QY and JD populations. Based on the clustering results and the ratio of the genetic differentiation coefficient (Fst), it can be inferred that the genetic relationship between the QY and JD subpopulations is closer, with a certain degree of genetic differentiation from the JZ subpopulation. This study supports the conservation of germplasm resources of Polygonatum cyrtonema Hua in China and provides new parental material for germplasm genetic improvement and breeding programs.

Effects of Solid Fermentation on Polygonatum cyrtonema Polysaccharides: Isolation, Characterization and Bioactivities

Polygonati Rhizoma is a widely used traditional Chinese medicine (TCM) with complex pre-processing steps. Fermentation is a common method for processing TCM to reduce herb toxicity and enhance their properties and/or produce new effects. Here, in this study, using Bacillus subtilis and Saccharomyces cerevisiae, we aimed to evaluate the potential application of solid fermentation in isolating different functional polysaccharides from Polygonatum cyrtonema Hua. With hot water extraction, ethanol precipitation, DEAE anion exchange chromatography and gel filtration, multiple neutral and acidic polysaccharides were obtained, showing different yields, content, compositions and functional groups after fermentation. Combining in vitro experiments and in vivo aging and immunosuppressed mouse models, we further compared the antioxidant and immunomodulating bioactivities of these polysaccharides and found a prominent role of a natural polysaccharide (BNP) from fermented P. cyrtonema via Bacillus subtilis in regulating intestinal antioxidant defense and immune function, which may be a consequence of the ability of BNP to modulate the homeostasis of gut microbiota. Thus, this work provides evidence for the further development and utilization of P. cyrtonema with fermentation, and reveals the potential values of BNP in the treatment of intestinal disorders.

Rapid and Green Methods for Qualitative Classification of Polygonati Rhizoma and Polygonati Odorati Rhizoma Using a Handheld near Infrared Instrument

The confusing use of Polygonati Rhizoma (PR) and Polygonati Odorati Rhizoma (POR) poses an unpredictable threat to the health of consumers. Sensitive, nondestructive, rapid, and multicomponent techniques for their detection are sought after. In this study, a low-cost, short-wavelength (898–1668 nm), and handheld near-infrared (NIR) spectrometer combined with multivariate spectral evaluation methods was used to establish calibration models for identifying PR and POR. NIR spectra were treated with a standard normal variate (SNV) before performing chemometric approaches. Then principal component analysis (PCA) and partial least squares discriminant analysis (PLS-DA) were tested for calibration model development. The PCA results showed that spectral differences existed between the two herbs. However, the evaluation techniques could not separate them with the required accuracy. The PLS-DA calibration model, on the other hand, could separate the two herbs according to their spectral information with the prediction accuracy of >98.3%. Thus, it has been proven that a rapid, green, and low-cost method to support on-site and practical inspection through a handheld NIR instrument has been established to identify PR and POR and ensure the safety of the clinical medication.

Benefits of neutral polysaccharide from rhizomes of Polygonatum sibiricum to intestinal function of aged mice

One purified neutral polysaccharide fraction was obtained from the rhizome of Polygonatum sibiricum by DEAE ion exchange and gel chromatography. Structure elucidation was performed by methanolysis, methylation, FT-IR, and NMR. The results indicated that PSP-NP was composed of 1,4-β-D-Gal,1, 4, 6-β-D-Gal, T-α-D-Man,1, 4-α-D-Glc, and T-α-D-Glc with a molecular weight of 43.0 kDa. We supplied this polysaccharide to aged mice and found it is of benefits to intestinal functions, as indicated by better tissue integrity and motility, improved oxidative stress and inflammation, reduced intestinal permeability and serum LPS level, as well as balanced gut microbial composition and short-chain fatty acids production. These results display a novel Polygonatum sibiricum polysaccharide to improve the intestinal function of aged mice, which provides pieces of evidence for its further development and utilization.

Comparative Analysis of Chloroplast Genome and New Insights Into Phylogenetic Relationships of Polygonatum and Tribe Polygonateae

Members of Polygonatum are perennial herbs that have been widely used in traditional Chinese medicine to invigorate Qi, moisten the lung, and benefit the kidney and spleen among patients. However, the phylogenetic relationships and intrageneric taxonomy within Polygonatum have long been controversial because of the complexity of their morphological variations and lack of high-resolution molecular markers. The chloroplast (cp) genome is an optimal model for deciphering phylogenetic relationships in related families. In the present study, the complete cp genome of 26 species of Trib. Polygonateae were de novo assembled and characterized; all species exhibited a conserved quadripartite structure, that is, two inverted repeats (IR) containing most of the ribosomal RNA genes, and two unique regions, large single sequence (LSC) and small single sequence (SSC). A total of 8 highly variable regions (rps16-trnQ-UUG, trnS-GCU-trnG-UCC, rpl32-trnL-UAG, matK-rps16, petA-psbJ, trnT-UGU-trnL-UAA, accD-psaI, and trnC-GCA-petN) that might be useful as potential molecular markers for identifying Polygonatum species were identified. The molecular clock analysis results showed that the divergence time of Polygonatum might occur at ∼14.71 Ma, and the verticillate leaf might be the ancestral state of this genus. Moreover, phylogenetic analysis based on 88 cp genomes strongly supported the monophyly of Polygonatum. The phylogenetic analysis also suggested that Heteropolygonatum may be the sister group of the Polygonatum, but the Disporopsis, Maianthemum, and Disporum may have diverged earlier. This study provides valuable information for further species identification, evolution, and phylogenetic research of Polygonatum.

Virtual Screening of Potential Anti-fatigue Mechanism of Polygonati Rhizoma Based on Network Pharmacology

BACKGROUND AND OBJECTIVE

A large number of people are facing the danger of fatigue due to the fast-paced lifestyle. Fatigue is common in some diseases, such as cancer. The mechanism of fatigue is not definite. Traditional Chinese medicine is often used for fatigue, but the potential mechanism of Polygonati Rhizoma (PR) is still not clear. This study attempts to explore the potential anti-fatigue mechanism of Polygonati Rhizoma through virtual screening based on network pharmacology.

METHODS

The candidate compounds of PR and the known targets of fatigue are obtained from multiple professional databases. PharmMapper Server is designed to identify potential targets for the candidate compounds. We developed a Herbal medicine-Compound-Disease-Target network and analyzed the interactions. Protein-protein interaction network is developed through the Cytoscape software and analyzed by topological methods. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment are carried out by DAVID Database. Finally, we develop Compound-Target-Pathway network to illustrate the anti-fatigue mechanism of PR.

RESULTS

This approach identified 12 active compounds and 156 candidate targets of PR. The top 10 annotation terms for GO and KEGG were obtained by enrichment analysis with 35 key targets. The interaction between E2F1 and PI3K-AKT plays a vital role in the anti-fatigue effect of PR due to this study.

CONCLUSION

This study demonstrates that PR has multi-component, multi-target and multipathway effects.

Evaluation of genetic diversity and construction of DNA fingerprinting in Polygonatum Mill. based on EST-SSR and SRAP molecular markers

Polygonatum sibiricum is widely consumed as a traditional Chinese herb and edible plant in China. Despite its nutritional and medical values, research on Polygonatum Mill. has been scarce, particularly as far as its genetic diversity is concerned. In this study, fourteen expressed sequence tag-derived simple sequence repeat (EST-SSR) and seven sequence-related amplified polymorphism (SRAP) markers were used to evaluate the genetic diversity in fifty Polygonatum Mill. accessions. The EST-SSRs and SRAPs produced 173 (90.58%) and 113 (93.39%) polymorphic bands, respectively. Unweighted Pair-Group Method Analysis (UPGMA) based on the combined data matrices of EST-SSRs and SRAPs divided the fifty Polygonatum Mill. accessions into fourteen groups. In addition, accessions of P. cyrtonema Hua obtained from Anhui and Zhejiang provinces were clustered according to their geographic origin. Furthermore, some accessions were gathered together based on species, such as P. kingianum Coll. et Hemsl, P. punctatum Royle ex Kunth, P. odoratum (Mill.) Druce, and P. sibiricum Red., and bootstrap analysis for clustering fully supported the grouping of the accessions. The Analysis of Molecular Variance (AMOVA) results revealed higher variation within populations (95%) rather than among populations (5%), indicating that Polygonatum Mill. has a low genetic differentiation between populations, and Principal Coordinate Analysis (PCoA) greatly supported the results of cluster analysis and AMOVA analysis. Finally, five markers which could produce abundant and stable bands were used to construct DNA fingerprinting database of Polygonatum Mill.. Our results demonstrated the utility of both EST-SSR and SRAP markers to successfully evaluate and identify Polygonatum Mill..

Study on Hybrid Characteristics of Medicinally Used Cultivated Codonopsis Species Using Ribosomal Internal Transcribed Spacer (ITS) Sequencing

Codonopsis taxa, as a traditional Chinese medicinal and edible plant, has found expanding domestic and foreign applications in recent decades. However, the poor management in germplasm resources market has inevitably caused an unnecessary hybrid of the provenances. In order to clarify the hybrid characteristics of germplasm resources in the main production area, the Codonopsis cultivars collected from the provinces Gansu, Shannxi, Shanxi, and Hubei of China were researched, using internal transcribed spacer (ITS) sequence technology. The confirmation of additive nucleotides based on the ITS sequencing of polymerase chain reaction (PCR) mixture was optimized and used to study the hybrid of Codonopsis cultivars. The results showed that when the ratio of PCR mixture increased up to 15 percent, the presence of a double peak in the sequencing electrophoresis map could be confirmed, suggesting the existence of additive nucleotides. According to the method above, 46 samples of Codonopsis cultivars collected during 2016 and 2017 were studied and compared with the samples collected from the year 2009 to 2010. All of the samples collected during 2016 and 2017 were hybridized and no genetic pure lines were found. In addition, the sites of variable base reduced greatly, concentrating at positions 122 and/or 226. These phenomena suggested that the genetic diversity of Codonopsis cultivars declined and the germplasm resources gradually converged. More attention should be paid to the reasonable exploitation and genetic breeding of Codonopsis taxa.