Integrative analysis of the transcriptome and metabolome provides insights into polysaccharide accumulation in Polygonatum odoratum (Mill.) Druce rhizome.

Background: Polygonatum odoratum (Mill.) Druce is a traditional Chinese herb that is widely cultivated in China. Polysaccharides are the major bioactive components in rhizome of P. odoratum and have many important biological functions. Methods: To better understand the regulatory mechanisms of polysaccharide accumulation in P. odoratum rhizomes, the rhizomes of two P. odoratum cultivars 'Y10' and 'Y11' with distinct differences in polysaccharide content were used for transcriptome and metabolome analyses, and the differentially expressed genes (DEGs) and differentially accumulated metabolites (DAMs) were identified. Results: A total of 14,194 differentially expressed genes (DEGs) were identified, of which 6,689 DEGs were down-regulated in 'Y10' compared with those in 'Y11'. KEGG enrichment analysis of the down-regulated DEGs revealed a significant enrichment of 'starch and sucrose metabolism', and 'amino sugar and nucleotide sugar metabolism'. Meanwhile, 80 differentially accumulated metabolites (DAMs) were detected, of which 52 were significantly up-regulated in 'Y11' compared to those in 'Y10'. The up-regulated DAMs were significantly enriched in 'tropane, piperidine and pyridine alkaloid biosynthesis', 'pentose phosphate pathway' and 'ABC transporters'. The integrated metabolomic and transcriptomic analysis have revealed that four DAMs, glucose, beta-D-fructose 6-phosphate, maltose and 3-beta-D-galactosyl-sn-glycerol were significantly enriched for polysaccharide accumulation, which may be regulated by 17 DEGs, including UTP-glucose-1-phosphate uridylyltransferase (UGP2), hexokinase (HK), sucrose synthase (SUS), and UDP-glucose 6-dehydrogenase (UGDH). Furthermore, 8 DEGs (sacA, HK, scrK, GPI) were identified as candidate genes for the accumulation of glucose and beta-D-fructose 6-phosphate in the proposed polysaccharide biosynthetic pathways, and these two metabolites were significantly associated with the expression levels of 13 transcription factors including C3H, FAR1, bHLH and ERF. This study provided comprehensive information on polysaccharide accumulation and laid the foundation for elucidating the molecular mechanisms of medicinal quality formation in P. odoratum rhizomes.

Fingerprinting and characterization of the polysaccharides from Polygonatum odoratum and the in vitro fermented effects on Lactobacillus johnsonii.

Polygonatum odoratum (Yu-Zhu) can be utilized to treat the digestive and respiratory illness. Previous studies have revealed that the underlying therapeutic mechanism of P. odoratum polysaccharides (POPs) is associated with remodeling the gut microbiota. However, POPs in terms of the chemical composition and fermentation activities have been understudied. Here we developed the three-level fingerprinting approaches to characterize the structures of POPs and probed into the beneficial effects on promoting the growth and fermentation of Lactobacillus johnsonii. POPs were prepared by water decoction followed by alcohol sedimentation, while trifluoroacetic acid under different conditions to prepare the hydrolyzed oligosaccharides and monosaccharides. POPs exhibited three main molecular distribution of 601-620 kDa, 4.12-6.09 kDa, and 3.57-6.02 kDa. Hydrolyzed oligosaccharides with degree of polymerization (DP) 2-13 got primarily characterized by analyzing the rich fragmentation information obtained by hydrophilic interaction chromatography/ion mobility-quadrupole time-of-flight mass spectrometry (HILIC/IM-QTOF-MS). Amongst them, the DP5 oligosaccharide was characterized as 1,6,6-kestopentaose. The molecular ratio of Fru: Ara: Glc: Gal: Xyl was 87.72: 0.30: 11.56: 0.19: 0.23. In vitro fermentation demonstrated that 4.5 mg/mL of POPs could significantly promote the growth of L. johnsonii. Co-cultivated with 4.5 mg/mL of POPs, L. johnsonii exhibited stronger antimicrobial activity against Klebsiella pneumoniae. The concentrations of short-chain fatty acids in the POPs-lactobacilli fermented products, including acetic acid, isobutyric acid, and isovaleric acid, were increased. Conclusively, POPs represent the promising prebiotic candidate to facilitate lactobacilli, which is associated with exerting the health benefits.

Rapid Raman spectroscopic identification of three homoisoflavanones in polygonatum odoratum based on twice chromatography derivatization.

The aim of this study was to establish a new method for the determination of homoisoflavanones (Ⅲ, Ⅳ, V) in polygonatum odoratum(POD) by combination of thin layer chromatography (TLC) and chemical derivative resonance Raman spectroscopy (RRS). The twice chromatography method of TLC was used to improve the specificity of the component to be tested; the method of the relative Rf was used to reduce the use of the reference substance of the component to be tested; the chemical derivatization method was used to improve the signal intensity of Raman spectrum for the component to be tested in POD, so as to obtain a trace amount fingerprint structure information of the measured component. The method exhibits robust specificity, high sensitivity, and reliable stability, there by offering a novel reference approach for the identification and evaluation of homoisoflavanones (Ⅲ, Ⅳ, V) in POD.

Polygonatum odoratum polysaccharide attenuates lipopolysaccharide-induced lung injury in mice by regulating gut microbiota.

Polygonatum odoratum is appreciated for its edible and medicinal benefits especially for lung protection. However, the contained active components have been understudied, and further research is required to fully exploit its potential application. We aimed to probe into the beneficial effects of Polygonatum odoratum polysaccharide (POP) in lipopolysaccharide-induced lung inflammatory injury mice. POP treatment could ameliorate the survival rate, pulmonary function, lung pathological lesions, and immune inflammatory response. POP treatment could repair intestinal barrier, and modulate the composition of gut microbiota, especially reducing the abundance of Klebsiella, which were closely associated with the therapeutic effects of POP. Investigation of the underlying anti-inflammatory mechanism showed that POP suppressed the generation of pro-inflammatory molecules in lung by inhibiting iNOS+ M1 macrophages. Collectively, POP is a promising multi-target microecological regulator to prevent and treat the immuno-inflammation and lung injury by modulating gut microbiota.

Sortilin-induced lipid accumulation and atherogenesis are suppressed by HNF1b SUMOylation promoted by flavone of Polygonatum odoratum. / çŽ‰ç«¹é»„é ®é€šè¿‡ä¿ƒè¿›HNF1b蛋白的SUMO化修饰抑制sortilinä»‹å¯¼çš„è„‚è´¨ç§¯ç´¯åŠåŠ¨è„‰ç²¥æ ·ç¡¬åŒ–.

This study aims to investigate the impact of hepatocyte nuclear factor 1ß (HNF1b) on macrophage sortilin-mediated lipid metabolism and aortic atherosclerosis and explore the role of the flavone of Polygonatum odoratum (PAOA-flavone)-promoted small ubiquitin-related modifier (SUMO) modification in the atheroprotective efficacy of HNF1b. HNF1b was predicted to be a transcriptional regulator of sortilin expression via bioinformatics, dual-luciferase reporter gene assay, and chromatin immunoprecipitation. HNF1b overexpression decreased sortilin expression and cellular lipid contents in THP-1 macrophages, leading to a depression in atherosclerotic plaque formation in low-density lipoprotein (LDL) receptor-deficient (LDLR-/-) mice. Multiple SUMO1-modified sites were identified on the HNF1b protein and co-immunoprecipitation confirmed its SUMO1 modification. The SUMOylation of HNF1b protein enhanced the HNF1b-inhibited effect on sortilin expression and reduced lipid contents in macrophages. PAOA-flavone treatment promoted SUMO-activating enzyme subunit 1 (SAE1) expression and SAE1-catalyzed SUMOylation of the HNF1b protein, which prevented sortilin-mediated lipid accumulation in macrophages and the formation of atherosclerotic plaques in apolipoprotein E-deficient (ApoE-/-) mice. Interference with SAE1 abrogated the improvement in lipid metabolism in macrophage cells and atheroprotective efficacy in vivo upon PAOA-flavone administration. In summary, HNF1b transcriptionally suppressed sortilin expression and macrophage lipid accumulation to inhibit aortic lipid deposition and the development of atherosclerosis. This anti-atherosclerotic effect was enhanced by PAOA-flavone-facilitated, SAE1-catalyzed SUMOylation of the HNF1b protein.

Gastroprotective effects of Polygonatum odoratum in rodents by regulation of apoptotic proteins and inflammatory cytokines.

In an increasing interest in natural antiulcer compounds that may have gastric healing effects and possibly prevent ulcer recurrence, Polygonatum odoratum appears as a strong candidate. The gastroprotective potentials of P. odoratum rhizome extract (PORE) were explored on ethanol-induced gastric ulceration in rats. Sprague Dawley rats were caged in 5 groups, normal and ulcer control rats received CMC (1% carboxymethyl cellulose). Omeprazole (20 mg/kg) was given to reference Rats. Experimental rats were treated with 250 mg/kg and 500 mg/kg PORE, respectively. After an hour, the normal control rats received 1% CMC, whereas rat groups 2-5 were given absolute ethanol by oral gavage. After 60 min, rats received anesthesia and were sacrificed. Dissected gastric tissue was analyzed by histopathological and immunohistochemical techniques. PORE treatment significantly lowered the ethanol-induced gastric injury, as shown by up-surging gastric pH and mucus content, reduced leukocyte infiltration, lower ulcerative areas in mucosal layers, and increased antioxidants (SOD and CAT) and (MDA) levels. Furthermore, PORE pre-treated rats showed significantly increased expression of the Periodic acid-Schiff (PAS), HSP-70 protein, and decreased Bax protein in their gastric epithelial layers. PORE treatment showed an important regulation of inflammatory cytokines shown by decreasing the TNF-a, and IL-6 and increasing the IL-10 values. The detected biological activity of PORE is encouraging and presents the scientific evidence for its traditional use as a gastroprotection agent however further studies are required to determine the exact phytochemicals and mechanism pathway responsible for this bioactivity.

Qualitative and quantitative studies on two commercial specifications of Polygonatum odoratum.

The rhizoma of Polygonatum odoratum (PO) is used to treat yin injuries of the lung and stomach in traditional Chinese medicine. The chemical constituents of this herb are steroidal saponins, homoisoflavanones, and alkaloids. Xiangyuzhu (XPO) and Guanyuzhu (GPO) are available in the market as two specifications of the commodity. Nonetheless, systematic research on the identification and comparison of chemical constituents of these two commercial specifications is yet lacking. Herein, an integrated method combing ultra-high-performance liquid chromatography-quadruple time-of-flight mass spectrometry (UHPLC-Q-TOF/MS) with ultra-high-performance liquid chromatography-charged aerosol detection (UHPLC-CAD) was employed for the comprehensively qualitative and quantitative analyses of PO. A total of 62 compounds were identified by UHPLC-Q-TOF/MS, among which 13 potential chemical markers were screened out to distinguish two commercial specifications. Subsequently, the absolute determination method for polygodoraside G, polygonatumoside F, and timosaponin H1 was established and validated by UHPLC-CAD. The contents of the three compounds were 13.33-236.24 µg/g, 50.55-545.04 µg/g, and 13.34-407.83 µg/g, respectively. Furthermore, the ratio of timosaponin H1/polygodoraside G could be applied to differentiate the two specifications. Samples with a ratio <2 are considered XPO and >5 are considered GPO. Therefore, the above results provide a valuable means for the quality control of PO.

Integrated Analysis of microRNA and RNA-Seq Reveals Phenolic Acid Secretion Metabolism in Continuous Cropping of Polygonatum odoratum.

Polygonatum odoratum (Mill.) Druce is an essential Chinese herb, but continuous cropping (CC) often results in a serious root rot disease, reducing the yield and quality. Phenolic acids, released through plant root exudation, are typical autotoxic substances that easily cause root rot in CC. To better understand the phenolic acid biosynthesis of P. odoratum roots in response to CC, this study performed a combined microRNA (miRNA)-seq and RNA-seq analysis. The phenolic acid contents of the first cropping (FC) soil and CC soil were determined by HPLC analysis. The results showed that CC soils contained significantly higher levels of p-coumaric acid, phenylacetate, and caffeic acid than FC soil, except for cinnamic acid and sinapic acid. Transcriptome identification and miRNA sequencing revealed 15,788 differentially expressed genes (DEGs) and 142 differentially expressed miRNAs (DEMs) in roots from FC and CC plants. Among them, 28 DEGs and eight DEMs were involved in phenolic acid biosynthesis. Meanwhile, comparative transcriptome and microRNA-seq analysis demonstrated that eight miRNAs corresponding to five target DEGs related to phenolic acid synthesis were screened. Among them, ath-miR172a, ath-miR172c, novel_130, sbi-miR172f, and tcc-miR172d contributed to phenylalanine synthesis. Osa-miR528-5p and mtr-miR2673a were key miRNAs that regulate syringyl lignin biosynthesis. Nta-miR156f was closely related to the shikimate pathway. These results indicated that the key DEGs and DEMs involved in phenolic acid anabolism might play vital roles in phenolic acid secretion from roots of P. odoratum under the CC system. As a result of the study, we may have a better understanding of phenolic acid biosynthesis during CC of roots of P. odoratum.

Antihyperglycemic mechanism of Polygonatum odoratum polysaccharides based on sweet taste receptor signaling pathway / 中成药

AIM To explore the antihyperglycemic mechanism of Polygonatum odoratum polysaccharides based on sweet taste receptor signaling pathway.METHODS After the successful diabetic modeling by high-fat and high-sugar diet combined with streptozotocin,the rats were randomly divided into the model group,the metformin group(200 mg/kg)and the low,medium and high dose P.odoratum polysaccharides groups(100,200 and 400 mg/kg),in contrast to the control group with 8 normal rats.The rats had measurement of their fasting blood glucose level from tail vein blood before the intervention and 2,4,6 and 8 weeks after the corresponding administration;detection of their serum GLP-1 and insulin levels by ELISA,and their oral glucose tolerance test after 7 weeks;detection of their blood lipid level,observation of their morphology of pancreas and liver,and detection of their mRNA expressions of T1R2,T1R3,α-gustducin,TRPM5,SGLT-1 and GLUT-2 in ileum by RT-qPCR after 8 weeks.HuTu-80 cells treated with P.odoratum polysaccharides solution had their the levels of cAMP and GLP-1 detected by ELISA;their fluorescence intensity of Ca2+ detected by laser confocal method;and the expression of sweet taste receptor mRNA detected by RT-qPCR.RESULTS The result of animal experiments showed that the groups intervened with middle or high dose of P.odoratum polysaccharides displayed decreased levels of fasting blood glucose,area under the time-blood glucose curve(AUC)and the levels of serum TG,TC and LDL-C(P<0.05),increased levels of serum GLP-1 and insulin and the mRNA expressions of T1R2 and TRPM5 in ileum(P<0.05),in contrast to the model group,in addition to the increased serum HDL-C level and mRNA expressions of T1R2,α-gustducin in ileum tissue in the high dose group.The result of cell experiment showed that P.odoratum polysaccharides increased the levels of cAMP,GLP-1 and Ca2+ in cells(P<0.05),and enhanced the mRNA expressions of sweet taste receptors T1R2 and T1R3(P<0.05).CONCLUSION P.odoratum polysaccharides may contribute antihyperglycemic effects through GLP-1 secretion promotion via activation of the sweet taste receptor signaling pathway due to its efficacy in up-regulating expression of molecules.

HPLC fingerprint analysis of polysaccharides from different accessions of Polygonatum odoratum.

Polysaccharide was one of the considered major active ingredient in Polygonatum odoratum which was crucial for its quality evaluation. In this study, High performance liquid chromatography (HPLC) combined with chemometrics methods were performed to assess the quality of P. odoratum polysaccharide (POP) harvested from different locations. The methodology validation and similarity evaluation results showed that the analysis method was able to meet the requirement of fingerprint analysis, and 10 batches of POPs had a high degree of similarity based on the similarity values were greater than 0.960. The results of hierarchical cluster analysis (HCA) showed that different regions POPs could be classified by clustering analysis based on their nuances. The results of principal component analysis (PCA) showed that the mannose (58.13%∼78.18%) and glucuronic acid (2.36%∼11.72%) could be selected as herb markers for the quality control of P. odoratum. In conclusion, a more quantitative quality control method was established, and could be applied to the identification and quality control of different P. odoratum and their products.