Characterization, Classification, and Authentication of Polygonatum sibiricum Samples by Volatile Profiles and Flavor Properties

Structural characterization and mechanisms of macrophage immunomodulatory activity of a novel polysaccharide with a galactose backbone from the processed Polygonati Rhizoma

A purified polysaccharide with a galactose backbone (SPR-1, Mw 3,622 Da) was isolated from processed Polygonati Rhizoma with black beans (PRWB) and characterized its chemical properties. The backbone of SPR-1 consisted of [(4)-β-D-Galp-(1]9 → 4,6)-β-D-Galp-(1 → 4)-α-D-GalpA-(1 → 4)-α-D-GalpA-(1 → 4)-α-D-Glcp-(1 → 4,6)-α-D-Glcp-(1 → 4)-α/β-D-Glcp, with a branch chain of R1: β-D-Galp-(1 → 3)-β-D-Galp-(1→ connected to the →4,6)-β-D-Galp-(1→ via O-6, and a branch chain of R2: α-D-Glcp-(1 → 6)-α-D-Glcp-(1→ connected to the →4,6)-α-D-Glcp-(1→ via O-6. Immunomodulatory assays showed that the SPR-1 significantly activated macrophages, and increased secretion of NO and cytokines (i.e., IL-1β and TNF-α), as well as promoted the phagocytic activities of cells. Furthermore, isothermal titration calorimetry (ITC) analysis and molecular docking results indicated high-affinity binding between SPR-1 and MD2 with the equilibrium dissociation constant (K D) of 18.8 μM. It was suggested that SPR-1 activated the immune response through Toll-like receptor 4 (TLR4) signaling and downstream responses. Our research demonstrated that the SPR-1 has a promising candidate from PRWB for the TLR4 agonist to induce immune response, and also provided an easily accessible way that can be used for PR deep processing.

Quality assessment of traditional Chinese medicine based on data fusion combined with machine learning: A review

The authenticity and quality of traditional Chinese medicine (TCM) directly impact clinical efficacy and safety. Quality assessment of traditional Chinese medicine (QATCM) is a global concern due to increased demand and shortage of resources. Recently, modern analytical technologies have been extensively investigated and utilized to analyze the chemical composition of TCM. However, a single analytical technique has some limitations, and judging the quality of TCM only from the characteristics of the components is not enough to reflect the overall view of TCM. Thus, the development of multi-source information fusion technology and machine learning (ML) has further improved QATCM. Data information from different analytical instruments can better understand the connection between herbal samples from multiple aspects. This review focuses on the use of data fusion (DF) and ML in QATCM, including chromatography, spectroscopy, and other electronic sensors. The common data structures and DF strategies are introduced, followed by ML methods, including fast-growing deep learning. Finally, DF strategies combined with ML methods are discussed and illustrated for research on applications such as source identification, species identification, and content prediction in TCM. This review demonstrates the validity and accuracy of QATCM-based DF and ML strategies and provides a reference for developing and applying QATCM methods.

Effects of saponins isolated from Polygonatum sibiricum on H2O2-induced oxidative damage in RIN-m5F cells and its protective effect on pancreas

The damage of islet cells caused by oxidative stress is closely related to diabetes. The aim of this study is to investigate the protective effect of saponins isolated from polygonatum sibiricum (PSS) on pancreas injury by using in vitro and in vivo models. The oxidative stress model of RIN-m5F cells induced by H₂O₂ was established. We found that PSS could decrease the apoptosis of RIN-m5F cells under oxidative stress. After PSS treatment, ROS and MDA levels in cells significantly decreased. Moreover, the levels of SOD and GSH were significantly increased. PSS could increase the insulin secretion level of cells under oxidative stress. The expression level of intracellular Bcl-2 increased, and the expression levels of Bax, caspase-3, caspase-8, and caspase-9 decreased significantly. In addition, the type 2 diabetes mouse model was established. The results showed that PSS had a protective effect on the injury of the pancreas in T2DM mice. PSS can relieve oxidative stress and high glucose-mediated pancreas cytotoxicity. PSS may be a promising candidate for diabetes intervention and functional foods.

Health-Promoting Activities and Associated Mechanisms of Polygonati Rhizoma Polysaccharides

Polygonati Rhizoma, a typical homology of medicine and food, possesses remarkable anti-fatigue, anti-aging, metabolic regulatory, immunomodulatory, anti-inflammatory, neuroprotective, anti-diabetes, and anti-cancer effects. Among bioactive phytochemicals in Polygonati Rhizoma, polysaccharides play important roles in the health-promoting activities through the mechanisms mentioned above and potential synergistic effects with other bioactives. In this review, we briefly introduce the updated biosynthesis of polysaccharides, the purification method, the structure characterization, and food applications, and discuss in detail the biological activities of Polygonati Rhizoma polysaccharides and associated mechanisms, aiming at broadening the usage of Polygonati Rhizoma as functional food and medicine.

Identification of key gene networks controlling polysaccharide accumulation in different tissues of Polygonatum cyrtonema Hua by integrating metabolic phenotypes and gene expression profiles

Plant polysaccharides, a type of important bioactive compound, are involved in multiple plant defense mechanisms, and in particular polysaccharide-alleviated abiotic stress has been well studied. Polygonatum cyrtonema Hua (P. cyrtonema Hua) is a medicinal and edible perennial plant that is used in traditional Chinese medicine and is rich in polysaccharides. Previous studies suggested that sucrose might act as a precursor for polysaccharide biosynthesis. However, the role of sucrose metabolism and transport in mediating polysaccharide biosynthesis remains largely unknown in P. cyrtonema Hua. In this study, we investigated the contents of polysaccharides, sucrose, glucose, and fructose in the rhizome, stem, leaf, and flower tissues of P. cyrtonema Hua, and systemically identified the genes associated with the sucrose metabolism and transport and polysaccharide biosynthesis pathways. Our results showed that polysaccharides were mainly accumulated in rhizomes, leaves, and flowers. Besides, there was a positive correlation between sucrose and polysaccharide content, and a negative correlation between glucose and polysaccharide content in rhizome, stem, leaf, and flower tissues. Then, the transcriptomic analyses of different tissues were performed, and differentially expressed genes related to sucrose metabolism and transport, polysaccharide biosynthesis, and transcription factors were identified. The analyses of the gene expression patterns provided novel regulatory networks for the molecular basis of high accumulation of polysaccharides, especially in the rhizome tissue. Furthermore, our findings explored that polysaccharide accumulation was highly correlated with the expression levels of SUS, INV, SWEET, and PLST, which are mediated by bHLH, bZIP, ERF, ARF, C2H2, and other genes in different tissues of P. cyrtonema Hua. Herein, this study contributes to a comprehensive understanding of the transcriptional regulation of polysaccharide accumulation and provides information regarding valuable genes involved in the tolerance to abiotic stresses in P. cyrtonema Hua.

Effects of steam on polysaccharides from Polygonatum cyrtonema based on saccharide mapping analysis and pharmacological activity assays

Background

Polygonatum cyrtonema, one of origins of Polygonata Rhizoma (HuangJing in Chinese), is traditionally steamed repeatedly before being used as herbal medicine in China. However, there has no standard for steaming of HuangJing. Therefore, a comprehensive study for effects of steam on polysaccharides from Polygonatum cyrtonema based on saccharide mapping, a powerful method developed for polysaccharides analysis, and pharmacological activity are still necessary, which is helpful to explore the effect of steam on the physiochemical and biological activities of its polysaccharides and develop steaming standard of Polygonatum cyrtonema.

Methods

To explore the effect of steam on physiochemical and biological activities of P. cyrtonema polysaccharides (PCP), six polysaccharides named PCP0, PCP1, PCP2, PCP3, PCP4 and PCP5 were extracted from the herb consecutively steamed for 0–5 times, respectively. Their molecular weight distribution, monosaccharide composition and PACE fingerprints were investigated through HPSEC-MALLS-RID, HPAEC-PAD and saccharide mapping based on polysaccharides analysis by using carbohydrate gel electrophoresis (PACE) and HPTLC, respectively. In addition, their antioxidant ability and immunostimulatory activities on RAW 264.7 cells in terms of NO production and phagocytosis were compared.

Results

Results suggested that molecular weights could be changed during steam, which increased by first steaming and then decreased with further steaming though all polysaccharides’ molecular weights were 10⁵-10⁷ Da. They all showed irregularly spherical conformation in aqueous solution based on AFM imaging. Their monosaccharide composition and PACE fingerprints were significantly different after steaming, i.e., galactose increased while glucose and mannose decreased, and β-1,4-Galp appeared while β-1,4-Manp increased, after steaming. Steamed PCP significantly increased scavenging activity against ABTS radicals, while PCP0 had the best immunostimulatory effect on RAW 264.7 in terms of NO production and phagocytosis.

Conclusions

In summary, steam significantly affected the chemical composition and bioactivities of polysaccharides from P. cyrtonema. Considering the balance beneficial effects of steaming on antioxidant and immunopotentiation activities of PCP, 2 times of continuous steam is the optimal choice under the given conditions.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13020-022-00650-3.

Comprehensive determination of the processing level of rhizome of Polygonatum sibiricum by macroscopic, micromorphological, and microscopic characterizations

The rhizome of Polygonatum sibiricum Red. (PR, Huangjing in Chinese) has served as traditional medicine and foodstuff in China for over 2000 years. However, due to its irritating effect on the throat, Huangjing must be processed before clinical use. People have been exploring to determine the processing level of traditional Chinese medicine in an accurate tool. The evaluation of PR processing levels based on macroscopic and microscopic characteristics has not yet been performed. This study aimed to provide a convenient method to determine the level of PR processing by monitoring the changes in color and crystal inclusion. According to the Chinese Pharmacopeia (2020 edition), macroscopic, micromorphological, and microscopic observations were performed with a polarized light microscope. Color quantization based on the CIE L^* a^* b^* color system using a CM-2300d colorimeter. Color parameters h^° , L^* , and ΔE^* had a significant influence on the differentiation ability. The inner transverse section of PR samples gradually turned into moist black with specular luster, which was consistent with the traditional identification of "brightness like oil and color like black lacquer." The change rate of the needle crystal morphology increased with the processing level, and the change rate of the needle crystal of the fifth product was over 90%. Combined with the correlation analysis, needle-like crystals were related to color parameters and could be used as an alternative marker to discriminate PR samples from different processing levels. The results confirmed the potential applicability of macroscopic and microscopic features for the classification of PR samples with different processing levels.