Research progress in steroidal saponins from the genus Polygonatum: Chemical components, biosynthetic pathways and pharmacological effects

Integrated metabolomics and proteomics analysis reveals the accumulation mechanism of bioactive components in Polygonatum odoratum

Polygonatum odoratum (Mill.) Druce is rich in bioactive components with high medicinal value. To maximize the clinical benefits, it is of great significance to efficiently extract key bioactive components from appropriate growth stages in which they are most abundant. In this study, we analyzed the changes of metabolite accumulation and protein expression in P. odoratum rhizomes at different growth stages using targeted metabolomics combined with proteomics, and identified a total of 1,237 differentially abundant metabolites (DAMs). Flavonoids accumulated most in winter, and the biosynthesis pathways associated with flavonoids, isoflavonoids, flavones and flavonols exhibited significant differentially expressed proteins (DEPs). Among them, PGT, FLS, CYP75B1, HIDH, IF7MAT, and UFT73C6 were positively correlated with flavonoid accumulation. Steroid saponins accumulated most in spring, and the biosynthetic pathways of steroid and brassinosteroid biosynthesis exhibited DEPs. Among them, FDFT1, TM7SF2, DHCR7, CAS1, and 3BETAHSDD were positively correlated with steroidal saponin accumulation. In summary, these results revealed the accumulation of secondary metabolites P. odoratum in different growth stages, which can provide an effective reference for the extraction of specific bioactive components and the study of their regulatory mechanisms.

The analysis of raw and processed Polygonatum kingianum saponins and stimulatory mechanism in Caenorhabditis elegans

Polygonati Rhizoma, a Chinese medicine often used in the clinic, can irritate the tongue and throat, so it must be processed before use. Polygonati Rhizoma contains a variety of chemical components, with saponins being one of the main active ingredients. Saponins can be highly irritating to human mocous membranes and have toxicity. In this study, total saponins were extracted from raw and processed Polygonati Rhizoma and detected by UPLC-Q-TOF-MS to identify their constituents. A total of 46 saponins were detected in TSRPR(total saponins of raw Polygonati Rhizoma), TSSPR(total saponins of steamed Polygonati Rhizoma) and TSWPR(total saponins of Polygonati Rhizoma steamed in wine). Of these, 9 compounds that were present in TSRPR were not detected in TSSPR and TSWPR. C.elegans was used as a model animal to study the neurotoxic effect and its mechanisms. TSRPR was found to have neurotoxic effects on C.elegans, but TSSPR and TSWPR had no adverse effects on the nematodes. The disappearance of the irritant effect of raw Polygonati Rhizoma after processing might be related to the changes in the composition of saponins, and the main reason might be the structural transformation of saponins. In particular, the sugar chains of some highly irritating saponins may have been removed or highly irritating saponins isomerized into weakly irritating saponins. The mechanisms of neurotoxic effects on C.elegans may include upregulation of ced-3 and egl-1 expression to promote apoptosis, damage to GABAergic and cholinergic neurons, downregulation of the GABA transmitter receptor genes ggr-1 and gab-1, and a decrease in glutamate levels that impairs nerve signal transmission.

Quantitative Changes and Transformation Mechanisms of Saponin Components in Chinese Herbal Medicines during Storage and Processing: A Review

Saponins are an important class of active components in Chinese herbal medicines (CHMs), which are present in large quantities in Ginseng Radix et Rhizoma, Notoginseng Radix et Rhizoma, Polygonati Rhizoma, etc., and have immune regulation, anti-tumor, anti-inflammatory, anti-cardiovascular disease, and hypoglycemic activities. Storage and processing are essential processes in the production process of CHMs which affect the stability of saponin components and then reduce the medicinal and economic value. Therefore, it is of great importance to investigate the effects of storage and processing conditions on the content of saponin components in CHMs. In this paper, the effects of various storage and processing factors, including temperature, pH, enzymes, meta lions, extraction methods, etc., on the saponin content of CHMs are investigated and the underlying mechanisms for the quantitative changes of saponin are summarized. These findings may provide technical guidance for the production and processing of saponin-rich CHMs.

Antitumor activity of Polygonatum sibiricum polysaccharides

Cancer is a global public health problem. Natural polysaccharides have been shown to enhance the effectiveness of cancer treatments. Polygonatum sibiricum (PS) has been used for millennia to treat diverse diseases. PS comprises numerous active constituents, including saponins, peptides, volatile oils, polysaccharides, and lectins. Many studies have highlighted the crucial role of polysaccharides in PS. Modern studies have shown that Polygonatum sibiricum polysaccharide (PSP) exhibits diverse pharmacological activities, including immunomodulatory, antitumor, antioxidant, and anti-aging effects. However, further study of the antitumor mechanisms is difficult because the activities of PSP are closely associated with its complex structural features and the different molecular weights of its components. Therefore, this review focuses on the research background and the extraction and purification of PSP. Studies related to the mechanism of the antitumor effects of PSP constituents of different molecular weights are also summarized, and perspectives on PSP research are presented.

Study on the components changes of polysaccharides and saponins during nine steaming and drying of Polygonatum sibiricum

BACKGROUND

In this study, the content and structure of Polygonatum sibiricum polysaccharides and saponins during different processing stages were determined.

RESULTS

After processing of Polygonatum, the content of polysaccharide and glucose decreased, and the content of galactose, glucuronic acid and sugar substitution gradually increased. The content of total saponins increased significantly. Only 18 compounds were found in raw Polygonatum and 17 new compounds were presented in processed Polygonatum. During the processing of Polygonatum, the polysaccharide was partially degraded into oligosaccharides, the molecular weight gradually decreased, and the neutral sugar was converted into uronic acid, resulting in a decrease in polysaccharide content. The saponins were partially degraded into sapogenins or modified.

CONCLUSION

This study clarifies the changes in the content and structure of polysaccharides and saponins in processed Polygonatum, which will pave the way for elucidating the processing mechanism. © 2024 Society of Chemical Industry.

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.

Structural characterization and hypoglycemic effect of polysaccharides of Polygonatum sibiricum

Polygonatum sibiricum polysaccharide (PSP) was extracted and purified from raw material obtained from P. sibiricum. The structural features of PSP were investigated by Congo red, circular dichroism spectrum, high-performance gel permeation chromatography, scanning electron microscope, atomic force microscope, ultraviolet spectroscopy, and Fourier transform infrared spectroscopy analysis. In vitro simulations were conducted to investigate the kinetics of PSP enzyme inhibition. Moreover, a type II diabetes mouse model (T2DM) with streptozotocin-induced insulin resistance was established, and the indexes of lipid quadruple, insulin resistance index, oral glucose tolerance (OGTT), organ index, and pancreatic morphology of model mice were measured. The results showed that PSP mainly consists of monosaccharides, such as mannose, glucose, galactose, xylose, and arabinose. It also has a β-glycosidic bond of a pyranose ring and an irregular reticulated aggregated structure with a triple helix. In vitro enzyme inhibition assays revealed that PSP acts as a reversible competitive inhibitor of α-glucosidase and α-amylase. Furthermore, PSP was found to reduce insulin resistance index, increase OGTT and serum insulin levels, decrease free fatty acid content to improve lipid metabolism, and lower glycated serum protein content to enhance glucose metabolism in T2DM mice, thereby leading to a reduction in blood glucose concentration. Additionally, PSP exhibited reparative effects on the damaged liver tissue cells and pancreatic tissue in T2DM mice. The experiment results provide a preliminary basis for the therapeutic mechanism of PSP about type II diabetes and a theoretical reference for application in food and pharmaceutical development.

Advances in antitumor activity and mechanism of natural steroidal saponins: A review of advances, challenges, and future prospects

BACKGROUND

Cancer, the second leading cause of death worldwide following cardiovascular diseases, presents a formidable challenge in clinical settings due to the extensive toxic side effects associated with primary chemotherapy drugs employed for cancer treatment. Furthermore, the emergence of drug resistance against specific chemotherapeutic agents has further complicated the situation. Consequently, there exists an urgent imperative to investigate novel anticancer drugs. Steroidal saponins, a class of natural compounds, have demonstrated notable antitumor efficacy. Nonetheless, their translation into clinical applications has remained unrealized thus far. In light of this, we conducted a comprehensive systematic review elucidating the antitumor activity, underlying mechanisms, and inherent limitations of steroidal saponins. Additionally, we propose a series of strategic approaches and recommendations to augment the antitumor potential of steroidal saponin compounds, thereby offering prospective insights for their eventual clinical implementation.

PURPOSE

This review summarizes steroidal saponins' antitumor activity, mechanisms, and limitations.

METHODS

The data included in this review are sourced from authoritative databases such as PubMed, Web of Science, ScienceDirect, and others.

RESULTS

A comprehensive summary of over 40 steroidal saponin compounds with proven antitumor activity, including their applicable tumor types and structural characteristics, has been compiled. These steroidal saponins can be primarily classified into five categories: spirostanol, isospirostanol, furostanol, steroidal alkaloids, and cholestanol. The isospirostanol and cholestanol saponins are found to have more potent antitumor activity. The primary antitumor mechanisms of these saponins include tumor cell apoptosis, autophagy induction, inhibition of tumor migration, overcoming drug resistance, and cell cycle arrest. However, steroidal saponins have limitations, such as higher cytotoxicity and lower bioavailability. Furthermore, strategies to address these drawbacks have been proposed.

CONCLUSION

In summary, isospirostanol and cholestanol steroidal saponins demonstrate notable antitumor activity and different structural categories of steroidal saponins exhibit variations in their antitumor signaling pathways. However, the clinical application of steroidal saponins in cancer treatment still faces limitations, and further research and development are necessary to advance their potential in tumor therapy.

Quality analysis and function prediction of soil microbial communities of Polygonatum cyrtonema in two indigenous-origins

Polygonatum cyrtonema Hua (PCH), as an important economic crop, is used as raw industrial materials and traditional Chinese medicine. There are significant variations in the quality of PCH from different geographical origins. It can be due to the change of the endophytic fungi and soil microbial communities of PCH. Therefore, the aim of this study is to investigate the composition and functional prediction of the main microbial communities in the rhizomes and soil of PCH and explore their impact on medicinal quality. High-throughput sequencing techniques targeting ITS and 16S rDNA were employed to compare the structure and biodiversity differences of endophytic fungi in the rhizomes and soil microbial communities of PCH from 12 different locations in Sichuan and Guangxi province. Heatmap analysis was used for comprehensive statistics and visualization of the richness of rhizome and soil microbial communities from all locations. Venn analysis was conducted to determine the total number of shared fungi between rhizomes and soil, and GraphPad Prism analysis was employed to predict and compare the microbial communities related to phenotypes at the genus level in Sichuan and Guangxi. Tax4Fun and Fungild were used for metabolic function prediction of microbial communities in the rhizomes and soil of PCH. The results revealed the identification of 19,387 bacterial amplicon sequence variants (ASVs) in the rhizomes and 37,990 bacterial ASVs in the soil, with 6,889 shared bacterial ASVs. In addition, 2,948 fungal ASVs were identified in the rhizomes and 8,868 in the soil, with 1,893 shared fungal ASVs. Microbial sequencing results indicated that the fungal communities between soil and rhizomes were mainly composed of Ascomycota and Basidiomycota, while bacterial communities included Proteobacteria, Acidobacteria, Bacteroidota, Gammatimonadota, and Firmicutes. Dominant bacterial groups such as Nitrospira, Acidibacter, and fungal groups including Mortierella, Ceratobasidium, and Fusarium were identified as potential contributors to the observed traits. In the top 15 microbial genera, both Sichuan and Guangxi contain 15 bacterial genera, but there are differences in their abundance. Guangxi has three unique fungal genera, including the genera Scleroderma, Russula, and Gliocladiopsis. On the other hand, Sichuan has the unique fungal genus Chamaeota. The correlation analysis between the microbiota and the chemical content from 12 different collecting spots was performed by GraphPad Prism. Burkholderia-Caballeronia-Paraburkholderia, Acidibacter, and Amycolatopsis show an inverse proportionality to total polysaccharides and saponins, while Enterobacter shows a direct proportionality to total polysaccharides and inverse proportionality to saponins. The metabolism pathways show a significant positive correlation with PCH polysaccharides and saponins. This study provide new insights into the mechanisms underlying the quality differences between the two major indigenous areas.

Pharmacological properties of Polygonatum and its active ingredients for the prevention and treatment of cardiovascular diseases

Despite continued advances in prevention and treatment strategies, cardiovascular diseases (CVDs) remain the leading cause of death worldwide, and more effective therapeutic methods are urgently needed. Polygonatum is a traditional Chinese herbal medicine with a variety of pharmacological applications and biological activities, such as antioxidant activity, anti-inflammation, antibacterial effect, immune-enhancing effect, glucose regulation, lipid-lowering and anti-atherosclerotic effects, treatment of diabetes and anticancer effect. There has also been more and more evidence to support the cardioprotective effect of Polygonatum in recent years. However, up to now, there has been a lack of comprehensive studies on the active ingredients and their pharmacotoxicological effects related to cardiovascular diseases. Therefore, the main active components of Polygonatum (including Polysaccharides, Flavonoids, Saponins) and their biological activities were firstly reviewed in this paper. Furthermore, we summarized the pharmacological effects of Polygonatum's active components in preventing and treating CVDs, and its relevant toxicological investigations. Finally, we emphasize the potential of Polygonatum in the prevention and treatment of CVDs.