Platycodon grandiflorum root extract inhibits Aß deposition by breaking the vicious circle linking oxidative stress and neuroinflammation in Alzheimer's disease.

Alzheimer's disease (AD) is a progressive neurodegenerative disease accompanied by irreversible cognitive impairment. A deleterious feedback loop between oxidative stress and neuroinflammation in early AD exacerbates AD-related pathology. Platycodon grandiflorum root extract (PGE) has antioxidant and anti-inflammatory effects in several organs. However, the mechanisms underlying the effects of PGE in the brain remain unclear, particularly regarding its impact on oxidative/inflammatory damage and Aß deposition. Thus, we aim to identify the mechanism through which PGE inhibits Aß deposition and oxidative stress in the brain by conducting biochemical and histological analyses. First, to explore the antioxidant mechanism of PGE in the brain, we induced oxidative stress in mice injected with scopolamine and investigated the effect of PGE on cognitive decline and oxidative damage. We also assessed the effect of PGE on reactive oxygen species (ROS) generation and the expressions of antioxidant enzymes and neurotrophic factor in H2O2- and Aß-treated HT22 hippocampal cells. Next, we investigated whether PGE, which showed antioxidant effects, could reduce Aß deposition by mitigating neuroinflammation, especially microglial phagocytosis. We directly verified the effect of PGE on microglial phagocytosis, microglial activation markers, and pro-inflammatory cytokines in Aß-treated BV2 microglial cells. Moreover, we examined the effect of PGE on neuroinflammation, inducing microglial responses in Aß-overexpressing 5XFAD transgenic mice. PGE exerts antioxidant effects in the brain, enhances microglial phagocytosis of Aß, and inhibits neuroinflammation and Aß deposition, ultimately preventing neuronal cell death in AD. Taken together, our findings indicate that the therapeutic potential of PGE in AD is mediated by its targeting of multiple pathological processes.

Polysaccharides from Platycodon grandiflorum: A review of their extraction, structures, modifications, and bioactivities.

Platycodon grandiflorum (P. grandiflorum) has long been used as a food and traditional herbal medicine. As a food, P. grandiflorum is often transformed into pickles for consumption, and as a traditional Chinese medicine, P. grandiflorum clears the lung, nourishes the pharynx, dispels phlegm, and discharges pus. Polysaccharides are among the main active components of P. grandiflorum. Recent literature has described the preparation, identification, and pharmacological activity of these polysaccharides. Studies have shown that these polysaccharides exhibit a variety of significant biological effects in vitro and in vivo, such as immune stimulation and antioxidant, anti-liver injury, anti-apoptosis and antitumour effects. However, there is no systematic summary of the related research articles on P. grandiflorum polysaccharide, which undoubtedly brings some difficulties to the future research. The purpose of this review is to comprehensively describe research progress on the extraction, purification, structural characterization, modification, and biological activity of P. grandiflorum polysaccharides. The shortcomings of recent research are summarized, further research on their biological activity is proposed to provide new reference value for the application of P. grandiflorum polysaccharides in drugs and health products in the future.

Cloning, Expression Characteristics of Farnesyl Pyrophosphate Synthase Gene from Platycodon grandiflorus and Functional Identification in Triterpenoid Synthesis.

Platycodon grandiflorus is a medicinal plant whose main component is platycodins, which have a variety of pharmacological effects and nutritional values. The farnesyl pyrophosphate synthase (FPS) is a key enzyme in the isoprenoid biosynthesis pathway, which catalyzes the synthesis of farnesyl diphosphate (FPP). In this study, we cloned the FPS gene from P. grandiflorus (PgFPS) with an ORF of 1260 bp, encoding 419 amino acids with a deduced molecular weight and theoretical pI of 46,200.98 Da and 6.52, respectively. The squalene content of overexpressed PgFPS in tobacco leaves and yeast cells extract was 1.88-fold and 1.21-fold higher than that of the control group, respectively, and the total saponin content was also increased by 1.15 times in yeast cells extract, which verified the biological function of PgFPS in terpenoid synthesis. After 48 h of MeJA treatment and 6 h of ethephon treatment, the expression of the PgFPS gene in roots and stems reached its peak, showing a 3.125-fold and 3.236-fold increase compared to the untreated group, respectively. Interestingly, the expression of the PgFPS gene in leaves showed a decreasing trend after exogenous elicitors treatment. The discovery of this enzyme will provide a novel perspective for enhancing the efficient synthesis of platycodins.

Platycodon grandiflorum saponins: Ionic liquid-ultrasound-assisted extraction, antioxidant, whitening, and antiaging activity.

This study explored the use of ionic liquid-ultrasound (ILU)-assisted extraction to enhance the extraction rate of Platycodon grandiflorum saponins (PGSs), and the content, extraction mechanism, antioxidant activity, whitening, and antiaging activity of PGSs prepared using ILU, ultrasound-water, thermal reflux-ethanol, and cellulase hydrolysis were compared. The ILU method particularly disrupted the cell wall, improved PGS extraction efficiency, and yielded a high total saponin content of 1.45 ± 0.02 mg/g. Five monomeric saponins were identified, with platycodin D being the most abundant at 1.357 mg/g. PGSs displayed excellent in vitro antioxidant activity and exhibited inhibitory effects on tyrosinase, elastase, and hyaluronidase. The results suggest that PGSs may have broad antioxidant, skin-whitening, and antiaging potential to a large extent. Overall, this study provided valuable insights into the extraction, identification, and bioactivities of PGSs, which could serve as a reference for future development and application of these compounds in the functional foods industry.

Genome-wide analysis of bZIP transcription factors and their expression patterns in response to methyl jasmonate and low-temperature stresses in Platycodon grandiflorus.

Background: Platycodon grandiflorus belongs to the genus Platycodon and has many pharmacological effects, such as expectorant, antitussive, and anti-tumor properties. Among transcription factor families peculiar to eukaryotes, the basic leucine zipper (bZIP) family is one of the most important, which exists widely in plants and participates in many biological processes, such as plant growth, development, and stress responses. However, genomic analysis of the bZIP gene family and related stress response genes has not yet been reported in P. grandiflorus. Methods: P. grandiflorus bZIP (PgbZIP) genes were first identified here, and the phylogenetic relationships and conserved motifs in the PgbZIPs were also performed. Meanwhile, gene structures, conserved domains, and the possible protein subcellular localizations of these PgbZIPs were characterized. Most importantly, the cis-regulatory elements and expression patterns of selected genes exposed to two different stresses were analyzed to provide further information on PgbZIPs potential biological roles in P. grandiflorus upon exposure to environmental stresses. Conclusions: Forty-six PgbZIPs were identified in P. grandiflorus and divided into nine groups, as displayed in the phylogenetic tree. The results of the chromosomal location and the collinearity analysis showed that forty-six PgbZIP genes were distributed on eight chromosomes, with one tandem duplication event and eleven segmental duplication events identified. Most PgbZIPs in the same phylogenetic group have similar conserved motifs, domains, and gene structures. There are cis-regulatory elements related to the methyl jasmonate (MeJA) response, low-temperature response, abscisic acid response, auxin response, and gibberellin response. Ten PgbZIP genes were selected to study their expression patterns upon exposure to low-temperature and MeJA treatments, and all ten genes responded to these stresses. The real-time quantitative polymerase chain reaction (RT-qPCR) results suggest that the expression levels of most PgbZIPs decreased significantly within 6 h and then gradually increased to normal or above normal levels over the 90 h following MeJA treatment. The expression levels of all PgbZIPs were significantly reduced after 3 h of the low-temperature treatment. These results reveal the characteristics of the PgbZIP family genes and provide valuable information for improving P. grandiflorus's ability to cope with environmental stresses during growth and development.

Platycodi radix aqueous extract salvages doxorubicin-induced senescence by mitochondrial reactive oxygen species reduction in umbilical cord matrix stem cells.

Platycodi radix is a widely used herbal medicine that contains numerous phytochemicals beneficial to health. The health and biological benefits of P. radix have been found across various diseases. The utilization of umbilical cord stromal stem cells, derived from Wharton's jelly of the human umbilical cord, has emerged as a promising approach for treating degenerative diseases. Nevertheless, growing evidence indicates that the function of stem cells declines with age, thereby limiting their regenerative capacity. The primary objective in this study is to investigate the beneficial effects of P. radix in senescent stem cells. We conducted experiments to showcase that diminished levels of Lamin B1 and Sox-2, along with an elevation in p21, which serve as indicative markers for the senescent stem cells. Our findings revealed the loss of Lamin B1 and Sox-2, coupled with an increase in p21, in umbilical cord stromal stem cells subjected to a low-dose (0.1 µM) doxorubicin (Dox) stimulation. However, P. radix restored the Dox-damage in the umbilical cord stromal stem cells. P. radix reversed the senescent conditions when the umbilical cord stromal stem cells exposed to Dox-induced reactive oxygen species (ROS) and mitochondrial membrane potential are significantly changed. In Dox-challenged aged umbilical cord stromal stem cells, P. radix reduced senescence, increased longevity, prevented mitochondrial dysfunction and ROS and protected against senescence-associated apoptosis. This study suggests that P. radix might be as a therapeutic and rescue agent for the aging effect in stem cells. Inhibition of cell death, mitochondrial dysfunction and aging-associated ROS with P. radix provides additional insights into the underlying molecular mechanisms.

Platycodin D Ameliorates Type 2 Diabetes-Induced Myocardial Injury by Activating the AMPK Signaling Pathway.

The current study aimed to assess the effectiveness of pharmacological intervention with Platycodin D (PD), a critically active compound isolated from the roots of Platycodon grandiflorum, in mitigating cardiotoxicity in a murine model of type 2 diabetes-induced cardiac injury and in H9c2 cells in vitro. Following oral administration for 4 weeks, PD (2.5 mg/kg) significantly suppressed the elevation of fasting blood glucose (FBG) levels, improved dyslipidemia, and effectively inhibited the rise of the cardiac injury markers creatine kinase isoenzyme MB (CK-MB) and cardiac troponin T (cTnT). PD treatment could ameliorate energy metabolism disorders induced by impaired glucose uptake by activating AMPK protein expression in the DCM mouse model, thereby promoting the GLUT4 transporter and further activating autophagy-related proteins. Furthermore, in vitro experiments demonstrated that PD exerted a concentration-dependent increase in cell viability while also inhibiting palmitic acid and glucose (HG-PA)-stimulated H9c2 cytotoxicity and activating AMPK protein expression. Notably, the AMPK activator AICAR (1 mM) was observed to upregulate the expression of AMPK in H9c2 cells after high-glucose and -fat exposure. Meanwhile, we used AMPK inhibitor Compound C (20 µM) to investigate the effect of PD activation of AMPK on cells. In addition, the molecular docking approach was employed to dock PD with AMPK, revealing a binding energy of -8.2 kcal/mol and indicating a tight interaction between the components and the target. PD could reduce the expression of autophagy-related protein p62, reduce the accumulation of autophagy products, promote the flow of autophagy, and improve myocardial cell injury. In conclusion, it has been demonstrated that PD effectively inhibits cardiac injury-induced type 2 diabetes in mice and enhances energy metabolism in HG-PA-stimulated H9c2 cells by activating the AMPK signaling pathway. These findings collectively unveil the potential cardioprotective effects of PD via modulation of the AMPK signaling pathway.

Screening of Platycodonis Radix Fractions for Antiobesity Activities and Elucidation of Its Molecular Mechanisms in High-Fat Diet-Fed C57BL/6 Mice.

Obesity is a threat to public health and effective new medications are required. Platycodonis Radix (PR) is a traditional medicinal/dietary plant with activities against obesity. Using mice given a diet rich in fat, the antiobesity components of PR were identified and their molecular mechanisms were clarified further in this investigation. Initially, the impacts of PR fractions on liver histology and biochemical markers were assessed. Subsequently, the degrees of lipogenic and lipolytic gene and protein expressions were determined. Oral administration of PR polysaccharides (PG) (0.80 g/kg body weight) improved liver function (alanine aminotransferase and aspartate aminotransferase) and its antioxidant activities (total superoxide dismutase, glutathione peroxidase, and malondialdehyde), as well as alleviated blood lipid (total cholesterol, total triglyceride, high-density lipoprotein cholesterol, and low-density lipoprotein cholesterol) values, inflammatory systemic (TNF-α and IL-1ß), and histological abnormalities within the liver. Furthermore, PG administration downregulated the expression for lipogenic genes (ACC and FAS) and upregulated the expression for the lipolytic gene (PPARα, LPL, CPT1, and HSL). Importantly, PG raised AMPK phosphorylation and decreased SREBP-1c protein synthesis. Thus, it is possible that PG stimulates the AMPK-LPL/HSL path (lipolytic route) plus the AMPK-ACC/PPARα-CPT1 path (associated to ß-oxidation of fatty acids), while inhibiting the AMPK/(SREBP-1c)-ACC/FAS path (lipogenic route). In summary, PG has the ability to regulate lipid metabolism, and it may be useful to pharmacologically activate AMPK with PG to prevent and cure obesity.

Platycodon grandiflorus polysaccharide inhibits the inflammatory response of 3D4/21 cells infected with PCV2.

Porcine circovirus type 2 (PCV2) infection cause multi-systemic inflammation in pigs. Platycodon grandiflorus polysaccharide (PGPSt) has been reported to have the effects of immune regulation and disease resistance. Nevertheless, the role and mechanism of PGPSt in the inflammatory response of 3D4/21 cells induced by PCV2 infection remain unclear. The present study aims to investigate effects of PGPSt on inflammatory response and its possible underlying mechanisms in vitro models. Cells were treated with PCV2 for 36 h to construct a cell inflammation model. The 3D4/21 cell lines were pretreated with or without PGPSt, and the changes of inflammation-related markers and the signaling pathway were detected by CCK-8, ELISA, qPCR and Western blot. The results showed that PGPSt was non-toxic to cells and protected PCV2-infected cells from inflammatory damage. PGPSt could significantly inhibit the high acetylation of histone H3 (AcH3) and histone H4 (AcH4), down-regulate HAT and up-regulate HDAC activity, and reduce the expression of pro-inflammatory enzymes iNOS and COX-2 proteins levels. Then the levels of IL-1ß, IL-6 and TNF-α were significantly inhibited, and the level of IL-10 was promoted. We also observed that PGPSt inhibited the phosphorylation of p65, p38 and Erk1/2, which subsequently inhibited nuclear translocation of NF-κB p65 to express pro-inflammatory factors. In conclusion, PGPSt can reduce the inflammatory response by regulating histone acetylation, reducing the release of inflammatory factors, reducing the expression of pro-inflammatory enzymes, and inhibiting the activation of NF-κB and MAPKs signaling pathways. This suggests that PGPSt had an anti-inflammatory effect on the inflammatory response caused by PCV2 infection, which provided theoretical data support for the research.

In vitro immune-enhancing effects of Platycodon grandiflorum combined with Salvia plebeian via MAPK and NF-κB signaling in RAW264.7 cells.

The immune-enhancing activity of the combination of Platycodon grandiflorum and Salvia plebeian extracts (PGSP) was evaluated through macrophage activation using RAW264.7 cells. PGSP (250-1000 µg/mL) showed a higher release of NO in a dose-dependent manner. The results showed that PGSP could significantly stimulate the production of PGE2, COX-2, TNF-α, IL-1ß, and IL-6 in RAW264.7 cells and promote iNOS, COX-2, TNF-α, IL-1ß, IL-4, and IL-6 mRNA expression. Western blot analysis demonstrated that the protein expression of iNOS and COX-2 and the phosphorylation of ERK, JNK, p38, and NF-κB p65 were greatly increased in PGSP-treated cells. PGSP also promoted the phagocytic activity of RAW264.7 cells. All these results indicated that PGSP might activate macrophages through MAPK and NF-κB signaling pathways. Taken together, PGSP may be considered to have immune-enhancing activity and might be used as a potential immune-enhancing agent.

Recent advances in Platycodon grandiflorum polysaccharides: Preparation techniques, structural features, and bioactivities.

Platycodon grandiflorum, a globally recognized medicinal and edible plant, possesses significant nutritional value and pharmacological value. In traditional Chinese medicine, it has the effects of tonifying the spleen and replenishing the Qi, moistening the lung and relieving the cough, clearing the heat and detoxifying, and relieving the pain. Accumulating evidence has revealed that the polysaccharides from P. grandiflorum (PGPs) are one of the major and representative biologically active macromolecules and have diverse biological activities, such as immunomodulatory activity, anti-inflammatory activity, anti-tumor activity, regulation of the gut microbiota, anti-oxidant activity, anti-apoptosis activity, anti-angiogenesis activity, hypoglycemic activity, anti-microbial activity, and so on. Although the polysaccharides extracted from P. grandiflorum have been extensively studied for the extraction and purification methods, structural characteristics, and pharmacological activities, the knowledge of their structures and bioactivity relationship, toxicologic effects, and pharmacokinetic profile is limited. The main purpose of the present review is to provide comprehensively and systematically reorganized information on extraction and purification, structure characterizations, and biological functions as well as toxicities of PGPs to support their therapeutic potentials and sanitarian functions. New valuable insights for future research regarding PGPs were also proposed in the fields of therapeutic agents and functional foods.

Genome-wide identification and expression profiling of the WRKY gene family reveals abiotic stress response mechanisms in Platycodon grandiflorus.

The WRKY family of transcription factors (TFs) is an important gene family involved in abiotic stress responses. Although the roles of WRKY TFs in plant abiotic stress responses are well studied, little is known about the stress-induced changes in WRKY family in Platycodon grandiflorus. 42 PgWRKY genes in seven subgroups were identified in the P. grandiflorus genome. The content of eight platycodins in P. grandiflorus was investigated under cold, heat, and drought stresses. Platycodin D levels significantly increased under three abiotic stresses, while the content changes of other platycodins varied. Transcriptome analysis showed that different WRKY family members exhibited varied expression patterns under different abiotic stresses. PgWRKY20, PgWRKY26, and PgWRKY39 were identified as three key candidates for temperature and drought stress responses, and were cloned and analysed for sequence characteristics, gene structure, subcellular localisation, and expression patterns. The RT-qPCR results showed that PgWRKY26 expression significantly increased after heat stress for 48 h, cold stress for 6 h, and drought stress for 2 d (DS_2 d). The PgWRKY39 expression level significantly increased at DS_2 d. This study provides a theoretical basis for clarifying the molecular mechanism of the abiotic stress responses of the WRKY gene family in P. grandiflorus.

Preparation methods, structural characteristics, and biological activity of polysaccharides from Platycodon grandiflorus.

Platycodon grandiflorus (P. grandiflorus), a traditional Chinese medicinal herb used for both medicine and food, has a long history of treating respiratory infections, bronchitis, pneumonia, and other lung-related diseases. The therapeutic effects of P. grandiflorus are attributed to its chemical components, including polysaccharides. Among these components, Platycodon grandiflorus polysaccharides (PGP) are recognized as one of the most important and abundant active ingredients, exhibiting various biological activities such as prebiotic, antioxidant, antiviral, anticancer, antiangiogenic, and immune regulatory properties. Incorporating the principles of traditional Chinese medicine, carrier concepts, and modern targeted drug delivery technologies, PGP can influence the target sites and therapeutic effects of other drugs while also serving as a drug carrier for targeted and precise treatments. Therefore, it is essential to provide a comprehensive review of the extraction, separation, purification, physicochemical properties, and biological activities of PGP. In the future, by integrating new concepts, technologies, and processes, further references and guidance can be provided for the comprehensive development of PGP. This will contribute to the advancement of P. grandiflorus in various fields such as pharmaceuticals, health products, and food.

Revealing the "Yin-Jing" mystery veil of Platycodon grandiflorum by potentiating therapeutic effects and lung-oriented guidance property.

ETHNIC PHARMACOLOGICAL RELEVANCE: "Yin-Jing" medicine (YJM) has been widely used by both ancient and modern Chinese medicine practitioners during long-term clinical practice. However, it remains unclear how to best guide other medicines to the targeted organs in a traditional Chinese medicine (TCM) prescription. Here, in an attempt to explain the scientific connotation of the YJM property (YJMP) attributed to a basic TCM theory, Platycodon grandiflorum (PG) was chosen as a case study to reveal the mystery of YJMP theory. AIM OF THE STUDY: The main purpose of this study is to employ modern chemical and molecular biology methods to confirm the "Yin-Jing" effect of PG, and further clarify its material basis and related possible mechanism. MATERIALS AND METHODS: The ammonia-induced lung injury rat model was utilized to determine the optimal dosage of traditional prescription Hui Yan Zhu Yu decoction (HYZYD) using Wright Giemsa staining, HE staining, Masson staining, and TUNEL analysis. With the same way, PG was confirmed to have potentiating therapeutic effect (PTE) by comparison with HYZYD and [HYZYD-PG]. TMT proteomics was used to reveal the "Yin-Jing" mechanism of action. Western blot assay (WB) was employed for verification of differentially expressed proteins. Additionally, four non-crossing fragmentations (Fr. A-D) were characterized by RPLC/SEC-ELSD and HILIC-ESI--Q-OT-IT-MS techniques. The PTE and guidance property assays were utilized to evaluate "Yin-Jing" functions by a compatible combination of hydroxysafflor yellow A (HYA) using qPCR, FCM, WB, HPLC, high content cell imaging (HCI) and high-resolution live-cell imaging (HRLCI) techniques. RESULTS: The HYZYD-M (medium dose group) significantly improved the lung injury level in a pneumonia model of rats. PG enhanced the therapeutic effect of HYZYD ascribed to Yin-Jing PTE functions. TMT proteomics revealed a category of differentially expressed proteins ascribed to Golgi-ER between HYZYD and [HYZYD-PG]. Fr. C (i.e., saponins) and Fr. D (i.e., lipids) were determined as therapeutic fragmentations via the LPS-induced A549 cell injury model; however, Fr. B (fructooligosaccharides and small Mw fructans) had no therapeutic effect. Further compatibility PTE assays confirmed Fr. B significantly improved efficiency by a combination of HYA. The guidance assays showed Fr. B could significantly increase the uptake and distribution of HYA into lung cells and tissues. HCI assays showed that Fr. B increased uptake of HYA accompanied by significant activation of Golgi-ER. Unlike Fr. B, HRLCI showed that Fr. A, C and D were not only unobvious activations of Golgi-ER but also insignificant facilitation of colocalizations between HYA and Golgi-ER. CONCLUSIONS: Fr. B is believed to be a key YJMP material basis of PG attributed to Yin-Jing PTE with characteristic of lung-oriented guidance property, whereas another abound Fr. C was determined to have synergistic effects rather than Yin-Jing material basis.

Identification and functional characterization of two trans-isopentenyl diphosphate synthases and one squalene synthase involved in triterpenoid biosynthesis in Platycodon grandiflorus.

MAIN CONCLUSION: Two trans-isopentenyl diphosphate synthase and one squalene synthase genes were identified and proved to be involved in the triterpenoid biosynthesis in Platycodon grandiflorus. Platycodon grandiflorus is a commonly used traditional Chinese medicine. The main bioactive compounds of P. grandiflorus are triterpenoid saponins. The biosynthetic pathway of triterpenoid saponins in P. grandiflorus has been preliminarily explored. However, limited functional information on related genes has been reported. A total of three trans-isopentenyl diphosphate synthases (trans-IDSs) genes (PgFPPS, PgGGPPS1 and PgGGPPS2) and one squalene synthase (SQS) gene (PgSQS) in P. grandiflorus were screened and identified from transcriptome dataset. Subcellular localization of the proteins was defined based on the analysis of GFP-tagged. The activity of genes was verified in Escherichia coli, demonstrating that recombinant PgFPPS catalysed the production of farnesyl diphosphate. PgGGPPS1 produced geranylgeranyl diphosphate, whereas PgGGPPS2 did not exhibit catalytic activity. By structural identification of encoding genes, a transmembrane region was found at the C-terminus of the PgSQS gene, which produced an insoluble protein when expressed in E. coli but showed no apparent effect on the enzyme function. Furthermore, some triterpenoid saponin synthesis-related genes were discovered by combining the component content and the gene expression assays at the five growth stages of P. grandiflorus seedlings. The accumulation of active components in P. grandiflorus was closely associated with the expression level of genes related to the synthesis pathway.

Heterologous Expression of Platycodon grandiflorus PgF3'5'H Modifies Flower Color Pigmentation in Tobacco.

Flavonoid-3',5'-hydroxylase (F3'5'H) is the key enzyme for the biosynthesis of delphinidin-based anthocyanins, which are generally required for purple or blue flowers. Previously, we isolated a full-length cDNA of PgF3'5'H from Platycodon grandiflorus, which shared the highest homology with Campanula medium F3'5'H. In this study, PgF3'5'H was subcloned into a plant over-expression vector and transformed into tobacco via Agrobacterium tumefaciens to investigate its catalytic function. Positive transgenic tobacco T0 plants were obtained by hygromycin resistance screening and PCR detection. PgF3'5'H showed a higher expression level in all PgF3'5'H transgenic tobacco plants than in control plants. Under the drive of the cauliflower mosaic virus (CaMV) 35S promoter, the over-expressed PgF3'5'H produced dihydromyricetin (DHM) and some new anthocyanin pigments (including delphinidin, petunidin, peonidin, and malvidin derivatives), and increased dihydrokaempferol (DHK), taxifolin, tridactyl, cyanidin derivatives, and pelargonidin derivatives in PgF3'5'H transgenic tobacco plants by ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis, resulting in a dramatic color alteration from light pink to magenta. These results indicate that PgF3'5'H products have F3'5'H enzyme activity. In addition, PgF3'5'H transfer alters flavonoid pigment synthesis and accumulation in tobacco. Thus, PgF3'5'H may be considered a candidate gene for gene engineering to enhance anthocyanin accumulation and the molecular breeding project for blue flowers.

Optimization of ultrasonic-assisted extraction of Platycodon grandiflorum polysaccharides and evaluation of its structural, antioxidant and hypoglycemic activity.

The study aimed to improve the extraction rate of Platycodon grandiflorum roots polysaccharides (PGPs) using ultrasound-assisted extraction (UAE). A comparative analysis was undertaken to evaluate polysaccharides content, molecular weight distribution, monosaccharide composition, preliminary structure, antioxidant, and hypoglycemic activity of UAE in comparison with heating water extraction (HWE). The optimum extraction conditions included a liquid-to-material ratio of 20 mL/g, ultrasonic power of 150 W, extraction temperature of 70 ℃, and extraction time of 20 min, resulting in a significantly greater polysaccharides (12.011 ± 0.91 %) compared to HWE (7.62 ± 0.18 %). Through Sephacryl S-100 column elution, two homogenous fraction (PGP-U extracted with UAE and PGP-H extracted with HAE) were obtained. The molecular weight of PGP-U and PGP-H was 3.14 kDa and 3.44 kDa, respectively, mainly composed of different proportions of fourteen monosaccharides. Fourier transform infrared spectroscopy (FT-IR) and Nuclear Magnetic Resonance (NMR) spectra experiment results showed that the two polysaccharides were pyranose ring with α- and ß-glycoside bond. PGP-U and PGP-H exhibited specific antioxidant activities, encompassing total reducing force, scavenging of DPPH radicals, ABTs radicals and hydroxyl radicals in vitro, along with mitigation of H2O2-induced damage in HepG2 cells. Moreover, PGP-U exerted significantly stronger inhibitory activities against α-amylase and α-glucosidase and could significantly enhances the glucose uptake capacity and intracellular glycogen content of insulin-resistant HepG2 (IR-HepG2) cells.

Polysaccharides from Platycodon grandiflorus attenuates high-fat diet induced obesity in mice through targeting gut microbiota.

The root of Platycodon grandiflorus (PG), abundant in soluble polysaccharides, has a long history in traditional Asian diets and herbal medicine due to its anti-inflammatory activity and anti-obesity effects. Our previous study was the first to establish a link between the beneficial effects of PG and changes in the gut microbiota, and suggested potential roles that the polysaccharide components play. However, more evidence was needed to understand the anti-obesity functions of polysaccharides from PG (PS) and their relationship with the regulation of the gut microbiota. In this study, we first performed an experiment to explore the anti-obesity activities of PS: Male C57BL/6 mice (six-weeks-old) were fed either a standard control diet (CON), or a high-fat diet (HFD) to induce obesity, or a HFD supplemented with PS (HFPS) for 8 weeks. Body weight and food intake were monitored throughout. Lipid metabolism were determined and related gene expression changes in adipose tissues were analyzed by RNA-seq. Amplicon sequencing of the bacterial 16 S rRNA gene was used to explore gut microbiota structure in fecal samples. Then, we performed the second experiment to explore whether the anti-obesity activities of PS were dependent on the regulation of the gut microbiota: Male C57BL/6 mice (six-weeks-old), treated with an antibiotic cocktail to reduce the gut microbial load, were fed either a HFD (A-HFD) or a HFPS (A-HFPS) diet for 8 weeks. Finally, we used in vitro fermentation experiments to verify the effects of PS on the growth and metabolic activities of the gut microbes. We found that PS significantly reduced HFD-induced weight gain and excessive fat accumulation, changed the expression of key genes involved in lipid metabolism, and attenuated HFD-induced changes in the gut microbiota. However, PS did not affect fat accumulation or lipid metabolism in the gut microbiota depleted mice. Overall, our results show that PS has significant effects on the gut microbiota in the mouse model, and the anti-obesity effects of PS are mediated via changes in the gut microbiota composition and metabolic activity.

Quality control of Platycodon grandiflorum (Jacq.) A. DC. based on value chains and food chain analysis.

Platycodon grandiflorum (Jacq.) A. DC. has been proposed as a medicine and food homology, thus playing an important role in disease prevention and health promotion, with great potential for research and value in clinical application. We aimed to analyze stakeholders' production behavior and financial performance from a value chain (VC) perspective and provide a basis for improving the quality of P. grandiflorum and the interests of stakeholders. P. grandiflorum collected from different producing areas were chemically analyzed, and the quality of platycodin D was evaluated. Rstudio3.6.0 was used to analyze the correlation between total platycodins (as platycodin D, platycoside E, and platycodin D3) and platycodin D in P. grandiflorum, providing the basis for quality control of P. grandiflorum. In addition, we studied the anti-inflammatory and anti-cancer activities of P. grandiflorum extract under different links. Based on the food chain energy pyramid, the transfer efficiency of active components of P. grandiflorum in different links was studied. Accordingly, 10 different types of VCs were determined in producing P. grandiflorum. Our results show that vertical coordination has led to a more consistent traceability system and strict regulation of supply chains.

Comparative analysis of the molecular response characteristics in Platycodon grandiflorus irradiated with heavy ion beams and X-rays.

The response of plants to radiation is an essential topic in both space plant cultivation and mutation breeding by radiation. In this study, heavy ion beams (HIB) generated by the ground accelerator and X-rays (XR) were used as models of high linear energy transfer (LET) and low LET radiation to study the molecular response mechanism of Platycodon grandiflorus (P. grandiflorus) seedlings after irradiation. The gene and protein expression profiles of P. grandiflorus after 15 Gy HIB and 20 Gy XR radiation were analyzed by transcriptome and proteome. The results showed that the number of differentially expressed genes (DEGs) induced by HIB radiation was less than that of XR group, but HIB radiation induced more differentially expressed proteins (DEPs). Both HIB and XR radiation activated genes of RNA silencing, double-strand break repair and cell catabolic process. DNA replication and cell cycle related genes were down-regulated. The genes of cell wall and external encapsulating structure were up-regulated after HIB radiation. The gene expression of protein folding and glucan biosynthesis increased after XR radiation. Protein enrichment analysis indicated that HIB radiation resulted in differential protein enriched in photosynthesis and secondary metabolite biosynthesis pathways, while XR radiation induced differential protein of glyoxylate and dicarboxylate metabolism and carbon metabolism. After HIB and XR radiation, the genes of antioxidant system and terpenoid and polyketide metabolic pathways presented different expression patterns. HIB radiation led to the enrichment of non-homologous end-joining pathway. The results will contribute to understanding the biological effects of plants under space radiation.