Cyclocarya Research Articles

Effect of Sodium Selenite Foliar Treatment on the Nutritional Quality of Cyclocarya paliurus (Batalin) Iljinsk

Cyclocarya paliurus (Batalin) Iljinskaja is a rare, endemic tree species in China. The leaves of C. paliurus contain a high concentration of biologically active compounds, and they are often used to make herbal tea. Exogenous selenium (Se) enrichment can promote the levels of active ingredients in C. paliurus. To explore the effects of exogenous Se enrichment, this study applied different concentrations of sodium selenite solution on the leaves (0, 40, 80, 120, 160, and 300 mg/L) and measured the changes in Se, secondary metabolites, soluble sugar, soluble protein, starch, and trace elements in the leaves at different treatment times. The results showed that with the increase in the concentration of sodium selenite spray, the selenium content in the leaves of C. paliurus gradually increased, and high selenium concentrations could cause seedling burning to the leaf surface (>160 mg/kg). When the selenium treatment concentration was 80 mg/kg, the selenium content reached the maximum value of the selenium-rich tea standard (4 mg/kg). The content of polyphenols and most elements reached their maxima under the treatment of 40 mg/L Na2SeO3, except for Mg and Mn, which peaked at 300 mg/L. The content of soluble sugars (38.1 mg/g) and starch reached their maxima under relatively high selenium treatment concentrations, whereas soluble protein (10.63 mg/g) exhibited its maximum value in the control group. The optimal harvest time was mainly concentrated in the 10–20 day treatment period. The objective of this research is to investigate the effects of exogenous selenium application on the nutritional quality of C. paliurus leaves. The findings will provide guidance for the effective cultivation of selenium-enriched Poria cocos as a medicinal and health-promoting product.

Genome-Wide Characterization of the GRAS Gene Family in Cyclocarya paliurus and Its Involvement in Heterodichogamy

Genome-Wide Characterization of the GRAS Gene Family in Cyclocarya paliurus and Its Involvement in Heterodichogamy

The impact of genetic similarity and environment on the flavonoids variation pattern of Cyclocarya paliurus

The leaves of Cyclocarya paliurus (Batalin) Iljinskaja, an endemic tree with a scattered distribution in subtropical China, are rich in flavonoids with beneficial, health-promoting properties. To understand the impact of environment and genetic similarity on the variation pattern of flavonoids in this species, we analyzed C. paliurus germplasm resources from 26 different populations previously sampled from the main distribution area. Environmental, genetic and biochemical data was associated by genetic structure analysis, non-parametric tests, correlation analysis and principal component analysis. We found that populations with higher flavonoid contents were distributed at higher elevations and latitudes and fell into two groups with similar genetic diversities. Significant accumulations of isoquercitrin and kaempferol 3-O-glucoside were detected in the higher flavonoid-content resources. In addition, the genetic clusters with higher flavonoid contents exhibited broader environmental-adaptive capacities. Even in the presence of environmental factors promoting C. paliurus flavonoid accumulation, only those populations having a specific level of genetic similarity were able to exploit such environments.

Cyclocarysaponins A–J, dammarane-type triterpenoid glycosides from the leaves of Cyclocarya paliurus

Ten previously undescribed dammarane-type triterpenoid glycosides, cyclocarysaponins A-J (1-10), were isolated from the leaves of Cyclocarya paliurus (Batal.) Iljinskaja. The structures of these compounds were characterized through detailed spectroscopic analysis, including 1D and 2D nuclear magnetic resonance (NMR) and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS). The cytotoxic activities of all isolates were assessed against five human cancer cell lines (Bel-7402, Caski, BGC-823, A2780, and HCT-116). Of the tested compounds, compounds 1, 7, and 9 exhibited selective cytotoxicity against one or more human cancer cell lines.

Metabolite Profiling and Identification of Sweet/Bitter Taste Compounds in the Growth of Cyclocarya Paliurus Leaves Using Multiplatform Metabolomics.

Cyclocarya paliurus tea, also known as "sweet tea", an herbal tea with Cyclocarya paliurus leaves as raw material, is famous for its unique nutritional benefits and flavor. However, due to the unique "bittersweet" of Cyclocarya paliurus tea, it is still unable to fully satisfy consumers' high-quality taste experience and satisfaction. Therefore, this study aimed to explore metabolites in Cyclocarya paliurus leaves during their growth period, particularly composition and variation of sweet and bitter taste compounds, by combining multi-platform metabolomics analysis with an electronic tongue system and molecular docking simulation technology. The results indicated that there were significant differences in the contents of total phenols, flavonoids, polysaccharides, and saponins in C. paliurus leaves in different growing months. A total of 575 secondary metabolites were identified as potential active metabolites related to sweet/bitter taste using nontargeted metabolomics based on UHPLC-MS/MS analysis. Moreover, molecular docking technology was utilized to study interactions between the candidate metabolites and the sweet receptors T1R2/T1R3 and the bitter receptors T2R4/T2R14. Six key compounds with high sweetness and low bitterness were successfully identified by using computational simulation analysis, including cis-anethole, gluconic acid, beta-D-Sedoheptulose, asparagine, proline, and citrulline, which may serve as candidates for taste modification in Cyclocarya paliurus leaves. These findings provide a new perspective for understanding the sweet and bitter taste characteristics that contribute to the distinctive sensory quality of Cyclocarya paliurus leaves.

Qingqianliutianosides A–E: five new sweet dammarane triterpenoid glycosides derived from the leaves of Cyclocarya paliurus – identification, characterization and interactions with T1R2/T1R3 sweet taste receptors

AbstractBACKGROUNDCyclocarya paliurus, as a new food resource, is utilized extensively in human and animal diets due to its bioactive compounds, health benefits, and its highly prized sweet flavor. This study aimed to investigate the sweet‐taste ingredient of C. paliurus leaves.RESULTSFive new dammarane triterpenoid glycosides were isolated and identified as qingqianliutianosides A–E (1–5) by comprehensive spectroscopic data analysis and a single crystal X‐ray diffraction experiment. Qingqianliutianoside A (1) and qingqianliutianoside C (3), present in relatively high quantities in the plant, were shown to exhibit sweetness by sensory evaluation and electronic tongue analysis. Further monitoring was conducted on the content changes in 3 in leaves at different growth stages, indicating that 3 reached its peak content in April and then showed a decreasing trend. Molecular docking studies revealed that T1R2/T1R3 receptors Ser212, Ser105, Thr239, Asn380, Thr305, and Val381 may play critical roles, demonstrating that hydrogen bonding and hydrophobic interactions were the dominant interaction forces between all of the identified compounds and the active sites in the Venus flytrap module of the T1R2/T1R3 receptors.CONCLUSIONQingqianliutianosides A–E are promising natural source sugar substitutes for use in functional foods and beverages. © 2024 Society of Chemical Industry.

Regulation of exogenous sugars on the biosynthesis of key secondary metabolites in Cyclocarya paliurus.

The biosynthesis and accumulation of secondary metabolites play a vital role in determining the quality of medicinal plants, with carbohydrate metabolism often influencing secondary metabolism. To understand the potential regulatory mechanism, exogenous sugars (sucrose, glucose/fructose) were applied to the leaves of Cyclocarya paliurus, a highly valued and multiple function tree species. The results showed that exogenous sugars enhanced the accumulation of soluble sugar and starch while increasing the enzyme activity related to carbohydrate metabolism. In addition, the plant height was increased by a mixture of exogenous mixed sugars, the addition of sucrose promoted the net photosynthetic rate, while all types of exogenous sugars facilitated the accumulation of flavonoids and terpenoids. Based on weighted gene co-expression network analysis (WGCNA), two key gene modules and four candidate transcription factors (TFs) related to carbohydrate metabolism and secondary metabolite biosynthesis were identified. A correlation analysis between transcriptome and metabolome data showed that exogenous sugar up-regulated the expression of key structural genes in the flavonoid and terpenoid biosynthetic pathway. The expression levels of the four candidate TFs, TIFY 10A, WRKY 7, EIL 3 and RF2a, were induced by exogenous sugar and were strongly correlated with the key structural genes, which enhanced the synthesis of specific secondary metabolites and some plant hormone signal pathways. Our results provide a comprehensive understanding of key factors in the quality formation of medicinal plants and a potential approach to improve the quality.

Nine new nor-3,4-seco-dammarane triterpenoids from the leaves of Cyclocarya paliurus and their hypoglycemic activity

This manuscript describes the isolation of nine new nor-3,4-seco-dammarane triterpenoids, norqingqianliusus A-I (1–9) and one known nortriterpenoid (10) from Cyclocarya paliurus leaves. Norqingqianliusus A and B (1 and 2) possess a unique 3,4-seco-dammarane-type C26 tetranortriterpenoid skeleton. The compounds were structurally characterized through modern spectroscopic techniques. Moreover, the potential mechanism of hypoglycemic activity was further explored by studying the effects on glucosamine-induced insulin resistant HepG2 cells. In vitro hypoglycemic effects of all of the isolates were investigated using insulin resistant HepG2 cells. The glucose consumption was significantly promoted by compound 10, in a dose-dependent manner, thus alleviating damage in IR-HepG2 cells. Besides, it reduced the PEPCK and GSK3β gene expression, involved in glucose metabolism. The anti-diabetic effects of the plant, utilized traditionally, can hence be attributed to the presence of nor-3,4-seco-dammarane triterpenoids in the leaves.

Blended Tea Ameliorates T2DM via Modulation of Gut Microflora.

Increasing evidences suggest that type 2 diabetes mellitus (T2DM) is closely related to gut microflora dysbiosis, which can be improved by dietary intervention. Four natural plant products, including Cyclocarya paliurus, Fu brick tea, Ampelopsis grossedentata, and Lithocarpus litseifolius, were blended to form a blended tea product for obtaining the better flavor. The blended tea was also expected to have excellent pharmacological activity. Therefore, the ameliorative effect of blended tea on T2DM and underlying mechanisms were studied in this study. The results showed that the blended tea extract effectively attenuated the symptoms of glucose and lipid metabolism-related disorders in T2DM mice fed by high-fat and high-sucrose diet. Furthermore, blended tea extract intervention significantly attenuated gut microbiota dysbiosis, the abundance of bacteria such as Bacteroidetes and Firmicutes, which aid in the hydrolysis and utilization of carbohydrates, significantly increased, while the abundance of pathogenic bacteria such as Proteobacteria significantly decreased. Certain core microorganisms involved in energy metabolism, including Ruminococcaceae_UCG-005, Butyricimonas, Roseburia, Oscillibacter, [Eubacterium]_nodatum_group, Muribaculaceae, Prevotellaceae UCG 001, were also found to be improved by blended tea extract. Collectively, our results demonstrated that the blended tea may ameliorate T2DM through modulation of gut microflora. The blended tea may serve as novel functional drink for the treatment of T2DM and dysbiosis of gut microbiota.

Cholesterol-Lowering Effect of Polysaccharides from Cyclocarya paliurus In Vitro and in Hypercholesterolemia Mice.

In this study, a new component of Cyclocarya paliurus polysaccharides (CPP20) was precipitated by the gradient ethanol method, and the protective effect of CPP20 on hypercholesterolemia mice was investigated. In vitro, CPP20 had the ability to bind bile salts and inhibit cholesterol micelle solubility, and it could effectively clear free radicals (DPPH•, •OH, and ABTS+). In vivo, CPP20 effectively alleviated hypercholesterolemia and liver damage in mice. After CPP20 intervention, the activity of antioxidant enzymes (SOD, CAT, and GSH-Px) and the level of HDL-C in liver and serum were increased, and the activity of aminotransferase (ALT and AST) and the level of MDA, TC, TG, LDL-C, and TBA were decreased. Molecular experiments showed that CPP20 reduced cholesterol by regulating the mRNA expression of antioxidation-related genes (SOD, GSH-Px, and CAT) and genes related to the cholesterol metabolism (CYP7A1, CYP27A1, SREBP-2, HMGCR, and FXR) in liver. In addition, CPP20 alleviated intestinal microbiota disturbances in mice with hypercholesterolemia and increased levels of SCFAs. Therefore, CPP20 alleviates hypercholesterolemia by alleviating oxidative damage, maintaining cholesterol homeostasis, and regulating gut microbiota.

Transcriptome profiling reveals the protective mechanism of sulfated Cyclocarya paliurus polysaccharides against oxidative damage of IEC-6 cell.

Our previous studies have shown that sulfated Cyclocarya paliurus polysaccharides (SCP3) can alleviate intestinal oxidative stress (OS) damage by improving the antioxidant capacity of the intestine, but its mechanism still needs further exploration. This study aimed to reveal the possible underlying protective mechanism of SCP3 against OS damage of intestinal epithelial cells (IEC-6) based on transcriptome profiling. The results showed that SCP3 could increase the activity of superoxide dismutase and reduce the production of malondialdehyde and reactive oxygen species. In addition, the SCP3 could also alleviate the H2O2-induced high apoptosis rate and mitochondrial membrane potential decrease in IEC-6 cells. RNA-sequencing results showed that there were 2152 differentially expressed genes between the control group and the SCP3 group, and the mitogen-activated protein kinases (MAPK) and PI3K-Akt signaling pathways are the main signaling pathways that contributed to SCP3 protecting IEC-6 cells from OS damage. In summary, the SCP3 plays a role in improving intestinal cell damage by inhibiting OS, which may be closely related to the PI3K/Akt and MAPK signaling pathways. PRACTICAL APPLICATION: This study provides a theoretical basis for the practical application of Cyclocarya paliurus polysaccharides as an antioxidant ingredient in auxiliary medicines and functional foods.

One new triterpene glycoside from Cyclocarya paliurus

One previously undescribed triterpene glycoside (1) and two known compounds were isolated from the leaves of Cyclocarya paliurus (2-3). Their structures were elucidated based on methods of spectroscopic analysis and NMR data comparison with those in the literature. Compound 1 showed a moderate inhibitory effect on melanogenesis with an IC50 value of 282.3 μM, with the positive drug arbutin showing an IC50 value of 168.5 μM.

Effects of Foliar Dressing with Chemical Nano-Selenum and Na2SeO3 on the Antioxidant System and Accumulation of Se and Bioactive Components in Cyclocarya paliurus (Sweet Tea Tree).

Selenium (Se)-rich Cyclocarya paliurus is popular for its bioactive components, and exogenous Se fortification is the most effective means of enrichment. However, the effects of exogenous Se fortification on the nutritional quality of C. paliurus are not well known. To investigate the nutrient contents and antioxidant properties of C. paliurus following Se treatment, we used a foliar spray to apply Se in two forms-chemical nano-Se (Che-SeNPs) and sodium selenite (Na2SeO3). Sampling began 10 days after spraying and was conducted every 5 days until day 30. The Se, secondary metabolite, malondialdehyde contents, antioxidant enzyme activity, Se speciation, and Se-metabolism-related gene expression patterns were analyzed in the collected samples. Exogenous Se enhancement effectively increased the Se content of leaves, reaching a maximum on days 10 and 15 of sampling, while the contents of flavonoids, triterpenes, and polyphenols increased significantly during the same period. In addition, the application of Se significantly enhanced total antioxidant activity, especially the activity of the antioxidant enzyme peroxidase. Furthermore, a positive correlation between the alleviation of lipid peroxidation and Se content was observed, while methylselenocysteine formation was an effective means of alleviating Se stress. Finally, Na2SeO3 exhibited better absorption and conversion efficiency than Che-SeNPs in C. paliurus.

α-Glucosidase inhibitory flavonol glycosides from Cyclocarya paliurus (Batalin) Iljinskaja and their kinetics characteristics

Seven previously undescribed flavonol glycosides including four rare flavonol glycoside cyclodimers, dicyclopaliosides A-C (1-3) with truxinate type and dicyclopalioside D (4) with truxillate type, as well as three kaempferol glycoside derivatives cyclopaliosides A-C (5–7), were obtained from the leaves of Cyclocarya paliurus. Their structures were elucidated by extensive spectroscopic methods and chemical analyses. All compounds were evaluated for their inhibitory α-glucosidase activities. Among them, compounds 1–4 display strong inhibitory activities with IC50 values of 82.76 ± 1.41, 62.70 ± 4.00, 443.35 ± 16.48, and 6.31 ± 0.88 nM, respectively, while compounds 5–7 showed moderate activities with IC50 values of 4.91 ± 0.75, 3.64 ± 0.68, and 5.32 ± 0.53 μΜ, respectively. The structure-activity relationship analysis assumed that the cyclobutane cores likely contribute to the enhancement of α-glucosidase inhibitory activities of dimers. Also, the interaction mechanism between flavonol glycoside dimers and α-glucosidase were explored by the enzyme kinetic assay, indicating that compounds 1–3 exhibited mixed-type inhibition, while 4 showed uncompetitive inhibition. Additionally, the active compounds have also undergone molecular docking evaluation.

The auxin response factor (ARF) gene family in Cyclocarya paliurus: genome-wide identification and their expression profiling under heat and drought stresses.

The online version contains supplementary material available at 10.1007/s12298-024-01474-1.

Discovery and identification of natural alkaloids with potential to impact insulin resistance syndrome in Cyclocarya paliurus. (Batal) leaves by UPLC-QTOF-MS combined with HepG2 cells

Cyclocarya paliurus (Batal.) leaves, which contain a range of bioactive compounds, have been used as a traditional Chinese medicine homologous food since ancient times. However, there is a paucity of literature on comprehensive studies of alkaloids in the leaves of Cyclocarya paliurus (Batal.). For the first time, this study aimed to discover and identify alkaloids extracted from Cyclocarya paliurus (Batal.) leaves by ultra-high performance liquid chromatography-quadrupole-time-of-flight tandem mass spectrometry (UPLC-QTOF-MS). A total of ten alkaloids have been identified from Cyclocarya paliurus (Batal.) leaves based on accurate mass spectra (mass accuracy, isotopic spacing and distribution) and comparison to fragmentation spectra reported in the literature. In vitro, alkaloids alleviated insulin resistance by increasing glucose consumption and glycogen content in insulin resistance HepG2 cells. The RNA-seq and western blotting results showed that alkaloids could upregulate the expression of phosphatidylinositol 3-kinase (PI3K), and increase the phosphorylation of insulin receptor protein kinase B (AKT). This study not only clarified the chemical constituents and revealed that diverse alkaloids also presented from Cyclocarya paliurus (Batal.) leaves, also, it will provide chemical information on potential compounds for developing new drugs.

Characterization and antioxidant properties of three exopolysaccharides produced by the Cyclocarya paliurus endophytic fungus

In recent years, the considerable potential of endophytic bacteria and fungi as prolific producers of exopolysaccharides (EPSs) have attracted interest. In this study, 56 endophytes were isolated from Cyclocarya paliurus, and the secondary metabolites of EPSs were extracted from Monascus purpureus, Penicillium citrinum and Aspergillus versicolor, screened, and named MPE, PCE and AVE, respectively. In this work, the physicochemical properties and antioxidant activities of three EPSs, their cell proliferation activity on IEC-6 and RAW264.7 were investigated. The three EPSs were mainly composed of neutral sugar and differ in microstructure. However, MPE had a loose structure, and PCE exhibited a dense and sheet-like structure. In addition, the three EPSs performed ordinary antioxidant activity in vitro but showed excellent cell proliferation activity on IEC-6 and RAW264.7. The cell proliferation activity of PCE was 1.4-fold that of the controls at a concentration of 800 μg/mL on IEC-6, and MPE exhibited 1.3-fold increase on RAW264.7. This study provided scientific evidence and insights into the application of endophytes as a novel plant resource possessing huge application potential.

Antitumor effects of Cypaliuruside F from Cyclocarya paliurus on HepG2 cells

An undescribed dammarane triterpenoid saponin Cypaliuruside F was isolated from the leaves of Cyclocarya paliurus in our preliminary study. The MTT assay, flow cytometry, cell scratch, and DAPI staining were used to detect the antitumor effects of Cypaliuruside F on HepG2 cells. Subsequently, network pharmacology and molecular docking analysis were used to analyse the key targets of Cypaliuruside F against HCC. In addition, a Western blot was performed to determine the effects of Cypaliuruside F on the expression of key proteins in HepG2 cells. The experimental results indicated that the damarane triterpenoid saponin Cypaliuruside F from Cyclocarya paliurus inhibits the proliferation of HepG2 cells by inducing apoptosis and cell cycle arrest. These changes may promote the apoptosis of HepG2 cells by inhibiting the expression of mTOR, STAT3, and Bcl-2 while activating Bax.

Effect of gelatin-chitosan-Cyclocarya paliurus flavonoids edible coating film on the preservation of chilled beef

The effect of gelatin-chitosan (GEL-CS) films supplemented with different concentration (0.1%, 0.2%, 0.3%) of Cyclocarya paliurus flavonoid (CPF) on the freshness of beef was investigated for 14 days at 4 °C. The results showed that CPF-added GEL-CS film maintained the freshness of beef better than GEL-CS film. The beef coated with CPF-added film maintained good color, pH, and texture during storage, and the total volatile base nitrogen (TVB-N) was 15.517 mg/100 g at day 14, which was 36.75 mg/100 g lower than that of the control group. In addition, the CPF-added film retarded the oxidation of lipids and proteins in beef compared to the GEL-CS film and promoted the retention of beef quality by inhibiting the deterioration reaction, with a TBA value of 0.33 mg MDA/kg at 14 days of storage, which was 2.081 mg MDA/kg lower than that of the control group. In addition, the CPF-added film showed higher antimicrobial activity against spoilage microorganisms compared to the GEL-CS film, thus further ensuring the edible quality of chilled beef. In conclusion, this study shows that CPF-added GEL-CS film can be used as a packaging film for beef preservation and effectively extend the shelf life of beef up to 14 days.

Cyclocarya paliurus leaves alleviate high-sucrose diet-induced obesity by improving intestinal metabolic disorders.

High-sucrose diets are common in daily life but harmful to human health. Cyclocarya paliurus leaves (CPL) are a kind of tea used to alleviate metabolic diseases and are widely used in China. However, the effects of CPL on high-sucrose-induced obesity are unknown. This study aimed to describe the changes in gut metabolism induced by a high-sucrose diet and to reveal the potential mechanisms through which CPL alleviate high-sucrose diet-induced obesity. A high-sucrose-induced obesity model was generated in C57BL/6J and KM mice. The effects of CPL on obese mice were evaluated, and changes in the gut microbiota and intestinal metabolites induced by CPL treatment were observed. Furthermore, the fecal microbiota transplantation (FMT) method was used to prove that the effects of CPL on high-sucrose induced obesity depend on the changes of gut microbiota. The results of the C57BL/6J mouse experiment revealed that high-sucrose intake induced fat deposition and altered the gut microbiota. CPL treatment decreased fat deposition and alleviated disorders of the gut microbiota. Furthermore, CPL treatment increased the utilization of amnio acids, long fatty acids and saccharides and produced more bile acids, indole derivatives and less trimethylamine (TMA). A confirmatory experiment in KM mice also revealed that CPL can alleviate obesity, ameliorate intestinal metabolic disorders, and upregulate the expression of tight junction proteins in the intestinal mucosa. These results demonstrated that CPL could prevent high sucrose-induced obesity and generate more beneficial intestinal microbial metabolites but less harmful intestinal microbial metabolites.