Isolation and identification of terpenoids from chicory roots and their inhibitory activities against yeast α-glucosidase

Chemical profile of Rhododendron luteum Sweet leaf supercritical CO2 extracts and their anti-inflammatory and antidiabetic potential

Introduction

Terpenes are a diverse class of natural metabolites that exhibit a range of biological activities, including antidiabetic, antiproliferative, and anti-inflammatory effects. The present study was designed to determine the chemical profile and biological activity of Rhododendron luteum leaf (RLL) supercritical CO2 (SC-CO2) extracts.

Materials and methods

The LC-APCI-MS/MS method was used to determine the composition and content of the triterpenes (including sterols). In turn, LC-ESI-MS/MS was applied for the analysis of polyphenolic compounds. The volatile composition of RLL extracts was analysed using the HS-SPME-GC-FID-MS technique. The inhibitory activity against enzymes such as xanthine oxidase (XO), lipoxygenase (LOX), hyaluronidase, α-amylase, and α-glucosidase was assessed using in vitro bioassays.

Results and discussion

The LC-MS analyses revealed high levels of oleanolic acid, ursolic acid, and β-sitosterol, which belong to terpenes, as well as polyphenols such as syringic acid, ferulic acid, and p-coumaric acid, along with apigenin and its 7-glucoside. Among volatiles, the most prominent were limonene, eugenol, β-phenylethanol, and β-caryophyllene. In vitro assays showed a high hyaluronidase and moderate lipoxygenase and xanthine oxidase inhibitory activity presented by RLL supercritical extracts. Moreover, the samples were found to present α-glucosidase inhibitory activity. This may indicate the anti-inflammatory and antidiabetic potential of RLL supercritical extracts.

Sesquiterpene lactones from Cichorium intybus exhibit potent anti-inflammatory and hepatoprotective effects by repression of NF-κB and enhancement of NRF2

ETHNOPHARMACOLOGICAL RELEVANCE

Cichorium intybus is a traditional medicinal herb for hepatitis treatment in China and Europe. Sesquiterpene lactones are the main active ingredients in C. intybus. However, their structure-activity relationship (SAR) and molecular mechanisms of anti-inflammatory and hepatoprotective effects require further elucidation.

AIM OF THE STUDY

To identify new sesquiterpene lactones from C. intybus, and further evaluate their anti-inflammatory effects, SAR, and mechanisms of anti-inflammatory and hepatoprotective properties.

METHODS

Identification of sesquiterpene lactones from C. intybus using chromatographic fractionation, NMR, and mass spectrometry. The repression of inflammation was evaluated in RAW264.7 macrophages incubated with LPS. Western blotting was employed to investigate the anti-inflammatory mechanisms. The hepatoprotective effect was measured in LPS/D-galactosamine (D-GalN)-induced acute hepatitis in mice.

RESULTS

We identified 3 new sesquiterpene lactones and 15 known analogues from C. intybus. SAR analysis showed that the α-methylene-γ-lactone moiety was essential for their anti-inflammatory properties. Furthermore, 8-deoxylactucin was identified as the most potent anti-inflammatory component in LPS-induced RAW264.7 macrophages by reduction of nitric oxide production via inhibiting iNOS expression, and suppression of IL-1β, IL-6, and TNF-α expression. Mechanistically, 8-deoxylactucin not only blocked LPS-induced IKKα/β phosphorylation, IκBα phosphorylation and degradation, and NF-κB nuclear accumulation, but also enhanced NRF2 expression and nuclear translocation, HO-1 and NQO1 expression, and reduced ROS generation in vitro. In vivo, 8-deoxylactucin mitigated LPS/D-GalN-induced acute hepatitis, which manifested as reduction in inflammatory infiltration, live injury, serum levels of AST and ALT, and production of pro-inflammatory cytokines and 4-hydroxynonenal.

CONCLUSION

8-Deoxylactucin, the sesquiterpene lactone isolated from C. intybus, exerted anti-inflammatory and hepatoprotective effects by blocking NF-κB activation and enhancing NRF2 activation.

Amelioration of metabolic syndrome in high-fat diet-fed mice by total sesquiterpene lactones of chicory via modulation of intestinal flora and bile acid excretion

Chicory (Cichorium intybus L.) is a commonly used vegetable in Europe and is also regarded as a plant for both medicinal and edible uses in China. Chicory exhibits a substantial abundance of sesquiterpene lactone compounds within its composition. The prevalence of metabolic syndrome (MetS) is increasing and has become a global public health issue threatening the well-being of the general population. Recent studies have identified plant secondary metabolites as potential substances for treating MetS. Sesquiterpene lactones, a type of secondary metabolite with diverse biological activities, have been reported to exhibit anti-inflammatory effects, reduce lipid accumulation, and normalize blood glucose levels. However, the therapeutic effects of chicory sesquiterpene lactones on MetS remain to be explored, and little is known about sesquiterpene lactones' effects on intestinal flora and bile acids (BAs). Therefore, the effects of total sesquiterpene lactones (TSLs) from chicory on metabolic disorders, intestinal flora, and BAs were investigated in this study. In this study, C57BL/6J mice were fed a high-fat diet (HFD) for 8 weeks, followed by administration of TSLs, total chicory extract (TCE), and pioglitazone (Pio) for another 8 weeks. TSL, TCE, and Pio interventions reduced body weight gain, hepatic lipid accumulation, and lipogenesis in HFD-fed mice and attenuated plasma biochemical parameters. Among them, TSLs exhibited more significant effects, prompting further analysis of their impact on intestinal flora and bile acid metabolism. TSL intervention influenced the composition and structure of intestinal flora and BAs. TSL intervention impacted the composition and structure of the intestinal flora, characterized by a decrease in the abundances of Allobaculum, unidentified_Coriobacteriaceae, and Odoribacter, while the abundances of Prevotella, unidentified_Erysipelotrichaceae and Akkermansia were increased. Additionally, the levels of BAs TCDCA, GDCA, UDCA, 12-ketoLCA, 7-ketoLCA, and 6,7-diketoLCA were reduced. The research results indicated that TSLs from chicory may serve as potential agents for regulating metabolic abnormalities associated with MetS, as their effects can influence intestinal flora and BAs. The conclusions of this study are expected to open new research trajectories in the field of food science and nutrition, providing a solid scientific basis and innovative intervention approaches for the development of strategies targeting MetS prevention and management.

The Antidiabetic Effect of Grape Skin Extracts of Selected Indigenous Croatian White Grapevine Varieties

Grape skin is an excellent bioactive compound source with numerous beneficial health effects. This study aimed to determine and compare the antidiabetic potential of the grape skin of indigenous Croatian white grapevine varieties. The grape skin extracts (GSEs) were assessed for total polyphenols, antioxidant activity, and inhibition potential against α-amylase and α-glucosidase, enzymes responsible for carbohydrate metabolism. GSE of variety "Svetokriška belina" has the highest total phenols (TP) content (1404.87 mg of gallic acid equivalent), the highest antioxidant capacity against DPPH (544.82 mg ascorbic acid equivalent), and the highest inhibitory activity against α-amylase (99.60%). α-glucosidase was best inhibited by the variety "Kozjak" (93.53%), followed by a significantly lower inhibition by the GSE of "Svetokriška belina" (89.64%). The principal component analysis (PCA) revealed the relationship among the grape varieties by their inhibition potential, where the first PC explained 71.34% of the variation. Indigenous Croatian white grapevine varieties have great potential for developing new natural supplements to prevent and treat diabetes.

One new 12, 8-guaianolide sesquiterpene lactone with antihyperglycemic activity from the roots of Cichorium intybus

Three 12, 8-guaianolide sesquiterpene lactones, including a new compound intybusin F (1), and a new natural product cichoriolide I (2), along with six known 12, 6-guaianolide compounds (4-9) were isolated from the roots of Cichorium intybus L. Their structures were determined by extensive spectroscopic analysis. The absolute configurations of new compounds were elucidated based on analysis of the experimental and calculated electronic circular dichroism spectra. Compounds 1, 2, 4, 7, 8 showed significant effects on facilitating the glucose uptake in oleic acid plus high glucose-stimulated HepG2 cells at 50 μM. In addition, compounds 1, 2, 3, 6, 7 exhibited obvious inhibitory effects against NO production, of them, compounds 1, 2, 7 can significantly decrease the secretion of inflammatory cytokines (TNF-α, IL-6 and COX-2) levels in this hyperglycemic HepG2 cell model.

Discovery of potential mTOR inhibitors from Cichorium intybus to find new candidate drugs targeting the pathological protein related to the breast cancer: an integrated computational approach

Breast cancer is the most common malignancy among women. It is a complex condition with many subtypes based on the hormone receptor. The mammalian target of the rapamycin (mTOR) pathway regulates cell survival, metabolism, growth, and protein synthesis in response to upstream signals in both normal physiological and pathological situations, primarily in cancer. The objective of this study was to screen for a potential target to inhibit the mTOR using a variety of inhibitors derived from Cichorium intybus and to identify the one with the highest binding affinity for the receptor protein. Initially, AutoDock Vina was used to perform structure-based virtual screening, as protein-like interactions are critical in drug development. For the comparative analysis, 110 components of Cichorium intybus were employed and ten FDA-approved anticancer medicines, including everolimus, an mTOR inhibitor. Further, the drug-likeness and ADMET properties were investigated to evaluate the anti-breast cancer activity by applying Lipinski's rule of five to the selected molecules. The promising candidates were then subjected to three replica molecular dynamics simulations run for 100 ns, followed by binding free energy estimation using MM-GBSA. The data were analyzed using root-mean-square deviation (RMSD), root-mean-square fluctuation (RMSF), and protein-ligand interactions to determine the stability of the protein-ligand complex. Based on the results, taraxerone (98) revealed optimum binding affinities with mTOR, followed by stigmasterol (110) and rutin (104), which compared favorably to the control compounds. Subsequently, bioactive compounds derived from Cichorium intybus may serve as lead molecules for developing potent and effective mTOR inhibitors to treat breast cancer.

Sesquiterpene lactones with anti-inflammatory and cytotoxic activities from the roots of Cichorium intybus

Cichorium intybus L. (Asteraceae), belonging to the tribe Cichorieae of the family Asteraceae, has a long history as an edible and medicinal food. Sesquiterpene lactones are commonly considered as its major active constituents. In the current study, five unreported sesquiterpene lactones, including one 12,8-guaianolide and four 12,6-guaianolides were isolated from C. intybus roots, as well as 16 known analogues. The planar structures and relative configurations of these compounds were elucidated by extensive spectroscopic analysis. The absolute configurations were determined by the time-dependent density functional theory (TDDFT)-based electronic circular dichroism (ECD) calculation method. Bioassay results showed that seven of the isolates exhibited remarkable NO production inhibitory activity in LPS-stimulated RAW264.7 macrophages, with IC50 values ranging from 1.83 to 38.81 μM. Some of them can significantly decrease the secretion of inflammatory cytokines (TNF-α and IL-6). Cytotoxicity assays demonstrated that intybusins B, as well as four known compounds, displayed obvious inhibitory activities against four human tumor cells, with IC50 values ranging from 9.01 to 27.07 μM.

Chicory (Cichorium intybus L.) as a food ingredient - Nutritional composition, bioactivity, safety, and health claims: A review

Chicory (Cichorium intybus L.) is a perennial herb from the Cichorium genus, Asteraceae family, and is worldwide cultivated. So far, chicory has been used mainly in animal feed, but also in several cases in the food industry: as salad, for teas and tea blends, for coffee supplementation, and as a source for the inulin production. Nowadays there is an increasing interest in chicory utilization for food production and supplementation. Some compounds present in chicory, such as polyphenols, inulin, oligofructose and sesquiterpene lactones may be considered as potential carriers of food functionality. This review describes nutritional, mineral and bioactive composition of the chicory plant and summarized the main biological activities associated with the presence of bioactive compounds in the different plant parts. Finally, the review explores possibilities of uses of chicory and its implementation in food products, with intention to design new functional foods.

Phytochemical Profile, Antioxidant, Cardioprotective and Nephroprotective Activity of Romanian Chicory Extract

The present study analyzed the methanol extract and tincture obtained from the spontaneous Romanian Cichorium intybus species, in order to evaluate polyphenols content and some biological properties. Chromatographic and spectrophotometric methods were used for the analysis of polyphenols and the antioxidant capacity was assessed in vitro with DPPH● (2,2-diphenyl-picrylhydrazil) and FRAP (ferric-reducing antioxidant power) tests. The cardio-protective effects of Cichorii herba tincture on myocardial ischemia induced by isoprenaline and nephroprotection on renal failure induced by gentamicin were evaluated on rats. Also, aspartate aminotrasferase (AST), alanine aminotransferase (ALT), creatine kinase-MB (CK-MB) and creatinine clearance (CrCl) were measured. The antioxidant effect was evaluated by determining total oxidative stress (TOS), oxidative stress index (OSI, total antioxidant capacity (TAC), malondyaldehide (MDA), total thiols (SH) and total nitrites and nitrates (NOx). Cichoric acid was the main polyphenolic compound. The extracts had moderate in vitro antioxidant activity but the in vivo antioxidant and anti-inflammatory effects were significant and associated with myocardial and renal dysfunction improvement. The results were attributed to the content of polyphenols in the extracts, for which reason C. intybus may be considered an important raw material for pharmaceuticals formulations recommended in the prevention or treatment of heart or kidney diseases.

Systematic investigation of the mechanism of Cichorium glandulosum on type 2 diabetes mellitus accompanied with non-alcoholic fatty liver rats

Cichorium glandulosum(CG) can treat various diseases with multiple targets effectively. It has been widely used in folk medicine to treat nonalcoholic fatty liver disease (NAFLD) as well as type 2 diabetes mellitus (T2DM). However, the active compounds and underlying mechanisms of CG on T2DM accompanied with NAFLD (T2DM-NAFLD) remain unclear. In this study, a systems pharmacology method was used to explain the pharmacology mechanism of CG for treatment of T2DM-NAFLD. Twenty four main compounds were detected by UPLC-Q-TOF-MS, of which 13 showed favorable pharmacokinetic profiles. We demonstrated with target fishing and pathway analysis that CG has protective effects on T2DM-NAFLD, probably through the regulation of 88 targets and 86 pathways. Forty nine targets were related to T2DM, and 39 were related to NAFLD, while 27 targets, primarily involved in insulin resistance and inflammation were common to T2DM and NAFLD related pathways. A NF-κB signaling pathway was chosen to validate the impacts of CG on T2DM-NAFLD because CG can ameliorate T2DM-NAFLD by regulating the NF-κB signaling pathway according to animal experiments. These findings systematically interpreted the active compounds and mechanism of the efficiency of CG for treating T2DM-NAFLD. This study not only laid a basis for understanding the active compounds and action mechanism of CG, but also provides a reference for a study of the mechanism of a herbal medicine for the treatment of multiple diseases.

Thermal inactivation kinetics and effects of drying methods on the phenolic profile and antioxidant activities of chicory (Cichorium intybus L.) leaves

The thermal inactivation kinetics of enzymes, including polyphenol oxidase (PPO) and peroxidase (POD), in chicory (Cichorium intybus L.) leaves were evaluated. In addition, the influences of different drying techniques (shade drying, hot air drying and freeze drying) on the phenolic profiles and antioxidant activities of chicory leaves were determined. The antioxidant activities of chicory leaves were evaluated on the basis of their 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activity, reducing power, and 2,2-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging activity. The results showed that the activation energy for PPO and POD inactivation were 123.00 kJ/mol and 78.99 kJ/mol, respectively. Preliminary treatment with hot water for 3 min at 90 °C was beneficial for preserving the phenolics present in fresh leaves. Hot air drying was better for the phenolics preservation. The hot air-dried and freeze-dried leaves possessed good antioxidant activities. The leaves with higher phenolics contents had better antioxidant activities, which indicated that the preservation of the phenolics was important for maintaining the antioxidant activity of chicory leaves.

Chemical and biological studies on Cichorium intybus L

Cichorium intybus L. (Asteraceae family) is a world-wide grown plant known as chicory. In traditional medicine, this plant is used as diuretic, anti-inflammatory, digestive, cardiotonic and liver tonic. Chromatographic purification of the supercritical fluid extract of aerial parts of C. intybus on silica gel column led to isolation of three compounds: new compound, 28β-hydroxytaraxasterol (I), and two known compounds usnic acid (II) and β-sitosterol (III). Purification of the ethanolic extract of aerial parts of this plant on silica gel column chromatography yielded four compounds: 1,3-dioleylglycerate (IV), sitoindoside II (V), 11β-13-dihydrolactucin (VI) and β-sitosterol-3-O-glucoside (VII). The structures of the isolated compounds were determined by their 1D, 2D NMR and MS spectral data. All the fractions and isolated compounds were tested for cannabinoid and opioid receptor binding, as well as antibacterial, antifungal and antimalarial activities. Compound I showed moderate activity (60.5% displacement) towards CB1 receptor.