Lignan Glucosides and Serotonin Phenylpropanoids from the Seeds of Leuzea carthamoides

Exploring the anti-inflammatory, sedative, antidiabetic, and antioxidant potential in in-vitro and in-vivo models and phenolic profiling of Atractylis aristata Batt

ETHNOPHARMACOLOGICAL RELEVANCE

Atractylis aristata batt., as an endemic plant from the Asteraceae family, holds a significant position in the Ahaggar region of southern Algeria's traditional medicine. The aerial parts of Atractylis aristata was used to cure inflammation, fever, and stomach disorders.

AIM OF THE STUDY

The objective of the present investigation was to ascertain the overall bioactive components and phytochemical components and examine the antioxidant, antidiabetic, anti-inflammatory, acute toxicity, and sedative properties of the crude extract obtained from the aerial portions of Atractylis aristata (AaME).

MATERIALS AND METHODS

The AaME's antioxidant activity was assessed by the use of pyrogallol autoxidation, (1,1 diphenyl-2-picrylhydrazyl) (DPPH), 2,2'-azino-bis-(3-ethylbenzothiazoline-6-sulfonic acid (ABTS), and reducing power (RP) techniques. 1 mg/mL of AaME was used to evaluate the antidiabetic activity by applying the enzyme α-amylase inhibitory power test. At the same time, the bovine serum albumin (BSA) denaturation method was employed to quantify the in vitro anti-inflammatory activity at different concentrations (1.5625, 0.78125, 0.390625, 0.1953125 and 0.09765625 mg/mL). In contrast, following the Organization for Economic Co-operation and Development (OECD) guideline No. 423, which covers acute oral toxicity testing protocols, the limit dosage test was employed to assess in vivo acute toxicity. At the dose of 0.08 mg/mL, the carrageenan-induced paw edema approach was used to assess the anti-inflammatory efficacy in vivo, and the sedative activity was carried out at the dose of 0.08 mg/mL using the measurement of the locomotor method. Different bioactive compounds were identified within AaME using LC-MS/MS and HPLC-UV analysis.

RESULTS

The acute toxicity study showed no fatalities or noticeable neurobehavioral consequences at the limit test; this led to their classification in Globally Harmonized System (GHS) category Five, as the OECD guideline No 423 recommended. At a concentration of 0.08 mg/mL (2000 mg/kg), AaME showed apparent inhibition of paw edema and a significant (p = 0.01227) reduction in locomotor activity compared to the control animals. Our findings showed that AaME exhibited considerable antioxidant (IC50 = 0.040 ± 0.003 mg/mL (DPPH), IC50 = 0.005 ± 5.77 × 10-5 mg/mL (ABTS), AEAC = 91.15 ± 3.921 mg (RP) and IR% = 23.81 ± 4.276 (Inhibition rate of pyrogallol) and rebuts antidiabetic activities (I% = 57.6241% ± 2.81772). Our findings revealed that the maximum percentage of BSA inhibition (70.84 ± 0.10%) was obtained at 1.562.5 mg/mL. Thus, the AaME phytochemical profile performed using phytochemical screening, HPLC-UV, and LC-MS/MS analysis demonstrated that A. aristata can be a valuable source of chemicals with biological activity for pharmaceutical manufacturers.

CONCLUSION

The phytochemical profiling, determined through HPLC-UV and LC-MS/MS applications, reveals this plant's therapeutic value. The aerial parts of Atractylis aristata contain bioactive molecules such as gallic acid, ascorbic acid, and quercetin, contributing to its significant antioxidant capabilities. Furthermore, identifying alizarin, the active compound responsible for its anti-inflammatory properties, could provide evidence supporting the anti-inflammatory capabilities of this subspecies.

The Ethnopharmacological Uses, Metabolite Diversity, and Bioactivity of Rhaponticum uniflorum (Leuzea uniflora): A Comprehensive Review

Rhaponticum uniflorum (L.) DC. (syn. Leuzea uniflora (L.) Holub) is a plant species of the Compositae (Asteraceae) family that is widely used in Asian traditional medicines in China, Siberia, and Mongolia as an anti-inflammatory and stimulant remedy. Currently, R. uniflorum is of scientific interest to chemists, biologists, and pharmacologists, and this review includes information from the scientific literature from 1991 to 2022. The study of the chemodiversity of R. uniflorum revealed the presence of 225 compounds, including sesquiterpenes, ecdysteroids, triterpenes, sterols, thiophenes, hydroxycinnamates, flavonoids, lignans, nucleosides and vitamins, alkanes, fatty acids, and carbohydrates. The most studied groups of substances are phenolics (76 compounds) and triterpenoids (69 compounds). Information on the methods of chromatographic analysis of selected compounds, as well as on the quantitative content of some components in various organs of R. uniflorum, is summarized in this work. It has been shown that the extracts and some compounds of R. uniflorum have a wide range of biological activities, including anti-inflammatory, antitumor, immunostimulatory, anxiolytic, stress-protective, actoprotective, antihypoxic, anabolic, hepatoprotective, inhibition of PPARγ receptors, anti-atherosclerotic, and hypolipidemic. Published research on the metabolites and bioactivity of R. uniflorum does not include clinical studies of extracts and pure compounds; therefore, an accurate study of this traditional medicinal plant is needed.

Anti-inflammatory Constituents from Caulis Trachelospermi

Caulis Trachelospermi, the stems with leaves of Trachelospermum jasminoides, is a well-known herbal drug of the Apocynaceae family recorded in the Chinese pharmacopeia and used for the treatment of inflammation-related diseases by ethnic minorities of China. The mechanism of anti-inflammatory activity and responsible constituents of T. jasminoides have not been well elucidated in previous studies. Preliminary investigation showed that both the water and the ethyl ester extracts of T. jasminoides exhibited potent inhibitory activity on nitric oxide (NO) production using lipopolysaccharide (LPS)-stimulated murine macrophages. Phytochemical investigation on these extracts afforded 23 compounds, including three new compounds (1:  -3: ) identified on the basis of spectroscopic and mass spectrometric data. Anti-inflammatory bioassay showed that compounds 17, 18, 22: , and 23: inhibited significantly the production of NO in a concentration-dependent manner. Further studies indicated that compound 23: inhibited significantly TNF-α and IL-6 produced by LPS-stimulated RAW 264.7 cells with good selectivity, as well as protein expression of iNOS in RAW 264.7 cells. These chemical constituents may contribute to the anti-inflammatory potential of T. jasminoides.

Chemical Characterisation-Biological Evaluation of Greek Cultivar Cardoon Seeds (Cynara cardunculus). A By-product with Potential High Added Value

Cynara cardunculus (artichoke) is a perennial plant of the Mediterranean basin, known since antiquity as food and for its therapeutic properties. Cynara is a relatively small genus with two cultivated species and one wild one. Recently, successful efforts have been made to cultivate wild cardoon and monetise it as a bioenergy crop. In this study, the seeds of an established Greek cultivar of C. cardunculus, cultivated in the experimental field and used as biofuel, have been researched for their chemical profile and nutritional value. According to the results, six lignans were isolated [arctigenin, arctiin, trachelogenin, tracheloside, cynarinine, and ethylate of trachelogenin (isolated for the first time from a natural source)] as well as the most characteristic metabolites of the genus (linoleic acid, trilinolein, and 3,5-dicaffeoylquinic acid). Moreover, the total phenolic content (31.18 - 54.51 mg gallic acid equivalents/g extract) and antioxidant and enzyme inhibitory activities of the seeds have been evaluated and showed strong antioxidant properties (44.42 - 516.81 mg gallic acid equivalents/g extract) as well as satisfactory bleaching (enzyme tyrosinase, 16.95 - 23.80 mg kojic acid equivalents/g extract), antidiabetic (enzymes a-amylase, a-glucosidase, 0.14 - 1.75 mmol acarbose equivalents/g extract), and protective against neurodegenerative disease (cholinesterase enzymes, 0.49 - 1.22 mg galanthamine equivalents/g extract) activities. The nutritional evaluation of the seeds confirmed them as a rich source of unsaturated fatty acids, dietary fibre (24.1%), and high protein content (19.3%). It is noteworthy that such a neglected bioactive by-product, with essentially high nutritional value, as the studied seeds could be investigated for its value-added applications towards food and food supplements areas.

Alkaloids and phenylpropanoid from Rhizomes of Arundo donax L

A new bis-indole alkaloid, named arundaline (1), a new phenylpropanoid, named arundalcohol (2), and four known alkaloids, N-acetyltryptamine (3), trans-N-(p-coumaroyl)serotonin (4), trans-N-feruloylserotonin (5), and tuberosine B (6), were isolated from 70% aqueous ethanol extracts of the rhizomes of Arundo donax L. Their structures were elucidated by spectroscopic analysis and comparison of the data with literature values. Compounds 3-6 were isolated from the genus Arundo for the first time.

Chemodiversity of Cirsium fruits: Antiproliferative lignans, neolignans and sesquineolignans as chemotaxonomic markers

While analyzing the fruit composition of nine European Cirsium species representing three sections (i.e., Cephalonoplos, Chamaeleon and Eriolepis), four lignans, three neolignans and three sesquineolignans were determined and used as chemotaxonomic markers. Among them, desmethyl balanophonin and desmethyl picrasmalignan were determined for the first time in the plant kingdom, as the main metabolites of the Chamaeleon section. Prebalanophonin and prepicrasmalignan, identified so far exclusively in C. eriophorum, were also confirmed in C. boujartii and C. vulgare, highlighting the chemotaxonomic significance of these compounds in the Eriolepis section. The antiproliferative assay of the compounds isolated from their optimum sources, confirmed a dose-dependent inhibitory effect of the structures bearing the 4',7-epoxy moiety (balanophonin, picrasmalignan, desmethyl balanophonin, desmethyl picrasmalignan) against SW480 colon cancer cells, while those bearing the 4',7-dihydroxy motif (prebalanophonin, prepicrasmalignan) were inactive.

Ecdysterones from Rhaponticum carthamoides (Willd.) Iljin reduce hippocampal excitotoxic cell loss and upregulate mTOR signaling in rats

Glutamate-induced excitotoxicity is a key pathological mechanism in many neurological disease states. Ecdysterones derived from Rhaponticum carthamoides (Willd.) Iljin (RCI) have been shown to alleviate glutamate-induced neuronal damage; although their mechanism of action is unclear, some data suggest that they enhance signaling in the mechanistic target of rapamycin (mTOR) signaling pathway. This study sought to elucidate the mechanisms underlying ecdysterone-mediated neuroprotection. We used in silico target prediction and simulation methods to identify putative ecdysterone binding targets, and to specifically identify those that represent nodes where several neurodegenerative diseases converge. We then used histological analyses in a rat hippocampal excitotoxicity model to test the effectiveness of ecdysterones in vivo. We found that RCI-derived ecdysterones should bind to glutamatergic NMDA-type receptors (NMDARs); specifically, in vivo modeling showed binding to the GRIN2B subunit of NMDARs, which was found also to be a node of convergence in several neurodegenerative disease pathways. Computerized network construction by using pathway information from the Kyoto Encyclopedia of Genes and Genomes (KEGG) database showed putative links between GRIN2B and mTOR pathway elements including phosphoinositide-3kinase (PI3K), mTOR, and protein kinase C (PKC); these elements are associated with neuronal survival. Brain tissue western blots of ecdysterone-treated rats showed upregulated PI3K, Akt, mTOR, and phosphorylated Akt and mTOR, and down regulated GRIN2B and the apoptotic enzyme cleaved caspase-3. Ecdysterone treatment also prevented glutamate-induced rat hippocampal cell loss. In summary, RCI-derived ecdysterones appear to prevent glutamatergic excitotoxicity by increasing mTOR/Akt/PI3K signaling activity.

Enzyme-hydrolyzed Fruit of Jurinea mollis: A Rich Source of (-)-(8R,8′R)-Arctigenin

In Jurinea mollis fruit, the dibenzylbutyrolactone-type lignan glycoside arctiin and its aglycone arctigenin were determined for the first time using a combination of optimized enzymatic treatment and complementary spectrometric (HPLC-MS, GC-MS) and spectroscopic (CD and NMR) methods. Analysis of separated fruit parts, i.e., the fruit wall and embryo, demonstrated the specific accumulation of arctiin, since it was exclusively found in the embryo. Arctiin in the embryo samples (71.5 mg/g) was found to be quantitatively converted into arctigenin (50.7 mg/g) by endogenous enzymatic hydrolysis, resulting in one of the highest arctigenin-containing plant tissues reported to date and allowing the selective isolation of arctigenin by our recently reported three-step isolation method. The absolute configuration of the isolated arctigenin was determined to be (-)-(8 R,8′ R). Conformational analysis of arctigenin was also performed, resulting in three major low energy conformations.

On the pharmacology of oxidative burst of human neutrophils

The effect of three therapeutically used drugs and five polyphenolic compounds on the mechanism of oxidative burst was compared in whole blood and isolated neutrophils at cellular and molecular level. In 10 microM concentration, the compounds investigated decreased the oxidative burst of whole blood in the rank order of potency: N-feruloylserotonin (N-f-5HT) > curcumin (CUR) > quercetin (QUER) > arbutin (ARB) > resveratrol (RES) > dithiaden (DIT) > carvedilol (CARV) > brompheniramine (BPA). The ratio between the percentage inhibition of extracellular versus intracellular chemiluminescence (CL) followed the rank order QUER > N-f-5HT > RES > CUR > DIT and is indicative of the positive effect of the compounds tested against oxidative burst of neutrophils, demonstrating suppression of reactive oxygen species extracellularly with minimal alteration of intracellular reactive oxygen species (ROS). Activation of protein kinase C was significantly decreased by DIT, CUR, QUER and N-f-5HT. CARV, DIT, QUER and ARB reduced activated neutrophil myeloperoxidase release more significantly compared with the effect on superoxide anion generation. All compounds tested increased the activity of caspase-3 in cell-free system. It is suggested that other regulatory mechanisms than protein kinase C might participate in the inhibition of neutrophil activation with the compounds tested. Different mechanisms are concerned in controlling the assembly of NADPH oxidase and the regulatory role of calcium ions is suggested. Compounds decreasing the amount of extracellular ROS generation, yet affecting but minimally intracellular ROS generation, are promising for further investigation in vivo.

Effect of N-Feruloylserotonin and Methotrexate on Severity of Experimental Arthritis and on Messenger RNA Expression of Key Proinflammatory Markers in Liver

Rheumatoid arthritis (RA) is a chronic inflammatory disease, leading to progressive destruction of joints and extra-articular tissues, including organs such as liver and spleen. The purpose of this study was to compare the effects of a potential immunomodulator, natural polyphenol N-feruloylserotonin (N-f-5HT), with methotrexate (MTX), the standard in RA therapy, in the chronic phase of adjuvant-induced arthritis (AA) in male Lewis rats. The experiment included healthy controls (CO), arthritic animals (AA), AA given N-f-5HT (AA-N-f-5HT), and AA given MTX (AA-MTX). N-f-5HT did not affect the body weight change and clinical parameters until the 14th experimental day. Its positive effect was rising during the 28-day experiment, indicating a delayed onset of N-f-5HT action. Administration of either N-f-5HT or MTX caused reduction of inflammation measured as the level of CRP in plasma and the activity of LOX in the liver. mRNA transcription of TNF-α and iNOS in the liver was significantly attenuated in both MTX and N-f-5HT treated groups of arthritic rats. Interestingly, in contrast to MTX, N-f-5HT significantly lowered the level of IL-1β in plasma and IL-1β mRNA expression in the liver and spleen of arthritic rats. This speaks for future investigations of N-f-5HT as an agent in the treatment of RA in combination therapy with MTX.

Optimum yields of dibenzylbutyrolactone-type lignans from Cynareae fruits, during their ripening, germination and enzymatic hydrolysis processes, determined by on-line chromatographic methods

INTRODUCTION

Dibenzylbutyrolactone-type lignans are the physiologically active constituents of the achene fruits of Cynareae. These lignans occur in glycoside/aglycone forms: in the highest quantity of the arctiin/arctigenin, matairesinoside/matairesinol and tracheloside/trachelogenin pairs found in the fruits of Arctium lappa L., Centaurea scabiosa L. and Cirsium arvense (L.) Scop.

OBJECTIVE

To optimise the extraction yield of the arctiin/arctigenin, matairesinoside/matairesinol and tracheloside/trachelogenin glycoside/aglycone pairs, from the fruits of Arctium lappa, Centaurea scabiosa and Cirsium arvense, under the ripening, germination and enzymatic hydrolysis processes of the fruits.

METHODOLOGY

Identification and quantification of lignans were performed with on-line gas chromatography-mass spectrometry (GC-MS) and with high performance liquid chromatography (HPLC), both with UV and mass selective detections (HPLC-UV/MS).

RESULTS

As novelties to the field it was confirmed that: (i) the unripe fruits provide a high amount of lignans, similar to the ripe fruit; (ii) the fruits of Arctium lappa and Cirsium arvense do have glycosidase activity to hydrolyse their lignan glycosides into free lignans; (iii) the glycosidase of Centaurea scabiosa fruit becomes activated under its germination process only; and (iv) the overwhelming part of the fruits lignan contents (80-94%) in all three species are accumulated in the embryo.

CONCLUSION

The best sources of (i) lignan aglycones are the enzyme-hydrolysed embryos, separating spontaneously during the germination process, and (ii) lignan glycosides are the unripe fruits.

Naturally appearing N-feruloylserotonin isomers suppress oxidative burst of human neutrophils at the protein kinase C level

N-feruloylserotonin (N-f-5HT) isomers, isolated from seeds of Leuzea carthamoides (Wild) DC, inhibited dose-dependent oxidative burst in human whole blood and isolated neutrophils in vitro, which were measured by luminol- and/or isoluminol-enhanced chemiluminescence in the following rank order of stimuli: PMA > OpZ > calcium ionophore A23187. In isolated neutrophils that were stimulated with PMA, N-f-5HT isomers were effective against extracellular and intracellular reactive oxygen species. Liberation of ATP, analysis of apoptosis, and recombinant caspase-3 activity revealed that N-f-5HT isomers, used in concentrations up to 100 μM, did not alter the viability and integrity of isolated neutrophils. Western blot analysis documented that in concentrations of 10 and 100 μM, N-f-5HT isomers significantly decreased PMA-induced phosphorylation of PKC α/β II. The results suggest that N-f-5HT isomers are an effective, naturally occurring substance with a potent pharmacological effect on the oxidative burst of human neutrophils. It should be further investigated for its pharmacological activity against oxidative stress in ischemia-reperfusion, inflammation and other pathological conditions.

Immunobiological properties of selected natural and chemically modified phenylpropanoids

Effects of natural and structurally transformed lignans compared with stilbenes or stilbenoids on production of nitric oxide (NO) triggered by lipopolysaccharide (LPS) and interferon-γ (IFN-γ), tested under in vitro conditions using murine resident peritoneal macrophages, are reviewed. Relation between the molecular structure and immunobiological activity was investigated, and implication of substituents, double bond stereochemistry, or cyclic attachments (double bond geometry fixation) was assessed. The focus was on lignans and stilbenoids because they were originally selected for a joint project of common interest to phytochemical and pharmacological investigation and because they represent well interesting and universally attractive groups of polyphenols with a feasible potential for therapeutic or nutraceutic utilization.

Lack of interference of common phytoecdysteroids with production of nitric oxide by immune-activated mammalian macrophages

Effects of selected common phytoecdysteroids on immunobiological responses triggered by lipopolysaccharide and interferon-gamma (IFN-gamma) were tested under in vitro conditions using murine resident peritoneal macrophages. Namely, production of nitric oxide was investigated. The series of test agents encompassed ecdysteroids occurring often as major components of the ecdysteroid fraction in numerous plant extracts: 20-hydroxyecdysone (20E), polypodine B, ajugasterone C, ponasterone A and inokosterone. Their structural variability concerns only variation in the number and position of hydroxyls. Two additional side-chain modified ecdysteroids: makisterone A (with a methyl substituent at position 24) and carthamosterone (with a cyclic side-chain lactone), and three ecdysteroid analogs: poststerone, rubrosterone and dihydrorubrosterone (devoid of side chains) were included into the test series. All test compounds, except of ponasterone A, represent natural substances isolated from the medicinal plant Leuzea carthamoides and are supposed to be significant for the often reported pharmacological activities of preparations derived from this species. However, the tested ecdysteroids did not interfere with the immunobiological activity of the immunocompetent cells. Our results thus differ from the so far reported information.

The selective effect of N-feruloylserotonins isolated from Leuzea carthamoides on nociception and anxiety in rats

The effects of N-feruloylserotonins, substances isolated from the seeds of Leuzea carthamoides (WILLD.) DC., on nociception and anxiety were studied in Wistar rats. Nociceptive responses were measured using the plantar and tail-flick tests which were administered before and after swimming stress (3 min, water temperature 32 degrees C). Anxiety was evaluated using an elevated plus maze. In Experiment I, neither basal nociception nor stress-induced analgesia was influenced significantly. Separating the animals into groups based on their basal nociceptive sensitivity, either high- or low-pain threshold revealed that N-feruloylserotonins have selective effects, especially on rats with high-pain thresholds. In these animals, N-feruloylserotonins reduced the stress-induced analgesia that followed swimming stress. In Experiment II, basal nociceptive sensitivity correlated with indicators of anxiety; high-pain threshold rats were more anxious in the elevated plus maze, with less frequent visits to open arms. The opposite effect was seen in low-pain threshold rats. N-feruloylserotonins did not influence anxiety in low-pain threshold rats, although it reduced anxiety in the high-pain threshold rats as indicated by the increased ratio of open arm visit frequency compared to closed arm visit frequency in the elevated plus maze. From these results we concluded that N-feruloylserotonins have selective stress-reducing effects in stress-sensitive animals.