Cerebrosides from the roots of Serratula chinensis

An inulin-type fructan isolated from Serratula chinensis alleviated the dextran sulfate sodium-induced colitis in mice through regulation of intestinal barrier and gut microbiota

Herein, we aimed to explore the polysaccharide material basis of Serratula chinensis and establish its beneficial effects against colitis. A neutral polysaccharide (SCP) was extracted from S. chinensis in high yield using hot water. The molecular weights were calculated by HPSEC as Mw = 2928 Da, Mn = 2634 Da, and Mw/Mn = 1.11. FT-IR and 1D/2D-NMR spectroscopic analyses confirmed that SCP was an inulin-type fructan with α-D-Glcp-(1 → [1)-β-D-Fruf-(2]17) linkages. Treatment with SCP (200 or 400 mg/kg) alleviated dextran sulfate sodium (DSS)-induced mouse colitis symptoms, including the loss of body weight, increase of disease activity index score, and shortening of colon length. Histopathological and immunofluorescence assessments revealed that SCP could reduce pathological damage to the colon, restore the number of goblet cells, increase the content of glycoproteins in goblet cells and mucins in crypts, and enhance the expression of tight junction proteins ZO-1 and occludin. In addition, metagenomic sequencing revealed that SCP could improve the dysbiosis of gut microbiomes and act on multiple microbial functions. Moreover, SCP treatment increased the content of colonic acetic acid and butanoic acid. Collectively, these results indicated that SCP could alleviate the DSS-induced colitis in mice through regulation of intestinal barrier and gut microbiota.

Antileishmanial and Antiplasmodial Activities of Secondary Metabolites from the Root of Antrocaryon klaineanum Pierre (Anacardiaceae)

Antrocaryon klaineanum is traditionally used for the treatment of back pain, malaria, female sterility, chlamydiae infections, liver diseases, wounds, and hemorrhoid. This work aimed at investigating the bioactive compounds with antileishmanial and antiplasmodial activities from A. klaineanum. An unreported glucocerebroside antroklaicerebroside (1) together with five known compounds (2-6) were isolated from the root barks of Antrocaryon klaineanum using chromatographic techniques. The NMR, MS, and IR spectroscopic data in association with previous literature were used for the characterization of all the isolated compounds. Compounds 1-4 are reported for the first time from A. klaineanum. The methanol crude extract (AK-MeOH), the n-hexane fraction (AK-Hex), the dichloromethane fraction (AK-DCM), the ethyl acetate fraction (AK-EtOAc), and compounds 1-6 were all evaluated for their antiparasitic effects against Plasmodium falciparum strains susceptible to chloroquine (3D7), resistant to chloroquine (Dd2), and promastigotes of Leishmania donovani (MHOM/SD/62/1S). The AK-Hex, AK-EtOAc, AK-MeOH, and compound 2 were strongly active against Dd2 strain with IC₅₀ ranging from 2.78 ± 0.06 to 9.30 ± 0.29 µg/mL. Particularly, AK-MeOH was the most active-more than the reference drugs used-with an IC₅₀ of 2.78 ± 0.06 µg/mL. The AK-EtOAc as well as all the tested compounds showed strong antileishmanial activities with IC₅₀ ranging from 4.80 ± 0.13 to 9.14 ± 0.96 µg/mL.

Three new 30-norfriedelane and a new friedelane triterpenes from the trunk bark of Caloncoba welwitschii (Oliv.) Gilg (Achariaceae)

Phytochemical investigation of the methanolic extract of the trunk bark of Caloncoba welwitschii (Oliv.) Gilg (Achariaceae) led to the isolation of four new compounds, including three new 30-norfriedelane triterpenes, welwitschiilactones D-F (1-3), one new friedelane triterpene, welwitschioic acid (4) as well as ten known compounds: stigmastane-3,6-dione (7), a mixture of β-sitosterol and stigmasterol (6a and 6b), a mixture of β-sitosterol and stigmasterol glucoside (11a and 11b), (2S,3S,4R,5R)-N-(1,3,4,5-tetrahydroxyndecan-2-yl)tetradecanamide (10), 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2'R)-2-hydroxylpalmitoylamino]-8-octadecene-1,3-diol (12), 3β,21β-dihydroxy-27-oxo-30-nor-(D:A)-friedo-olean-20(29))en-27,19α-lactone (8), 21β-hydroxy-3,27-dioxo-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (9) and 2β,21β-dihydroxy-27-oxo-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (5). The structures of all the isolated compounds were determined by extensive spectroscopic analyses (1D and 2D NMR as well as ESI-MS). The relative configuration of the 20-oxymethine in 1 as well as that of 19-oxymethine in 2 and 3 has been established using the NOESY spectrum. In an experiment, a sample of welwitschiilactone C (5) was chemically modified through reduction reaction to give a new hemi-synthetic derivative namely 2β,3β,21β-trihydroxy-30-nor-(D:A)-friedo-olean-20(29)-en-27,19α-lactone (5a).

Metabolites of Serratula L. and Klasea Cass. (Asteraceae): Diversity, Separation Methods, and Bioactivity

Serratula L. and Klasea Cass. are two systematically related genera of the family Asteraceae, which are distributed in most of the Eurasia area and are used as food and colorants and in traditional medicines as a drug. Since 1967, 261 metabolites have been isolated and identified from five Serratula species and 21 Klasea species. This review provides information on the chemodiversity of the terpenes, penolics, lipids, and other compounds found in both genera and their occurrence in individual species. Among the studied species, the most studied are S. coronata subsp. coronata, K. centauroides, and K. centauroides subsp. centauroides. This review also provides information on the methods of extraction, isolation, and analysis of ecdysteroids and flavonoids as the most valuable metabolites. For the first time, we provide general information about the biological activity of these extracts and individual compounds. The data presented in this review demonstrate the prospects of Serratula and Klasea species as sources of bioactive metabolites.

Phytoecdysteroids: Distribution, Structural Diversity, Biosynthesis, Activity, and Crosstalk with Phytohormones

Phytoecdysteroids (PEs) are naturally occurring polyhydroxylated compounds with a structure similar to that of insect molting hormone and the plant hormone brassinosteroids. PEs have a four-ringed skeleton composed of 27, 28, 29, or 30 carbon atoms (derived from plant sterols). The carbon skeleton of ecdysteroid is known as cyclopentanoperhydrophenanthrene and has a β-sidechain on C-17. Plants produce PEs via the mevalonate pathway with the help of the precursor acetyl-CoA. PEs are found in algae, fungi, ferns, gymnosperms, and angiosperms; more than 500 different PEs are found in over 100 terrestrial plants. 20-hydroxyecdysone is the most common PE. PEs exhibit versatile biological roles in plants, invertebrates, and mammals. These compounds contribute to mitigating biotic and abiotic stresses. In plants, PEs play a potent role in enhancing tolerance against insects and nematodes via their allelochemical activity, which increases plant biological and metabolic responses. PEs promote enzymatic and non-enzymatic antioxidant defense systems, which decrease reactive oxygen species in the form of superoxide radicals and hydroxyl radicals and reduce malondialdehyde content. PEs also induce protein biosynthesis and modulate carbohydrate and lipid synthesis. In humans, PEs display biological, pharmacological, and medicinal properties, such as anti-diabetic, antioxidant, anti-microbial, hepatoprotective, hypoglycemic, anti-cancer, anti-inflammatory, antidepressant, and tissue differentiation activity.

Chloroform fraction of Serratulae chinensis S. Moore suppresses proliferation and induces apoptosis via the phosphatidylinositide 3-kinase/Akt pathway in human gastric cancer cells

The chloroform fraction of the folk Chinese medicine, Serratulae chinensis S. Moore (CSC) and its anti-inflammatory activity is well recognized. However, the molecular mechanisms underlying the beneficial anticancer effects of CSC remain largely unknown. The aim of the present study was to examine the effects of CSC on the regulation of cell proliferation and apoptosis in SGC-7901 gastric cancer cells, as well as to investigate the underlying molecular mechanisms involved. The results from the present study demonstrated that CSC treatment inhibited SGC-7901 cell viability and survival in a dose- and/or time-dependent manner. CSC treatment further induced the apoptosis of SGC-7901 cells, characterized by distinct chromatin condensation and fragmented nuclear morphology. In addition, CSC treatment suppressed protein kinase-B (Akt) phosphorylation and phosphatidylinositide 3-kinase (PI3K) expression in SGC-7901 cells, which in turn promoted cancer cell apoptosis and inhibited cell proliferation. Furthermore, CSC treatment altered the expression pattern of several key target genes of the PI3K/Akt signaling pathway through the downregulation of Cyclin D1, cyclin-dependent kinase-4 and B-cell lymphoma-2 and the upregulation of Bcl-2-associated X protein. Therefore, the results from the present study demonstrated that CSC suppressed cell survival and induced apoptosis in human gastric cancer cells, via targeting the PI3K/Akt pathway.

Iridoids and sfingolipids from Hedyotis diffusa

Seven new compounds were isolated from the aerial part of Hedyotis diffusa, including three iridoid glycosides, hedyoiridoidside A - C (1-3), two cerebrosides, hedyocerenoside F (4) and G (5), and two new ceramides, hedyoceramide A (6) and B (7). And six known iridoid glycosides (8-13) were also obtained. Their structures were established by their physico-chemical constants and spectroscopic analysis. The cytotoxicity of all compounds against tumor cell lines of human cervical cancer HeLa, human leukemia HL-60, human lung cancer A459, human hepatoma HepG2, human gastric gland carcinoma BCG-823, human nasopharyngeal cancer CNE-2, human colon cancer HCT15, and human prostate cancer PC-3 were also evaluated in vitro. As a result, new compound 1 exhibited evident cytotoxicity to all tumor cell lines, and the IC₅₀ values are from 9.5μM to 28.2μM, while new compound 2 exhibited evident cytotoxicity to Hela, HL-60, A459, HepG2, BGC-823, CNE-2, and HCT15, and the IC₅₀ values are from 15.8μM to 26.2μM. Known compound 11 also exhibited evident cytotoxicity to HL-60, A459, HepG2, BGC-823, CNE-2, and HCT15, and the IC₅₀ values are from 16.5μM to 40.4μM. New compounds 4-7 and known compounds 12 and 13 showed moderate cytotoxicity to some tumor cell lines.

New ecdysteroid and ecdysteroid glycosides from the roots of Serratula chinensis

Three new ecdysteroid glycosides (1-3) and one new ecdysteroid (4), were isolated from the roots of Serratula chinensis. Their structures were established on the basis of extensive spectroscopic analysis and chemical methods.

Separation and Identification of Four New Compounds with Antibacterial Activity from Portulaca oleracea L

The Portulaca oleracea L. (P. oleracea) has been used to treat bacillary dysentery for thousands of years in China. Pharmacology studies on P. oleracea have also showed its significant antibacterial effects on the enteropathogenic bacteria, which might reveal the treatment of P. oleracea in cases of bacillary dysentery to some extent. To date, however, the therapeutic basis of P. oleracea treating on bacillary dysentery remains unknown. We determined the antibacterial effective fraction of P. oleracea in a previous study. The current study, which is based on our previous study, was first designed to isolate, identify and screen antibacterial active constituents from P. oleracea. As a result, four new compounds (1–4), portulacerebroside B (1), portulacerebroside C (2), portulacerebroside D (3) and portulaceramide A (4) along with five known compounds (5–9) were isolated, and structures were established by their physico-chemical constants and spectroscopic analysis. The antibacterial activities against common enteropathogenic bacteria were evaluated for all compounds and the new compounds 1–4 showed significant antibacterial effect on enteropathogenic bacteria in vitro, which might contribute to revealing the treatment of P. oleracea in cases of bacillary dysentery.

Bioactivity-guided isolation of antiplasmodial constituents from Conyza sumatrensis (Retz.) E.H. Walker

Conyza sumatrensis (Retz.) E.H. Walker (Cs) leaves are used for traditional treatment of malaria in Cameroon. However, the antimalarial activity of the leaf constituents of this plant is still unexplored. The aim of our investigation was to evaluate the antiplasmodial activity of some bioactive constituents from Cs leaves. Compounds were isolated from Cs leaves and structurally elucidated using extensive spectroscopic analysis. The in vitro antiplasmodial activity of the extracts and pure compounds were evaluated on chloroquine-sensitive strain (NF54) of Plasmodium falciparum. The in vivo assay was done by administering seven doses of extracts in mice infected with Plasmodium berghei K173 through oral route. Cytotoxicity of pure compounds on murine macrophage cells was performed through [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide] (MTT) test. Hemolysis and lactate dehydrogenase assays were also carried out using standard procedures. The in silico prediction of bioactive constituents was performed through Autodock Vina. Polarity-based extracts from Cs were found to be active against P. falciparum (NF54) and P. berghei (K173) in vitro and in vivo respectively. Further, bioactivity-guided isolation of n-hexane fraction yielded three compounds, (1), (2) and (3) with IC50 of 34, 17.9 and 18μg/ml, respectively, while the ethyl acetate fraction afforded the fourth compound with an IC50 of 25μg/ml, indicating anti-malarial potential of Cs through PfLDH interaction without compromising normal cell growth. This study reports for the first time, the antiplasmodial activity of bioactive constituents from Cs and confirms its traditional use.

Leptocarposide: a new triterpenoid glycoside from Ludwigia leptocarpa (Onagraceae)

A new triterpenoid bidesmoside (leptocarposide) possessing an acyl group in their glycosidic moiety (1), together with the known luteolin-8-C-glucoside (2) and 1-O-β-D-glucopyranosyl-(2S,3R,8E)-2-[(2'R)-2-hydroxypalmitoylamino]-8-octadecen-1,3-diol (3) was isolated from the n-butanol-soluble fraction of whole plant of Ludwigia leptocarpa (Nutt) Hara (Onagraceae). Structure of compound 1 has been assigned on the basis of spectroscopic data ((1)H and (13)C NMR, (1)H-(1)H COSY, HSQC, HMBC, and ROESY), mass spectrometry, and by comparison with the literature. This compound was further screened for its potential antioxidant properties by using the radical scavenging assay model 2,2-diphenyl-1-picrylhydrazyl and reveals non-potent antioxidant activities, while compound 2 shows SC50 of 0,038 mM.

Two new sphingolipids from the leaves of Piper betle L

Two new sphingolipids, pipercerebrosides A (1) and B (2), were isolated from the leaves of Piper betle L. Their structures, including absolute configurations, were determined by spectroscopic analysis and chemical degradation. These two compounds did not show significant cytotoxic activity against the cancer cell lines K562 and HL-60 in a MTT assay.

Use of Bodipy-labeled sphingolipid and cholesterol analogs to examine membrane microdomains in cells

Much evidence has accumulated to show that cellular membranes such as the plasma membrane, contain multiple "microdomains" of differing lipid and protein composition and function. These domains are sometimes enriched in cholesterol and sphingolipids and are believed to be important structures for the regulation of many biological and pathological processes. This review focuses on the use of fluorescent (Bodipy) labeled analogs of sphingolipids and cholesterol to study such domains. We discuss the similarities between the behavior of Bodipy-cholesterol and natural cholesterol in artificial bilayers and in cultured cells, and the use of Bodipy-sphingolipid analogs to visualize membrane domains in living cells based on the concentration-dependent monomer-excimer fluorescence properties of the Bodipy-fluorophore. The use of Bodipy-D-erythro-lactosylceramide is highlighted for detection of domains on the plasma membrane and endosome membranes, and the importance of the sphingolipid stereochemistry in modulating domain formation is discussed. Finally, we suggest that Bodipy-sphingolipids may be useful in future studies to examine the relationship between membrane domains at the cell surface and domains enriched in other lipids and proteins on the inner leaflet of the plasma membrane.