Novel stilbenoids, including cannabispiradienone glycosides, from Tragopogon tommasinii (Asteraceae, Cichorieae) and their potential anti-inflammatory activity

Design, synthesis, and antitumor study of a series of novel 1-Oxa-4-azaspironenone derivatives

A series of 1-oxa-4-azaspiro[4,5]deca-6,9-diene-3,8-dione derivatives containing structural fragments of conjugated dienone have been synthesized previously by our group, however the Michael addition reaction between conjugated dienone and nucleophilic groups in the body may generate harmful and adverse effects. To reduce harmful side effects, the authors started with p-aminophenol to make 1-oxo-4- azaspirodecanedione derivatives, then utilized the Michael addition and cyclopropanation to eliminate α, β unsaturated olefinic bond and lower the Michael reactivity of the compounds in vivo for optimization. At the same time, heteroatoms are put into the molecules in order to improve the hydrophilicity of the molecules and the binding sites of the molecules and the target molecules, establishing the groundwork for improved antitumor activity. The majority of the compounds had moderate to potent activity against A549 human lung cancer cells, MDA-MB-231 breast cancer cells, and Hela human cervical cancer cells. Among them, the compound 6d showed the strongest effect on A549 cell line with IC50 of 0.26 μM; the compound 8d showed the strongest cytotoxicity on MDA-MB-231 cell line with IC50 of 0.10 μM; and the compound 6b showed the strongest activity on Hela cell line with IC50 of 0.18 μM.

9,10-Dihydro-5-hydroxy-2,3,6-trimethoxyphenanthrene-1,4-dione: a new dihydrophenanthrene from commercial cannabis and its effect on zebrafish larval behaviour

A new dihydrophenanthrene derivative namely 9,10-dihydro-5-hydroxy-2, 3,6-trimethoxyphenanthrene-1,4-dione (1) was isolated from commercial cannabis product together with 4,5-dihydroxy-2,3,6-trimethoxy-9,10-dihydrophenanthrene (2), 4-hydroxy-2,3,6,7-tetramethoxy-9,10-dihydrophenanthrene (3), combretastatin B-2 (4) and isocannbispiradienone (5). Structure elucidation of the isolated compounds were done based on the interpretation of the mass spectrometry (MS) and nuclear magnetic resonance (NMR) data. New dihydrophenanthrene derivative (1) was tested for its effect on zebrafish larval behaviour. Preliminary results suggested that the new dihydrophenanthrene derivative (1) exhibits similar effect on zebrafish larval behaviour as cannabidiol (CBD), a biologically active component of Cannabis.

The genus Tragopogon (Asteraceae): A review of its traditional uses, phytochemistry, and pharmacological properties

ETHNOPHARMACOLOGICAL RELEVANCE

Species of Tragopogon are used in traditional medicine, and consumed as vegetables across the world. In terms of the medicinal uses of Tragopogon, different species have found use in traditional medicine, including uses for wound-healing, treatment of gastrointestinal and hepatic complaints, cancer, kidney and liver dysfunction, inflamed skin and certain cutaneous diseases, as well as constipation, fatigue and anoxia.

AIM OF THE STUDY

The aim of this review is to highlight and critically summarize those species of the genus that have been studied as a source of interesting lead compounds, and their traditional uses and bioactivities.

MATERIALS AND METHODS

A comprehensive and systematic review of literature on traditional uses, phytochemicals and pharmacological properties of the genus Tragopogon was carried out. Information was retrieved from secondary databases such as Scopus, Chemical Abstracts Services (Scifinder), Pubmed, Google Scholar and ScienceDirect, in addition to primary sources including books, PhD and MSc dissertations, and official websites. Species names were validated using "The Plant List" (www.theplantlist.org).

RESULTS

The taxa of the genus Tragopogon are known for their local and traditional uses as medicine for treatment of various diseases, and have been consumed as vegetables and snacks for generations in Eurasia, the Mediterranean, Caucasus, Europe and North America. From the approximately 110 species of Tragopogon, only twelve species have been scientifically evaluated for their bioactivity and/or phytochemical composition. Tragopogon species are a rich source of phytochemical constituents and among those that have been identified are 19 flavonoids, 35 terpenoids, seven bibenzyl derivatives, five benzylphtalides, six stilbenes, nine dihydroisocoumarin derivatives, nine phenylmethane derivatives, three hydroxyphenylacetic acid derivatives, four phenylpropane derivatives, four esters of phenylpropanoic acids, a coumarin derivative, and a spermine derivative. Various extracts of the taxa, in addition to the isolated compounds, demonstrated pharmacological properties such as antitumor, antimicrobial, anti-inflammatory and enzyme inhibitory activities, in addition to hepatoprotective, antihyperlipidaemic and wound-healing properties.

CONCLUSION

This review highlights the traditional uses, phytochemistry and pharmacological properties of the few studied taxa of the genus Tragopogon. Some of the reviewed papers were not of an appropriate methodological standard. For instance, phytochemical profiles were not determined, and the fundamental requirements of the pharmacological properties were not defined such as including appropriate positive and negative controls, and calculating the MIC values. Furthermore, these studies did not provide an in depth evaluation of bioactivity of the extracts and the isolated compounds or in vivo experiments which could indicate therapeutic relevance. From a phytopharmacological point of view, this review recommends more high quality evidence-based research on Tragopogon species for further development of plant-derived remedies and compounds.

Modulatory Effect of Chelidonium majus Extract and Its Alkaloids on LPS-Stimulated Cytokine Secretion in Human Neutrophils

Due to certain differences in terms of molecular structure, isoquinoline alkaloids from Chelidonium majus engage in various biological activities. Apart from their well-documented antimicrobial potential, some phenanthridine and protoberberine derivatives as well as C. majus extract present with anti-inflammatory and cytotoxic effects. In this study, the LC–MS/MS method was used to determine alkaloids, phenolic acids, carboxylic acids, and hydroxybenzoic acids. We investigated five individually tested alkaloids (coptisine, berberine, chelidonine, chelerythrine, and sanguinarine) as well as C. majus root extract for their effect on the secretion of IL-1β, IL-8, and TNF-α in human polymorphonuclear leukocytes (neutrophils). Berberine, chelidonine, and chelerythrine significantly decreased the secretion of TNF-α in a concentration-dependent manner. Sanguinarine was found to be the most potent inhibitor of IL-1β secretion. However, the overproduction of IL-8 and TNF-α and a high cytotoxicity for these compounds were observed. Coptisine was highly cytotoxic and slightly decreased the secretion of the studied cytokines. The extract (1.25–12.5 μg/mL) increased cytokine secretion in a concentration-dependent manner, but an increase in cytotoxicity was also noted. The alkaloids were active at very low concentrations (0.625–2.5 μM), but their potential cytotoxic effects, except for chelidonine and chelerythrine, should not be ignored.

Inhibitory activity of Podospermum canum and its active components on collagenase, elastase and hyaluronidase enzymes

Present study is aimed to investigate in vitro inhibitory effects of the extract prepared from the aerial parts of Podospermum canum (syn: Scorzonera cana var. jacquiniana) (Asteraceae) on hyaluronidase, collagenase, and elastase enzymes using a bioassay-guided fractionation. Inhibitory effects of the extract, sub-extracts, fractions obtained by column chromatography, and isolated compounds on collagenase, elastase, and hyaluronidase were performed by using in vitro enzyme inhibitory assays based on spectrophotometric evaluation. The methanolic extract obtained from P. canum exhibited strong inhibitory activities on elastase and collagenase while the insignificant activity was observed on hyaluronidase. Through bioactivity-guided fractionation, the ethyl acetate and remaining water sub-extracts obtained from the methanolic extract displayed significant inhibitory activities on collagenase and elastase, while petroleum ether and chloroform extracts did not show any inhibitory activity. Eleven known compounds: arbutin, 6́-O-caffeoylarbutin, cichoriin, 3,5-dicaffeoylquinic acid methyl ester, apigenin 7-O-β-glucoside, luteolin 7-O-β-glucoside, apigenin 7-O-β-rutinoside, isoorientin, orientin, vitexin, procatechuic acid, and new compound 4-hydroxy-benzoic acid 4-(6-O-α-rhamnopyranosyl-β-glucopyranosyl) benzyl ester have been obtained from ethyl acetate sub-extract. Results of the present study have revealed that apigenin 7-O-β-glucoside, luteolin 7-O-β-glucoside, apigenin 7-O-β-rutinoside, and isoorientin showed potent enzyme inhibitory activities. However, methanolic extract of P. canum displayed a greater inhibitory activity than fractions and isolated compounds both on collagenase and elastase.

Antioxidant Activity of Selected Stilbenoid Derivatives in a Cellular Model System

The stilbenoids, a group of naturally occurring phenolic compounds, are found in a variety of plants, including some berries that are used as food or for medicinal purposes. They are known to be beneficial for human health as anti-inflammatory, chemopreventive, and antioxidative agents. We have investigated a group of 19 stilbenoid substances in vitro using a cellular model of THP-1 macrophage-like cells and pyocyanin-induced oxidative stress to evaluate their antioxidant or pro-oxidant properties. Then we have determined any effects that they might have on the expression of the enzymes catalase, glutathione peroxidase, and heme oxygenase-1, and their effects on the activation of Nrf2. The experimental results showed that these stilbenoids could affect the formation of reactive oxygen species in a cellular model, producing either an antioxidative or pro-oxidative effect, depending on the structure pinostilbene (2) worked as a pro-oxidant and also decreased expression of catalase in the cell culture. Piceatannol (4) had shown reactive oxygen species (ROS) scavenging activity, whereas isorhapontigenin (18) had a mild direct antioxidant effect and activated Nrf2-antioxidant response element (ARE) system and elevated expression of Nrf2 and catalase. Their effects shown on cells in vitro warrant their further study in vivo.

Biologically active compounds from two members of the Asteraceae family: Tragopogon dubius Scop. and Tussilago farfara L

Tragopogon dubius and Tussilago farfara are consumed as vegetables and used in folk medicine to manage common diseases. Herein, the chemical compositions and biological activities of different leaf extracts (ethyl acetate, methanol, and water) of T. dubius and T. farfara were evaluated. The antibacterial, antifungal, and antioxidant abilities of the extracts were tested using different assays including free radical scavenging, reducing power, phosphomolybdenum, and metal chelating assays. Enzyme inhibitory potentials were evaluated against cholinesterases, tyrosinase, α-amylase and α-glucosidase. Complexes of bioactive compounds (chlorogenic and rosmarinic acid) were docked into the enzymatic cavity of α-glucosidase and subjected to molecular dynamic calculation, enzyme conformational stability, and flexibility analysis. T. dubius and T. farfara extracts showed remarkable antioxidant potentials. Ethyl acetate extracts of T. dubius and T. farfara were the most potent inhibitors of acetylcholinesterase and butyrylcholinesterase. T. dubius ethyl acetate extract and T. farfara methanolic extract showed noteworthy activity against α-glucosidase. High performance liquid chromatography analysis revealed the abundance of some phenolic compounds including chlorogenic and rosmarinic acids. Ethyl acetate extract of T. dubius showed notable antifungal activity against all strains. Docking studies showed best pose for chlorogenic acid was stabilized by a network of hydrogen bonds with residues Asp1157, Asp1279, whereas rosmarinic acid showed several hydrogen bonds with Asp1157, Asp1420, Asp1526, Lys1460 and Trp1369. This study further validates the use of T. dubius and T. farfara in traditional medicine, as well as act as a stimulus for further studies for future biomedicine development. Communicated by Ramaswamy H. Sarma.

Sesquiterpene lactones and their precursors as chemosystematic markers in the tribe Cichorieae of the Asteraceae revisited: An update (2008-2017)

Ten years after the first overview on sesquiterpene lactones in the Cichorieae tribe of the Asteraceae family, we present an update. This review summarizes all chemosystematically relevant reports on sesquiterpene lactones and their immediate precursors from the Cichorieae (syn.: Lactuceae) tribe of the Asteraceae published between 2008 and 2017 and also includes some corrections to the 2008 review. The number of sesquiterpene lactones and sesquiterpenic acids as immediate precursor of sesquiterpene lactones reported for the Cichorieae has increased from 360 to 475 (+32%) within one decade. The number of known source species increased from 139 to 157 (+13%) and the number of chemosystematic reports (reported compounds per taxon) increased from 838 to 1241 (+48%). Notwithstanding this high interest in sesquiterpene lactones of the Cichorieae, still only from 30 out of 94 currently accepted genera within the Cichorieae at least one sesquiterpene lactone has been reported so far.

Parallel in vitro and in silico investigations into anti-inflammatory effects of non-prenylated stilbenoids

Stilbenoids represent a large group of bioactive compounds, which occur in food and medicinal plants. Twenty-five stilbenoids were screened in vitro for their ability to inhibit COX-1, COX-2 and 5-LOX. Piceatannol and pinostilbene showed activity comparable to the zileuton and ibuprofen, respectively. The anti-inflammatory potential of stilbenoids was further evaluated using THP-1 human monocytic leukemia cell line. Tests of the cytotoxicity on the THP-1 and HCT116 cell lines showed very low toxic effects. The tested stilbenoids were evaluated for their ability to attenuate the LPS-stimulated activation of NF-κB/AP-1. Most of the tested substances reduced the activity of NF-κB/AP-1 and later attenuated the expression of TNF-α. The effects of selected stilbenoids were further investigated on inflammatory signaling pathways. Non-prenylated stilbenoids regulated attenuation of NF-ĸB/AP-1 activity upstream by inhibiting the phosphorylation of MAPKs. A docking study used to in silico analyze the tested compounds confirmed their interaction with NF-ĸB, COX-2 and 5-LOX.

Evaluation of the toxicity and anti-inflammatory activities of the infusion of leaves of Campomanesia guazumifolia (Cambess.) O. Berg

ETHNOPHARMACOLOGICAL RELEVANCE

Some species of Campomanesia are used in the folk medicine due to anti-inflammatory, anti-diarrheal, anti-diabetes and hypercholesterolemic. However studies with Campomanesia guazumifolia (Cambess.) O. Berg. are scarce.

AIM OF THE STUDY

This study investigated the anti-inflammatory activity and toxicological profile of infusion obtained from leaves of Campomanesia guazumifolia in mice.

MATERIALS AND METHODS

Leaves infusion of C. guazumifolia was obtained in the proportion of 20 g/L (leaves/water) at 95-100 °C for 10 min in an enclosed container. The acute toxicity of the leaves infusion of C. guazumifolia lyophilized (ICG) was assessed by oral administration to female mice at doses of 500, 1000, 2000, and 5000 mg/kg, and the general behavior and toxic symptoms were observed for 14 days. In the subacute toxicity model, female mice were treated orally with the ICG (250, 500, and 1000 mg/kg) during 28 days, and biochemical, toxic signs and the estrous cycle were evaluated. The anti-inflammatory activity of the ICG (70, 300 and 700 mg/kg) was analyzed using carrageenan-induced pleurisy and inflammatory paw (mechanical and thermal hyperalgesia).

RESULTS

Three flavonoids glycosylated and a cyclohexanecarboxylic acid were identified in the ICG: quercetin pentose, quercetin deoxyhexoside, myricetin deoxyhexoside and quinic acid. No clinical signs of acute toxicity were observed, suggesting that the LD₅₀ (Lethal Dose) is above 5000 mg/kg. Subacute exposure of mice to the ICG did not change significantly the hematological and biochemical parameters as well as histology of organs. The ICG increased the duration of estrous cycle in all phases, showing anti-inflammatory potential by decreasing leukocyte migration, extravasation protein in the pleural cavity and antiedematogenic activity. The ICG treatment at a dose of 700 mg/kg decreased the mechanical hyperalgesia, while at doses of 300 mg/kg and 700 mg/kg, decreased the sensitivity to the cold.

CONCLUSION

The results evidenced the anti-inflammatory potential with low toxicity of infusion of the leaves of C. guazumifolia, supporting the popular use of this species.

Main pathways of action of Brazilian red propolis on the modulation of neutrophils migration in the inflammatory process

BACKGROUND

Brazilian propolis is popularly used as treatment for different diseases including the ones with inflammatory origin. Brazilian red propolis chemical profile and its anti-inflammatory properties were recently described however, its mechanism of action has not been investigated yet.

AIM

Elucidate Brazilian red propolis major pathways of action on the modulation of neutrophil migration during the inflammatory process.

METHODS

The ethanolic extract of propolis (EEP) activity was investigated for neutrophil migration into the peritoneal cavity, intravital microscopy (rolling and adhesion of leukocytes), quantification of cytokines TNF-α, IL-1β and chemokines CXCL1/KC, CXCL2/MIP-2, neutrophil chemotaxis induced by CXCL2/MIP-2, calcium influx and CXCR2 expression on neutrophils.

RESULTS

EEP at 10mg/kg prevented neutrophil migration into peritoneal cavity (p < 0.05), reduced leukocyte rolling and adhesion on the mesenteric microcirculation (p < 0.05) and inhibited the release TNF-α, IL-1β, CXCL1/KC and CXCL2/MIP-2 (p < 0.05). EEP at 0.01, 0.1 and 1µg/ml reduced the CXCL2/MIP-2-induced neutrophils chemotaxis (p < 0.05) without affect cell viability (p > 0.05).EEP at 1µg/ml decreased the calcium influx induced by CXCL2/MIP-2 (p<0.05). On the other hand, none of EEP concentrations tested altered CXCR2 expression by neutrophils (p>0.05).

CONCLUSION

Brazilian red propolis appears as a promising anti-inflammatory natural product which mechanism seems to be by reducing leukocyte rolling and adhesion; TNF-α, IL-1β, CXCL1/KC and CXCL2/MIP-2 release; CXCL2/MIP-2-induced chemotaxis and calcium influx.