Screening of several biological activities induced by different sesquiterpene lactones isolated from Centaurea behen L. and Rhaponticum repens (L.) Hidalgo

Bioactivity and molecular docking of lactones isolated from Centaurea pseudosinaica Czerep

Two cytotoxic sesquiterpene lactones, 17-epichlorohyssopifolin A (1) and chlorjanerin (2), and a monoterpene lactone, loliolide (3) were isolated from Centaurea pseudosinaica. The cytotoxicity of the total extract and terpenoids 1-3 were evaluated against three human cancer cells (HepG2, PC-3, and HT-29), along with the human normal primary epidermal keratinocytes (HEKa) cells. With IC₅₀ values ranging between 0.6 ± 0.04 and 5.0 ± 0.61 μg/mL against HepG2; 0.2 ± 0.01 and 11.9 ± 1.31 μg/mL against PC-3, and 0.04 ± 0.013 and 8.9 ± 0.97 μg/mL against HT-29, the total extract, and lactones 1-3 demonstrated cytotoxic effects. Compound 1 displayed the strongest impact on all cancer cells and a slightly safe effect on the normal cells HEKa. Compound 1 caused accumulation of HepG2 and HT-29 cells in G1 phase as displayed cell cycle analysis. On the other hand, the cell distributions were increased in the S phase in PC-3 cells. Furthermore, 1 caused apoptosis in PC-3 and HePG2 cells with 91.50%, and 79.72 %, respectively. A higher fraction of necrotic cells was observed in HT-29 cells amounting to 23.60%. These results suggested that the promising cytotoxicity exhibited by 1 is brought by the apoptosis induction in the cancer cells, which were evaluated. As the compounds showed antiproliferative effect against the HT-29 cells, the docking simulation was performed aiming at determining how they would interact with the EGFR enzyme, whose PDB: 4I23 is considered one of the two distinct wild types of EGFR enzymes. The antibacterial activity results revealed that 3 showed the most remarkable antibacterial effects, especially against the examined Gram-positive bacteria. The total extract exhibited potent activity against all examined bacteria. The total extract showed a potent antifungal effect against two Candida and two Aspergillus pathogens. The antioxidant activity revealed the potency of the total extract and 3 as antioxidant candidates. The obtained results refer to the importance of Centaurea pseudosinaica as a source of potent antiproliferative agents and the whole plant as an antipathogenic and antioxidant agent.

Natural products in attenuating renal inflammation via inhibiting the NLRP3 inflammasome in diabetic kidney disease

Diabetic kidney disease (DKD) is a prevalent and severe complications of diabetes and serves as the primary cause of end-stage kidney disease (ESKD) globally. Increasing evidence indicates that renal inflammation is critical in the pathogenesis of DKD. The nucleotide - binding oligomerization domain (NOD) - like receptor family pyrin domain containing 3 (NLRP3) inflammasome is the most extensively researched inflammasome complex and is considered a crucial regulator in the pathogenesis of DKD. The activation of NLRP3 inflammasome is regulated by various signaling pathways, including NF- κB, thioredoxin-interacting protein (TXNIP), and non-coding RNAs (ncRNA), among others. Natural products are chemicals extracted from living organisms in nature, and they typically possess pharmacological and biological activities. They are invaluable sources for drug design and development. Research has demonstrated that many natural products can alleviate DKD by targeting the NLRP3 inflammasome. In this review, we highlight the role of the NLRP3 inflammasome in DKD, and the pathways by which natural products fight against DKD via inhibiting the NLRP3 inflammasome activation, so as to provide novel insights for the treatment of DKD.

Antibacterial and Antifungal Terpenes from the Medicinal Angiosperms of Asia and the Pacific: Haystacks and Gold Needles

This review identifies terpenes isolated from the medicinal Angiosperms of Asia and the Pacific with antibacterial and/or antifungal activities and analyses their distribution, molecular mass, solubility, and modes of action. All data in this review were compiled from Google Scholar, PubMed, Science Direct, Web of Science, ChemSpider, PubChem, and library searches from 1968 to 2022. About 300 antibacterial and/or antifungal terpenes were identified during this period. Terpenes with a MIC ≤ 2 µg/mL are mostly amphiphilic and active against Gram-positive bacteria, with a molecular mass ranging from about 150 to 550 g/mol, and a polar surface area around 20 Ų. Carvacrol, celastrol, cuminol, dysoxyhainic acid I, ent-1β,14β-diacetoxy-7α-hydroxykaur-16-en-15-one, ergosterol-5,8-endoperoxide, geranylgeraniol, gossypol, 16α-hydroxy-cleroda-3,13 (14)Z-diene-15,16-olide, 7-hydroxycadalene, 17-hydroxyjolkinolide B, (20R)-3β-hydroxy-24,25,26,27-tetranor-5α cycloartan-23,21-olide, mansonone F, (+)-6,6'-methoxygossypol, polygodial, pristimerin, terpinen-4-ol, and α-terpineol are chemical frameworks that could be candidates for the further development of lead antibacterial or antifungal drugs.

Effectiveness of "Centaurea behen" root on quality of life in patients with systolic heart failure: A randomized clinical trial

Introduction: The effect of Centaurea behen (Cb) on patients with systolic heart failure is not known academically. This study was conducted to evaluate the effect of Cb on improving the quality of life (QoL) and echocardiographic and biochemical blood parameters in patients with systolic heart failure. Methods: This study was a parallel double-blind, placebo-controlled randomized trial of 60 patients with systolic heart failure, was conducted from May 2018 up to August 2019. Intervention group received 150 mg twice daily Cb capsules for two months + Guideline directed medical therapy (GDMT), and control group received GDMT + placebo capsules for two months. The main aim of the present study were to assess the QoL based on the 6-minute walk test (6MWT) and the Minnesota living with heart failure questionnaire (MLHFQ). Independent T-test, paired T-test, and ANOVA were used for the analysis. Results: At the beginning of the present study there were no significant differences between study groups in terms of QoL and clinical results. After treatment, the average values of QoL based on MLHFQ and 6MWT instruments were significantly improved 15.5 and 36.18, respectively (P<0.05). Conclusion: Based on the MLHFQ, and 6MWT tests, the consumption of Centaurea behen root extract was associated with significant improvement in the quality of life of patients with systolic heart failure.

Phytochemicals, Antioxidant and Antimicrobial Potentials and LC-MS Analysis of Centaurea parviflora Desf. Extracts

Centaurea parviflora (C. parviflora), belonging to the family Asteraceae, is an Algerian medicinal plant used in folk medicine to treat different diseases related to hyperglycemic and inflammatory disorders, as well as in food. The present study aimed to assess the total phenolic content, in vitro antioxidant and antimicrobial activity and phytochemical profile of the extracts of C. parviflora. The extraction of phenolic compounds from aerial parts was conducted using solvents of increasing polarity starting from methanol, resulting in crude extract (CE), to chloroform extract (CHE), ethyl acetate extract (EAE) and butanol extract (BUE). The total phenolic, flavonoid and flavonol contents of the extracts were determined using the Folin-Ciocalteu and AlCl₃ methods, respectively. The antioxidant activity was measured with seven methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay, galvinoxyl free-radical-scavenging test, 2,2'-Azino-Bis(3-Ethylbenzothiazoline-6-Sulfonic Acid) (ABTS) assay, cupric reducing antioxidant capacity (CUPRAC), reducing power, Fe⁺²-phenanthroline reduction assay and superoxide-scavenging test. The disc-diffusion method aimed at testing the sensitivity of bacterial strains toward our extracts. A qualitative analysis with thin-layer chromatography of the methanolic extract was performed. Moreover, HPLC-DAD-MS was used to establish the phytochemical profile of the BUE. The BUE was found to contain high amounts of total phenolics (175.27 ± 2.79 µg GAE/mg E), flavonoids (59.89 ± 0.91 µg QE/mg E) and flavonols (47.30 ± 0.51 µg RE/mg E). Using TLC, different components such as flavonoids and polyphenols were noted. The highest radical-scavenging ability was recorded for the BUE against DPPH (IC₅₀ = 59.38 ± 0.72 µg/mL), galvinoxyl (IC₅₀ = 36.25 ± 0.42 µg/mL), ABTS (IC₅₀ = 49.52 ± 1.54 µg/mL) and superoxide (IC₅₀ = 13.61 ± 0.38 µg/mL). The BUE had the best reducing power according to the CUPRAC (A_0.5 = 71.80 ± 1.22 μg/mL), phenanthroline test (A_0.5 = 20.29 ± 1.16 μg/mL) and FRAP (A_0.5 = 119.17 ± 0.29 μg/mL). The LC-MS analysis of BUE allowed us to identify eight compounds including six phenolic acids and two flavonoids: quinic acid, five chlorogenic acid derivatives, rutin and quercetin 3-o-glucoside. This preliminary investigation revealed that the extracts of C. parviflora have a good biopharmaceutical activity. The BUE possesses an interesting potential for pharmaceutical/nutraceutical applications.

Chemical Composition, Antioxidant and Antiproliferative Activities of Taraxacum officinale Essential Oil

Taraxacum officinale (TO) has been historically used for medicinal purposes due to its biological activity against specific disorders. To investigate the antioxidant and the antiproliferativepotential of TO essential oil in vitro and in vivo, the chemical composition of the essential oil was analyzed by GC-MS. The in vivo antioxidant capacity was assessed on liver and kidney homogenate samples from mice subjected to acetaminophen-induced oxidative stress and treated with TO essential oil (600 and 12,000 mg/kg BW) for 14 days. The in vitro scavenging activity was assayed using the 1,1-diphenyl-2-picrylhydrazyl (DPPH) and the reducing power methods. The cytotoxic effects against the HeLa cancer cell line were analyzed. The GC-MS analysis showed the presence of 34 compounds, 8 of which were identified as major constituents. The TO essential oil protected mice’s liver and kidneys from acetaminophen-induced oxidative stress by enhancing antioxidant enzymes (catalase, superoxide dismutase, and glutathione) and lowering malondialdehyde levels. In vitro, the TO essential oil demonstrated low scavenging activity against DPPH (IC₅₀ = 2.00 ± 0.05 mg/mL) and modest reducing power (EC₅₀ = 0.963 ± 0.006 mg/mL). The growth of the HeLa cells was also reduced by the TO essential oil with an inhibition rate of 83.58% at 95 µg/mL. Current results reveal significant antioxidant and antiproliferative effects in a dose-dependent manner and suggest that Taraxacum officinale essential oil could be useful in formulations for cancer therapy.

Differential Metabolomic Fingerprinting of the Crude Extracts of Three Asteraceae Species with Assessment of Their In Vitro Antioxidant and Enzyme-Inhibitory Activities Supported by In Silico Investigations

The Asteraceae is a large family, rich in ornamental, economical, and medicinally valuable plants. The current study involves the analytical and pharmacological assessment of the methanolic extracts of three less investigated Asteraceae plants, namely Echinops ritro, Centaurea deflexa, and Tripleurospermum decipiens, obtained by three different extraction methodologies viz. maceration (MAC), ultrasound-assisted extraction (UAE), and homogenizer-assisted extraction (HAE). LC-MS-MS analysis of E. ritro, C. deflexa, and T. decipiens extracts led to the identification of ca. 29, 20, and 33 metabolites, respectively, belonging to flavonoids, phenolic acids, and fatty acids/amides. Although there were significant differences in the quantitative metabolite profiles in the extracts of E. ritro and T. decipiens based on the used extraction method, no significant variation was observed in the extracts of C. deflexa in the three implemented extraction techniques. The antioxidant activities of the nine extracts were assessed in vitro using six different assays viz. DPPH, ABTS, CUPRAC, FRAP, PDA, and metal chelation assay (MCA). The HAE/UAE extracts of E. ritro and the UAE/ MAC extracts of C. deflexa displayed the highest antioxidant activity in the DPPH assay, while the UAE extract of T. decipiens showed the strongest antioxidant activity in both the CUPRAC and MCA assays. The enzyme inhibitory activities of the nine extracts were studied in vitro on five different enzymes viz. tyrosinase, α-amylase, α-glucosidase, acetylcholinesterase (AChE), and butyrylcholinestrase (BChE), affecting various pathological diseases. Concerning C. deflexa, its MAC /UAE extracts showed the strongest inhibition on α-amylase, while its UAE/HAE extracts displayed strong inhibitory power on AChE. However, no significant difference was observed on their effects on tyrosinase or BChE. For T. decipiens, its UAE/HAE showed potent inhibition to α-glucosidase, MAC/ HAE significantly inhibited AChE and BChE, while UAE could strongly inhibit tyrosinase enzyme. For E. ritro, all extracts equally inhibited α-amylase and α-glucosidase, MAC/HAE strongly affected tyrosinase, HAE/MAC best inhibited BChE, while HAE inhibited AChE to a greater extent. Chemometric analysis using PCA plot was able to discriminate between the plant samples and between the implemented extraction modes. The in vitro enzyme inhibitory activities of the extracts were supported by in silico data, where metabolites, such as the lignan arctiin and the flavonoid vicenin-2, dominating the extract of C. deflexa, displayed strong binding to AChE. Similarly, chlorogenic and dicaffeoyl quinic acids, which are some of the major metabolites in the extracts of E. ritro and T. decipiens, bound with high affinity to α-glucosidase.

Bioactive terpenoids derived from plant endophytic fungi: An updated review (2011-2020)

Plant endophytes have been considered as novel sources of naturally occurring compounds with various biological activities, including cytotoxic, antimicrobial, anti-inflammatory, anticancer, herbicides, antileishmanial and antioxidant. A variety of specialised products, comprising terpenoids, alkaloids, polyketides, phenolic compounds, coumarins, and quinone derivatives have been reported from various strains. An increasing number of products, especially terpenoids, are being isolated from endophytes. Herein, the isolated new terpenoids from plant endophytic fungi, their hosts, as well as biological activities, from January 2011 until the end of 2020 are reviewed. In this period, 516 terpenoids are classified into monoterpenes (5), sesquiterpenes (299), diterpenes (76), sesterterpens (22), meroterpenes (83), triterpenes (29), and other terpenoids (2), were isolated from different plant endophytic fungi species.

Cytotoxic sesquiterpene lactones and lignans from Cousinia turkmenorum Bornm (Asteraceae)

Seven sesquiterpene lactones, chlorophyssopifolin E (1), aguerin B (2), repdiolide triol (3), solistitiolide (4), aitchisonolide (5), sinicin B (6), cynaropicrin (7), along with four lignans arctigenin (8), arctiin (9), matairesinol (10), and matairesinoside (11) were isolated for the first time from the aerial parts of Cousinia turkmenorum Bornm. Among the isolated compounds, aguerin B (2) showed the most cytotoxic activity against MCF7 cell lines with IC₅₀ value of 18.9 μM. Findings of this study could be useful for the development of new anticancer agents from nature.

Janerin Induces Cell Cycle Arrest at the G2/M Phase and Promotes Apoptosis Involving the MAPK Pathway in THP-1, Leukemic Cell Line

Janerin is a cytotoxic sesquiterpene lactone that has been isolated and characterized from different species of the Centaurea genus. In this study, janerin was isolated form Centaurothamnus maximus, and its cytotoxic molecular mechanism was studied in THP-1 human leukemic cells. Janerin inhibited the proliferation of THP-1 cells in a dose-dependent manner. Janerin caused the cell cycle arrest at the G2/M phase by decreasing the CDK1/Cyclin-B complex. Subsequently, we found that janerin promoted THP-1 cell death through apoptosis as indicated by flow cytometry. Moreover, apoptosis induction was confirmed by the upregulation of Bax, cleaved PARP-1, and cleaved caspase 3 and the downregulation of an anti-apoptotic Bcl-2 biomarker. In addition, immunoblotting indicated a dose dependent upregulation of P38-MAPK and ERK1/2 phosphorylation during janerin treatment. In conclusion, we have demonstrated for the first time that janerin may be capable of inducing cell cycle arrest and apoptosis through the MAPK pathway, which would be one of the mechanisms underlying its anticancer activity. As a result, janerin has the potential to be used as a therapeutic agent for leukemia.

Antioxidant Potential of Flower Extracts from Centaurea spp. Depends on Their Content of Phenolics, Flavonoids and Free Amino Acids

Scientists intensely search for new sources of antioxidants, perceived as important health-promoting agents. Some species of the large genus Centaurea provide raw materials for the pharmaceutical and cosmetic industries, as well as produce edible flowers. This is the first study that determines the content of total polyphenols, flavonoids, reducing sugars, free amino acids and the antioxidant potential in the flower extracts of C. nigra L., C. orientalis L. and C. phrygia L. The total polyphenol and flavonoid content is the highest in the extract of C. orientalis, and the lowest in that of C. phrygia. Similarly, C. orientalis shows the greatest scavenging activity on DPPH (1,1-diphenyl-2-picryl-hydrazyl), ABTS [2,2′-azobis(3-ethylbenzothiazoline-6-sulfonate)] and Fe³⁺ reducing power assays, whereas the lowest activity is found for C. phrygia. The highest content of reducing sugars is found in C. nigra, while C. orientalis has the highest levels of free amino acids. We find a strong positive correlation between total phenolics and flavonoids and the antioxidant capacity of all three Centaurea species. Moreover, the content of free amino acids strongly and positively correlates with the levels of total phenolics and flavonoids, antioxidant activity assessed by DPPH and ABTS assays and Fe³⁺ reducing power. Summing up, C. orientalis exhibits the strongest antioxidant potential of the investigated Centaurea species. This species could potentially be a natural source of antioxidant substances for the pharmacy, cosmetics and food industries. The content of free amino acids may be used as a marker of the antioxidant status of Centaurea species.

Anticancer Potential of Aguerin B, a Sesquiterpene Lactone Isolated from Centaurea behen in Metastatic Breast Cancer Cells

BACKGROUND

Breast carcinoma is a malignant disease that represents the most common non-skin malignancy and a chief reason of cancer death in women. Large interest is growing in the use of natural products for cancer treatment, especially with goal of suppression angiogenesis, tumor cell growth, motility, as well as invasion and metastasis with low/no toxicity. It is evident from recent patents on the anticancer properties of sesquiterpene lactones such as parthenolide.

OBJECTIVE

In this study, using MDA-MB-231 cells of a human breast adenocarcinoma, the effects of aguerin B, as a natural sesquiterpene lactone, has been evaluated, in terms of the expression of metastatic-related genes (Pak-1, Rac-1 and HIF-1α).

METHODS

Cytotoxicity of aguerin B was tested toward MDA-MB-231 breast tumor cells using MTT. Scratch assay was accomplished to evaluate the tumor cell invasion. To understand the underlying molecular basis, the mRNA expressions were evaluated by real time PCR.

RESULTS

It was found that aguerin B significantly inhibited human breast cancer cell growth in vitro (IC50 = 2μg/mL) and this effect was accompanied with a persuasive suppression on metastasis. Our results showed that aguerin B in IC50 concentration down-regulated Rac-1, Pak-1, Hif-1α and Zeb-1 transcriptional levels.

CONCLUSION

Taken together, this study demonstrated that aguerin B possessed potential anti-metastatic effect, suggesting that it may consider as a potential multi target bio compound for treatment of breast metastatic carcinoma.

Guaianolide Sesquiterpene Lactones from Centaurothamnus maximus

Centaurothamnus maximus (family Asteraceae), is a leafy shrub indigenous to the southwestern Arabian Peninsula. With a paucity of phytochemical data on this species, we set out to chemically characterize the plant. From the aerial parts, two newly identified guaianolides were isolated: 3β-hydroxy-4α(acetoxy)-4β(hydroxymethyl)-8α-(4-hydroxy methacrylate)-1αH,5αH, 6αH-gual-10(14),11(13)-dien-6,12-olide (1) and 15-descarboxy picrolide A (2). Seven previously reported compounds were also isolated: 3β, 4α, 8α-trihydroxy-4-(hydroxymethyl)-lαH, 5αH, 6βH, 7αH-guai-10(14),11(13)-dien-6,12-olide (3), chlorohyssopifolin B (4), cynaropikrin (5), hydroxyjanerin (6), chlorojanerin (7), isorhamnetin (8), and quercetagetin-3,6-dimethyl ether-4’-O-β-d-pyranoglucoside (9). Chemical structures were elucidated using spectroscopic techniques, including High Resolution Fast Atom Bombardment Mass Spectrometry (HR-FAB-MS), 1D NMR; ¹H, ¹³C NMR, Distortionless Enhancement by Polarization Transfer (DEPT), and 2D NMR (¹H-¹H COSY, HMQC, HMBC) analyses. In addition, a biosynthetic pathway for compounds 1–9 is proposed. The chemotaxonomic significance of the reported sesquiterpenoids and flavonoids considering reports from other Centaurea species is examined.

4,5-Seco-5,10-friedo-abietane-type diterpenoids with anticancer activity from Salvia atropatana Bunge

The purpose of this study is cytotoxicity-guided isolation of the petroleum ether fraction from the roots of Salvia atropatana for the first time, which has shown to growth inhibition and apoptosis induction in MCF-7 and PC3 cells. Bioassay-guided isolation method was conducted for finding compounds with highest cytotoxicity. Different extracts were prepared from the roots of Salvia atropatana. All extracts were tested for their cytotoxic activity against three cancer cell lines (PC3, MCF-7, and MDA-MB-231). The most cytotoxic extract was chosen for further isolation by column chromatography and HPLC. The chemical structures were determined by spectroscopic methods including 1D and 2D NMR. From the petroleum ether extract, four abietane-type diterpenoids, including a new abietane-type diterpenoid, named atropatanene (1), together with three known diterpenoids, 7α-acetoxyroyleanone (2), and a mixture of two isomers, saprorthoquinone and aethiopinone (3+4), were isolated. The latter exhibited substantial cytotoxicity with IC₅₀ value of 8.73 μg/ml against PC3 cells and led to an increasing number of cells in the subG1 region and an increase in the amount of Bax and cleavage of PARP protein, indicating apoptotic cell death. Owing to its numerous biological activities, Salvia species could be represented as a natural potential source against several cancer cell lines.

Antiproliferative and apoptosis inducing effects of the methanolic extract of Centaurea hermannii in human cervical cancer cell line

We investigated the antiproliferative and apoptosis inducing effects of a methanolic extract of Centaurea hermannii in Vero and HeLa cell lines. Both cell lines also were treated with doxorubicin. Antiproliferative effects were assessed by MTT assay and cell index parameters were determined using the xCELLigence real time cell analysis system (RTCA). The IC₅₀, the half maximal inhibitory concentration, and selectivity index (SI) values for doxorubicin and the C. hermannii extract were determined for both cell lines. At 48 h culture, the C. hermannii extract exhibited a potent cytotoxic effect in HeLa cells. Our MTT findings were consistent with morphological evaluation and analysis by the xCELLigence RTCA. The apoptosis inducing effect of the C. hermannii extract in HeLa cells was determined by flow cytometry; caspases 3, 7 and 9 activation assays; and quantitative reverse transcription polymerase chain reaction analysis. Our findings suggest that components of C. hermannii extract should be investigated as possible anticancer drugs.

Applications of Sesquiterpene Lactones: A Review of Some Potential Success Cases

Sesquiterpene lactones, a vast range of terpenoids isolated from Asteraceae species, exhibit a broad spectrum of biological effects and several of them are already commercially available, such as artemisinin. Here the most recent and impactful results of in vivo, preclinical and clinical studies involving a selection of ten sesquiterpene lactones (alantolactone, arglabin, costunolide, cynaropicrin, helenalin, inuviscolide, lactucin, parthenolide, thapsigargin and tomentosin) are presented and discussed, along with some of their derivatives. In the authors’ opinion, these compounds have been neglected compared to others, although they could be of great use in developing important new pharmaceutical products. The selected sesquiterpenes show promising anticancer and anti-inflammatory effects, acting on various targets. Moreover, they exhibit antifungal, anxiolytic, analgesic, and antitrypanosomal activities. Several studies discussed here clearly show the potential that some of them have in combination therapy, as sensitizing agents to facilitate and enhance the action of drugs in clinical use. The derivatives show greater pharmacological value since they have better pharmacokinetics, stability, potency, and/or selectivity. All these natural terpenoids and their derivatives exhibit properties that invite further research by the scientific community.

Wild and Cultivated Centaurea raphanina subsp. mixta: A Valuable Source of Bioactive Compounds

Centaurea raphanina subsp. mixta (DC.) Runemark is a wild edible species endemic to Greece. This study evaluated the chemical composition and bioactive properties of wild and cultivated C. raphanina subsp. mixta plants. Wild plants had higher nutritional value than cultivated ones, whereas cultivated plants contained more tocopherols. Glucose and sucrose were higher in cultivated plants and trehalose in wild ones. Oxalic and total organic acids were detected in higher amounts in cultivated samples. The main fatty acids were α-linolenic, linoleic and palmitic acid, while wild plants were richer in polyunsaturated fatty acids. Two pinocembrin derivatives were the main phenolic compounds being detected in higher amounts in wild plants. Regarding the antioxidant activity, wild and cultivated plants were more effective in the oxidative haemolysis (OxHLIA) and thiobarbituric acid reactive substances (TBARS) assays, respectively. Moreover, both extracts showed moderate cytotoxicity in non-tumor cell lines (PLP2), while cultivated plants were more effective against cervical carcinoma (HeLa), breast carcinoma (MCF-7) and non-small lung cancer (NCI-H460) cell lines. Finally, wild plants showed higher antimicrobial activity than cultivated plants against specific pathogens. In conclusion, the cultivation of C.raphanina subsp. mixta showed promising results in terms of tocopherols content and antiproliferative effects, however further research is needed to decrease oxalic acid content.

Chemical composition, in vitro antioxidant and antibacterial activities of Centaurea resupinata subsp. dufourii (dostál) greuter

The current study focuses on the chemical composition, and evaluation of antioxidant and antibacterial activity of the aerial parts of Centaurea resupinata subsp. dufourii. Using different chromatographic methods nine compounds 1-9 were isolated. The structural identification of isolated compounds was achieved using several spectroscopic methods NMR techniques (¹H NMR, ¹³C NMR, COSY, HSQC, HMBC) and mass spectroscopy (ESI-MS) and by comparison with literature data. The structures of these compounds were identified as nicotiflorin (1), apigetrin (2), chrysoeriol (3), apigenin (4), chrysin (5), daucosterol (6), β-sitosterol (7), taraxastrerol (8) and lupeol (9). The antibacterial and antioxidant activities of ethyl acetate and n-butanol extracts have been evaluated. The antioxidant activity was assessed in vitro using DPPH radical scavenging method, which showed that ethyl acetate extract possessed an interesting antioxidant potential (IC₅₀ = 36.263 ± 0.005 μg/mL).

Sesquiterpene Lactones and Flavonoids from Psephellus pyrrhoblepharus with Antiproliferative Activity on Human Gynecological Cancer Cell Lines

Multistep chromatographic separations of the chloroform extract of the Turkish endemic plant Psephellus pyrrhoblepharus (Boiss.) Wagenitz (syn. Centaurea pyrrhoblephara Boiss.) resulted in the isolation of six guaianolid-type sesquiterpenes, chlorojanerin (1), 19-deoxychlorojanerin (2), 15-hydroxyjanerin (3), aguerin B (4), cynaropicrin (5), eleganin (6); three flavonoids, apigenin, 6-methoxyluteolin and jaceosidine; two glycosides, benzyl-1-O-β-d-glucoside and 3(Z)-hexenyl-1-O-β-d-glucoside; and the coumarin scopoletin. The structures were established by the interpretation of their ESI-MS and 1D and 2D NMR data including ¹H-NMR, JMOD, ¹H,¹H-COSY, HSQC, HMBC, and NOESY experiments. All compounds were isolated for the first time from P. pyrrhoblepharus. Compounds 1-6, the isolated flavonoids and scopoletin were evaluated for their antiproliferative activities on human gynecological cancer cell lines (SiHa, HeLa, and MDA-MB-231 cells) using the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. Chlorojanerin (1), 19-deoxychlorojanerin (2), aguerin B (4), cynaropicrin (5), eleganin (6) were shown to have noteworthy effects on all of the tested cell lines, while apigenin, jaceosidine, and 6-methoxyluteolin were moderately active on HeLa cells. The highest activities were demonstrated by the chlorine-containing derivatives chlorojanerin (1) and 19-deoxychlorojanerin (2) with IC₅₀ values of 2.21 and 2.88 µM, respectively, against the triple negative breast cancer model MDA-MB-231 cells.

Centaurea microcarpa Coss. & Dur. (Asteraceae) extracts: New cyanogenic glucoside and other constituents

The phytochemical investigation of both chloroform and ethyl acetate extracts of Centaurea microcarpa Coss. & Dur. led to the isolation of a new cyanogenic glucoside 6'-methacrylate prunasin (3) together with seven known compounds: hydroxy-11β,13-dihydro onopordaldehyde (1), β-sitosterol (2), daucosterol (4), nepetin (5), prunasin (6), astragalin (7) and 7-O-β-D-glucopyranosyl centaureidin (8). Their structures were established by spectral analysis, mainly UV, IR, ESI-MS, 1D & 2D-NMR experiments (COSY, HSQC, HMBC and ROESY).

Artesunate ameliorates high glucose-induced rat glomerular mesangial cell injury by suppressing the TLR4/NF-κB/NLRP3 inflammasome pathway

Inflammatory response is important for the development and progression of diabetic nephropathy (DN). Artesunate (ART), an antimalarial drug, possesses anti-inflammatory effect and exhibits protective effect on chronic kidney diseases. However, the effect of ART on DN is unknown. The aim of the present study was to evaluate the effect and the molecular mechanism of ART on DN in an in vitro model. The rat mesangial cell line, HBZY-1, was induced by high glucose (HG; 30 mM d-glucose) in the presence or absence of ART (15 and 30 μg/ml) and incubated for 24 h. We found that HG induced the proliferation of HBZY-1 cells, while treatment with ART inhibited the cell proliferation. Treatment with ART inhibited HG-induced inflammatory cytokines production and expression of extracellular matrix (ECM). Besides, HG induced reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and inhibited the superoxide dismutase (SOD) activity of HBZY-1 cells, and the effects were attenuated by ART treatment. ART decreased HG-induced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation primary response gene 88 (MyD88), nuclear factor κB (NF-κB) p-p65, and nod-like receptor protein 3 (NLRP3). Inhibition of the TLR4/NF-κB pathway suppressed NLRP3 inflammasome in HBZY-1 cells. In conclusion, ART exhibited protective effect on HG-induced HBZY-1 cells by inhibiting the inflammatory response, oxidative stress and ECM accumulation. The TLR4/NF-κB/NLRP3 inflammasome pathway was involved in the protective effect of ART. The results suggested that ART might be a potential therapy agent for the DN treatment.

Bio-guided isolation of Centaurea bruguierana subsp. belangerana cytotoxic components

Centaurea bruguierana subsp. belangerana was extracted by 80% ethanol. The total extract was then partitioned into four fractions including chloroform, ethyl acetate and methanol. Cytotoxic effect of fractions was examined by MTT assay in K562 (chronic myelogenous leukemia), AGS (gastric adenocarcinoma), MCF-7 (breast adenocarcinoma) and SW742 (colon adenocarcinoma) cell lines. The Chloroform fraction, with the lowest LC₅₀ against K-562 cell lines, was partitioned into 14 subfractions and subjected to further purification by reversed-phase (C18) silica gel and sephadex LH-20 column chromatography. Three flavonoids including cirsimaritin, cirsilinelol and eupatilin were isolated for the first time from the species and the structures were confirmed by spectroscopic data. The high selectivity index of the purified flavonoids indicates valuable components with potential few side effects for normal cell lines. However, solubility tests for isolated components indicates the need for novel pharmaceutical dosage forms, in the case for using natural flavonoids as chemotherapeutic agents.