Isolation of Secondary Metabolites from Achillea grandifolia Friv. (Asteraceae) and Main Compounds' Effects on a Glioblastoma Cellular Model

Identification, targeted separation, and in vivo and in vitro anti-vascular endothelial injury abilities of bioactive compounds from Acanthopanax senticosus

Acanthopanax senticosus (Rupr. et Maxim.) Harms, a traditional medicinal and edible crop cultivated in China, exhibits extensive biological activities. In the present research, a screening and targeted isolation method using affinity ultrafiltration-UPLC-MS with GNPS (AUF-LC-MS-GNPS) methods was established and used to further verify the protective effect and potential mechanism of monomers on a vascular endothelial injury model. By utilizing the AUF-LC-MS-GNPS strategy, 9 potential active monomers were target isolated and 22 other compounds were obtained from Acanthopanax senticosus. The anti-endothelial injury activity of the monomers was further verified through in vitro cell experiments, which showed that the 9 monomers had protective effects on HUVECs damaged by oxidized low-density lipoprotein (ox-LDL), and could increase the levels of endothelial nitric oxide synthase (eNOS) and vascular endothelial growth factor A (VEGFA) while reducing the level of endothelin (ET)-1. Furthermore, an in vivo zebrafish experiment against lipopolysaccharide (LPS) damage proved the protective effects of the isolated monomers. Our research established a bioactive screening and targeted separation method by comprehensively utilizing an AUF, LC-MS and GNPS network. Concurrently, Acanthopanax senticosus may be a natural source of bioactive components, as well as possessing anti-endothelial injury activity.

Synergistic Anti-Cancer Effects of Isocnicin and Radiotherapy in Glioblastoma: A Natural Compound's Potential

BACKGROUND/OBJECTIVES

Glioblastoma (GBM) is the most aggressive type of brain tumor in adults. Currently, the only treatments available are surgery, radiotherapy, and chemotherapy based on temozolomide (TMZ); however, the prognosis is dismal. Several natural substances are under investigation for cancer treatment. 8α-O-(3,4-dihydroxy-2-methylenebutanoyloxy) dehydromelitensine (Isocnicin) is a natural compound derived from Centaurea species and was found to exhibit cytostatic/cytotoxic effect against different cell lines. In this study, we investigated the anti-glioma effects of isocnicin in U87 and T98 glioblastoma cell lines, as well as the effects of combined treatment with radiotherapy.

METHODS

Cell viability was evaluated with the trypan blue exclusion assay, cell cycle distribution was examined using flow cytometry, and the effects of the combination treatment were analyzed with CompuSyn software(1.0).

RESULTS

The result showed that isocnicin significantly reduced cell viability in U87 and T98 cell lines in a dose-dependent manner and IC50 values were calculated. Administration of isocnicin alone induced both S and G2/M cell cycle arrest in U87 and T98 cells in a dose-dependent manner. Moreover, when cells were treated with increasing concentrations of isocnicin, followed by 2 or 4 Gy of radiation, the percentage distribution of the cells in the G2/M phase was increased considerably in both U87 and T98 cell lines.

CONCLUSIONS

Here, we show for the first time that co-treatment of isocnicin with radiation exerts a synergistic antiproliferative effect in glioblastoma cell lines. Natural compounds are promising for glioblastoma treatment. Further studies will be necessary to unravel isocnicin's mechanism of action and its synergistic effect with radiation on glioblastoma treatment.

Secondary Metabolites and Their Biological Evaluation from the Aerial Parts of Staehelina uniflosculosa Sibth. & Sm. (Asteraceae)

Phytochemical investigation of Staehelina uniflosculosa Sibth. & Sm. resulted in the isolation of twenty-two natural products: eleven sesquiterpene lactones, artemorin (1), tamirin (2), tanachin (3), reynosin (4), baynol C (5), desacetyl-β-cyclopyrethrosin (6), 1β-hydroxy-4α-methoxy-5α,7α,6β-eudesm-11(13)-en-6,12-olide (7), 1β,4α,6α-trihydroxyeudesm-11-en-8α,12-olide (8), 1β-hydroxy-arbusculin A (9), methyl-1β,4α,6α-trihydroxy-5α,7αH-eudesm-11(13)-en-12-oate (10) and methyl-1β,6α,8α-trihydroxy-5α,7αH-eudesma-4(15),11(13)-dien-12-oate (11); one lignan, pinoresinol (12); one norisoprenoid, loliolide (13); six flavonoids (four genins and two glycosides), hispidulin (14), nepetin (15), jaceosidin (16), eriodictyol (17), eriodictyol-3'-O-β-D-glucoside (18) and eriodictyol-7-O-β-D-glucuronide (19); and three phenolic derivatives (one phenolic acid and two phenolic glucosides), protocatechuic acid (20), arbutin (21) and nebrodenside A (22). From the isolated compounds, only nepetin (15) has been reported previously from the Staehelina genus and, to the best of our knowledge, it is the first time that compound (18) has been identified in Asteraceae. A number of these substances were tested for (a) inhibition of lipoxygenase and acetylocholinesterase, (b) their antioxidant activity using the DPPH (1,1-Diphenyl-2-picrylhydrazyl) method or/and (c) inhibition of lipid peroxidation. The tested components exhibited low antioxidant activity with the exception of 5 and 22, while the effectiveness of these compounds in the inhibition of acetylocholinesterase is limited. Furthermore, Molinspiration, an online computer tool, was used to determine the bioactivity ratings of the isolated secondary metabolites. The compounds' bioactivity ratings for potential therapeutic targets were very promising.

New Avenues and Major Achievements in Phytocompounds Research for Glioblastoma Therapy

Phytocompounds have been evaluated for their anti-glioblastoma actions for decades, with promising results from preclinical studies but only limited translation into clinics. Indeed, by targeting multiple signaling pathways deregulated in cancer, they often show high efficacy in the in vitro studies, but their poor bioavailability, low tumor accumulation, and rapid clearance compromise their efficacy in vivo. Here, we present the new avenues in phytocompound research for the improvement of glioblastoma therapy, including the ways to enhance the response to temozolomide using phytochemicals, the current focus on phytocompound-based immunotherapy, or the use of phytocompounds as photosensitizers in photodynamic therapy. Moreover, we present new, intensively evaluated approaches, such as chemical modifications of phytochemicals or encapsulation into numerous types of nanoformulations, to improve their bioavailability and delivery to the brain. Finally, we present the clinical trials evaluating the role of phytocompounds or phytocompound-derived drugs in glioblastoma therapy and the less studied phytocompounds or plant extracts that have only recently been found to possess promising anti-glioblastoma properties. Overall, recent advancements in phytocompound research are encouraging; however, only with more 3D glioblastoma models, in vivo studies, and clinical trials it is possible to upgrade the role of phytocompounds in glioblastoma treatment to a satisfactory level.

Chemical Constituents and Anticancer Activities of the Extracts from Phlomis × commixta Rech. f. (P. cretica × P. lanata)

The present work is the first report on the ingredients of the P. × commixta hybrid, a plant of the genus Phlomis. So far, thirty substances have been isolated by various chromatographic techniques and identified by spectroscopic methods, such as UV/Vis, NMR, GC-MS and LC-MS. The compounds are classified as flavonoids: naringenin, eriodyctiol, eriodyctiol-7-O-β-D-glucoside, luteolin, luteolin-7-O-β-D-glucoside, apigenin, apigenin-7-O-β-D-glucoside, diosmetin-7-O-β-D-glucoside, quercetin, hesperetin and quercetin-3-O-β-D-glucoside; phenylpropanoids: martynoside, verbascoside, forsythoside B, echinacoside and allysonoside; chromene: 5,7-dihydroxychromone; phenolic acids: caffeic acid, p-hydroxybenzoic acid, chlorogenic acid, chlorogenic acid methyl ester, gallic acid, p-coumaric acid and vanillic acid; aliphatic hydrocarbon: docos-1-ene; steroids: brassicasterol and stigmasterol; a glucoside of allylic alcohol, 3-O-β-D-apiofuranosyl-(1→6)-O-β-D-glucopyranosyl-oct-1-ene-3-ol, was fully characterized as a natural product for the first time. Two tyrosol esters were also isolated: tyrosol lignocerate and tyrosol methyl ether palmitate, the latter one being isolated as a natural product for the first time. Moreover, the biological activities of the extracts from the different polarities of the roots, leaves and flowers were estimated for their cytotoxic potency. All root extracts tested showed a high cytotoxic activity against the Hep2c and RD cell lines.