N-(p-coumaroyl) serotonin inhibits glioblastoma cells growth through triggering S-phase arrest and apoptosis

Targeting glioma with heteroaromatic alkaloids: A review of potential therapeutics

Glioblastoma multiforme (GBM), classified as a grade IV astrocytoma, is the most aggressive and deadly form of glioma, characterized by rapid progression, extensive genetic heterogeneity, and resistance to conventional therapies. Despite advancements in surgical techniques, radiation therapy, and the frontline chemotherapeutic agent temozolomide, the prognosis for GBM patients remains poor, with a median survival of 15 months and a 5-year survival rate of approximately 7 %. The absence of effective long-term treatments underscores the urgent, unmet clinical need for novel therapeutic strategies to improve patient outcomes. Natural products, particularly alkaloids, have garnered attention as a rich source of bioactive compounds with diverse pharmacological properties. Alkaloids, a structurally diverse group of natural products, are renowned for their chemotherapeutic properties and ability to cross the blood-brain barrier (BBB), making them promising candidates for glioma therapy. This review systematically examines all reported heteroaromatic alkaloids with documented anti-glioma activities, highlighting their mechanisms of action where available. By providing a comprehensive resource, it aims to facilitate the identification and optimisation of alkaloid-based compounds for glioma-targeted drug discovery. Additionally, this review emphasizes the importance of incorporating natural products into the drug development pipeline to address the pressing challenges associated with glioma, particularly GBM treatment.

Two-Step Flow Amidation of Natural Phenolic Acids as Antiradical and Antimicrobial Agents

Natural hydroxycinnamic acid amides (HCAAs) and riparins offer significant health benefits. However, their extraction from natural sources is difficult, and traditional synthetic methods remain wasteful, raising the need for more efficient alternatives. In this work, a two-step chemo-enzymatic flow method for the efficient esterification and amidation of phenolic acids was developed and successfully applied to the synthesis of riparin derivatives and HCAAs. The flow Fischer esterification was optimized using vanillic acid as a model starting material and SiliaBond Tosic Acid (SCX-3) as an immobilized acid catalyst, achieving a quantitative yield in a short residence time. The following amidation step, catalyzed by immobilized Candida antarctica lipase B, was optimized in toluene, leading to the desired amides. The synthesized compounds were evaluated for their radical scavenging, antibacterial, and antileishmanial properties. Overall, this work disclosed a novel approach for the efficient synthesis of riparin derivatives and HCAAs with interesting biological properties.

p-Coumaroyl Amides from the Plant Kingdom: A Comprehensive Review of Natural Sources, Biosynthesis, and Biological Activities

Hydroxycinnamic acids are widely distributed in the plant kingdom, both as free compounds and as conjugates with other molecules, such as amino acids, carbohydrates, alcohols or amines, and polyamines, forming different derivatives, such as amides, esters, thioesters, or ethers. Among the different hydroxycinnamic acids, p-coumaric acid has a high bioavailability and its amide derivatives, also known as phenolamides (PAs) and hydroxycinnamic acid amides (HCAAs), play specific roles in plant development and defense. They are also involved in several biological activities that affect human health. The present review collected data and described secondary and tertiary amides of p-coumaric acids found in plants, from their natural sources to their biosynthesis. The review also described the acyl-transferase mechanisms involved in their formation, their roles in plants, as well as studies of their biological activities in humans.

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.

A review of natural products and small-molecule therapeutics acting on central nervous system malignancies: Approaches for drug development, targeting pathways, clinical trials, and challenges

In 2021, the World Health Organization released the fifth edition of the central nervous system (CNS) tumor classification. This classification uses histopathology and molecular pathogenesis to group tumors into more biologically and molecularly defined entities. The prognosis of brain cancer, particularly malignant tumors, has remained poor worldwide, approximately 308,102 new cases of brain and other CNS tumors were diagnosed in the year 2020, with an estimated 251,329 deaths. The cost and time-consuming nature of studies to find new anticancer agents makes it necessary to have well-designed studies. In the present study, the pathways that can be targeted for drug development are discussed in detail. Some of the important cellular origins, signaling, and pathways involved in the efficacy of bioactive molecules against CNS tumorigenesis or progression, as well as prognosis and common approaches for treatment of different types of brain tumors, are reviewed. Moreover, different study tools, including cell lines, in vitro, in vivo, and clinical trial challenges, are discussed. In addition, in this article, natural products as one of the most important sources for finding new chemotherapeutics were reviewed and over 700 reported molecules with efficacy against CNS cancer cells are gathered and classified according to their structure. Based on the clinical trials that have been registered, very few of these natural or semi-synthetic derivatives have been studied in humans. The review can help researchers understand the involved mechanisms and design new goal-oriented studies for drug development against CNS malignancies.

Advances in glioblastoma multiforme: Integrating therapy and pathology perspectives

Glioblastoma, a highly lethal form of brain cancer, is characterized by its aggressive growth and resistance to conventional treatments, often resulting in limited survival. The response to therapy is notably influenced by various patient-specific genetic factors, underscoring the disease's complexity. Despite the utilization of diverse treatment modalities such as surgery, radiation, and chemotherapy, many patients experience local relapse, emphasizing the critical need for improved therapeutic strategies to effectively target these formidable tumors. Recent years have witnessed a surge in interest in natural products derived from plants, particularly alkaloids, for their potential anticancer effects. Alkaloids have shown promise in cancer chemotherapy by selectively targeting crucial signaling pathways implicated in tumor progression and survival. Specifically, they modulate the NF-κB and MAPK pathways, resulting in reduced tumor growth and altered gene expression across various cancer types. Additionally, alkaloids exhibit the capacity to induce cell cycle arrest, further impeding tumor proliferation in several malignancies. This review aims to delineate recent advances in understanding the pathology of glioblastoma multiforme (GBM) and to explore the potential therapeutic implications of alkaloids in managing this deadly disease. By segregating discussions on GBM pathology from those on alkaloid-based therapies, we provide a structured overview of the current challenges in GBM treatment and the promising opportunities presented by alkaloid-based interventions. Furthermore, we briefly discuss potential future directions in GBM research and therapy beyond alkaloids, including emerging treatment modalities or areas of investigation that hold promise for improving patient outcomes. In conclusion, our efforts offer hope for enhanced outcomes and improved quality of life for GBM patients through alkaloid-based therapies. By integrating insights from pathology and therapeutic perspectives, we underscore the significance of a comprehensive approach in addressing this devastating disease.

HormonomicsDB: a novel workflow for the untargeted analysis of plant growth regulators and hormones

Background

Metabolomics is the simultaneous determination of all metabolites in a system. Despite significant advances in the field, compound identification remains a challenge. Prior knowledge of the compound classes of interest can improve metabolite identification. Hormones are a small signaling molecules, which function in coordination to direct all aspects of development, function and reproduction in living systems and which also pose challenges as environmental contaminants. Hormones are inherently present at low levels in tissues, stored in many forms and mobilized rapidly in response to a stimulus making them difficult to measure, identify and quantify.

Methods

An in-depth literature review was performed for known hormones, their precursors, metabolites and conjugates in plants to generate the database and an RShiny App developed to enable web-based searches against the database. An accompanying liquid chromatography - mass spectrometry (LC-MS) protocol was developed with retention time prediction in Retip. A meta-analysis of 14 plant metabolomics studies was used for validation.

Results

We developed HormonomicsDB, a tool which can be used to query an untargeted mass spectrometry (MS) dataset against a database of more than 200 known hormones, their precursors and metabolites. The protocol encompasses sample preparation, analysis, data processing and hormone annotation and is designed to minimize degradation of labile hormones. The plant system is used a model to illustrate the workflow and data acquisition and interpretation. Analytical conditions were standardized to a 30 min analysis time using a common solvent system to allow for easy transfer by a researcher with basic knowledge of MS. Incorporation of synthetic biotransformations enables prediction of novel metabolites.

Conclusions

HormonomicsDB is suitable for use on any LC-MS based system with compatible column and buffer system, enables the characterization of the known hormonome across a diversity of samples, and hypothesis generation to reveal knew insights into hormone signaling networks.

Antineoplastic Activity of 9″-Lithospermic Acid Methyl Ester in Glioblastoma Cells

To date, many potent compounds have been found which are derived from plants and herbs and possess anticancer properties due to their antioxidant effects. 9″-Lithospermic acid methyl ester is an effective natural compound derived from the Thymus thracicus Velen. It has been proven that this compound has substantial properties in different diseases, but its effects in cancer have not been thoroughly evaluated. The aim of this work was to study the effects of 9″-Lithospermic acid methyl ester (9″-methyl lithospermate) in U87 and T98 glioblastoma cell lines. Its effects on cellular viability were assessed via Trypan Blue and Crystal Violet stains, the cell cycle analysis through flow cytometry, and cell migration by employing the scratch wound healing assay. The results demonstrated that 9″-methyl lithospermate was able to inhibit cellular proliferation, induce cellular death, and inhibit cell migration. Furthermore, these results were intensified by the addition of temozolomide, the most prominent chemotherapeutic drug in glioblastoma tumors. Further studies are needed to reproduce these findings in animal models and investigate if 9″-lithospermic acid methyl ester represents a potential new therapeutic addition for gliomas.

Naturally derived indole alkaloids targeting regulated cell death (RCD) for cancer therapy: from molecular mechanisms to potential therapeutic targets

Regulated cell death (RCD) is a critical and active process that is controlled by specific signal transduction pathways and can be regulated by genetic signals or drug interventions. Meanwhile, RCD is closely related to the occurrence and therapy of multiple human cancers. Generally, RCD subroutines are the key signals of tumorigenesis, which are contributed to our better understanding of cancer pathogenesis and therapeutics. Indole alkaloids derived from natural sources are well defined for their outstanding biological and pharmacological properties, like vincristine, vinblastine, staurosporine, indirubin, and 3,3′-diindolylmethane, which are currently used in the clinic or under clinical assessment. Moreover, such compounds play a significant role in discovering novel anticancer agents. Thus, here we systemically summarized recent advances in indole alkaloids as anticancer agents by targeting different RCD subroutines, including the classical apoptosis and autophagic cell death signaling pathways as well as the crucial signaling pathways of other RCD subroutines, such as ferroptosis, mitotic catastrophe, necroptosis, and anoikis, in cancer. Moreover, we further discussed the cross talk between different RCD subroutines mediated by indole alkaloids and the combined strategies of multiple agents (e.g., 3,10-dibromofascaplysin combined with olaparib) to exhibit therapeutic potential against various cancers by regulating RCD subroutines. In short, the information provided in this review on the regulation of cell death by indole alkaloids against different targets is expected to be beneficial for the design of novel molecules with greater targeting and biological properties, thereby facilitating the development of new strategies for cancer therapy.

An NF-κB- and Therapy-Related Regulatory Network in Glioma: A Potential Mechanism of Action for Natural Antiglioma Agents

High-grade gliomas are among the most aggressive malignancies, with significantly low median survival. Recent experimental research in the field has highlighted the importance of natural substances as possible antiglioma agents, also known for their antioxidant and anti-inflammatory action. We have previously shown that natural substances target several surface cluster of differentiation (CD) markers in glioma cells, as part of their mechanism of action. We analyzed the genome-wide NF-κB binding sites residing in consensus regulatory elements, based on ENCODE data. We found that NF-κB binding sites reside adjacent to the promoter regions of genes encoding CD markers targeted by antiglioma agents (namely, CD15/FUT4, CD28, CD44, CD58, CD61/SELL, CD71/TFRC, and CD122/IL2RB). Network and pathway analysis revealed that the markers are associated with a core network of genes that, altogether, participate in processes that associate tumorigenesis with inflammation and immune evasion. Our results reveal a core regulatory network that can be targeted in glioblastoma, with apparent implications in individuals that suffer from this devastating malignancy.

Safflower Seed Extract Attenuates the Development of Osteoarthritis by Blocking NF-κB Signaling

Although safflower seed extract exhibits pharmacological activity against various diseases, the effects of its individual compounds on osteoarthritis (OA) have not been elucidated. Here, we evaluated the effects of these extracts and their single compounds on OA. N-(p-Coumaroyl) serotonin and N-feruloyl serotonin, main components of safflower seed extract, were isolated by high-performance liquid chromatography. Under in vitro OA mimic conditions, the expression of the matrix metalloproteinases (MMPs) MMP3/13 and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) ADAMTS5 were reduced in mouse chondrocytes treated with safflower seed extract. Furthermore, the oral administration of safflower seed extract attenuated cartilage destruction in a mouse OA model induced by destabilization of the medial meniscus. N-(p-Coumaroyl) serotonin and N-feruloyl serotonin, but not serotonin, reduced MMP3, MMP13, and ADAMTS5 expression in IL-1β-treated chondrocytes. Additionally, they significantly blocked the nuclear factor-κB (NF-κB) pathway by inhibiting IκB degradation and p65 phosphorylation. Our results suggest that safflower seed extract and its single compounds can attenuate cartilage destruction by suppressing MMP and ADMATS5 expression. The anti-arthritic effects are mediated by NF-κB signaling and involve the inhibition of IκB degradation and p65 phosphorylation. These results indicate that safflower seed extract may serve as a novel therapeutic agent against OA.

Cellular and Molecular Mechanisms Underlying Glioblastoma and Zebrafish Models for the Discovery of New Treatments

Glioblastoma (GBM) is the most common of all brain malignant tumors; it displays a median survival of 14.6 months with current complete standard treatment. High heterogeneity, aggressive and invasive behavior, the impossibility of completing tumor resection, limitations for drug administration and therapeutic resistance to current treatments are the main problems presented by this pathology. In recent years, our knowledge of GBM physiopathology has advanced significantly, generating relevant information on the cellular heterogeneity of GBM tumors, including cancer and immune cells such as macrophages/microglia, genetic, epigenetic and metabolic alterations, comprising changes in miRNA expression. In this scenario, the zebrafish has arisen as a promising animal model to progress further due to its unique characteristics, such as transparency, ease of genetic manipulation, ethical and economic advantages and also conservation of the major brain regions and blood-brain-barrier (BBB) which are similar to a human structure. A few papers described in this review, using genetic and xenotransplantation zebrafish models have been used to study GBM as well as to test the anti-tumoral efficacy of new drugs, their ability to interact with target cells, modulate the tumor microenvironment, cross the BBB and/or their toxicity. Prospective studies following these lines of research may lead to a better diagnosis, prognosis and treatment of patients with GBM.

The Past, Present and Future of Flow Cytometry in Central Nervous System Malignancies

Central nervous system malignancies (CNSMs) are categorized among the most aggressive and deadly types of cancer. The low median survival in patients with CNSMs is partly explained by the objective difficulties of brain surgeries as well as by the acquired chemoresistance of CNSM cells. Flow Cytometry is an analytical technique with the ability to quantify cell phenotype and to categorize cell populations on the basis of their characteristics. In the current review, we summarize the Flow Cytometry methodologies that have been used to study different phenotypic aspects of CNSMs. These include DNA content analysis for the determination of malignancy status and phenotypic characterization, as well as the methodologies used during the development of novel therapeutic agents. We conclude with the historical and current utility of Flow Cytometry in the field, and we propose how we can exploit current and possible future methodologies in the battle against this dreadful type of malignancy.

Phenolamides: Plant specialized metabolites with a wide range of promising pharmacological and health-promoting interests

Phenolamides constitute a family of metabolites, widely represented in the plant kingdom, that can be found in all plant organs with a predominance in flowers and pollen grains. They represent a large and structurally diverse family, resulting from the association of phenolic acids with aliphatic or aromatic amines. Initially revealed as active compounds in several medicinal plant extracts, phenolamides have been extensively studied for their health-promoting and pharmacological properties. Indeed, phenolamides have been shown to exhibit antioxidant, anti-inflammatory, anti-cancer and antimicrobial properties, but also protective effects against metabolic syndrome and neurodegenerative diseases. The purpose of this review is to summarise this large body of literature, including in vitro and in vivo studies, by describing the diversity of their biological properties and our actual knowledge of the molecular mechanisms behind them. With regard to their considerable pharmacological interest, the question of industrial production is also tackled through chemical and biological syntheses in engineered microorganisms. The diversity of biological activities already described, together with the active discovery of the broad structural diversity of this metabolite family, make phenolamides a promising source of new active compounds on which future studies should be focused.

The Chemistry and Health Benefits of Dietary Phenolamides

Phenolamides, also known as hydroxycinnamic acid amides or phenylamides, have been reported throughout the plant kingdom, while a few of these amine-conjugated hydroxycinnamic acids are unique in foods. The current knowledge of their specific functions in plant development and defense is readily available as is their biosynthesis; however, their functionality in humans is still largely unknown. Of the currently known phenolamides, the most common are avenanthramides, which are unique in oats and similar to the well-known drug Tranilast, which possess anti-inflammatory, antioxidant, anti-itch, and antiatherogenic activities. While recent data have brought to light more information regarding the other known phenolamides, such as hordatines, dimers of agmatine conjugated to hydroxycinnamic acid, and kukoamines, spermine-derived phenolamides, the information is still severely limited, leaving their potential health benefits to speculation. Herein, to highlight the importance of dietary phenolamides to human health, we review and summarize the four major subgroups of phenolamides, including their chemical structures, dietary sources, and reported health benefits. We believe that the studies on phenolamides are still in the infancy stage and additional health benefits of these phenolamides may yet be identified.

Abuhamad A, Syahir A. Understanding Glioblastoma Biomarkers: Knocking a Mountain with a Hammer

Gliomas are the most frequent and deadly form of human primary brain tumors. Among them, the most common and aggressive type is the high-grade glioblastoma multiforme (GBM), which rapidly grows and renders patients a very poor prognosis. Meanwhile, cancer stem cells (CSCs) have been determined in gliomas and play vital roles in driving tumor growth due to their competency in self-renewal and proliferation. Studies of gliomas have recognized CSCs via specific markers. This review comprehensively examines the current knowledge of the most significant CSCs markers in gliomas in general and in glioblastoma in particular and specifically focuses on their outlook and importance in gliomas CSCs research. We suggest that CSCs should be the superior therapeutic approach by directly targeting the markers. In addition, we highlight the association of these markers with each other in relation to their cascading pathways, and interactions with functional miRNAs, providing the role of the networks axes in glioblastoma signaling pathways.

Deglucohellebrin: A Potent Agent for Glioblastoma Treatment

BACKGROUND

Glioblastoma is the most common primary brain tumor in adults with a dismal prognosis. To date, several anticancer agents have been isolated from plants. Helleborus odorus subsp. Cyclophyllus is an endemic plant of the Balcan flora. Herewith, we investigated for the first time, the anti-glioma effect of deglucohellebrin (DGH) extracted from the roots of Helleborus.

METHODS

We investigated the effect of DGH in U251MG, T98G and U87G glioblastoma cell lines. We selected the T98G cells because of their inherent temozolomide resistance.

RESULTS

The IC50 value of reduced viability for DGH was 7x10-5M in U251MG cells, 5x10-5M for the T98G cells and 4x10-5M in U87G cells during 72h treatment. DGH induced G2/M cell cycle arrest, caspace-8 activation and significant mitochondrial membrane depolarization, suggesting the activation of the intrinsic, mitochondrial- dependent apoptotic pathway. DGH and temozolomide induced changes in CDs' expression in U251MG and T98G cells. In zebrafish, DGH did not induce toxicity or behavioral alterations.

CONCLUSION

The present study is the first to determine the anti-glioma activity of DGH. DGH may be a potent agent for glioblastoma treatment and further studies are needed.

Anti-Tumor Activity of Cembranoid-Type Diterpenes Isolated from Nicotiana tabacum L

Recently, the incidence of hepatocellular carcinoma has increased worldwide. Cembranoid-type diterpenes (CBDs) from tobacco exhibit good antimicrobial, antitumor, and neuroprotective activities. Therefore, in this study, we isolated CBDs from Nicotiana tabacum L. and evaluated their antitumor activity against hepatoma cell lines. Particularly, the anti-tumor activity of α-2,7,11-cyprotermine-4,6-diol (α-CBD) was investigated against HepG2, SMMC-7721, and HL-7702 cells. The MTT assay revealed that α-CBD reduced the formation of cell clones and inhibited the proliferation of hepatocellular carcinoma cells. Morphological observations showed that α-CBD altered cell morphology and membrane permeability before inducing apoptosis. To further explore the antitumor mechanism of α-CBD, flow cytometry and transcriptome analysis were performed using HepG2 cells. The results showed that the number of HepG2 cells increased from 10.4% to 29.8%, indicating that α-CBD inhibits the proliferation of hepatocellular carcinoma cells in the S phase. The gene expression analysis of HepG2 cells treated with α-CBD showed 3068 genes with altered expression, among which 1289 were upregulated and 1779 were downregulated. Apoptosis induced by these differentially expressed genes might be mediated by the p53-PUMA, PI3K-Akt, and IL-1-NF-κB-IAP pathways. Comprehensively, our study shows that α-CBD isolated from N. tabacum L. can be potentially used as a natural antitumor agent.