Update and New Insights on Future Cancer Drug Candidates From Plant-Based Alkaloids

1-Aryl-3-Ethyl-3-Methyl- and 1-Aryl-3-Methylsuccinimides as Drug Candidates for Cancer: Toxicity Prediction, Molecular Docking, and In Vitro Assessment

Twenty-four succinimide derivatives were tested for their antiproliferative effect toward steroid hormone-responsive carcinoma cell lines: estrogen positive human breast carcinoma (MCF-7), lung carcinoma (A549), colon carcinoma (HT-29), and cervix carcinoma (HeLa). In addition, their antiproliferative effect was analyzed against late-stage estrogen and progesterone negative breast carcinoma (MDA-MB-231) and for safety were also investigated against normal fetal lung (MRC-5) cell lines. Molecular docking studies were conducted to observe their binding affinity for steroid hormone receptors and BCRP/ABCG2 transporter. All analyzed succinimides exhibited antiproliferative effects on at least one carcinoma cell line and were safe toward normal fetal lung cells. Their safety was confirmed based on in silico predictions. The succinimides were binding through the same π-stock interactions for the same Phe-778 of the progesterone receptor as the proven ligand and the same Phe-439 of the BCRP as the proven substrate and inhibitor. In addition, interactions with crucial amino acid residues for ligand antagonistic effects on estrogen receptors were observed. The QSAR analysis revealed that the succinimides' binding affinity for sex hormone receptors was governed by their flatness, polarity, size, and polarizability, while the affinity to bind for BCRP was lipophilicity dependent. The succinimides antiproliferative effect on A549 cell line given as IC50 was statistically significant associated with their molar refractivity (p = 0.033), and lipophilicity (XlogP3, p = 0.043), respectively. Finally, the most promising drug candidate with the most pronounced anticancer activity was compound D11 against lung carcinoma (A549) cell lines with an IC50 comparable to doxorubicin.

Lasso peptides: A focus on therapeutic index

Lasso peptides, a significant group of ribosomally synthesized and post-translationally modified peptides (RiPPs), have emerged as potential therapeutic agents owing to their unique structural features and diverse biological activities. These peptides are characterized by an isopeptide-bonded macrolactam ring and a tail threaded through the ring, forming a distinctive lasso structure that provides remarkable stability and functionality, leading to significant therapeutic potential for antimicrobial, antiviral, anticancer, and anti-inflammatory applications. This review highlights the structural diversity and therapeutic applications of lasso peptides, emphasizing their potential as next-generation therapeutics. Additionally, while their mechanisms of action and innovative therapeutic prospects are explored, the challenges and limitations associated with their use are also discussed.

Next-generation cancer nanotherapeutics: Pluronic® F127 based mixed micelles for enhanced drug delivery

Cancer, projected to become the second leading cause of mortality globally, underscores the critical need for precise drug delivery systems. Nanotechnology, particularly micelles, has emerged as a promising avenue. These nano-sized colloidal dispersions (< 100 nm) utilize amphiphilic molecules featuring a hydrophilic tail and hydrophobic core, facilitating efficient drug encapsulation and delivery. Pluronic® F127, a triblock copolymer (PEO101-PPO56-PEO101), has emerged as a promising drug carrier due to its non-ionic, less-toxic nature, which prolongs drug circulation time and improves drug delivery across blood-brain and intestinal barriers. Mixed micelles, formed using Pluronic® F127 combined with other polymers, surfactants, and drugs, enhance drug solubility, stability, and targeted delivery. This review highlights the key features of mixed micelles, including enhanced pharmacokinetics and targeting abilities, folic acid (FA) conjugation strategies, superior cytotoxicity with reduced side effects, overcoming multidrug resistance, and versatility across various cancer types and compounds. Additionally, the potential for clinical translation of Pluronic® F127-based mixed micelle in cancer treatment is discussed, addressing current challenges and paving the way for optimized applications.

Plant Alkaloids as Promising Anticancer Compounds with Blood-Brain Barrier Penetration in the Treatment of Glioblastoma: In Vitro and In Vivo Models

Glioblastoma (GBM) is one of the most invasive central nervous system tumors, with rising global incidence. Therapy resistance and poor prognosis highlight the urgent need for new anticancer drugs. Plant alkaloids, a largely unexplored yet promising class of compounds, have previously contributed to oncology treatments. While past reviews provided selective insights, this review aims to collectively compare data from the last decade on (1) plant alkaloid-based anticancer drugs, (2) alkaloid transport across the blood-brain barrier (BBB) in vitro and in vivo, (3) alkaloid mechanisms of action in glioblastoma models (in vitro, in vivo, ex vivo, and in silico), and (4) cytotoxicity and safety profiles. Additionally, innovative drug delivery systems (e.g., nanoparticles and liposomes) are discussed. Focusing on preclinical studies of single plant alkaloids, this review includes 22 botanical families and 28 alkaloids that demonstrated anti-GBM activity. Most alkaloids act in a concentration-dependent manner by (1) reducing glioma cell viability, (2) suppressing proliferation, (3) inhibiting migration and invasion, (4) inducing cell death, (5) downregulating Bcl-2 and key signaling pathways, (6) exhibiting antiangiogenic effects, (7) reducing tumor weight, and (8) improving survival rates. The toxic and adverse effect analysis suggests that alkaloids such as noscapine, lycorine, capsaicin, chelerythrine, caffeine, boldine, and colchicine show favorable therapeutic potential. However, tetrandrine, nitidine, harmine, harmaline, cyclopamine, cocaine, and brucine may pose greater risks than benefits. Piperine's toxicity and berberine's poor bioavailability suggest the need for novel drug formulations. Several alkaloids (kukoamine A, cyclovirobuxine D, α-solanine, oxymatrine, rutaecarpine, and evodiamine) require further pharmacological and toxicological evaluation. Overall, while plant alkaloids show promise in glioblastoma therapy, progress in assessing their BBB penetration remains limited. More comprehensive studies integrating glioma research and advanced drug delivery technologies are needed.

The CDK8 kinase module: A novel player in the transcription of translation initiation and ribosomal genes

Survival following stress is dependent upon reprogramming transcription and translation. Communication between these programs following stress is critical for adaptation but is not clearly understood. The Cdk8 kinase module (CKM) of the Mediator complex modulates the transcriptional response to various stresses. Its involvement in regulating translational machinery has yet to be elucidated, highlighting an existing gap in knowledge. Here, we report that the CKM positively regulates a subset of ribosomal protein (RP) and translation initiation factor (TIF)-encoding genes under physiological conditions in Saccharomyces cerevisiae. In mouse embryonic fibroblasts and HCT116 cells, the CKM regulates unique sets of RP and TIF genes, demonstrating some conservation of function across species. In yeast, this is mediated by Cdk8 phosphorylation of one or more transcription factors which control RP and TIF expression. Conversely, the CKM is disassembled following nutrition stress, permitting repression of RP and TIF genes. The CKM also plays a transcriptional role important for promoting cell survival, particularly during translational machinery stress triggered by ribosome-targeting antibiotics. Furthermore, in mammalian cells, the activity of CDK8 and its paralogue, CDK19, promotes cell survival following ribosome inhibition. These results provide mechanistic insights into the CKM's role in regulating expression of a subset of genes associated with translation.

Alkaloids in Cancer therapy: Targeting the tumor microenvironment and metastasis signaling pathways

The use of phytomedicine in cancer therapy is a growing field of research that takes use of the medicinal properties of plant-derived compounds. Under the domain of cancer therapy and management, alkaloids, a prominent group of natural compounds, have showed significant potential. Alkaloids often affect a wide range of essential cellular mechanisms involved in cancer progression. These multi-targeting capabilities, can give significant advantages to alkaloids in overcoming resistance mechanisms. For example, berberine, an alkaloid found in Berberis species, is widely reported to induce apoptosis by activating caspases and regulating apoptotic pathways. Notably, alkaloids like as quinine have showed promise in inhibiting the formation of new blood vessels required for tumor growth. In addition, alkaloids have shown anti-proliferative and anticancer properties mostly via modulating key signaling pathways involved in metastasis, including those regulating epithelial-mesenchymal transition. This work provides a comprehensive overview of naturally occurring alkaloids that exhibit anticancer properties, with a specific emphasis on their underlying molecular mechanisms of action. Furthermore, many methods to modify previously reported difficult physicochemical properties using nanocarriers in order to enhance its systemic bioavailability have been discussed as well. This study also includes information on newly discovered alkaloids that are now being studied in clinical trials for their potential use in cancer treatment. Further, we have also briefly mentioned on the application of high-throughput screening and molecular dynamics simulation for acceleration on the identification of potent alkaloids based compounds to target and treat cancer.

Unraveling the mechanism of carbonic anhydrase IX inhibition by alkaloids from Ruta chalepensis: A synergistic analysis of in vitro and in silico data

Due to the pivotal role of carbonic anhydrase IX (CA IX) in pathological conditions, there's a pressing need for novel inhibitors to improve patient outcomes and clinical management. Herein, we investigated the inhibitory efficacy of six alkaloids from Ruta chalepensis against CA IX through in vitro inhibition assay and computational modeling. Skimmianine and maculosidine displayed significant inhibitory activity in vitro, with low IC50 values of 105.2 ± 3.2 and 295.7 ± 14.1 nM, respectively. Enzyme kinetics analyses revealed that skimmianine exhibited a mixed inhibition mode, contrasting with the noncompetitive inhibition mechanism observed for the reference drug (acetazolamide), as indicated by intersecting lines in the Lineweaver-Burk plots. The findings of docking calculations revealed that skimmianine and maculosidine exhibited extensive polar interactions with the enzyme. These alkaloids demonstrate substantial binding interactions and occupy identical binding site as acetazolamide, thereby enhancing their efficacy as inhibitors of CA IX. Utilizing a 100 ns molecular dynamics (MD) simulation, the dynamic interactions between isolated alkaloids and CA IX were intensively assessed. Analysis of diverse MD parameters revealed that skimmianine and maculosidine displayed consistent trajectories and notable energy stabilization during their interaction with CA IX. The findings of MM/PBSA analysis depicted the minimum binding free energy for skimmianine and maculosidine. In addition, the Potential Energy Landscape (PEL) analysis revealed distinct and stable conformational states for the CA IX-ligand complexes, with Skimmianine showing the most stable and lowest energy configuration. These computational findings align with experimental results, emphasizing the potential efficacy of skimmianine and maculosidine as inhibitors of CA IX.

High-throughput sequencing reveals twelve cell death pattern prognostic target genes as potential drug-response-associated genes in the treatment of colorectal cancer cells with palmatine hydrochloride

Objectives

Palmatine Hydrochloride (PaH), an isoquinoline alkaloid from Phellodendron amurense and Coptis chinensis, has analgesic, anti-inflammatory, and anticancer properties. This study aimed to assess PaH’s effectiveness against SW480 colorectal cancer (CRC) cells and explore its molecular mechanisms.

Methods

PaH’s effects on SW480 CRC cells were evaluated using MTT assays for proliferation, scratch assays for migration, and flow cytometry for apoptosis. Differentially expressed genes (DEGs) were identified through high-throughput sequencing. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) analyses assessed DEG roles. Prognostic significance related to programmed cell death (PCD) was analyzed using R-Package with TCGA data. RT-qPCR validated key genes identified.

Results

PaH significantly inhibited SW480 cell growth, invasion, and apoptosis. The MTT assay showed inhibition rates increased from 5.49 % at 25 μg/mL to 52.48 % at 400 μg/mL. Scratch assays indicated reduced cell invasion over 24, 48, and 72 h. Apoptosis rose from 12.36 % in controls to 45.54 % at 400 μg/mL. Sequencing identified 3,385 significant DEGs, primarily in cancer pathways (p=0.004). Among 35 PCD-related DEGs, Lasso Cox regression highlighted 12 key genes, including TERT, TGFBR1, WNT4, and TP53. RT-qPCR confirmed TERT and TGFBR1 downregulation (0.614-fold, p=0.008; 0.41-fold, p<0.001) and TP53 and WNT4 upregulation (5.634-fold, p<0.001; 5.124-fold, p=0.002).

Conclusions

PaH inhibits CRC cell proliferation, migration, and invasion by modulating key PCD genes, suggesting its potential as a CRC therapeutic agent.

Photochemical Metal-Free synthesis and biological Assessment of isocryptolepine analogues targeting estrogen receptor Alpha in breast cancer cells

The aim of this study was to develop a new series of isocryptolepines and evaluate their antiproliferative and antiestrogenic activities on cancer cells. A series of isocryptolepine derivatives were synthesized using developed one-pot photochemical, metal-free protocol, employing readily available 2-arylindoles as starting compounds. The resulting isocryptolepines demonstrated (sub)micromolar inhibitory activity against selected breast cancer cell lines. The IC50 values ​​of lead compound 3c against hormone-dependent breast cancer types (MCF7 and T47D) were 0.3 μM and 0.12 μM, respectively, and significantly greater than 3 μM against estrogen receptor α (ERα)-deficient cell lines, MDA-MB-231 and HCC1954, respectively. To assess the antiestrogenic potency of compound 3c, MCF7 cells were transfected with a plasmid containing a luciferase reporter gene under the control of an estrogen-responsive element (ERE), creating the MCF7/ERE-LUC cell subline. In these cells, luciferase activity was induced by the natural ERα ligand, 17β-estradiol (E2). Compound 3c inhibited luciferase activity by 50 % at a concentration of 0.12 μM, highlighting its potent inhibitory effect on ERα. Molecular modeling further indicated that compound 3c could directly bind to ERα. Compound 3c induced apoptosis, as evidenced by PARP cleavage and downregulation of p-Bcl-2 and Bcl-2, and demonstrated synergistic effects in combination with the chemotherapeutic agent 5-fluorouracil. Compound 3c also showed selectivity towards hormone-dependent breast cancer cells, likely targeting ERα - a key driver in this cancer subtype. In summary, we report the development of a first-in-class antiestrogenic isocryptolepine with notable pro-apoptotic efficacy.

Natural compounds combined with imatinib as promising antileukemic therapy: An updated review

Natural products (NP) have been an alternative therapy for several diseases for centuries, and they also serve as an essential source of bioactive molecules, enhancing our drug discovery capacity. Among these NP, some phytochemicals have shown multiple biological effects, including anticancer activity, with higher effectiveness and less toxicity than actual treatments, suggesting their possible use on resilient human malignancies such as leukemia. Imatinib mesylate (Im) is a selective tyrosine kinase inhibitor widely used as an anticancer drug, the gold standard to attend chronic myeloid leukemia (CML). Nevertheless, resistance to this drug in patients with CML renders it insufficient to eliminate cells with Philadelphia chromosome (BCR/ABL+). Moreover, recent studies show that imatinib can induce genotoxic and chromosomic damage in some in vitro and in vivo models. These facts urge finding new therapeutic alternatives to increase the effectiveness of antileukemic treatment. Recent research has shown that the combined effects of phytochemicals with imatinib can improve the cytotoxicity or resensitized the resistant cells to this drug in diverse leukemia cell lines. Independent mechanisms of action among phytochemicals and imatinib include BCR/ABL regulation, downregulation of transcription factors, inhibition of anti-apoptotic and activation of pro-apoptotic proteins, apoptosis induction dependent- and independent of ROS-overproduction, membrane functions disruption, induction of cell cycle arrest, and cell death. This review summarizes and discusses the synergic effect of some phytochemicals combined with imatinib on leukemia cells and the mechanism of action proposed for these combinations, looking to contribute to developing new effective alternatives for leukemia treatment.

Piperlongumine and its derivatives against cancer: A recent update and future prospective

Piperlongumine, or piplartine (PL), is a bioactive alkaloid isolated from Piper longum L. and a potent phytoconstituent in Indian Ayurveda and traditional Chinese medicine with a lot of therapeutic benefits. Apart from all of its biological activities, it demonstrates multimodal anticancer activity by targeting various cancer-associated pathways and being less toxic to normal cells. According to their structure-activity relationship (SAR), the trimethylphenyl ring (cinnamoyl core) and 5,6-dihydropyridin-2-(1H)-one (piperdine core) are responsible for the potent anticancer activity. However, it has poor intrinsic properties (low aqueous solubility, poor bioavailability, etc.). As a result, pharmaceutical researchers have been trying to optimise or modify the structure of PL to improve the drug-likeness profiles. The present review selected 26 eligible research articles on PL derivatives published between 2012 and 2023, followed by the preferred reporting items for systematic reviews and meta-analyses (PRISMA) format. We have thoroughly summarised the anticancer potency, mode of action, SAR and drug chemistry of the proposed PL-derivatives against different cancer cells. Overall, SAR analyses with respect to anticancer potency and drug-ability revealed that substitution of methoxy to hydroxyl, attachment of ligustrazine and 4-hydroxycoumarin heterocyclic rings in place of phenyl rings, and attachment of heterocyclic rings like indole at the C7-C8 olefin position in native PL can help to improve anticancer activity, aqueous solubility, cell permeability, and bioavailability, making them potential leads. Hopefully, the large-scale collection and critical drug-chemistry analyses will be helpful to pharmaceutical and academic researchers in developing potential, less-toxic and cost-effective PL-derivatives that can be used against different cancers.

Homoharringtonine: updated insights into its efficacy in hematological malignancies, diverse cancers and other biomedical applications

HHT has emerged as a notable compound in the realm of cancer treatment, particularly for hematological malignancies. Its multifaceted pharmacological properties extend beyond traditional applications, warranting an extensive review of its mechanisms and efficacy. This review aims to synthesize comprehensive insights into the efficacy of HHT in treating hematological malignancies, diverse cancers, and other biomedical applications. It focuses on elucidating the molecular mechanisms, therapeutic potential, and broader applications of HHT. A comprehensive search for peer-reviewed papers was conducted across various academic databases, including ScienceDirect, Web of Science, Scopus, American Chemical Society, Google Scholar, PubMed/MedLine, and Wiley. The review highlights HHT's diverse mechanisms of action, ranging from its role in leukemia treatment to its emerging applications in managing other cancers and various biomedical conditions. It underscores HHT's influence on cellular processes, its efficacy in clinical settings, and its potential to alter pathological pathways. HHT demonstrates significant promise in treating various hematological malignancies and cancers, offering a multifaceted approach to disease management. Its ability to impact various physiological pathways opens new avenues for therapeutic applications. This review provides a consolidated foundation for future research and clinical applications of HHT in diverse medical fields.

Enhanced Cytotoxicity and Antimelanoma Activity of Novel Semisynthetic Derivatives of Betulinic Acid with Indole Conjugation

The prevalence and severity of skin cancer, specifically malignant melanoma, among Caucasians remains a significant concern. Natural compounds from plants have long been explored as potential anticancer agents. Betulinic acid (BI) has shown promise in its therapeutic properties, including its anticancer effects. However, its limited bioavailability has hindered its medicinal applications. To address this issue, two recently synthesized semisynthetic derivatives, N-(2,3-indolo-betulinoyl)diglycylglycine (BA1) and N-(2,3-indolo-betulinoyl)glycylglycine (BA2), were compared with previously reported compounds N-(2,3-indolo-betulinoyl)glycine (BA3), 2,3-indolo-betulinic acid (BA4), and BI. These compounds were evaluated for their effects on murine melanoma cells (B164A5) using various in vitro assays. The introduction of an indole framework at the C2 position of BI resulted in an increased cytotoxicity. Furthermore, the cytotoxicity of compound BA4 was enhanced by conjugating its carboxylic group with an amino acid residue. BA2 and BA3, with glycine and glycylglycine residues at C28, exhibited approximately 2.20-fold higher inhibitory activity compared to BA4. The safety assessment of the compounds on human keratinocytes (HaCaT) has revealed that concentrations up to 10 µM slightly reduced cell viability, while concentrations of 75 µM resulted in lower cell viability rates. LDH leakage assays confirmed cell membrane damage in B164A5 cells when exposed to the tested compounds. BA2 and BA3 exhibited the highest LDH release, indicating their strong cytotoxicity. The NR assay revealed dose-dependent lysosome disruption for BI and 2,3-indolo-betulinic acid derivatives, with BA1, BA2, and BA3 showing the most cytotoxic effects. Scratch assays demonstrated concentration-dependent inhibition of cell migration, with BA2 and BA3 being the most effective. Hoechst 3342 staining revealed that BA2 induced apoptosis, while BA3 induced necrosis at lower concentrations, confirming their anti-melanoma properties. In conclusion, the semisynthetic derivatives of BI, particularly BA2 and BA3, show promise as potential candidates for further research in developing effective anti-cancer therapies.

Dual anticancer and antibacterial activity of fluorescent naphthoimidazolium salts

Cancer has emerged as a significant global health challenge, ranking as the second leading cause of death worldwide. Moreover, cancer patients frequently experience compromised immune systems, rendering them susceptible to bacterial infections. Combining anticancer and antibacterial properties in a single drug could lead to improved overall treatment outcomes and patient well-being. In this context, the present study focused on a series of hydrophilic naphthoimidazolium salts with donor groups (NI-R), aiming to create dual-functional agents with antibacterial and anticancer activities. Among these compounds, NI-TPA demonstrated notable antibacterial activity, particularly against drug-resistant bacteria, with MIC value of 7.8 μg mL-1. Furthermore, NI-TPA exhibited the most potent cytotoxicity against four different cancer cell lines, with an IC50 range of 0.67-2.01 μg mL-1. The observed high cytotoxicity of NI-TPA agreed with molecular docking and dynamic simulation studies targeting c-Met kinase protein. Additionally, NI-TPA stood out as the most promising candidate for two-photo excitation, fluorescence bioimaging, and localization in lysosomes. The study findings open new avenues for the design and development of imidazolium salts that could be employed in phototheranostic applications for cancer treatment and bacterial infections.

Antibactericidal Ir(III) and Ru(II) Complexes with Phosphine-Alkaloid Conjugate and Their Interactions with Biomolecules: A Case of N-Methylphenethylamine

The phosphine ligand (Ph2 PCH2 N(CH3 )(CH2 )2 Ph, PNMPEA) obtained by the reaction of the (hydroxymethyl)diphenylphosphine with naturally occurring alkaloid N-methylphenethylamine, was used to synthesize the half-sandwich iridium(III) (Ir(η5 -Cp*)Cl2 Ph2 PCH2 N(CH3 )(CH2 )2 Ph, IrPNMPEA) and ruthenium(II) (Ru(η6 -p-cymene)Cl2 Ph2 PCH2 N(CH3 )(CH2 )2 Ph, RuPNMPEA) complexes. They were characterized using a vast array of methods, including 1D and 2D NMR, ESI(+)MS spectrometry, elemental analysis, cyclic voltammetry (CV), electron spectroscopy in the UV-Vis range (absorption, fluorescence) and density functional theory (DFT). The initial antimicrobial activity in vitro toward Gram-positive and Gram-negative bacterial strains was examined, indicating that both complexes are selective towards Gram-positive bacteria, e. g., Staphylococcus aureus, where the IrPNMPEA has been more bactericidal compared to RuPNMPEA. Additionally, the interactions of these compounds with various biomolecules, such as DNA (ctDNA, plasmid DNA, 9-ethylguanine (9-EtG), and 9-methyladenine (9-MeA)), nicotinamide adenine dinucleotide (NADH), glutathione (GSH), and ascorbic acid (Asc) were described. The results showed that both Ir(III) and Ru(II) complexes accelerate the oxidation process of NADH, GSH and Asc that appeared to occur by an electron transfer mechanism. Interestingly, only IrPNMPEA leads to the formation of various biomolecule adducts, which can explain its higher activity. Furthermore, RuPNMPEA and IrPNMPEA have been interacting with the DNA through weak noncovalent interactions.

Bioactive phytocompounds for oral cancer prevention and treatment: A comprehensive and critical evaluation

The high incidence of oral cancer combined with excessive treatment cost underscores the need for novel oral cancer preventive and therapeutic options. The value of natural agents, including plant secondary metabolites (phytochemicals), in preventing carcinogenesis and representing expansive source of anticancer drugs have been established. While fragmentary research data are available on antioral cancer effects of phytochemicals, a comprehensive and critical evaluation of the potential of these agents for the prevention and intervention of human oral malignancies has not been conducted according to our knowledge. This study presents a complete and critical analysis of current preclinical and clinical results on the prevention and treatment of oral cancer using phytochemicals. Our in-depth analysis highlights anticancer effects of various phytochemicals, such as phenolics, terpenoids, alkaloids, and sulfur-containing compounds, against numerous oral cancer cells and/or in vivo oral cancer models by antiproliferative, proapoptotic, cell cycle-regulatory, antiinvasive, antiangiogenic, and antimetastatic effects. Bioactive phytochemicals exert their antineoplastic effects by modulating various signaling pathways, specifically involving the epidermal growth factor receptor, cytokine receptors, toll-like receptors, and tumor necrosis factor receptor and consequently alter the expression of downstream genes and proteins. Interestingly, phytochemicals demonstrate encouraging effects in clinical trials, such as reduction of oral lesion size, cell growth, pain score, and development of new lesions. While most phytochemicals displayed minimal toxicity, concerns with bioavailability may limit their clinical application. Future directions for research include more in-depth mechanistic in vivo studies, administration of phytochemicals using novel formulations, investigation of phytocompounds as adjuvants to conventional treatment, and randomized clinical trials.

Molecular docking Study of Nuciferine as a Tyrosinase Inhibitor and Its Therapeutic Potential for Hyperpigmentation

Melanin is synthesized by tyrosinase to protect the skin from ultraviolet light. However, overproduction and accumulation of melanin can result in hyperpigmentation and skin melanoma. Tyrosinase inhibitors are commonly used in the treatment of hyperpigmentation. Natural tyrosinase inhibitors are often favored over synthetic ones due to the potential side effects of the latter, which can include skin irritation, allergies, and other adverse reactions. Nuciferine, an alkaloid derived from Nelumbo nucifera, exhibits potent antioxidant and anti-proliferative properties. This study focused on the in silico screening of nuciferine for anti-tyrosinase activity, using kojic acid, ascorbic acid, and resorcinol as standards. The tyrosinase protein target was selected through homology modeling. The residues of the substrate binding pocket and active site pockets were identified for the purposes of grid box optimization and docking. Nuciferine demonstrated a binding energy of -7.0 kcal/mol and a Ki of 5 µM, both of which were comparatively higher than the corresponding values of kojic acid, which showed -5.3 kcal/mol and 122 µM respectively. Therefore, nuciferine is a potent natural tyrosinase inhibitor and shows promising potential for application in the treatment of hyperpigmentation and skin melanoma.

Therapeutic Role of Alkaloids and Alkaloid Derivatives in Cancer Management

Cancer is a neoplastic disease that remains a global challenge with a reported prevalence that is increasing annually. Though existing drugs can be applied as single or combined therapies for managing this pathology, their concomitant adverse effects in human applications have led to the need to continually screen natural products for effective and alternative anticancer bioactive principles. Alkaloids are chemical molecules that, due to their structural diversity, constitute a reserve for the discovery of lead compounds with interesting pharmacological activities. Several in vitro studies and a few in vivo findings have documented various cytotoxic and antiproliferative properties of alkaloids. This review describes chaetocochin J, neopapillarine, coclaurine, reflexin A, 3,10-dibromofascaplysin and neferine, which belong to different alkaloid classes with antineoplastic properties and have been identified recently from plants. Despite their low solubility and bioavailability, plant-derived alkaloids have viable prospects as sources of viable lead antitumor agents. This potential can be achieved if more research on these chemical compounds is directed toward investigating ways of improving their delivery in an active form close to target cells, preferably with no effect on neighboring normal tissues.

Antiproliferative Activity of Krukovine by Regulating Transmembrane Protein 139 (TMEM139) in Oxaliplatin-Resistant Pancreatic Cancer Cells

Krukovine (KV) is an alkaloid isolated from the bark of Abuta grandifolia (Mart.) Sandw. (Menispermaceae) with anticancer potential in some cancers with KRAS mutations. In this study, we explored the anticancer efficacy and mechanism of KV in oxaliplatin-resistant pancreatic cancer cells and patient-derived pancreatic cancer organoids (PDPCOs) with KRAS mutation. After treatment with KV, mRNA and protein levels were determined by RNA-seq and Western blotting, respectively. Cell proliferation, migration, and invasion were measured by MTT, scratch wound healing assay, and transwell analysis, respectively. Patient-derived pancreatic cancer organoids (PDPCOs) with KRAS mutations were treated with KV, oxaliplatin (OXA), and a combination of KV and OXA. KV suppresses tumor progression via the downregulation of the Erk-RPS6K-TMEM139 and PI3K-Akt-mTOR pathways in oxaliplatin-resistant AsPC-1 cells. Furthermore, KV showed an antiproliferative effect in PDPCOs, and the combination of OXA and KV inhibited PDPCO growth more effectively than either drug alone.

Natural Alkaloids as Multi-Target Compounds towards Factors Implicated in Alzheimer's Disease

Alzheimer's disease (AD) is the most common cause of dementia in elderly people; currently, there is no efficient treatment. Considering the increase in life expectancy worldwide AD rates are predicted to increase enormously, and thus the search for new AD drugs is urgently needed. A great amount of experimental and clinical evidence indicated that AD is a complex disorder characterized by widespread neurodegeneration of the CNS, with major involvement of the cholinergic system, causing progressive cognitive decline and dementia. The current treatment, based on the cholinergic hypothesis, is only symptomatic and mainly involves the restoration of acetylcholine (ACh) levels through the inhibition of acetylcholinesterase (AChE). Since the introduction of the Amaryllidaceae alkaloid galanthamine as an antidementia drug in 2001, alkaloids have been one of the most attractive groups for searching for new AD drugs. The present review aims to comprehensively summarize alkaloids of various origins as multi-target compounds for AD. From this point of view, the most promising compounds seem to be the β-carboline alkaloid harmine and several isoquinoline alkaloids since they can simultaneously inhibit several key enzymes of AD's pathophysiology. However, this topic remains open for further research on detailed mechanisms of action and the synthesis of potentially better semi-synthetic analogues.

Ligand fishing as a tool to screen natural products with anticancer potential

Cancer is the second leading cause of death in the world and its incidence is expected to increase with the aging of the world's population and globalization of risk factors. Natural products and their derivatives have provided a significant number of approved anticancer drugs and the development of robust and selective screening assays for the identification of lead anticancer natural products are essential in the challenge of developing personalized targeted therapies tailored to the genetic and molecular characteristics of tumors. To this end, a ligand fishing assay is a remarkable tool to rapidly and rigorously screen complex matrices, such as plant extracts, for the isolation and identification of specific ligands that bind to relevant pharmacological targets. In this paper, we review the application of ligand fishing with cancer-related targets to screen natural product extracts for the isolation and identification of selective ligands. We provide critical analysis of the system configurations, targets, and key phytochemical classes related to the field of anticancer research. Based on the data collected, ligand fishing emerges as a robust and powerful screening system for the rapid discovery of new anticancer drugs from natural resources. It is currently an underexplored strategy according to its considerable potential.

The Antioxidant and Proapoptotic Effects of Sternbergia clusiana Bulb Ethanolic Extract on Triple-Negative and Estrogen-Dependent Breast Cancer Cells In Vitro

BACKGROUND

Sternbergia clusiana belongs to the Amaryllidaceae family and is recognized for the valuable biological activity of its major bioactive compounds. The aim of the current is to evaluate the anticancer effects of the ethanolic bulb extract of Sternbergia clusiana (ScBEE) on breast cancer cells in vitro and to further reveal the underlying cellular mechanism.

METHODS

An MTS cell viability assay was performed on MDA-MB-231 and MCF-7 cells, along with cell cycle analysis, cell death ELISA, Western blot analysis and an ROS production assay to decipher the mechanism of death. LC-MS/MS was also performed to identify the chemical composition of this ethanolic extract.

RESULTS

The results show a selective antiproliferative effect on both cell lines with no effect on normal mesenchymal stem cells. Further analysis suggested the activation of the apoptotic pathway as reflected by the increase in cellular and DNA fragmentation and alterations in apoptotic proteins such as Bax, Bcl-2 and c-PARP. ScBEE was also found to exhibit antioxidant effect, as shown by a decrease in ROS production. The underlying mechanism of action was explained by the presence of several bioactive compounds identified by LC-MS/MS, including alkaloids, terpenoids and phenols, which are elaborated in the manuscript.

CONCLUSION

This study highlights the antioxidant and anticancerous properties of S.clusiana for breast cancer treatment.

Synthesis and Anticancer Activity of Indole-Functionalized Derivatives of Betulin

Pentacyclic triterpenes, including betulin, are widespread natural products with various pharmacological effects. These compounds are the starting material for the synthesis of substances with promising anticancer activity. The chemical modification of the betulin scaffold that was carried out as part of the research consisted of introducing the indole moiety at the C-28 position. The synthesized new 28-indole-betulin derivatives were evaluated for anticancer activity against seven human cancer lines (A549, MDA-MB-231, MCF-7, DLD-1, HT-29, A375, and C32). It was observed that MCF-7 breast cancer cells were most sensitive to the action of the 28-indole-betulin derivatives. The study shows that the lup-20(29)-ene-3-ol-28-yl 2-(1H-indol-3-yl)acetate caused the MCF-7 cells to arrest in the G1 phase, preventing the cells from entering the S phase. The performed cytometric analysis of DNA fragmentation indicates that the mechanism of EB355A action on the MCF-7 cell line is related to the induction of apoptosis. An in silico ADMET profile analysis of EB355A and EB365 showed that both compounds are bioactive molecules characterized by good intestinal absorption. In addition, the in silico studies indicate that the 28-indole-betulin derivatives are substances of relatively low toxicity.

Multi-Target Potential of Berberine as an Antineoplastic and Antimetastatic Agent: A Special Focus on Lung Cancer Treatment

Despite therapeutic advancements, lung cancer remains the principal cause of cancer mortality in a global scenario. The increased incidence of tumor reoccurrence and progression and the highly metastatic nature of lung cancer are of great concern and hence require the investigation of novel therapies and/or medications. Naturally occurring compounds from plants serve as important resources for novel drugs for cancer therapy. Amongst these phytochemicals, Berberine, an alkaloid, has been extensively explored as a potential natural anticancer therapeutic agent. Several studies have shown the effectiveness of Berberine in inhibiting cancer growth and progression mediated via several different mechanisms, which include cell cycle arrest, inducing cell death by apoptosis and autophagy, inhibiting cell proliferation and invasion, as well as regulating the expression of microRNA, telomerase activity, and the tumor microenvironment, which usually varies for different cancer types. In this review, we aim to provide a better understanding of molecular insights of Berberine and its various derivative-induced antiproliferative and antimetastatic effects against lung cancer. In conclusion, the Berberine imparts its anticancer efficacy against lung cancers via modulation of several signaling pathways involved in cancer cell viability and proliferation, as well as migration, invasion, and metastasis.

New Betulin Derivatives with Nitrogen Heterocyclic Moiety-Synthesis and Anticancer Activity In Vitro

As part of the search for new medicinal substances with potential application in oncology, the synthesis of new compounds combining the betulin molecule and the indole system was carried out. The structure of the ester derivatives obtained in the Steglich reaction was confirmed by spectroscopic methods (¹H and ¹³C NMR, HR-MS). The obtained new 3-indolyl betulin derivatives were evaluated for anticancer activity against several human cancer cell lines (melanomas, breast cancers, colorectal adenocarcinomas, lung cancer) as well as normal human fibroblasts. The significant reduction in MCF-7 cells viability for 28-hydroxy-(lup-20(29)-ene)-3-yl 2-(1H-indol-3-yl)acetate was observed at a concentration of 10 µg/mL (17 µM). In addition, cytometric analysis showed that this compound strongly reduces the proliferation rate of breast cancer cells. For this, the derivative showing the promising cytotoxic effect on MCF-7 breast cancer cells, the pharmacokinetic profile prediction was performed using in silico methods. Based on the results obtained in the study, it can be concluded that indole-functionalized triterpene EB367 is a promising starting point for further research in the field of breast cancer therapy or the synthesis of new derivatives.

The emerging role of pyroptosis in pediatric cancers: from mechanism to therapy

Pediatric cancers are the driving cause of death for children and adolescents. Due to safety requirements and considerations, treatment strategies and drugs for pediatric cancers have been so far scarcely studied. It is well known that tumor cells tend to progressively evade cell death pathways, which is known as apoptosis resistance, one of the hallmarks of cancer, dominating tumor drug resistance. Recently, treatments targeting nonapoptotic cell death have drawn great attention. Pyroptosis, a newly specialized form of cell death, acts as a critical physiological regulator in inflammatory reaction, cell development, tissue homeostasis and stress response. The action in different forms of pyroptosis is of great significance in the therapy of pediatric cancers. Pyroptosis could be induced and consequently modulate tumorigenesis, progression, and metastasis if treated with local or systemic therapies. However, excessive or uncontrolled cell death might lead to tissue damage, acute inflammation, or even cytokine release syndrome, which facilitates tumor progression or recurrence. Herein, we aimed to describe the molecular mechanisms of pyroptosis, to highlight and discuss the challenges and opportunities for activating pyroptosis pathways through various oncologic therapies in multiple pediatric neoplasms, including osteosarcoma, neuroblastoma, leukemia, lymphoma, and brain tumors.

Green Synthesis of Gold Nanoparticles: An Eco-Friendly Approach

By virtue of their unique physicochemical properties, gold nanoparticles (AuNPs) have gained significant interest in a broad range of biomedical applications such as sensors, diagnosis, and therapy. AuNPs are generally synthesized via different conventional physical and chemical methods, which often use harmful chemicals that induce health hazards and pollute the environment. To overcome these issues, green synthesis techniques have evolved as alternative and eco-friendly approaches to the synthesis of environmentally safe and less-expensive nanoparticles using naturally available metabolites from plants and microorganisms such as bacteria, fungi, and algae. This review provides an overview of the advances in the synthesis of AuNPs using different biological resources with examples, and their profound applications in biomedicine. A special focus on the biosynthesis of AuNPs using different medicinal plants and their multifunctional applications in antibacterial, anti-inflammatory, and immune responses are featured. Additionally, the applications of AuNPs in cancer theranostics, including contrast imaging, drug delivery, hyperthermia, and cancer therapeutics, are comprehensively discussed. Moreover, this review will shed light on the importance of the green synthesis approach, and discuss the advantages, challenges, and prospects in this field.