Lycorine: A prospective natural lead for anticancer drug discovery

Lycorine relieves the CCl4-induced liver fibrosis mainly via the JAK2/STAT3 and PI3K/AKT signaling pathways

Liver fibrosis, a progressive process of fibrous scarring, results from the accumulation of extracellular matrix proteins (ECM). If left untreated, it often progresses to diseases such as cirrhosis and hepatocellular carcinoma. Lycorine, a natural alkaloid derived from medicinal plants, has shown diverse bioactivities by targeting JAK2/STAT3 signaling, but its pharmacological effects and potential molecular mechanisms in liver fibrosis remains largely unexplored. The purpose of this study is to elucidate the pharmacological activity and molecular mechanism of lycorine in anti-hepatic fibrosis. Findings indicate that lycorine significantly inhibited hepatic stellate cells (HSCs) activation by reducing the expression of α-SMA and collagen-1. In vivo, lycorine treatment alleviated carbon tetrachloride (CCl4) -induced mice liver fibrosis, improving liver function, decreasing ECM deposition, and inhibiting fibrosis-related markers' expression. Mechanistically, it was found that lycorine exerts protective activity through the JAK2/STAT3 and PI3K/AKT signaling pathways, as evidenced by transcriptome sequencing technology and small molecule inhibitors. These results underscore lycorine's potential as a therapeutic drug for liver fibrosis.

Short Formal Syntheses of Lycorine and Congeners Using a 5-Endo-Trig/6-Endo-Trig Radical Cyclization Sequence

Here, we report a practical route to medicinally interesting lycorine congeners alongside formal syntheses of various lycorine-type natural products, including lycorine itself. The efficiency of our strategy derives from a back-to-back 5-endo-trig/6-endo-trig radical cyclization sequence, which we systematically studied both experimentally and computationally. The results of our work will facilitate future development of urgently needed antiviral therapeutics based on lycorine.

Identification of transcription factor genes responsive to MeJA and characterization of a LaMYC2 transcription factor positively regulates lycorine biosynthesis in Lycoris aurea

Jasmonates (JAs) are among the main phytohormones, regulating plant growth and development, stress responses, and secondary metabolism. As the major regulator of the JA signaling pathway, MYC2 also plays an important role in plant secondary metabolite synthesis and accumulation. In this study, we performed a comparative transcriptome analysis of Lycoris aurea seedlings subjected to methyl jasmonate (MeJA) at different treatment times. A total of 31,193 differentially expressed genes (DEGs) were identified by RNA sequencing. Among them, 732 differentially expressed transcription factors (TFs) comprising 51 TF families were characterized. The most abundant TF family was WRKY proteins (80), followed by AP2/ERF-EFR (67), MYB (59), bHLH (52), and NAC protein (49) families. Subsequently, by calculating the Pearson's correlation coefficient (PCC) between the expression level of TF DEGs and the lycorine contents, 41 potential TF genes (|PCC| >0.8) involved in lycorine accumulation were identified, including 36 positive regulators and 5 negative regulators. Moreover, a MeJA-inducible MYC2 gene (namely LaMYC2) was cloned on the basis of transcriptome sequencing. Bioinformatic analyses revealed that LaMYC2 proteins contain the bHLH-MYC_N domain and bHLH-AtAIB_like motif. LaMYC2 protein is localized in the cell nucleus, and can partly rescue the MYC2 mutant in Arabidopsis thaliana. LaMYC2 protein could interact with most LaJAZs (especially LaJAZ3 and LaJAZ4) identified previously. Transient overexpression of LaMYC2 increased lycorine contents in L. aurea petals, which might be associated with the activation of the transcript levels of tyrosine decarboxylase (TYDC) and phenylalanine ammonia lyase (PAL) genes. By isolating the 887-bp-length promoter fragment upstream of the start codon (ATG) of LaTYDC, we found several different types of E-box motifs (CANNTG) in the promoter of LaTYDC. Further study demonstrated that LaMYC2 was indeed able to bind the E-box (CACATG) present in the LaTYDC promoter, verifying that the pathway genes involved in lycorine biosynthesis could be regulated by LaMYC2, and that LaMYC2 has positive roles in the regulation of lycorine biosynthesis. These findings demonstrate that LaMYC2 is a positive regulator of lycorine biosynthesis and may facilitate further functional research of the LaMYC2 gene, especially its potential regulatory roles in Amaryllidaceae alkaloid accumulation in L. aurea.

Dynamics of alkaloid accumulation in Narcissus cv. Hawera: a source of Sceletium-type alkaloids

The Sceletium-type alkaloids, known for their anxiolytic and antidepressant activities, have been recently found to be biosynthesized in Narcissus cv. Hawera, which is largely used as an ornamental plant. An alkaloid fraction enriched with Sceletium-type alkaloids from the plant has shown promising antidepressant and anxiolytic activities. In the present study, qualitative and quantitative analyses of the alkaloids in the plant organs were performed during one vegetation season by GC-MS. The alkaloid pattern and total alkaloid content was found to depend strongly on the stage of development and plant organ. The alkaloid content of bulbs was found to be highest during the dormancy period and lowest in sprouting bulbs. The leaves showed the highest alkaloid content during the intensive vegetative growth and lowest during flowering. In total, 13 alkaloids were detected in the methanol extracts of Narcissus cv. Hawera, six Sceletium-type and seven typical Amaryllidaceae alkaloids. Major alkaloids in the alkaloid pattern were lycorine, 6-epi-mesembrenol, mesembrenone, sanguinine, and galanthamine. The leaves of flowering plants were found to have the highest amount of 6-epi-mesembrenol. Mesembrenone was found to be dominant alkaloid in the leaves of sprouting bulbs and in the flowers. Considering the biomass of the plant, the dormant bulbs are the best source of alkaloid fractions enriched with 6-epi-mesembrenol. The flowers and the young leaves can be used for preparation of alkaloid fractions enriched with mesembrenone. The results indicates that Narcissus cv. Hawera is an emerging source of valuable bioactive compounds and its utilization can be extended as a medicinal plant.

Natural products reverse cancer multidrug resistance

Cancer stands as a prominent global cause of death. One of the key reasons why clinical tumor chemotherapy fails is multidrug resistance (MDR). In recent decades, accumulated studies have shown how Natural Product-Derived Compounds can reverse tumor MDR. Discovering novel potential modulators to reduce tumor MDR by Natural Product-Derived Compounds has become a popular research area across the globe. Numerous studies mainly focus on natural products including flavonoids, alkaloids, terpenoids, polyphenols and coumarins for their MDR modulatory activity. Natural products reverse MDR by regulating signaling pathways or the relevant expressed protein or gene. Here we perform a deep review of the previous achievements, recent advances in the development of natural products as a treatment for MDR. This review aims to provide some insights for the study of multidrug resistance of natural products.

Biosensor and machine learning-aided engineering of an amaryllidaceae enzyme

A major challenge to achieving industry-scale biomanufacturing of therapeutic alkaloids is the slow process of biocatalyst engineering. Amaryllidaceae alkaloids, such as the Alzheimer's medication galantamine, are complex plant secondary metabolites with recognized therapeutic value. Due to their difficult synthesis they are regularly sourced by extraction and purification from the low-yielding daffodil Narcissus pseudonarcissus. Here, we propose an efficient biosensor-machine learning technology stack for biocatalyst development, which we apply to engineer an Amaryllidaceae enzyme in Escherichia coli. Directed evolution is used to develop a highly sensitive (EC50 = 20 μM) and specific biosensor for the key Amaryllidaceae alkaloid branchpoint 4'-O-methylnorbelladine. A structure-based residual neural network (MutComputeX) is subsequently developed and used to generate activity-enriched variants of a plant methyltransferase, which are rapidly screened with the biosensor. Functional enzyme variants are identified that yield a 60% improvement in product titer, 2-fold higher catalytic activity, and 3-fold lower off-product regioisomer formation. A solved crystal structure elucidates the mechanism behind key beneficial mutations.

Role and regulation of FOXO3a: new insights into breast cancer therapy

Breast cancer is the most common malignancy in the world, particularly affecting female cancer patients. Enhancing the therapeutic strategies for breast cancer necessitates identifying molecular drug targets that effectively eliminate tumor cells. One of these prominent targets is the forkhead and O3a class (FOXO3a), a member of the forkhead transcription factor subfamily. FOXO3a plays a pivotal role in various cellular processes, including apoptosis, proliferation, cell cycle regulation, and drug resistance. It acts as a tumor suppressor in multiple cancer types, although its specific role in cancer remains unclear. Moreover, FOXO3a shows promise as a potential marker for tumor diagnosis and prognosis in breast cancer patients. In addition, it is actively influenced by common anti-breast cancer drugs like paclitaxel, simvastatin, and gefitinib. In breast cancer, the regulation of FOXO3a involves intricate networks, encompassing post-translational modification post-translational regulation by non-coding RNA (ncRNA) and protein-protein interaction. The specific mechanism of FOXO3a in breast cancer urgently requires further investigation. This review aims to systematically elucidate the role of FOXO3a in breast cancer. Additionally, it reviews the interaction of FOXO3a and its upstream and downstream signaling pathway-related molecules to uncover potential therapeutic drugs and related regulatory factors for breast cancer treatment by regulating FOXO3a.

Molecular mechanism of lycorine in the treatment of glioblastoma based on network pharmacology and molecular docking

Lycorine is a naturally active alkaloid that has been shown to have inhibitory effects on a variety of cancers. However, the underlying mechanism of lycorine in the treatment of glioblastoma (GBM) is unclear. In this study, we investigated the mechanism of lycorine in the treatment of GBM based on network pharmacology and molecular docking. Lycorine-related targets overlapped with GBM-related targets to obtain intersections that represent potential anti-GBM targets for lycorine. The protein-protein interaction (PPI) network was constructed using the STRING online database and analyzed by Cytoscape software, and 10 key target genes (AKT1, SRC, HSP90AA1, HRAS, MMP9, BCL2L1, IGF1, MAPK14, STAT1, and KDR) were obtained, which played an important role in the therapeutic effect of lycorine on GBM. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that lycorine acts on GBM by multiple pathways, including inducing apoptosis and reactive oxygen species production. The molecular docking results showed that lycorine had strong binding efficiency with the 10 key genes. In addition, we found that the use of lycorine-induced apoptosis in U-87 MG glioblastoma cells. Here, the mechanism of action of lycorine against GBM was elucidated and verified by experiments, which provided evidence support for its clinical application.

Preparation and Evaluation of Folate Modified PEG-PLLA Nanoparticles Loaded with Lycorine for Glioma Treatment

Lycorine is a kind of natural active ingredient with a strong antitumor effect. In this study, folate ligand-conjugated polyethylene glycol-block-poly(l-lactide) (PEG-PLLA) nanoparticles (FA-PEG-PLLA NPs) were designed to deliver lycorine to enhance its anti-glioma activity. The successful preparation of the FA-PEG-PLLA polymer was confirmed by 1H-NMR, FT-IR, XRD, TGA, and DSC. The optimal formulation for LYC@FA-PEG-PLLA NPs was determined by response surface analysis as follows: sodium dodecyl sulfate (SDS) of 1%, carrier material of 0.03 g, organic phase volume of 3 mL, and ultrasonic power of 20%. The LYC@FA-PEG-PLLA NPs exhibited an encapsulation efficiency of 83.58% and a particle size of 49.71 nm, demonstrating good stability. Hemolysis experiments, MTT assays, and cell scratch assays revealed excellent biocompatibility of FA-PEG-PLLA and superior anti-glioma activity of LYC@FA-PEG-PLLA NPs compared to the raw drug. Additionally, cell apoptosis assays, ROS experiments, and western blot analysis demonstrated that LYC@FA-PEG-PLLA NPs contributed to cell apoptosis by inducing ROS generation and increasing the expression of NF-κB inhibitory protein IκBα. These results suggested that LYC@FA-PEG-PLLA NPs hold promise for glioma treatment.

Influence of Sucrose and Activated Charcoal on Phytochemistry and Vegetative Growth in Zephyranthes irwiniana (Ravenna) Nic. García (Amaryllidaceae)

Zephyranthes irwiniana (Ravenna) Nic. García is an endemic, red list threatened species from the Brazilian savanna (Cerrado) with pharmacological potential to treat the symptoms of Alzheimer's Disease (AD). This work analyzed the vegetative growth and phytochemistry of its potential compounds, in response to variations in sucrose concentration and activated carbon (AC). Seeds were germinated in vitro and in the greenhouse. The in vitro bulbs were separated in six treatments with different sucrose concentrations (30, 45 and 60 gL-1) and/or AC (1 gL-1). Biomass increases in individuals grown in the greenhouse were higher than those cultivated in vitro. Sucrose concentration significantly increased biomass and root number. AC had a positive influence on leaf and root size, and a negative influence on root number. GC-MS analyses indicated great variation in the abundance of α-terpenyl-acetate, ethyl linoleate, clionasterol and lycorine between treatments, with maximum concentrations of 53.06%, 38.68, 14.34% and 2.57%, respectively. Histolocalization tests indicated the presence of alkaloids in the leaf chlorenchyma and bulb cataphylls. Finally, the present study provided new evidence that the constitution of the culture medium directly influences the vegetative growth and phytochemistry of this species, providing a good medium condition for propagating the species under threat.

SREBPs as the potential target for solving the polypharmacy dilemma

The phenomenon of polypharmacy is a common occurrence among older people with multiple health conditions due to the rapid increase in population aging and the popularization of clinical guidelines. The prevalence of metabolic syndrome is growing quickly, representing a serious threat to both the public and the worldwide healthcare systems. In addition, it enhances the risk of cardiovascular disease as well as mortality and morbidity. Sterol regulatory element binding proteins (SREBPs) are basic helix-loop-helix leucine zipper transcription factors that transcriptionally modulate genes that regulate lipid biosynthesis and uptake, thereby serving an essential role in biological systems regulation. In this article, we have described the structure of SREBPs and explored their activation and regulation of signals. We also reveal that SREBPs are intricately involved in the modulation of metabolic diseases and thus have tremendous potential as the novel target for single-drug therapy for multiple diseases.

Novel Insights on Ferroptosis Modulation as Potential Strategy for Cancer Treatment: When Nature Kills

Significance: The multifactorial nature of the mechanisms implicated in cancer development still represents a major issue for the success of established antitumor therapies. The discovery of ferroptosis, a novel form of programmed cell death distinct from apoptosis, along with the identification of the molecular pathways activated during its execution, has led to the uncovering of novel molecules characterized by ferroptosis-inducing properties. Recent advances: As of today, the ferroptosis-inducing properties of compounds derived from natural sources have been investigated and interesting findings have been reported both in vitro and in vivo. Critical Issues: Despite the efforts made so far, only a limited number of synthetic compounds have been identified as ferroptosis inducers, and their utilization is still limited to basic research. In this review, we analyzed the most important biochemical pathways involved in ferroptosis execution, with particular attention to the newest literature findings on canonical and non-canonical hallmarks, together with mechanisms of action of natural compounds identified as novel ferroptosis inducers. Compounds have been classified based on their chemical structure, and modulation of ferroptosis-related biochemical pathways has been reported. Future Directions: The outcomes herein collected represent a fascinating starting point from which to take hints for future drug discovery studies aimed at identifying ferroptosis-inducing natural compounds for anticancer therapies. Antioxid. Redox Signal. 40, 40-85.

Lewis-Base-Catalyzed N-Allylation of Silyl Carbamate Latent Pronucleophiles with Allylic Fluorides

Silyl carbamates, latent pronucleophile surrogates of carbamates, undergo allylation using allylic fluorides in the presence of common Lewis base catalysts. The reactions are rendered enantioselective in the presence of chiral Lewis base catalysts and produce suitably protected derivatives of enantioenriched chiral β-amino acids. The design of the latent pronucleophile featuring both a silyl group and an electron-deficient carbamate is instrumental in lowering the nucleophilicity of nitrogen and enabling enantioselective allylation in the presence of chiral cinchona alkaloid-based catalysts.

Lycorine inhibits pancreatic cancer cell growth and neovascularization by inducing Notch1 degradation and downregulating key vasculogenic genes

Pancreatic cancer is highly metastatic and lethal with an increasing incidence globally and a 5-year survival rate of only 8%. One of the factors contributing to the high mortality is the lack of effective drugs in the clinical setting. We speculated that effective compounds against pancreatic cancer exist in natural herbs and explored active small molecules among traditional Chinese medicinal herbs. The small molecule lycorine (MW: 323.77) derived from the herb Lycoris radiata inhibited pancreatic cancer cell growth with an IC50 value of 1 μM in a concentration-dependent manner. Lycorine markedly reduced pancreatic cancer cell viability, migration, invasion, neovascularization, and gemcitabine resistance. Additionally, lycorine effectively suppressed tumor growth in mouse xenograft models without obvious toxicity. Pharmacological studies revealed that the levels and half-life of Notch1 oncoprotein in the pancreatic cancer cells Panc-1 and Patu8988 were notably reduced. Moreover, the expression of the key vasculogenic genes Semaphorin 4D (Sema4D) and angiopoietin-2 (Ang-2) were also significantly inhibited by lycorine. Mechanistically, lycorine strongly triggered the degradation of Notch1 oncoprotein through the ubiquitin-proteasome system. In conclusion, lycorine effectively inhibits pancreatic cancer cell growth, migration, invasion, neovascularization, and gemcitabine resistance by inducing degradation of Notch1 oncoprotein and downregulating the key vasculogenic genes Sema4D and Ang-2. Our findings provide a new therapeutic candidate and treatment strategy against pancreatic cancer.

Progress on traditional Chinese medicine in improving hepatic fibrosis through inhibiting oxidative stress

Hepatic fibrosis is a common pathological process that occurs in the development of various chronic liver diseases into cirrhosis and liver cancer, characterized by excessive deposition of the extracellular matrix. In the past, hepatic fibrosis was thought to be a static and irreversible pathological process. In recent years, with the rapid development of molecular biology and the continuous in-depth study of the liver at the microscopic level, more and more evidence has shown that hepatic fibrosis is a dynamic and reversible process. Therefore, it is particularly important to find an effective, simple, and inexpensive method for its prevention and treatment. Traditional Chinese medicine (TCM) occupies an important position in the treatment of hepatic fibrosis due to its advantages of low adverse reactions, low cost, and multi-target effectiveness. A large number of research results have shown that TCM monomers, single herbal extracts, and TCM formulas play important roles in the prevention and treatment of hepatic fibrosis. Oxidative stress (OS) is one of the key factors in the occurrence and development of hepatic fibrosis. Therefore, this article reviews the progress in the understanding of the mechanisms of TCM monomers, single herbal extracts, and TCM formulas in preventing and treating hepatic fibrosis by inhibiting OS in recent years, in order to provide a reference and basis for drug therapy of hepatic fibrosis.

Benzoindolizidine Alkaloids Tylophorine and Lycorine and Their Analogues with Antiviral, Anti-Inflammatory, and Anticancer Properties: Promises and Challenges

Ongoing viral research, essential for public health due to evolving viruses, gains significance owing to emerging viral infections such as the SARS-CoV-2 pandemic. Marine and plant alkaloids show promise as novel potential pharmacological strategies. In this narrative review, we elucidated the potential of tylophorine and lycorine, two naturally occurring plant-derived alkaloids with a shared benzoindolizidine scaffold, as antiviral agents to be potentially harnessed against respiratory viral infections. Possible structure-activity relationships have also been highlighted. The substances and their derivatives were found to be endowed with powerful and broad-spectrum antiviral properties; moreover, they were able to counteract inflammation, which often underpins the complications of viral diseases. At last, their anticancer properties hold promise not only for advancing cancer research but also for mitigating the oncogenic effects of viruses. This evidence suggests that tylophorine and lycorine could effectively counteract the pathogenesis of respiratory viral disease and its harmful effects. Although common issues about the pharmacologic development of natural substances remain to be addressed, the collected evidence highlights a possible interest in tylophorine and lycorine as antiviral and/or adjuvant strategies and encourages future more in-depth pre-clinical and clinical investigations to overcome their drawbacks and harness their power for therapeutic purposes.

Insights into enterovirus a-71 antiviral development: from natural sources to synthetic nanoparticles

Enteroviruses are pathogens responsible for several diseases, being enterovirus A71 (EVA71) the second leading cause of hand, foot, and mouth disease (HFMD), especially in Asia-Pacific countries. HFMD is mostly common in infants and children, with mild symptoms. However, the disease can result in severe nervous system disorders in children as well as in immunosuppressed adults. The virus is highly contagious, and its transmission occurs via fecal-oral, oropharyngeal secretions, and fomites. The EVA71 burdens the healthy systems and economies around the world, however, up to date, there is no antiviral approved to treat infected individuals and the existent vaccines are not available or approved to be used worldwide. In this context, an extensive literature research was conducted to describe and summarize the recent advances in natural and/or synthetic compounds with antiviral activity against EVA71. The summarized data presented here might simply encourage the future studies in EVA71 antiviral development, by encouraging further research encompassing these compounds or even the application of the techniques and technologies to improve or produce new antiviral molecules.

Lycorine suppresses the malignancy of breast carcinoma by modulating epithelial mesenchymal transition and β-catenin signaling

Lycorine, an isoquinoline alkaloid can exhibit significant anti-cancer effects. The present study was conducted to illustrate the underlying mechanisms of action of lycorine on breast carcinoma under in vitro and in vivo settings Tandem Mass Tag assay and Kyoto Encyclopedia of Genes and Genomes analysis revealed that 20 signaling pathways were closely related to tumorigenesis, especially Wnt signaling pathway and tight junctions. The results demonstrated that lycorine evidently inhibited the proliferation of MDA-MB-231 and MCF-7 cells with IC50 values of 1.84 ± 0.21 μM and 7.76 ± 1.16 μM, respectively. It also blocked cell cycle in G2/M phase, caused a decrease in mitochondrial membrane potential, and induced apoptosis pathways through regulating caspase-3, caspase-8, caspase-9, and PARP expression. Moreover, lycorine effectively repressed the β-catenin signaling and reversed epithelial-mesenchymal transition (EMT) process. Furthermore, 4T1/Luc homograft tumor model was used to further demonstrate that lycorine significantly inhibited the growth and metastasis of breast tumor. These findings highlight the significance of lycorine as potential anti-neoplastic agent to combat breast cancer.

Chemical and Biological Aspects of Different Species of the Genus Clinanthus Herb. (Amaryllidaceae) from South America

The genus Clinanthus Herb. is found in the Andes Region (South America), mainly in Peru, Ecuador, and Bolivia. These plants belong to the Amaryllidaceae family, specifically the Amaryllidoideae subfamily, which presents an exclusive group of alkaloids known as Amaryllidaceae alkaloids that show important structural diversity and pharmacological properties. It is possible to find some publications in the literature regarding the botanical aspects of Clinanthus species, although there is little information available about their chemical and biological activities. The aim of this work was to obtain the alkaloid profile and the anti-cholinesterase activity of four different samples of Clinanthus collected in South America: Clinanthus sp., Clinanthus incarnatus, and Clinanthus variegatus. The alkaloid extract of each sample was analyzed by gas chromatography coupled with mass spectrometry (GC-MS), and their potential against the enzymes acetyl- and butyrylcholinesterase were evaluated. Thirteen alkaloids have been identified among these species, while six unidentified structures have also been detected in these plants. The alkaloid extract of the C. variegatus samples showed the highest structural diversity as well as the best activity against AChE, which was likely due to the presence of the alkaloid sanguinine. The results suggest this genus as a possible interesting new source of Amaryllidaceae alkaloids, which could contribute to the development of new medicines.

Elucidation of a Dearomatization Route in the Biosynthesis of Oxysporidinone Involving a TenA-like Cytochrome P450 Enzyme

Oxidative dearomatization of phenols is an important transformation for synthesis of complex molecules. Oxysporidinone and related 2-pyridones feature a hydroxy-substituted cyclohexanone ring, which has been proposed to form by phenol dearomatization, although the details of the biochemical process are still unknown. In this study, we identified the oxysporidinone biosynthetic gene cluster in Fusarium oxysporum by regulator activation and gene knockout studies. Through in vivo and in vitro studies, we confirmed that the phenol dearomatization process involves two enzymes. OsdM, a TenA-like cytochrome P450 with expected ring-expansion activity, converts the phenol ring and the 4-hydroxy-2-pyridone core into an unexpected fused [6-5-6] ring system. OsdN, on the other hand, catalyzes two successive ene reduction reactions, followed by hydroxylation by OsdM. This new route enriches current knowledge on enzymatic phenol dearomatization and the mechanism of TenA-like P450s.

Identification of Small Molecules Affecting the Secretion of Therapeutic Antibodies with the Retention Using Selective Hook (RUSH) System

Unlocking cell secretion capacity is of paramount interest for the pharmaceutical industry focused on biologics. Here, we leveraged retention using a selective hook (RUSH) system for the identification of human osteosarcoma U2OS cell secretion modulators, through automated, high-throughput screening of small compound libraries. We created a U2OS cell line which co-expresses a variant of streptavidin addressed to the lumen-facing membrane of the endoplasmic reticulum (ER) and a recombinant anti-PD-L1 antibody. The heavy chain of the antibody was modified at its C-terminus, to which a furin cleavage site, a green fluorescent protein (GFP), and a streptavidin binding peptide (SBP) were added. We show that the U2OS cell line stably expresses the streptavidin hook and the recombinant antibody bait, which is retained in the ER through the streptavidin-SBP interaction. We further document that the addition of biotin to the culture medium triggers the antibody release from the ER, its trafficking through the Golgi where the GFP-SBP moiety is clipped off, and eventually its release in the extra cellular space, with specific antigen-binding properties. The use of this clone in screening campaigns led to the identification of lycorine as a secretion enhancer, and nigericin and tyrphostin AG-879 as secretion inhibitors. Altogether, our data support the utility of this approach for the identification of agents that could be used to improve recombinant production yields and also for a better understanding of the regulatory mechanism at work in the conventional secretion pathway.

Alleviating effect of lycorine on CFA‑induced arthritic pain via inhibition of spinal inflammation and oxidative stress

Chronic pain is the primary symptom of osteoarthritis affecting a patient's quality of life. Neuroinflammation and oxidative stress in the spinal cord contribute to arthritic pain and represent ideal targets for pain management. In the present study, a model of arthritis was established by intra-articular injection of complete Freund's adjuvant (CFA) into the left knee joint in mice. After CFA inducement, knee width and pain hypersensitivity in the mice were increased, motor disability was impaired, spinal inflammatory reaction was induced, spinal astrocytes were activated, antioxidant responses were decreased, and glycogen synthase kinase 3β (GSK-3β) activity was inhibited. To explore the potential therapeutic options for arthritic pain, lycorine was intraperitoneally injected for 3 days in the CFA mice. Lycorine treatment significantly reduced mechanical pain sensitivity, suppressed spontaneous pain, and recovered motor coordination in the CFA-induced mice. Additionally, in the spinal cord, lycorine treatment decreased the inflammatory score, reduced NOD-like receptor protein 3 inflammasome (NLRP3) activity and IL-1β expression, suppressed astrocytic activation, downregulated NF-κB levels, increased nuclear factor erythroid 2-related factor 2 expression and superoxide dismutase activity. Furthermore, lycorine was shown to bind to GSK-3β through three electrovalent bonds, to inhibit GSK-3β activity. In summary, lycorine treatment inhibited GSK-3β activity, suppressed NLRP3 inflammasome activation, increased the antioxidant response, reduced spinal inflammation, and relieved arthritic pain.

Identification of Some Glutamic Acid Derivatives with Biological Potential by Computational Methods

Glutamic acid is a non-essential amino acid involved in multiple metabolic pathways. Of high importance is its relationship with glutamine, an essential fuel for cancer cell development. Compounds that can modify glutamine or glutamic acid behaviour in cancer cells have resulted in attractive anticancer therapeutic alternatives. Based on this idea, we theoretically formulated 123 glutamic acid derivatives using Biovia Draw. Suitable candidates for our research were selected among them. For this, online platforms and programs were used to describe specific properties and their behaviour in the human organism. Nine compounds proved to have suitable or easy to optimise properties. The selected compounds showed cytotoxicity against breast adenocarcinoma, lung cancer cell lines, colon carcinoma, and T cells from acute leukaemia. Compound 2Ba5 exhibited the lowest toxicity, and derivative 4Db6 exhibited the most intense bioactivity. Molecular docking studies were also performed. The binding site of the 4Db6 compound in the glutamine synthetase structure was determined, with the D subunit and cluster 1 being the most promising. In conclusion, glutamic acid is an amino acid that can be manipulated very easily. Therefore, molecules derived from its structure have great potential to become innovative drugs, and further research on these will be conducted.

Lycorine transfersomes modified with cell-penetrating peptides for topical treatment of cutaneous squamous cell carcinoma

BACKGROUND

Topical anticancer drugs offer a potential therapeutic modality with high compliance for treating cutaneous squamous cell carcinoma (cSCC). However, the existing topical treatments for cSCC are associated with limited penetrating ability to achieve the desired outcome. Therefore, there remains an urgent requirement to develop drugs with efficient anticancer activity suitable for treating cSCC and to overcome the skin physiological barrier to improve the efficiency of drug delivery to the tumor.

RESULTS

We introduced lycorine (LR) into the topical treatment for cSCC and developed a cell-penetrating peptide (CPP)-modified cationic transfersome gel loaded with lycorine-oleic acid ionic complex (LR-OA) (LR@DTFs-CPP Gel) and investigated its topical therapeutic effects on cSCC. The anti-cSCC effects of LR and skin penetration of LR-OA transfersomes were confirmed. Simultaneously, cationic lipids and modification of R5H3 peptide of the transfersomes further enhanced the permeability of the skin and tumor as well as the effective delivery of LR to tumor cells.

CONCLUSIONS

Topical treatment of cSCC-xenografted nude mice with LR@DTFs-CPP Gel showed effective anticancer properties with high safety. This novel formulation provides novel insights into the treatment and pathogenesis of cSCC.

Anti-SARS-CoV-2 Activity and Cytotoxicity of Amaryllidaceae Alkaloids from Hymenocallis littoralis

The Amaryllidaceae species are well-known as a rich source of bioactive compounds in nature. Although Hymenocallis littoralis has been studied for decades, its polar components were rarely explored. The current phytochemical investigation of Amaryllidaceae alkaloids from H. littoralis led to the identification of three previously undescribed compounds: O-demethyl-norlycoramine (1), (−)-2-epi-pseudolycorine (2) and (+)-2-epi-pseudolycorine (3), together with eight known compounds: 6α-hydroxyhippeastidine (4), 6β-hydroxyhippeastidine (5), lycorine (6), 2-epi-lycorine (7), zephyranthine (8), ungeremine (9), pancratistatin (10) and 9-O-demethyl-7-O-methyllycorenine (11). Among the eight previously reported compounds, five were isolated from H. littoralis for the first time (compounds 4, 5, 7, 8, and 9). Compounds 1, 4, 5, 7, 8, and 11 exhibited weak anti-SARS-CoV-2 activity (EC50 = 40–77 µM) at non-cytotoxic concentrations. Assessment of cytotoxicity on the Vero-E6 cell line revealed lycorine and pancratistatin as cytotoxic substances with CC50 values of 1.2 µM and 0.13 µM, respectively. The preliminary structure-activity relationship for the lycorine-type alkaloids in this study was further investigated, and as a result ring C appears to play a crucial role in their anti-SARS-CoV-2 activity.

Lycorine weakens tamoxifen resistance of breast cancer via abrogating HAGLR-mediated epigenetic suppression on VGLL4 by DNMT1

Much is known about the significance of lycorine, a natural alkaloid, in combating various types of cancer, including breast cancer (BC), but whether it participates in regulating tamoxifen (TAM) resistance and its underlying mechanism remain to be elucidated. Tamoxifen-resistant (TAMR) BC cells were first established by continuously exposed to increasing concentrations of TAM. Levels of targeted gene including HOXD antisense growth-associated lncRNA (HAGLR) and Vestigial like family member 4 (VGLL4) were analyzed by qRT-PCR and western blot, respectively. Cell proliferation ability was assessed by MTT and EdU assays. Flow cytometry was carried out to evaluate the apoptosis. VGLL4 promoter methylation was examined using methylation specific PCR (MSP). The role of HAGLR acting on the expression of VGLL4 via DNA hypermethylation was confirmed by RNA immunoprecipitation (RIP). Here, we reported that lycorine administration reduced the survival ratio of TAMR BC cells, decreased the IC₅₀ of TAM, and strengthened TAM-induced apoptosis. HAGLR, observed to be highly expressed in TAMR BC cells, was identified to be a downstream effector of lycorine, of which overexpression abolished lycorine-mediated TAMR inhibition. VGLL4 served as a target of HAGLR in regulating lycorine-mediated suppression on tamoxifen resistance of TAMR BC cells. Mechanistically, HAGLR epigenetically suppressed VGLL4 expression via DNA methyltransferase 1 (DNMT1)-mediated DNA hypermethylation. Taken together, our data highlights the pivotal role of lycorine in TAM resistance of BC, which may provide a potential agent for improving the effectiveness and efficacy of BC resistance.

Advances in the Development of Small Molecule Antivirals against Equine Encephalitic Viruses

Venezuelan, western, and eastern equine encephalitic alphaviruses (VEEV, WEEV, and EEEV, respectively) are arboviruses that are highly pathogenic to equines and cause significant harm to infected humans. Currently, human alphavirus infection and the resulting diseases caused by them are unmitigated due to the absence of approved vaccines or therapeutics for general use. These circumstances, combined with the unpredictability of outbreaks-as exemplified by a 2019 EEE surge in the United States that claimed 19 patient lives-emphasize the risks posed by these viruses, especially for aerosolized VEEV and EEEV which are potential biothreats. Herein, small molecule inhibitors of VEEV, WEEV, and EEEV are reviewed that have been identified or advanced in the last five years since a comprehensive review was last performed. We organize structures according to host- versus virus-targeted mechanisms, highlight cellular and animal data that are milestones in the development pipeline, and provide a perspective on key considerations for the progression of compounds at early and later stages of advancement.

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.

Antileishmanial Activity of Clinanthus milagroanthus S. Leiva & Meerow (Amaryllidaceae) Collected in Peru

Leishmaniasis is a worldwide infectious parasitic disease caused by different species of protozoa of the genus Leishmania, which are transmitted to animals and humans through the bite of insects of the Psychodidae family. In the present work, the antileishmanial activity of an alkaloid extract of the bulbs of Clinanthus milagroanthus S. Leiva & Meerow (Amaryllidaceae) was evaluated in vitro, in vivo, and in silico against the parasite Leishmania braziliensis, and the chemical profile of the sample was determined by GC-MS analysis. At concentrations of 1, 10, and 100 µg·mL−1, the alkaloid extract presented inhibition percentages of 8.7%, 23.1%, and 98.8%, respectively, against L. braziliensis with a p < 0.05, and IC50 values of 18.5 ± 0.3 µg·mL−1. Furthermore, at a dose of 1.0 mg·kg−1, a greater decrease in lesion size was observed (90%) for in vivo assays, as well as a decrease in infection (96%), finding no significant differences (p > 0.05) in comparison with amphotericin B (92% and 98%, respectively). Eleven alkaloids were identified in C. milagroanthus bulbs: galanthamine, vittatine/crinine, 8-O-demethylmaritidine, anhydrolycorine, 11,12-dehydroanhydrolycorine, hippamine, lycorine, 2-hydroxyanhydrolycorine, 7-hydroxyclivonine, 2α-hydroxyhomolycorine, and 7-hydroxyclivonine isomer. A molecular model of Leishmania braziliensis trypanothione reductase (TRLb) was built using computational experiments to evaluate in silico the potential of the Amaryllidaceae alkaloid identified in C. milagroanthus toward this enzyme. The structures galanthamine, 7-hydroxyclivonine isomer, and crinine showed better estimated free energy of binding than the reference compound, amphotericin B. In conclusion, this is the first in vitro, in vivo, and in silico report about the antileishmanial potential and alkaloid profiling of the extract of C. milagroanthus bulbs, which could become an interesting source of bioactive molecules.

Structural analysis of unusual alkaloids isolated from Narcissus pseudonarcissus cv. Carlton

Narciindole A, the first representative of Amaryllidaceae alkaloids with an indol-3-ylmethanone framework, was isolated from bulbs of Narcissus pseudonarcissus (L.) cv. Carlton, together with carltonine D and carltonine E, which share the same unusual structural motif as dimeric carltonine C (reported in 2020), exhibiting atropisomerism. Unambiguous structure elucidations have been achieved by NMR spectroscopy, HRMS, and comparison with literature data of related alkaloids. Furthermore, the chirality of known alkaloids with a galanthindole biaryl core was revised using optical rotation. Last, but not least, a biosynthetic pathway for dimeric carltonine-type alkaloids was proposed. Unfortunately, in terms of biological activity, the isolated alkaloids showed only moderate inhibition of human acetylcholinesterase and/or butyrylcholinesterase.

Effects and mechanisms of natural alkaloids for prevention and treatment of osteoporosis

Natural alkaloids are polycyclic, nitrogen-containing, and basic compounds obtained from plants. In this review, the advances in bioactive alkaloids with respect to their chemical structures, herbal sources, and effects for the prevention and treatment of osteoporosis are discussed. Anti-osteoporosis alkaloids are classified into six categories based on the chemical structure, namely, isoquinoline alkaloids, quinolizidine alkaloids, piperidine alkaloids, indole alkaloids, pyrrolizidine alkaloids and steroidal alkaloids. They promote mesenchymal stem cells differentiation, improve osteoblast proliferation, stimulate osteoblast autophagy and suppress osteoclast formation. These natural alkaloids can regulate multiple signaling pathways, including interrupting the tumor necrosis factor receptor associated factor 6- receptor activator of nuclear factor kappa B interaction, inhibiting the nuclear factor kappa B pathway in osteoclasts, activating the p38 mitogen-activated protein kinases pathway in osteoblasts, and triggering the wingless and int-1 pathway in mesenchymal stem cells. This review provides evidence and support for novel drug and clinical treatment of osteoporosis using natural alkaloids.

Therapeutic Options for the SARS-CoV-2 Virus: Is There a Key in Herbal Medicine?

SARS-CoV-2 has been responsible for over 500 million cumulative cases all over the world since December 2019 and has marked the third introduction of a highly pathogenic virus after SARS-CoV and MERS-CoV. This virus is in a winning situation because scientists are still racing to explore effective therapeutics, vaccines, and event treatment regimens. In view of progress in current disease management, until now none of the preventive/treatment measures can be considered entirely effective to treat SARS-CoV-2 infection. Therefore, it is required to look up substitute ways for the management of this disease. In this context, herbal medicines could be a good choice. This article emphasizes the antiviral potential of some herbal constituents which further can be a drug of choice in SARS-CoV-2 treatment. This article may be a ready reference for discovering natural lead compounds and targets in SARS-CoV-2 associated works.

Lycorine and organ protection: Review of its potential effects and molecular mechanisms

BACKGROUND

Multiorgan dysfunction, especially sepsis-related multiorgan damage, remains a major cause of high mortality in the late stages of infection and a great clinical challenge. In recent years, natural drugs have received widespread attention because of their low cost, wide sources, high efficacy, low toxicity, and limited side effects. Lycorine, a natural compound extracted from Amaryllidaceae, exhibits multiple pharmacological activities, including in the regulation of autophagy and the induction of cancer cell apoptosis, and has anti-inflammatory, antifungal, antiviral, antimalarial, and antitumor activities. However, studies on lycorine have mainly focused on its antitumor properties, and research on its use for organ protection, especially in sepsis-related organ injury, is relatively limited.

PURPOSE

To review and discuss the effects and mechanisms of lycorine in the treatment of multi-organ dysfunction, especially sepsis.

METHODS

Literature searches in electronic databases, such as Web of Science, Science Direct, PubMed, Google Scholar, and Scopus, were performed using 'Lycorine', 'Amaryllidaceae', 'Pharmacology', 'Pharmacokinetics', 'Anti-inflammation', 'Autophagy', 'Apoptosis', 'Anti-microbial and anti-parasitic', 'Antitumor', 'Organ protection', and 'Sepsis' as keywords, the correlated literature was extracted and conducted from the databases mentioned above.

RESULTS

By summarizing the progress made in existing research, we found that the general effects of lycorine involve the regulation of autophagy and the induction of cancer cell apoptosis, and anti-inflammatory, antifungal, antiviral, antimalarial, and antitumor effects; through these pathways, the compound can ameliorate organ damage. In addition, lycorine was found to have an important effect on organ damage in sepsis.

CONCLUSION

Lycorine is a promising natural organ protective agent. This review will provide a new theoretical basis for the treatment of organ protection, especially in sepsis.

Lycorine inhibits angiogenesis by docking to PDGFRα

Lycorine (Lyc) is a natural alkaloid derived from medicinal plants of the Amaryllidaceae family. Lyc has been reported to inhibit the recurrence and metastasis of different kinds of tumors. However, Lyc’s effect on angiogenesis and its specific mechanism are still not clear. This study was designed to test the antiangiogenesis effect of Lyc and to explore the possible mechanisms. We performed cell experiments to confirm Lyc’s inhibitory effect on angiogenesis and employed sunitinib as a positive control. Moreover, the synergistic effect of Lyc and sunitinib was also explored. Next, we conducted bioinformatics analyses to predict the potential targets of Lyc and verified them by western blotting and immunofluorescence. Molecular docking, kinase activity assays, Biacore assays and cellular thermal shift assays (CETSAs) were applied to elucidate the mechanism by which Lyc inhibited target activity. Lyc inhibited angiogenesis in human umbilical vein endothelial cells (HUVECs). Employing bioinformatics, we found that Lyc’s target was PDGFRα and that Lyc attenuated PDGFRα phosphorylation. We also found that Lyc inhibited PDGFRα activation by docking to it to restrain its activity. Additionally, Lyc significantly inhibited PDGF-AA-induced angiogenesis. This study provides new insights into the molecular functions of Lyc and indicates its potential as a therapeutic agent for tumor angiogenesis.

Biotechnological Approaches to Optimize the Production of Amaryllidaceae Alkaloids

Amaryllidaceae alkaloids (AAs) are plant specialized metabolites with therapeutic properties exclusively produced by the Amaryllidaceae plant family. The two most studied representatives of the family are galanthamine, an acetylcholinesterase inhibitor used as a treatment of Alzheimer’s disease, and lycorine, displaying potent in vitro and in vivo cytotoxic and antiviral properties. Unfortunately, the variable level of AAs’ production in planta restricts most of the pharmaceutical applications. Several biotechnological alternatives, such as in vitro culture or synthetic biology, are being developed to enhance the production and fulfil the increasing demand for these AAs plant-derived drugs. In this review, current biotechnological approaches to produce different types of bioactive AAs are discussed.

Lycorine Inhibits Hypertrophic Scar Formation by Inducing ROS-Mediated Apoptosis

Background: Hypertrophic scar (HS) is a fibrotic cutaneous disease with few effective therapies. Lycorine is a drug with pro-apoptotic ability and anti-fibrosis potential. This study aimed to test whether lycorine could trigger the apoptosis of hypertrophic scar fibroblasts (HSFs) to inhibit HS formation.

Methods: The proapoptotic and anti-fibrosis effects of lycorine on the viability and apoptosis of human primary HSFs and their reactive oxygen species (ROS) production as well as a rabbit ear model of HS were determined by CCK-8, flow cytometry, Western blot, immunofluorescence, transwell migration, collagen gel contraction assays.

Results: Lycorine treatment selectively decreased the viability of HSFs, and induced their apoptosis, but not normal fibroblasts (NFs). Lycorine treatment increased the relative levels of Bax and cleaved PARP expression, cytochrome C cytoplasm translocation, but decreased Bcl-2, caspase-3 and caspase-9 expression, the mitochondrial membrane potential (MMP) in HSFs. Lycorine inhibited the migration and contraction of HSFs, and reduced the expression of collagen I, collagen III and α-SMA. Mechanistically, lycorine treatment stimulated high levels of ROS production, leading to apoptosis of HSFs while treatment with NAC, a ROS inhibitor, significantly mitigated or abrogated the pro-apoptotic and antifibrotic activity of lycorine in HSFs. Moreover, lycorine treatment mitigated the severity of HS in rabbit ears by inducing fibroblast apoptosis.

Conclusion: These results indicate that lycorine has a potent anti-fibrotic activity and is a potential drug for intervention of HS.

Standardization of the ethanolic extract of Crinum latifolium leaves by two bioactive markers with antiproliferative activity against TGF-β-promoted prostate stromal cells (WPMY-1)

BACKGROUND

Crinum latifolium L. (Amaryllidaceae) has been used in Southeast Asian traditional medicine to alleviate the symptoms of benign prostatic hyperplasia (BPH). The pathological mechanism of BPH is associated with the induction of prostate stromal cell proliferation through transforming growth factor-beta (TGF-β). Standardization as well as investigation of the potential anti-BPH activity of C. latifolium extract could benefit the further development of BPH-related analyses and provide evidence to support the application of this extract for BPH treatment. This study aimed to standardize and investigate the antiproliferative activity of the ethanolic extract of C. latifolium leaves. The major alkaloids isolated from C. latifolium were also explored for their potential use as bioactive markers.

METHODS

Two major alkaloids were isolated from the ethanolic extract of C. latifolium leaves by chromatographic techniques, identified by NMR and MS, and quantified by a validated UHPLC method. Their antiproliferative activity was studied in human prostate stromal cells (WPMY-1) induced by TGF-β. The synergistic effect of combining the two major isolated alkaloids was analyzed by the zero interaction potency (ZIP) model.

RESULTS

Two alkaloids, lycorine (1) and 6α-hydroxybuphanidrine (2), were isolated from the ethanolic leaf extract of C. latifolium. A UHPLC method for the quantification of (1) and (2) was developed and validated in terms of linearity, precision, and accuracy. The C. latifolium leaf extract contained 0.279 ± 0.003% (1) and 0.232 ± 0.004% (2). The crude extract was more potent than either (1) and (2) alone against TGF-β-treated WPMY-1 cell proliferation. The drug combination study revealed that the greatest synergistic effect of (1) and (2) was achieved at a 1:1 ratio.

CONCLUSIONS

The results of this study support the anti-BPH activity of C. latifolium in traditional medicine and suggest that these the two isolated alkaloids may promote the efficacy of the C. latifolium extract. Additionally, major alkaloids (1) and (2) can be used as bioactive markers for the standardization of C. latifolium extracts.

Repositioning anticancer drugs as novel COVID-19 antivirals: targeting structural and functional similarities between viral proteins and cancer

The current COVID-19 pandemic contributed by the SARS-CoV-2 has put in place an urgent need for new and promising antiviral therapeutics. The viral RNA-dependent RNA polymerase (RdRp) enzyme plays a vital role in viral replication for all RNA viruses, including SARS-CoV-2, thereby making it a prime and promising candidate for novel antiviral targeting. Interestingly, the human telomerase reverse transcriptase (hTERT), a common catalytic subunit of the telomerase enzyme in many cancers, has also been identified with structural and functional similarities to the viral RdRp. Therefore, it becomes essential to evaluate and consider anticancer drugs that target hTERT towards antiviral RdRp activity, and vice versa. For instance, Floxuridine, an hTERT inhibitor, and VX-222, a hepatitis C virus RdRp inhibitor, are now gaining recognition as a potential antiviral against SARS-CoV-2 and anti-hTERT for cancer, simultaneously. While limited studies on hTERT inhibitors for use as viral RdRp, and anti-RdRp inhibitors as hTERT inhibitors are available, in this review, we aim at bringing to light this close structural and functional relationship between both these enzymes. We punctuate this idea with specific examples on how potential anticancer inhibitors can effectively be brought to use as inhibitors against the SARS-CoV-2 virus, a relatively new pathogen, compared to the very well-studied field of cancer research.

Potential Antiviral Action of Alkaloids

Viral infections and outbreaks have become a major concern and are one of the main causes of morbidity and mortality worldwide. The development of successful antiviral therapeutics and vaccines remains a daunting challenge. The discovery of novel antiviral agents is a public health emergency, and extraordinary efforts are underway globally to identify safe and effective treatments for different viral diseases. Alkaloids are natural phytochemicals known for their biological activities, many of which have been intensively studied for their broad-spectrum of antiviral activities against different DNA and RNA viruses. The purpose of this review was to summarize the evidence supporting the efficacy of the antiviral activity of plant alkaloids at half-maximum effective concentration (EC₅₀) or half-maximum inhibitory concentration (IC₅₀) below 10 μM and describe the molecular sites most often targeted by natural alkaloids acting against different virus families. This review highlights that considering the devastating effects of virus pandemics on humans, plants, and animals, the development of high efficiency and low-toxicity antiviral drugs targeting these viruses need to be developed. Furthermore, it summarizes the current research status of alkaloids as the source of antiviral drug development, their structural characteristics, and antiviral targets. Overall, the influence of alkaloids at the molecular level suggests a high degree of specificity which means they could serve as potent and safe antiviral agents waiting for evaluation and exploitation.

Lycorine improves peripheral nerve function by promoting Schwann cell autophagy via AMPK pathway activation and MMP9 downregulation in diabetic peripheral neuropathy

Diabetic peripheral neuropathy (DPN) is the most common complication of diabetes mellitus and no effective therapy is approved. Here, lycorine, a natural alkaloid, was identified as a potential drug for DPN by the bioinformatics analysis of GEO datasets and Connectivity Map database. Lycorine administration improved peripheral nerve function and autophagy-associated proteins of diabetic mice. Again, in vitro high glucose-cultured rat Schwann cells (RSC96) showed enhanced autophagosome marker LC3-II with the treatment of lycorine. Additionally, beclin-1 and Atg3 were decreased in high glucose-stimulated RSC96 cells, which were reversed by lycorine treatment. Furthermore, DPN-associated differentially expressed genes (DEGs) from GEO datasets and lycorine-drug targets from PubChem and PharmMapper were visually analyzed and revealed that MMP9 was both DPN-associated DEGs and lycorine-drug target. Functional enrichment analysis of MMP9-relevant genes showed that cell energy metabolism was involved. Moreover, lycorine reduced high glucose-enhanced MMP9 expression in RSC96 cells. Overexpression of MMP9 attenuated lycorine-induced the expression of beclin-1, Atg3 and LC3-II in high glucose-cultured RSC96 cells. In addition, AMPK pathway activation was confirmed in lycorine-treated high glucose-cultured RSC96 cells. Then AMPK pathway inhibition attenuated lycorine-reduced MMP9 expression in high glucose-treated RSC96 cells. Molecular docking analysis revealed that lycorine bound the domain of AMPK containing Thr 172 site, which affected AMPK (Thr 172) phosphorylation. Finally, AMPK pathway activation and MMP9 downregulation were also revealed in the sciatic nerves of diabetic mice administrated with lycorine. Taken together, lycorine was advised to promote Schwann cell autophagy via AMPK pathway activation and MMP9 downregulation-induced LC3-II transformation in diabetic peripheral neuropathy.

The novel role of the aquaporin water channel in lycopene preventing DEHP-induced renal ionic homeostasis disturbance in mice

Di-(2-ethylhexyl) phthalate (DEHP), an extensively used plasticizer, can cause environmental pollution and organ injury. Lycopene (LYC) is a natural carotene that has the potential to prevent chronic diseases. To reveal the effect of DEHP and/or LYC on the kidney, male mice were treated with LYC (5 mg/kg) and/or DEHP (500 mg/kg or 1000 mg/kg) by gavage for 28 days. The study indicated that DEHP caused glomerular atrophy, tubular expansion, disappearance of the mitochondrial membrane, and cristae rupture. DEHP exposure can increase the expression of aquaporin (AQP) subunits and the activity of Ca²⁺-Mg²⁺-ATPase and decrease the activity of Na⁺-K⁺-ATPase, which results in ion disorder. However, LYC can relieve kidney injury by regulating the activity of ATPase, the expression of ATPase subunits, and AQP subunit expression. The results indicated that AQP was a target for LYC in antagonizing the disturbance of DEHP-induced renal damage.

Lycorine nanoparticles induce apoptosis through mitochondrial intrinsic pathway and inhibit migration and invasion in HepG2 cells

Lycorine-nanoparticles (LYC-NPs) were successfully synthesized using anti-solvent precipitation-freeze drying method, and characterized using transmission electron microscopy (TEM), particle size analysis and Fourier transform infrared spectroscopy (FTIR). Then, the antitumor effects of LYC-NPs against HepG2 cells were investigated, and the underlying molecular mechanisms were explored. Our results showed that LYC-NPs displayed potent antiproliferative against HepG2 cells concentration dependently. Flow cytometry analysis exhibited that LYC-NPs triggered apoptosis and impeded cell cycle in G0/G1 phase. Moreover, the up-regulated expression of cleaved caspases-3 and Bax, and decrease of mitochondrial membrane potential and the Bcl-2 expression were involved in LYC-NPs apoptosis, implying that LYC-NPs induced apoptosis via the mitochondrial-mediated apoptosis pathway. Furthermore, LYC-NPs distinctly impaired HepG2 cells migration and invasion with down-regulation of matrix metalloproteinase-2 (MMP-2) and MMP-9 expression. These results indicated that LYC-NPs could be an favorable agent for restraining the growth and metastasis of HepG2 cells.

Semisynthetic Derivatives of Selected Amaryllidaceae Alkaloids as a New Class of Antimycobacterial Agents

The search for novel antimycobacterial drugs is a matter of urgency, since tuberculosis is still one of the top ten causes of death from a single infectious agent, killing more than 1.4 million people worldwide each year. Nine Amaryllidaceae alkaloids (AAs) of various structural types have been screened for their antimycobacterial activity. Unfortunately, all were considered inactive, and thus a pilot series of aromatic esters of galanthamine, 3-O-methylpancracine, vittatine and maritidine were synthesized to increase biological activity. The semisynthetic derivatives of AAs were screened for their in vitro antimycobacterial activity against Mycobacterium tuberculosis H37Ra and two other mycobacterial strains (M. aurum, M. smegmatis) using a modified Microplate Alamar Blue Assay. The most active compounds were also studied for their in vitro hepatotoxicity on the hepatocellular carcinoma cell line HepG2. In general, the derivatization of the original AAs was associated with a significant increase in antimycobacterial activity. Several pilot derivatives were identified as compounds with micromolar MICs against M. tuberculosis H37Ra. Two derivatives of galanthamine, 1i and 1r, were selected for further structure optimalization to increase the selectivity index.

Ferroptosis is involved in the anti-tumor effect of lycorine in renal cell carcinoma cells

Renal cell carcinoma (RCC) is a most common malignant tumor in the genitourinary system. Studies have shown that Lycorine has promising anticancer activities with minor side effects. However, the effect of lycorine on the proliferation of RCC cells and its underlying anti-tumor mechanism have not yet been fully elucidated. The human renal cancer cell lines 786-O, A498 and Caki-1 were cultured and treated with different concentrations of lycorine or ferrostatin-1, a ferroptosis inhibitor. Cell viability and colony formation assays were used to measure cell proliferation. The 5-, 12- and 15-HETE hydroxyeicosatetraenoic acid (HETE) and MDA levels, as well as the reduced to oxidized glutathione (GHS/GSSG) ratio, were analyzed. Western blot analysis was used to detect the expression of glutathione peroxidase 4 (GPX4) and acyl-CoA synthetase long chain family member 4 (ACSL4), which are key markers of ferroptosis. Transmission electron microscopy was used to observe the morphological features associated with ferroptosis. Lycorine was found to inhibit the proliferation of RCC cells. After lycorine treatment, the expression levels of GPX4 in RCC cells decreased, whereas those of ACSL4 increased. Lycorine induced the expression of 5-HETE, 12-HETE, 15-HETE and MDA in RCC cells, and reduced the GSH/GSSG ratio. In addition, ferrostatin-1 could prevent lycorine-induced ferroptosis in RCC cells.

Structural Diversity and Biological Potential of Alkaloids from the Genus Hippeastrum, Amaryllidaceae: an Update

The subfamily Amaryllidoideae, Amaryllidaceae, presents an exclusive group of structures known as Amaryllidaceae alkaloids, which have a broad spectrum of biological activities. These plants are classified into 59 genera, including Hippeastrum Herb., which comprises approximately 60 species distributed mainly in South America, being widely used as ornamental plants due to the beauty of its flowers. This review presents an update about the alkaloid profiling of Hippeastrum extracts published between 2012 and 2021, as well as an approach to the biological potential of these compounds.

Effects of Natural Products on Neuromuscular Junction

Neuromuscular junction (NMJ) disorders result from damage, malfunction or absence of one or more key proteins involved in neuromuscular transmission, comprising a wide range of disorders. The most common pathology is antibody-mediated or downregulation of ion channels or receptors, resulting in Lambert-Eaton myasthenic syndrome, myasthenia gravis, and acquired neuromyotonia (Isaac's syndrome), and rarely congenital myasthenic syndromes caused by mutations in NMJ proteins. A wide range of symptomatic treatments, immunomodulating therapies, or immunosuppressive drugs have been used to treat NMJ diseases. Future research must be directed at better understanding of the pathogenesis of these diseases, and developing novel disease-specific treatments. Numerous secondary metabolites, especially alkaloids isolated from plants have been used to treat NMJ diseases in traditional and clinical practices. An ethnopharmacological approach has provided leads for identifying new treatment for NMJ diseases. In this review, we performed a literature survey in Pubmed, Science Direct, and Google Scholar to gather information on drug discovery from plant sources for NMJ disease treatments. To date, most research has focused on the effect of herbal remedies on cholinesterase inhibitory and antioxidant activities. This review provides leads for identifying potential new drugs from plant sources for the treatment of NMJ diseases.

Antiviral and virucidal activities of lycorine on duck tembusu virus in vitro by blocking viral internalization and entry

Duck tembusu virus (DTMUV) was firstly identified in 2010 in China; since then, it has caused enormous economic loss to breeding industry. Great efforts have been made to develop drugs and vaccines against DTMUV. However, current available vaccines or anti-DTMUV drugs are consistently inefficient. Hence, various more broadly effective drugs have become important for the treatment of DTMUV infection; among these, lycorine, one of the important sources of active alkaloids, is a promising example. Nevertheless, it is not known whether lycorine has any antiviral activities against DTMUV. Therefore, the purpose of the present study is to investigate the anti-DTMUV abilities of lycorine. The cytotoxicity of lycorine was evaluated on BHK-21 cells by CCK-8 assay, and its antiviral effect against DTMUV was examined by real-time PCR assays, virus titer determination, Western blot and immunofluorescence (IFA) assays, respectively. Furthermore, the underlying mechanisms of the anti-DTMUV effects of lycorine were also investigated. The results indicated that the highest nontoxicity concentration of lycorine on BHK-21 cells was 5 µM. Lycorine possessed the antiviral ability against DTMUV on BHK-21 cells, as demonstrated by the reduction of virus titers and copy numbers in vitro. Western blot and IFA analysis showed the inhibitory effect of lycorine on DTMUV envelope (E) protein expression. Moreover, using time-of-addition assays, we found that lycorine displays its antivirus and virucidal activities through blocking viral internalization and entry in vitro. Taken together, our findings firstly demonstrate the antiviral activities of lycorine against DTMUV, suggesting that lycorine can be a potential drug for the treatment of DTMUV infection.

In vitro screening of novel anti-Babesia gibsoni drugs from natural products

Babesia gibsoni is a tick-transmitted intraerythrocytic apicomplexan parasite that causes babesiosis in dogs. Due to the strong side effects and lack of efficacy of current drugs, novel drugs against B. gibsoni are urgently needed. Natural products as a source for new drugs is a good choice for screening drugs against B. gibsoni. The current study focuses on identifying novel potential drugs from natural products against B. gibsoniin vitro. Parasite inhibition was verified using a SYBR green I-based fluorescence assay. A total of 502 natural product compounds were screened for anti-B. gibsoni activity in vitro. Twenty-four compounds showed high growth inhibition (>80%) on B. gibsoni and 5 plant-derived compounds were selected for further study. The half-maximal inhibitory concentration (IC₅₀) values of lycorine (LY), vincristine sulfate (VS), emetine·2HCl (EME), harringtonine (HT) and cephaeline·HBr (CEP) were 784.4 ± 3.3, 643.0 ± 2.8, 253.1 ± 1.4, 23.4 ± 1.2, and 108.1 ± 4.3 nM, respectively. The Madin-Darby canine kidney (MDCK) cell line was used to assess cytotoxicity of hit compounds. All compounds showed minimal toxicity to the MDCK cells. The effects of hit compounds combined with diminazene aceturate (DA) on B. gibsoni were further evaluated in vitro. VS, EME, HT or CEP combined with DA showed synergistic effects against B. gibsoni, whereas LY combined with DA showed an antagonistic effect against B. gibsoni. The results obtained in this study indicate that LY, VS, EME, HT and CEP are promising compounds for B. gibsoni treatment.

Amplification of oxidative stress with lycorine and gold-based nanocomposites for synergistic cascade cancer therapy

BACKGROUND

Despite advances of surgery and neoadjuvant chemotherapy during the past few decades, the therapeutic efficacy of current therapeutic protocol for osteosarcoma (OS) is still seriously compromised by multi-drug resistance and severe side effects. Amplification of intracellular oxidative stress is considered as an effective strategy to induce cancer cell death. The purpose of this study was to develop a novel strategy that can amplify the intracellular oxidative stress for synergistic cascade cancer therapy.

METHODS AND RESULTS

A novel nanocomposite, composed of folic acid (FA) modified mesoporous silica-coated gold nanostar (GNS@MSNs-FA) and traditional Chinese medicine lycorine (Ly), was rationally designed and developed. Under near-infrared (NIR) irradiation, the obtained GNS@MSNs-FA/Ly could promote a high level of ROS production via inducing mitochondrial dysfunction and potent endoplasmic reticulum (ER) stress. Moreover, glutathione (GSH) depletion during ER stress could reduce ROS scavenging and further enable efficient amplification of intracellular oxidative stress. Both in vitro and in vivo studies demonstrated that GNS@MSNs-FA/Ly coupled with NIR irradiation exhibited excellent antitumor efficacy without noticeable toxicity in MNNG/HOS tumor-bearing mice.

CONCLUSION

All these results demonstrated that GNS@MSNs-FA/Ly coupled with NIR irradiation could dramatically amplify the intra-tumoral oxidative stress, exhibiting excellent antitumor ability without obvious systemic toxicity. Taken together, this promising strategy provides a new avenue for the effective cancer synergetic therapy and future clinical translation.