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.

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.

Lycorine protects against septic myocardial injury by activating AMPK-related pathways

Cardiac dysfunction is a common complication in patients with sepsis triggering high morbidity and mortality. Lycorine (LYC), the main effective monomer component extracted from Lycoris bulbs, possesses antiviral, anti-inflammatory, analgesic, liver protection properties. In this study, the effect of LYC pre- and post-treatment as well as the underlying mechanism were evaluated in the cecal ligation and puncture (CLP) model of Balb/c mice. The survival rate, anal temperature, sepsis score, blood biochemical/routine indicators, cardiac function, sepsis-related pathophysiological processes, and AMPK signaling in septic mice were observed by echocardiography, histological staining, western blot, qPCR, and etc. LYC pretreatment attenuated myocardial injury in septic mice by improving survival rate, sepsis score, blood biochemical/routine indicators, cardiac function and structure, inhibiting inflammation and oxidative stress, improving mitochondrial function, modulating endoplasmic reticulum stress, and activating AMPK pathway. In particular, AMPK deficiency and AMPK inhibitor (Compound C) partially reversed the protective effects of LYC in septic mice. In addition, LYC posttreatment also has slight protective phenotypes on septic myocardial injury, but the effect is not as ideal as pretreatment. Taken together, these findings suggest that LYC may be a potential drug for the treatment of sepsis.

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.

Cyclin-dependent kinase 1 as a potential target for lycorine against hepatocellular carcinoma

The pathological changes and possible underlying molecular mechanisms of hepatocellular carcinoma (HCC) are currently unclear. Effective treatment of this pathological state remains a challenge. The purpose of this study is to obtain some key genes with diagnostic and prognostic meaning and to identify potential therapeutic agents for HCC treatment. Here, CDK1, CCNB1 and CCNB2 were found to be highly expressed in HCC patients and accompanied by poor prognosis, and knockdown of them by siRNA drastically induced autophagy and senescence in hepatoma cells. Simultaneously, the anti-HCC effect of lycorine was comparable to that of interfering with these three genes, and lycorine significantly promoted the decrease both in protein and mRNA expression of CDK1. Molecular validation mechanistically demonstrated that lycorine might attenuate the degradation rate of CDK1 via interaction with it, which had been confirmed by cellular thermal shift assay and drug affinity responsive targets stability assay. Taken together, these findings suggested that CDK1, CCNB1 and CCNB2 could be regarded as potential diagnostic and prognostic biomarkers for HCC, and CDK1 might serve as a promising therapeutic target for lycorine against HCC.

Narciclasine attenuates sepsis-induced myocardial injury by modulating autophagy

Acute myocardial injury (AMI) is often secondary to sepsis, which is a life-threatening disease associated with severe cardiac inflammation. Narciclasine, a plant alkaloid isolated from different members of the Amaryllidaceae family, has been extensively characterized as an antitumor and anti-inflammatory compound. In addition, autophagy is critical for sepsis-induced myocardial injury. However, the role and mechanism of autophagy by which narciclasine confers cardioprotection are still unclear. The present study aimed to investigate the underlying mechanism by which narciclasine affects the pathogenesis of sepsis-induced myocardial injury. Narciclasine effectively attenuated LPS-induced myocardial inflammation in vitro and in vivo. In addition, narciclasine protected cardiac function and suppressed the expression of inflammatory cytokines in LPS-induced heart tissue. Furthermore, narciclasine upregulated LPS-induced autophagic activity, and the autophagy inhibitor 3-MA abrogated narciclasine-mediated protection against LPS-induced AMI. Importantly, narciclasine exerted an inhibitory effect on the JNK signaling pathway, and JNK activity was tightly associated with narciclasine-induced autophagy and the consequent protective effects during AMI. Taken together, our findings indicate that narciclasine protects against LPS-induced AMI by inducing JNK-dependent autophagic flux; hence, narciclasine may be an effective and novel agent for the clinical treatment of sepsis-induced myocardial injury.

Chemistry and Biological Activity of Alkaloids from the Genus Lycoris (Amaryllidaceae)

Lycoris Herbert, family Amaryllidaceae, is a small genus of about 20 species that are native to the warm temperate woodlands of eastern Asia, as in China, Korea, Japan, Taiwan, and the Himalayas. For many years, species of Lycoris have been subjected to extensive phytochemical and pharmacological investigations, resulting in either the isolation or identification of more than 110 Amaryllidaceae alkaloids belonging to different structural types. Amaryllidaceae alkaloids are frequently studied for their interesting biological properties, including antiviral, antibacterial, antitumor, antifungal, antimalarial, analgesic, cytotoxic, and cholinesterase inhibition activities. The present review aims to summarize comprehensively the research that has been reported on the phytochemistry and pharmacology of the genus Lycoris.

Functionalized aromatic esters of the Amaryllidaceae alkaloid haemanthamine and their in vitro and in silico biological activity connected to Alzheimer's disease

A novel series of aromatic esters (1a-1m) related to the Amaryllidaceae alkaloid (AA) haemanthamine were designed, synthesized and tested in vitro with particular emphasis on the treatment of neurodegenerative diseases. Some of the synthesized compounds revealed promising acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory profile. Significant human AChE (hAChE) inhibition was demonstrated by 11-O-(3-nitrobenzoyl)haemanthamine (1j) with IC₅₀value of 4.0 ± 0.3 µM. The strongest human BuChE (hBuChE) inhibition generated 1-O-(2-methoxybenzoyl)haemanthamine (1g) with IC₅₀ value 3.3 ± 0.4 µM. Moreover, 11-O-(2-chlorbenzoyl)haemanthamine (1m) was able to inhibit both enzymes in dose-dependent manner. The mode of hAChE and hBuChE inhibition was minutely inspected using enzyme kinetic analysis in tandem with in silico experiments, the latter elucidating crucial interaction in 1j-, 1m-hAChE and 1g-, 1m-hBuChE complexes. The blood-brain barrier (BBB) permeability was investigated applying the parallel artificial membrane permeation assay (PAMPA) to predict the CNS availability of the compounds.

Lycorine Suppresses Endplate-Chondrocyte Degeneration and Prevents Intervertebral Disc Degeneration by Inhibiting NF-κB Signalling Pathway

BACKGROUND/AIMS

Cartilaginous endplate (CEP) degeneration is an important cause for intervertebral disc (IVD) degeneration that leads to low-back pain. The identification of compounds that may prevent CEP degeneration is of interest for the prevention of IVD degeneration.

METHODS

Catabolic protease expression in the CEP of disc degeneration patients was first assessed. The toxicity, function and underlying mechanism of lycorine (LY) on CEP-derived chondrocytes degeneration were assessed in vitro by flow cytometry analysis and western blotting. The concentration and function of LY in rat-tail disc-degeneration models were also assessed by HPLC (High Performance Liquid Chromatography) quantification and histological analysis.

RESULTS

In CEP cells, Interleukin (IL)-1β upregulated the expression of matrix metalloproteinase (MMP)-3, MMP-13, a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4 and ADAMTS-5 that is critical for the degradation of cartilage extracellular matrix. Interestingly, LY suppressed the expression of these enzymes via the inhibition of nuclear factor-κB (NFκB) signalling and thus prevented IL-1β-induced endplate cell degeneration in vitro. More importantly, LY also reduced the expression of MMP-3, MMP-13, ADAMTS-4 and ADAMTS-5 in CEP and exerted a protective effect on both CEP and nucleus pulposus (NP) degeneration. In addition to its inhibitory effect on matrix-degrading protease expression, LY treatment also reduced positive regulators of proinflammatory cytokines, such as MIF, which can be secreted by CEP cells and subsequently target NP cells.

CONCLUSION

LY could serve as a potential drug for treating IVD disease.

Narciclasine attenuates diet-induced obesity by promoting oxidative metabolism in skeletal muscle

Obesity develops when caloric intake exceeds metabolic needs. Promoting energy expenditure represents an attractive approach in the prevention of this fast-spreading epidemic. Here, we report a novel pharmacological strategy in which a natural compound, narciclasine (ncls), attenuates diet-induced obesity (DIO) in mice by promoting energy expenditure. Moreover, ncls promotes fat clearance from peripheral metabolic tissues, improves blood metabolic parameters in DIO mice, and protects these mice from the loss of voluntary physical activity. Further investigation suggested that ncls achieves these beneficial effects by promoting a shift from glycolytic to oxidative muscle fibers in the DIO mice thereby enhancing mitochondrial respiration and fatty acid oxidation (FAO) in the skeletal muscle. Moreover, ncls strongly activates AMPK signaling specifically in the skeletal muscle. The beneficial effects of ncls treatment in fat clearance and AMPK activation were faithfully reproduced in vitro in cultured murine and human primary myotubes. Mechanistically, ncls increases cellular cAMP concentration and ADP/ATP ratio, which further lead to the activation of AMPK signaling. Blocking AMPK signaling through a specific inhibitor significantly reduces FAO in myotubes. Finally, ncls also enhances mitochondrial membrane potential and reduces the formation of reactive oxygen species in cultured myotubes.

Narciclasine is a natural compound that attenuates diet-induced obesity in mice by promoting energy expenditure; it also induces a number of beneficial metabolic effects and activates AMPK signaling in skeletal muscle.

Obesity results from the imbalance of food intake and energy expenditure. Since the restriction of food intake is difficult and inefficient in maintaining long-term weight loss, enhancing energy expenditure is now an attractive approach in combating obesity. Here, we analysed the role in this process of a natural compound called narciclasine. We showed that narciclasine treatment reduces excess fat accumulation in peripheral metabolic tissues, improves blood metabolic parameters and insulin sensitivity in obese mice, and protects these mice from the loss of voluntary physical activity. Further investigation suggested that narciclasine enhances mitochondrial respiration and fatty acid consumption in the skeletal muscle. In addition, narciclasine strongly activates the AMP-activated protein kinase (AMPK) signaling, which is a central sensor of the cellular energy status and a key player in maintaining energy homeostasis, specifically in the skeletal muscle. Mechanistically, we found that narciclasine increases cAMP concentration and ADP/ATP ratio in muscle cells, which further lead to AMPK activation. Finally, we observed that narciclasine increases mitochondrial membrane potential and reduces the production of reactive oxygen species in muscle cells. Our findings suggest that narciclasine is a natural compound that attenuates diet-induced obesity in mice by promoting energy expenditure.

The effect of Amaryllidaceae alkaloids haemanthamine and haemanthidine on cell cycle progression and apoptosis in p53-negative human leukemic Jurkat cells

Plants from the Amaryllidaceae family have been shown to be a promising source of biologically active natural compounds of which some selected are currently in pre-clinical development. Regardless of interesting pioneer works, little is known about Amaryllidaceae alkaloids that have shown promising anti-cancer activities. The crinane group of the Amaryllidaceae, including haemanthamine and haemanthidine, was amongst the first of these compounds to exhibit an interesting cytotoxic potential against cancer cell lines. However, the mechanism of cytotoxic and anti-proliferative activity is not yet entirely clear. The primary objectives of the current study were to investigate the effects of haemanthamine and haemanthidine on the induction of apoptosis and the cell cycle regulatory pathway in p53-null Jurkat cells. Results indicate that haemanthamine and haemanthidine treatment decreases cell viability and mitochondrial membrane potential, leads to a decline in the percentage of cells in the S phase of the cell cycle, induces apoptosis detected by Annexin V staining and increases caspase activity. Dose dependent apoptosis was cross verified by fluorescence and bright field microscopy through Annexin V/propidium iodine staining and morphological changes which characteristically attend programmed cell death. The apoptotic effect of haemanthamine and haemanthidine on leukemia cells is more pronounced than that of gamma radiation. Contrary to gamma radiation, Jurkat cells do not completely halt the cell cycle 24h upon haemanthamine and haemanthidine exposure. Both Amaryllidaceae alkaloids accumulate cells preferentially at G1 and G2 stages of the cell cycle with increased p16 expression and Chk1 Ser345 phosphorylation. Concerning the pro-apoptotic effect, haemanthidine was more active than haemanthamine in the Jurkat leukemia cell line.

Quantitative determination of Amaryllidaceae alkaloids from Galanthus reginae-olgae subsp. vernalis and in vitro activities relevant for neurodegenerative diseases

In the present work the qualitative and quantitative analysis of Amaryllidaceae-type alkaloids in the aerial parts and bulbs of Galanthus reginae-olgae Orph. subsp. vernalis Kamari is presented for the first time using GC-MS analysis. The alkaloids galanthamine, lycorine, and tazettine were identified in both extracts while crinine and neronine were found only in the bulbs. The yield of alkaloid fraction from bulbs (36.8%) is very high compared to the yield from aerial parts (9.34%). Lycorine was the major component in both fractions. The antioxidant potential was determined by three complementary methods. The preparations to reduce the stable free radical DPPH to the yellow-colored 1,1-diphenyl-2-picrylhydrazyl with IC(50) values of 39 and 29 mug/mL for MeOH extracts from aerial parts and bulbs, respectively. The higher activity was given by EtOAc fraction of aerial parts with IC(50) of 10 mug/mL. This activity is probably due to the presence in EtOAc fraction of polar compounds such as polyphenols. The fraction exhibited a significant antioxidant capacity also in the beta-carotene-linoleic acid test system. A higher level of antioxidant activity was observed for EtOAc fraction from bulbs with IC(50) of 10 mug/mL after 30 min and 9 mug/mL after 60 min of incubation. In contrast, the fraction from bulbs performed poorly in the lipid peroxidation liposomes assay. Significant activity was obtained for dichloromethane fraction from aerial parts (IC(50) of 74 mug/mL). The major abundance of alkaloid in dichloromethane fraction may be responsible of the bulbs anti-cholinesterase highest activity (38.5%) at 0.5 mg/mL.

Induction of Apoptotic Cell Death Specifically in Rat and Human Cancer Cells by Pancratistatin

The major challenge in the battle against cancer is the specific targeting of cancer cells. Most chemotherapeutics and radiotherapies induce cancer cell death by inducing DNA damage. These treatments also cause severe side effects by affecting normal cells causing toxicity and mutations that may predispose them to become cancerous. Some non-genotoxic drugs such as tamoxifen are useful but are of limited applicability. Natural compounds such as paclitaxel have been useful in cancer treatment, but due to its effect as a general microtubule stabilizer and genotoxic agent, it also induces death of normal cells. Pancratistatin is a natural compound isolated from Pancratium littorale that has been shown to have anti-viral and anti-neoplastic activity. The objective in the present study was to elucidate the mechanism of the anti-neoplastic action of pancratistatin and evaluate the specificity of this compound for cancer cells.

METHODS

We used cancer cell lines and normal human endothelial and fibroblast cells to investigate the effect of pancratistatin treatment. Further, we compared the toxic effects of paclitaxel and VP-16 to that of pancratistatin on non-cancerous cells.

RESULTS

Pancratistatin induced apoptosis in all the cancer cell lines used in this study at sub-micromolar concentrations. Interestingly, normal human fibroblasts and endothelial cells remained unaffected by pancratistatin treatment under identical conditions whereas paclitaxel and VP-16 were both toxic to these two normal cell lines.

CONCLUSION

The capability of pancratistatin to selectively induce apoptosis in cancer cells is an exciting finding and makes it a suitable anti-cancer agent. Since pancratistatin shows little structural similarity to any DNA intercalating drug or to paclitaxel derivatives, it appears to be non-genotoxic. Additionally, due to the unprecedented differential cytotoxicity observed in cancerous cells, we believe pancratistatin may act upon a novel target, allowing selective induction of apoptosis in cancer cells.

Biological evaluation of structurally diverse amaryllidaceae alkaloids and their synthetic derivatives: discovery of novel leads for anticancer drug design

Twenty-nine Amaryllidaceae alkaloids and their derivatives belonging to the five most common groups, including lycorine, lycorenine, tazettine, crinine, and narciclasine types, were evaluated for antiproliferative, apoptosis-inducing, and anti-invasive activities in vitro. The antiproliferative properties of each test compound are in agreement with those reported in the literature, while the high potency of amarbellisine is reported for the first time. It was also found that with the exception of ungeremine, amarbellisine, and hippeastrine, the antiproliferative effect of the potent compounds is apoptosis mediated. Thus, apoptosis in Jurkat cells was triggered by narciclasine, narciclasine tetraacetate, C10b-R-hydroxypancratistatin, cis-dihydronarciclasine, trans-dihydronarciclasine, lycorine, 1-O-acetyllycorine, lycorine-2-one, pseudolycorine, and haemanthamine. With the exception of narciclasine, lycorine, and haemanthamine, the apoptosis-inducing properties of these compounds are reported for the first time. The collagen type I invasion assay revealed potent anti-invasive properties associated with N-methyllycorine iodide, hippeastrine, clivimine, buphanamine, and narciclasine tetraacetate, all of which were tested at non-toxic concentrations. The anti-invasive activity of buphanamine is particularly promising because this alkaloid is not toxic to cells even at much higher doses. This work has resulted in the identification of several novel leads for anticancer drug design.

Treatment of lycorine on SCID mice model with human APL cells

In our previous study, lycorine, a natural alkaloid extracted from Amaryllidaceae, exhibited anti-leukemia effects in vitro. To determine whether lycorine has an anti-tumor effect in vivo, a series of experiments were carried out in this study. HL-60 cells (5 × 10⁶) were inoculated i.v. into severe combined immuno-deficiency (SCID) mice after these mice had been irradiated (total body receiving 200 cGy χ irradiation). Treatment was given once a day from day 2 to 6, and from day 14 to 18. Lycorine (5 or 10 mg/kg/day i.p.) was found to decrease the percentages of immature granular leukocytes and of monocytes among the peripheral blood cells, and the mean survival time of both lycorine-treated groups was longer than that of the control group. Compared with the asynchronous and cytosine arabinoside- (Ara-C) treated (20 mg/kg/day i.p.) group, treatment with lycorine was more effective. Lycorine was also found to alleviate the infiltration of tumor cells into the liver, bone, and marrow. When SCID mice inoculated with HL-60 cells were then treated with lycorine, no severe adverse effects were observed. This study revealed that lycorine, when tested in the human leukemia xenograft models, appears to exhibit anti-tumor activity in vivo and is a useful therapy against acute promyelocytic leukemia.

A synthesis of 3-deoxydihydrolycoricidine: Refinement of a structurally minimum pancratistatin pharmacophore

The synthesis of 3-deoxydihydrolycoricidine, a key element toward elucidation of the pancratistatin anticancer pharmacophore, is described. Biological evaluation of this compound showed it to be significantly less active against tumor cells than pancratistatin. In addition to those features previously identified, the requirement of a 2,3,4-triol functionalized ring-C is now definitely established as the minimum pharmacophoric element for potent anticancer activity.