Noscapine modulates hypoxia-induced angiogenesis and hemodynamics: Insights from a zebrafish model investigation.

We investigated the angiogenesis-modulating ability of noscapine in vitro using osteosarcoma cell line (MG-63) and in vivo using a zebrafish model. MTT assay and the scratch wound healing assay were performed on the osteosarcoma cell line (MG-63) to analyze the cytotoxic effect and antimigrative ability of noscapine, respectively. We also observed the antiangiogenic ability of noscapine on zebrafish embryos by analyzing the blood vessels namely the dorsal aorta, and intersegmental vessels development at 24, 48, and 72 h postfertilization. Real-time polymerase chain reaction was used to analyze the hypoxia signaling molecules' gene expression in MG-63 cells and zebrafish embryos. The findings from the scratch wound healing demonstrated that noscapine stopped MG-63 cancer cells from migrating under both hypoxia and normoxia. Blood vessel development and the heart rate in zebrafish embryos were significantly reduced by noscapine under both hypoxia and normoxia which showed the hemodynamics impact of noscapine. Noscapine also downregulated the cobalt chloride (CoCl2) induced hypoxic signaling molecules' gene expression in MG-63 cells and zebrafish embryos. Therefore, noscapine may prevent MG-63 cancer cells from proliferating and migrating, as well as decrease the formation of new vessels and the production of growth factors linked to angiogenesis in vivo under both normoxic and hypoxic conditions.

Noscapine and Apoptosis in Breast and Other Cancers.

Breast cancer is the second leading contributor to the age-standardized mortality rate, for both sexes and all ages worldwide. In Europe and the United States, it is the second leading cause of mortality, with an incidence rate of about 2.6 million cases per year. Noscapine, a well-known alkaloid used as a cough suppressant, demonstrated anti-tumor effects by triggering apoptosis in various cancer cell lines and has the potential to become another ally against breast, ovarian, colon, and gastric cancer, among other types of malignancy. Apoptosis plays a crucial role in the treatment of cancer. Noscapine affected BAX, CASP8, CASP9, NFKBIA, and RELA gene and protein expression in the MCF-7 and MDA-MB-231 cell lines. Gene expression was higher in tumor than in normal tissue, including the BAX expression levels in lung, ovary, endometrium, colon, stomach, and glioblastoma patients; BCL2L1 expression in endometrium, colon, and stomach patients; CASP8 gene expression levels in lung, endometrium, colon, stomach, and glioblastoma patients; RELA in colon, stomach, and glioblastoma patients; and NFKBIA in glioblastoma patients. It can be concluded that noscapine affected genes and proteins related to apoptosis in cancer cell lines and several types of cancer patients.

Using chitosan-coated magnetite nanoparticles as a drug carrier for opioid delivery against breast cancer.

Over the past decades, opium derivatives have been discovered as new anticancer agents. In our study, Fe3O4 superparamagnetic nanoparticles (SPIONs) decorated with chitosan were loaded with papaverine or noscapine to surmount drug delivery-related obstacles. Modifying the magnetic nanoparticles (MNP) surface with polymeric materials such as chitosan prevents oxidation and provides a site for drug linkage, which renders them a great drug carrier. The obtained systems were characterized by DLS (20-40 nm were achieved for MNPs and drug- loaded MNPs), TEM (spherical with average size of 11-20 nm) FTIR, XRD, and VSM (71.3 - 42.8 emu/g). Contrary to noscapine, papaverine-MNPs attenuated 4T1 murine breast cancer cell proliferation (11.50 ± 1.74 µg/mL) effectively compared to the free drug (62.35 ± 2.88 µg/mL) while sparing L-929 fibroblast cells (138.14 ± 4.38 µg/mL). Furthermore, SPION and SPION-chitosan displayed no cytotoxic activity. Colony-formation assay confirmed the long-term cytotoxicity of nanostructures. Both developed formulations promoted ROS production accompanied by late apoptotic cell death. The biocompatible nanoparticle exerted an augmenting effect to deliver papaverine to metastatic breast cancer cells.

Impact of noscapine on halting the progression of pentylenetetrazole induced kindling epilepsy in mice.

Epilepsy is caused by an excessive recurrent excitatory neuronal firing, characterized by motor, psychomotor, and sensory impairments. Current therapies fail to produce 100% outcomes because of the complexity of the disease, poor diagnosis, and upsurge to drug-resistant epilepsy. The study repurposed the drug 'noscapine' mainly known for its anti-tussive properties. For the management of epilepsy and its associated secondary complications. To confirm the effect of noscapine, adult mice were injected with pentylenetetrazole (PTZ) (35 mg/kg i.p.) on an alternate day for 29 days to induce epilepsy. Animals were pretreated with noscapine in three doses (5, 10, and 20 mg/kg i.p.) for 33 days. Various behavioural assessments like the open field test, Morris water maze, and tail suspension test were performed to observe animals' locomotor activity, spatial memory, and anxiety-depressive behaviour. On the 34th day, animals were sacrificed, and brains were removed for biochemical estimations. Prolonged PTZ treatment reduced locomotor, learning activity, and increased anxiety-depressive behaviour, which was further confirmed by reduced antioxidant levels such as reduced glutathione (GSH), superoxide dismutase (SOD), and catalase because of increased oxido-nitrosative stress, that is, malondialdehyde (MDA) and nitrite in the brain. In comparison, noscapine pretreatment attenuated PTZ-induced behavioural and biochemical changes in the animals. The results indicate that noscapine ameliorates the oxido-nitrosative stress. However, studies indicate that oxido-nitrosative stress is a significant concern for the GABAergic neurons and promotes the disease progression. Further studies are required to explore the molecular mechanism of noscapine, which might be a practical approach as a newer antiepileptic agent.

Antiproliferative Noscapinoids Bearing an Amidothiadiazole Scaffold as Apoptosis Inducers: Design, Synthesis and Molecular Docking.

Noscapine an FDA-approved antitussive agent. With low cytotoxicity with higher concentrations, noscapine and its derivatives have been shown to have exceptional anticancer properties against a variety of cancer cell lines. In order to increase its potency, in this study, we synthesized a series of new amido-thiadiazol coupled noscapinoids and tested their cytotoxicity in vitro. All of the newly synthesised compounds demonstrated potent cytotoxic potential, with IC50 values ranging from 2.1 to 61.2 µM than the lead molecule, noscapine (IC50 value ranges from 31 to 65.5 µM) across all cell lines, without affecting normal cells (IC50 value is>300 µM). Molecular docking of all these molecules with tubulin (PDB ID: 6Y6D, resolution 2.20 Å) also revealed better binding affinity (docking score range from -5.418 to -9.679 kcal/mol) compared to noscapine (docking score is -5.304 kcal/mol). One of the most promising synthetic derivatives 6aa (IC50 value ranges from 2.5 to 7.3 µM) was found to bind tubulin with the highest binding affinity (ΔGbinding is -28.97 kcal/mol) and induced apoptosis in cancer cells more effectively.

Inhibition of Myeloperoxidase Pro-Fibrotic Effect by Noscapine in Equine Endometrium.

Myeloperoxidase is an enzyme released by neutrophils when neutrophil extracellular traps (NETs) are formed. Besides myeloperoxidase activity against pathogens, it was also linked to many diseases, including inflammatory and fibrotic ones. Endometrosis is a fibrotic disease of the mare endometrium, with a large impact on their fertility, where myeloperoxidase was shown to induce fibrosis. Noscapine is an alkaloid with a low toxicity, that has been studied as an anti-cancer drug, and more recently as an anti-fibrotic molecule. This work aims to evaluate noscapine inhibition of collagen type 1 (COL1) induced by myeloperoxidase in equine endometrial explants from follicular and mid-luteal phases, at 24 and 48 h of treatment. The transcription of collagen type 1 alpha 2 chain (COL1A2), and COL1 protein relative abundance were evaluated by qPCR and Western blot, respectively. The treatment with myeloperoxidase increased COL1A2 mRNA transcription and COL1 protein, whereas noscapine was able to reduce this effect with respect to COL1A2 mRNA transcription, in a time/estrous cycle phase-dependent manner (in explants from the follicular phase, at 24 h of treatment). Our study indicates that noscapine is a promising drug to be considered as an anti-fibrotic molecule to prevent endometrosis development, making noscapine a strong candidate to be applied in future endometrosis therapies.

Natural isoquinoline alkaloids: Pharmacological features and multi-target potential for complex diseases.

Complex diseases such as neurodegenerative disorders and cancer constitute a growing public health problem due to the rising incidence and lack in effective therapies. Since pharmacotherapy based on a single target has been insufficient for drug development in complex diseases, the emerging multi-target approach is a promising strategy for the search of new drug candidates. Plant-derived isoquinoline alkaloids comprise a vast source of multimodal agents with unique structural diversity, and variated range of pharmacological activities. This review offers an exhaustive compilation of the pharmacological relevance and multi-target potential of natural isoquinolines, emphasizing their features and promising activity in complex diseases such as Alzheimer, Parkinson, and Cancer. Selected examples were discussed in depth to illustrate the most relevant structural motifs and their possible relationship with the multimodal activity offering a comprehensive baseline in the search and optimization of isoquinoline scaffolds with polypharmacological potential for complex diseases.

9-Ethynyl noscapine induces G2/M arrest and apoptosis by disrupting tubulin polymerization in cervical cancer.

Noscapine is a phthalide isoquinoline alkaloid present in the latex of Papaver somniferum and has demonstrated potent antitumor activity in various cancer models. Structural changes in the core molecule of noscapine architecture have produced a number of potent analogs. We have recently synthesized the novel noscapine analogs (3, 4, and 5) with different functional groups appended at ninth position of natural noscapine. The anticancer activity of these compounds has been investigated using various human cancer cell lines such as HeLa (cervical cancer), DU-145 (prostate cancer), MCF-7 (breast cancer), and IMR-32 (neuroblastoma). One of the compounds in this series, 9-ethynyl noscapine (5), has demonstrated good anticancer activity against HeLa cells. Biological studies demonstrated that compound 5 decreased cell viability and colony formation in HeLa cells in a concentration dependent manner. To further uncover the mechanism in detail, we evaluated compound 5 effect on cell cycle progression, microtubule dynamics, and apoptosis. Cell cycle and western blotting analysis revealed that 9-ethynyl noscapine treatment resulted in cell cycle arrest at G2/M and decreased CDK1 and cyclinB1 protein expression. We also observed that 9-ethynyl noscapine (5) treatment leads to disruption in tubulin polymerization and induction of apoptosis by decreasing expression of bcl2, pro-caspase 3, and activation of cytochrome C. Taken together, our results indicate that 9-ethynyl noscapine (5) effectively supresses the growth of cervical cancer cells (HeLa) by disrupting tubulin polymerization, cell cycle progression leading to apoptosis.

Antibacterial activity of noscapine analogs.

The antibacterial properties of close noscapine analogs have not been previously reported. We used our pDualrep2 double-reporter High Throughput Screening (HTS) platform to identify a series of noscapine derivatives with promising antibacterial activity. The platform is based on RPF (SOS-response/DNA damage) and Katushka2S (inhibition of translation) proteins and simultaneously provides information on antibacterial activity and the mechanism of action of small-molecule compounds against E. coli. The most potent compound exhibited an MIC of 13.5 µM(6.25 µg/ml) and a relatively low cytotoxicity against HEK293 cells (CC50 = 71 µM, selectivity index: ~5.5). Some compounds from this series induced average Katushka2S reporter signals, indicating inhibition of translation machinery in the bacteria; however, these compounds did not attenuate translation in vitro in a luciferase-based translation assay. The most effective compounds did not significantly arrest the mitotic cycle in HEK293 cells, in contrast to the parent compound in a flow cytometry assay. Several molecules showed activity against clinically relevant gram-negative and gram-positive bacterial strains. Compounds from the discovered series can be reasonably regarded as good templates for further development and evaluation.

Identification of novel anti-cancer agents by the synthesis and cellular screening of a noscapine-based library.

Noscapine is a natural product first isolated from the opium poppy (Papaver somniferum L.) with anticancer properties. In this work, we report the synthesis and cellular screening of a noscapine-based library. A library of novel noscapine derivatives was synthesized with modifications in the isoquinoline and phthalide scaffolds. The so generated library, consisting of fifty-seven derivatives of the natural product noscapine, was tested against MDA-MB-231 breast cancer cells in a cellular proliferation assay (with a Z' > 0.7). The screening resulted in the identification of two novel noscapine derivatives as inhibitors of MDA cell growth with IC50 values of 5 µM and 1.5 µM, respectively. Both hit molecules have a five-fold and seventeen-fold higher potency, compared with that of lead compound noscapine (IC50 26 µM). The identified active derivatives retain the tubulin-binding ability of noscapine. Further testing of both hit molecules, alongside the natural product against additional cancer cell lines (HepG2, HeLa and PC3 cells) confirmed our initial findings. Both molecules have improved anti-proliferative properties when compared to the initial natural product, noscapine.

Noscapine Acts as a Protease Inhibitor of In Vitro Elastase-Induced Collagen Deposition in Equine Endometrium.

Endometrosis is a reproductive pathology that is responsible for mare infertility. Our recent studies have focused on the involvement of neutrophil extracellular traps enzymes, such as elastase (ELA), in the development of equine endometrosis. Noscapine (NOSC) is an alkaloid derived from poppy opium with anticough, antistroke, anticancer, and antifibrotic properties. The present work investigates the putative inhibitory in vitro effect of NOSC on collagen type I alpha 2 chain (COL1A2) mRNA and COL1 protein relative abundance induced by ELA in endometrial explants of mares in the follicular or mid-luteal phases at 24 or 48 h of treatment. The COL1A2 mRNA was evaluated by qPCR and COL1 protein relative abundance by Western blot. In equine endometrial explants, ELA increased COL 1 expression, while NOSC inhibited it at both estrous cycle phases and treatment times. These findings contribute to the future development of new endometrosis treatment approaches. Noscapine could be a drug capable of preventing collagen synthesis in mare's endometrium and facilitate the therapeutic approach.

Noscapine Prevents Rotenone-Induced Neurotoxicity: Involvement of Oxidative Stress, Neuroinflammation and Autophagy Pathways.

Parkinson's disease is characterized by the loss of dopaminergic neurons in substantia nigra pars compacta (SNpc) and the resultant loss of dopamine in the striatum. Various studies have shown that oxidative stress and neuroinflammation plays a major role in PD progression. In addition, the autophagy lysosome pathway (ALP) plays an important role in the degradation of aggregated proteins, abnormal cytoplasmic organelles and proteins for intracellular homeostasis. Dysfunction of ALP results in the accumulation of α-synuclein and the loss of dopaminergic neurons in PD. Thus, modulating ALP is becoming an appealing therapeutic intervention. In our current study, we wanted to evaluate the neuroprotective potency of noscapine in a rotenone-induced PD rat model. Rats were administered rotenone injections (2.5 mg/kg, i.p.,) daily followed by noscapine (10 mg/kg, i.p.,) for four weeks. Noscapine, an iso-qinulinin alkaloid found naturally in the Papaveraceae family, has traditionally been used in the treatment of cancer, stroke and fibrosis. However, the neuroprotective potency of noscapine has not been analyzed. Our study showed that administration of noscapine decreased the upregulation of pro-inflammatory factors, oxidative stress, and α-synuclein expression with a significant increase in antioxidant enzymes. In addition, noscapine prevented rotenone-induced activation of microglia and astrocytes. These neuroprotective mechanisms resulted in a decrease in dopaminergic neuron loss in SNpc and neuronal fibers in the striatum. Further, noscapine administration enhanced the mTOR-mediated p70S6K pathway as well as inhibited apoptosis. In addition to these mechanisms, noscapine prevented a rotenone-mediated increase in lysosomal degradation, resulting in a decrease in α-synuclein aggregation. However, further studies are needed to further develop noscapine as a potential therapeutic candidate for PD treatment.

Discovery of noscapine derivatives as potential ß-tubulin inhibitors.

Twenty novel 1,2,3-triazole noscapine derivatives were synthesized starting from noscapine by consecutive N-demethylation, reduction of lactone ring, N-propargylation and Huisgen 1,3-dipolar cycloaddition reaction. In order to select the most promising molecules to subject to further biophysical and biological evaluation, a molecular docking analysis round was performed using noscapine as reference compound. The molecules featuring docking predicted binding affinity better than that of noscapine were then subjected to MTT assay against MCF7 cell line. The obtained results disclosed that all the selected triazole derivatives exhibited a remarkably lower cell viability compared to noscapine in the range of 20 µM in 48 h. In an attempt to correlate the biological activity with the ability to bind tubulin, the surface plasmon resonance (SPR) assay was employed. Compounds 8a, 8h, 9c, 9f and 9j were able to bind tubulin with affinity constant values in the nanomolar range and higher if compared to noscapine. Integrating computational predictions and experimental evaluation, two promising compounds (8h and 9c) were identified, whose relevant cytotoxicity was supposed to be correlated with tubulin binding affinity. These findings shed lights onto structural modifications of noscapine toward the identification of more potent cytotoxic agents targeting tubulin.

Synthesis, in-vitro antiprotozoal activity and molecular docking study of isothiocyanate derivatives.

Novel isothiocyanate derivatives were synthesized starting from noscapine, bile acids, amino acids, and some aromatic compounds. Antiparasitic activities of the synthesized derivatives were tested against four unicellular protozoa, i.e., Trypanosoma brucei rhodesiense, T. cruzi, Leishmania donovani, and Plasmodium falciparum. Interestingly, seven isothiocyanate analogues displayed promising antiparasitic activity against Leishmania donovani with IC50 values between 0.4 and 1.0 µM and selectivity index (SI) ranged from 7.8 to 18.4, comparable to the standard drug miltefosine (IC50 = 0.7 µM). Compound 7h demonstrated the best antileishmanial activity with an IC50 value of 0.4 µM. Seven products exhibited inhibition activity against T. brucei rhodesiense with IC50s below 2.0 µM and SI between 2.7 and 29.3. Four primary amine derivatives of noscapine and five isothiocyanate derivatives exhibited antiplasmodial activity with IC50s in the range of 1.1-2.7 µM and SI values between 1.1 and 14.5. The isothiocyanate derivative 7c showed against T. cruzi with an IC50 value of 1.9 µM and SI 4. Molecular docking and ADMET studies were performed to investigate the interaction between active ligands and T. brucei trypanothione reductase active site. The docking studies showed significant binding affinity of noscapine derivatives to enzyme active site and good compatibility with experimental data.

Noscapine protects the H9c2 cardiomyocytes of rats against oxygen-glucose deprivation/reperfusion injury.

Noscapine is an antitumor alkaloid derived from Papaver somniferum plants. Our previous study has demonstrated that exposure of noscapine on primary murine fetal cortical neurons exposed to oxygen-glucose deprivation/reperfusion (OGD/R) has neuroprotective effects. In current study, the effects of noscapine on cardiomyocytes (H9c2 cells) damage caused by 120 minutes (min) of OGD/R were evaluated and we determined whether the addition of BD1047, sigma-one receptor antagonist, prevents the protective effects of noscapine in H9c2 cells through the production of nitric oxide (NO) and apoptosis. To initiate OGD, H9c2 cells was transferred to glucose-free DMEM, and placed in a humidified incubation chamber. Cell viability was assessed with noscapine (1-5 µM) in the presence or absence of BD1047, 24 hours (h) after OGD/R. Cell viability, NO production and apoptosis ratio were evaluated by the MTT assay, the Griess method and the quantitative real-time PCR. Noscapine considerably improved the survival of H9c2 cells compared to OGD/R. Also, noscapine was extremely capable of reducing the concentrations of NO and Bax/Bcl-2 ratio expression. While the BD1047 administration alone diminished cell viability and increased the Bax/Bcl-2 ratio and NO levels. The addition of noscapine in the presence of BD1047 did not increase the cell viability relative to noscapine alone. Noscapine exerted cardioprotective effects exposed to OGD/R-induced injury in H9c2 cells, at least partly via attenuation of NO production and Bax/Bcl-2 ratio, which indicates that the sigma-one receptor activation is involved in the protection by noscapine of H9c2 cells injured by OGD/R.

A Combinational Approach Towards Treatment of Breast Cancer: an Analysis of Noscapine-Loaded Polymeric Nanoparticles and Doxorubicin.

Our aim in this study was to clarify the combination anticancer effect of Noscapine (Nos) loaded in a polymeric nanocarrier with Doxorubicin (Dox) on breast cancer cells. Nanoprecipitation method was used to prepare methoxy polyethylene glycol (mPEG), poly lactic-co-glycolic acid (PLGA) nanoparticles (NPs) containing Nos. Transmission electron microscopy (TEM) and dynamic light scattering (DLS) were used to characterize the prepared Nos NPs. The anticancer activity of Nos NPs alone and in combination with Dox was assessed on 4T1 breast cancer cell line and in mice model. Spherical-shaped Nos NPs were prepared, with size of 101 ± 4.80 nm and zeta potential of - 15.40 ± 1 mV. Fourier transform infrared (FTIR) spectroscopy results demonstrated that Nos chemical structure was kept stable during preparation process. However, differential scanning calorimetric (DSC) thermogram proved that crystalline state of Nos changed to amorphous state in Nos NPs. The entrapment efficacy % (EE%) and drug loading % (DL%) of Nos NPs were about 87.20 ± 3.50% and 12.50 ± 2.30%, respectively. Synergistic anticancer effects of Nos both in free form (in hydrochloride form, Nos HCl) and Nos NPs form with Dox hydrochloride (Dox HCl) were observed on 4T1 cells. Combination of Nos NPs and Dox HCl inhibited tumor growth (68.50%) in mice more efficiently than Nos NPs (55.10%) and Dox HCl (32%) alone. Immunohistochemical (IHC) analysis of the tumor tissues confirmed antiangiogenic effect of Nos NPs. The findings highlighted efficacy of Nos NPs alone and in combination with Dox HCl on breast cancer tumors.

Cytotoxic, anti-proliferative and apoptotic effects of noscapine on human estrogen receptor positive (MCF-7) and negative (MDA-MB-231) breast cancer cell lines.

AIM: Noscapine, a naturally occurring alkaloid obtained from opium poppy, is a microtubule-targeting agent. This study is aimed to investigate the effects of noscapine on human breast cancer cell lines by comparing them with those of tamoxifen and docetaxel. METHODS: MCF-7 and MDA MB-23 cell lines were used to observe the effects of docetaxel, tamoxifen, and noscapine on cell proliferation. For each drug, cell blocks were prepared from cultured cells treated with IC50 dose of each drug and these were examined histologically. The expressions of Ki-67, Bcl-2, BAX, and cyclin-D1 were assessed immunohistochemically. RESULTS: Although noscapine showed cytotoxic effects on both cell lines in a time and dose dependent manner, MDA-MB-231 cells were more susceptible to its effects. Noscapine inhibited MCF-7 and MDA-MB-231 cells proliferation in vitro with IC50 value of 29 µM and 69 µM, respectively, which was comparable with IC50 of tamoxifen (40 µM and 50 µM) and docetaxel (43 nM and 32 nM). Noscapine showed anti-proliferative effects by decreasing Ki-67, cyclin-D1 and apoptotic effects by increasing BAX/Bcl-2 ratio in both breast cancer cells. Its effect was comparable with tamoxifen and docetaxel. CONCLUSION: Noscapine may be a good chemotherapeutic agent for the treatment of breast cancer, especially in estrogen receptor­negative breast cancer (Tab. 2, Fig. 7, Ref. 40).

Heterodimeric O-methyltransferases involved in the biosynthesis of noscapine in opium poppy.

Noscapine biosynthesis in opium poppy involves three characterized O-methyltransferases (OMTs) and a fourth responsible for the 4'-methoxyl on the phthalide isoquinoline scaffold. The first three enzymes are homodimers, whereas the latter is a heterodimer encoded by two linked genes (OMT2 and OMT3). Neither OMT2 nor OMT3 form stable homodimers, but yield a substrate-specific heterodimer when their genes are co-expressed in Escherichia coli. The only substrate, 4'-O-desmethyl-3-O-acetylpapaveroxine, is a seco-berbine pathway intermediate that undergoes ester hydrolysis subsequent to 4'-O-methylation leading to the formation of narcotine hemiacetal. In the absence of 4'-O-methylation, a parallel pathway yields narcotoline hemiacetal. Dehydrogenation produces noscapine and narcotoline from the corresponding hemiacetals. Phthalide isoquinoline intermediates with a 4'-hydroxyl (i.e. narcotoline and narcotoline hemiacetal), or the corresponding 1-hydroxyl on protoberberine intermediates, were not accepted. Norcoclaurine 6OMT, which shares 81% amino acid sequence identity with OMT3, also formed a functionally similar heterodimer with OMT2. Suppression of OMT2 transcript levels in opium poppy increased narcotoline accumulation, whereas reduced OMT3 transcript abundance caused no detectable change in the alkaloid phenotype. Opium poppy chemotype Marianne accumulates high levels of narcotoline and showed no detectable OMT2:OMT3 activity. Compared with the active subunit from the Bea's Choice chemotype, Marianne OMT2 exhibited a single S122Y mutation in the dimerization domain that precluded heterodimer formation based on homology models. Both subunits contributed to the formation of the substrate-binding domain, although site-directed mutagenesis revealed OMT2 as the active subunit. The occurrence of physiologically relevant OMT heterodimers increases the catalytic diversity of enzymes derived from a smaller number of gene products.

Noscapine, a Non-addictive Opioid and Microtubule-Inhibitor in Potential Treatment of Glioblastoma.

Noscapine is a phthalide isoquinoline alkaloid that easily traverses the blood brain barrier and has been used for years as an antitussive agent with high safety. Despite binding opioid receptors, noscapine lacks significant hypnotic and euphoric effects rendering it safe in terms of addictive potential. In 1954, Hans Lettré first described noscapine as a mitotic poison. The drug was later tested for cancer treatment in the early 1960's, yet no effect was observed likely as a result of its short biological half-life and limited water solubility. Since 1998, it has regained interest thanks to studies from Emory University, which showed its anticancer activity in animal models with negligible toxicity. In contrast to other microtubule-inhibitors, noscapine does not affect the total intracellular tubulin polymer mass. Instead, it forces the microtubules to spend an increased amount of time in a paused state leading to arrest in mitosis and subsequently inducing mitotic slippage/mitotic catastrophe/apoptosis. In experimental models, noscapine does not induce peripheral neuropathy, which is common with other microtubule inhibitors. Noscapine also inhibits tumor growth and enhances cancer chemosensitivity via selective blockage of NF-κB, an important transcription factor in glioblastoma pathogenesis. Due to their anticancer activities and high penetration through the blood-brain barrier, noscapine analogues strongly deserve further study in various animal models of glioblastoma as potential candidates for future patient therapy.

In Vitro Cytotoxicity and Interaction of Noscapine with Human Serum Albumin: Effect on Structure and Esterase Activity of HSA.

Noscapine is effective to inhibit cellular proliferation and induced apoptosis in nonsmall cell, lung, breast, lymphoma, and prostate cancer. It also shows good efficiency to skin cancer cells. In the current work, we studied the mechanism of interaction between the anticancer drug noscapine (NOS) and carrier protein human serum albumin (HSA) by using a variety of spectroscopic techniques (fluorescence spectroscopy, time-resolved fluorescence, UV-visible, fluorescence resonance energy transfer (FRET), Fourier transform infrared (FTIR), and circular dichroism (CD) spectroscopy), electrochemistry (cyclic voltammetry), and computational methods (molecular docking and molecular dynamic simulation). The steady-state fluorescence results showed that fluorescence intensity of HSA decreased in the presence of NOS via a static quenching mechanism, which involves ground state complex formation between NOS and HSA. UV-visible and FRET results also supported the fluorescence result. The corresponding thermodynamic result shows that binding of NOS with HSA is exothermic in nature, involving electrostatic interactions as major binding forces. The binding results were further confirmed through a cyclic voltammetry approach. The FRET result signifies the energy transfer from Trp214 of HSA to the NOS. Molecular site marker, molecular docking, and MD simulation results indicated that the principal binding site of HSA for NOS is site I. Synchronous fluorescence spectra, FTIR, 3D fluorescence, CD spectra, and MD simulation results reveal that NOS induced the structural change in HSA. In addition, the MTT assay study on a human skin cancer cell line (A-431) was also performed for NOS, which shows that NOS induced 80% cell death of the population at a 320 µM concentration. Moreover, the esterase-like activity of HSA with NOS was also done to determine the variation in protein functionality after binding with NOS.