Comparative assessment of 9-bromo noscapine ionic liquid and noscapine: Synthesis, in-vitro studies plus computational & biophysical evaluation with human hemoglobin.

Noscapine is a proficient anticancer drug active against wide variety of tumors including lung cancer. Over time, several noscapine analogues have been assessed to maximize the efficiency of the drug, amongst which 9-bromo noscapine remains one of the most potent analogues till date. In the present work, we have synthesized 9-bromo noscapine ionic liquid [9-Br-Nos]IBr2, an active pharmaceutical ingredient based ionic liquid (API-IL) to address the existing issues of solubility and targeted drug delivery in the parent alkaloid as well as the synthesized analogues. We have devised a novel two-step synthesis route (first-ever ionic to ionic bromination) to obtain the desired [9-Br-Nos]IBr2 which is advantageous to its organic analogue in terms of increased solubility, lesser reaction time and better yield. Furthermore, we have compared 9-bromo noscapine ionic liquid with noscapine based on its binding interaction with human hemoglobin (Hb) studied via computational along with spectroscopic studies, and bioactivity against non-small cell lung cancer. We inferred formation of a complex between [9-Br-Nos]IBr2 and Hb in the stoichiometric ratio of 1:1, similar to noscapine. At 298 K, [9-Br-Nos]IBr2-Hb binding was found to exhibit Kb and ∆G of 36,307 M-1 and -11.5 KJmol-1, respectively, as compared to 159 M-1 and -12.5 KJmol-1 during Noscapine-Hb binding. This indicates a more stronger and viable interaction between [9-Br-Nos]IBr2 and Hb than the parent compound. From computational studies, the observed higher stability of [9-Br-Nos]I and better binding affinity with Hb with a binding energy of -91.75 kcalmol-1 supported the experimental observations. In the same light, novel [9-Br-Nos]IBr2 was found to exhibit an IC50 = 95.02 ± 6.32 µM compared to IC50 = 128.82 ± 2.87 µM for noscapine on A549 (non-small lung cancer) cell line at 48 h. Also, the desired ionic liquid proved to be more cytotoxic inducing a mortality rate of 87 % relative to 66 % evoked by noscapine at concentrations of 200 µM after 72 h.

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.

Insight into the Tubulin-Targeted Anticancer Potential of Noscapine and its Structural Analogs.

Cancer is known as a notorious disease responsible for threatening millions of lives every year. Natural products which act by disrupting the microtubule assembly and dynamics have proven to be highly successful as anticancer agents but their high toxicity owing to lower selectivity has limited their usage. Recently, Noscapine (NOS), a known anti-tussive, has come out to be an effective anti-tubulin candidate with far lesser toxicity. Since its first report as an anti-mitotic agent in 1998, NOS has been extensively studied and modified by various groups of researchers to optimize its anti-tubulin activity. In this review, the recent advancements about the potential of these therapeutic candidates against various cancers have been compiled and analyzed for their inhibitory mechanism in distinct health conditions. It has been observed that the non-polar substitutions (e.g., halides, aryl groups) at specific sites (9-position and N-sites of isoquinoline ring; and modification of a methoxy group) have an enhanced effect on efficacy. The mechanistic studies of NOS and its modified analogs have shown their inhibitory action primarily through interaction with microtubules dynamics thus disrupting the cell-cycle and leading to apoptosis. This review highlights the latest research in the field by providing a rich resource for the researchers to have a hands-on analysis of NOS analogs and the inhibitory action in comparison to other microtubule disrupting anti-cancer agents. The article also documents the newer investigations in studying the potential of noscapine analogs as possible anti-microbial and antiviral agents.

Biological and pharmacological activities of noscapine: Focusing on its receptors and mechanisms.

Noscapine has been mentioned as one of the effective drugs with potential therapeutic applications. With few side effects and amazing capabilities, noscapine can be considered different from other opioids-like structure compounds. Since 1930, extensive studies have been conducted in the field of pharmacological treatments from against malaria to control cough and cancer treatment. Furthermore, recent studies have shown that noscapine and some analogues, like 9-bromonoscapine, amino noscapine, and 9-nitronoscapine, can be used to treat polycystic ovaries syndrome, stroke, and other diseases. Given the numerous results presented in this field and the role of different receptors in the therapeutic effects of noscapine, we aimed to review the properties, therapeutic effects, and the role of receptors in the treatment of noscapine.

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.

Synergistic interaction of N-3-Br-benzyl-noscapine and docetaxel abrogates oncogenic potential of breast cancer cells.

Noscapine, an opium alkaloid, was discovered to bind tubulin, arrest dividing cells at mitosis, and selectively induce apoptosis to cancer cells. N-3-Br-Benzyl-Noscapine (Br-Bn-Nos), one of the derivatives of noscapine, was demonstrated to have improved anticancer potential compared with noscapine. We approached to evaluate the single and combined effect of Br-Bn-Nos and docetaxel (DOX) based on molecular modeling and cellular study. The individual predicted free energy of binding (∆Gbind,pred ) for Br-Bn-Nos and DOX with tubulin was found to be -28.89 and -36.07 kcal/mol based on molecular mechanics generalized Born solvation area (MM-GBSA) as well as -26.21 and -34.65 kcal/mol based on molecular mechanics Poisson Boltzmann solvation area (MM-PBSA), respectively. However, the ∆Gbind,pred of Br-Bn-Nos was significantly reduced (-33.02 and -30.24 kcal/mol using MM-GBSA and MM-PBSA) in the presence of DOX on its binding pocket. Parenthetically, the ∆Gbind,pred of DOX was significantly reduced (-37.17 and -32.80 kcal/mol using MM-GBSA and MM-PBSA) in the presence of Br-Bn-Nos on its binding pocket. The reduced ∆Gbind,pred in the presence of Br-Bn-Nos and DOX together indicated a combination effect of both the ligands. The combined interaction of both the agents onto tubulin dimmer was also determined experimentally using purified tubulin, in which a combination regimen of Br-Bn-Nos and DOX reduced the fluorescence intensity of tubulin to a higher value (68%) compared with the single regimen. Further, isobologram analysis revealed the synergistic effect of Br-Bn-Nos and DOX in antiproliferative activity using MCF-7 cell line at 48 hr (sum FIC = 0.49) and at 72 hr (sum FIC = 0.62). The combination dose regimen of Br-Bn-Nos and DOX blocks the cell cycle progression at the G2/M phase and induces apoptosis to cancer cells more effectively compared with the single regimen. Taken together, our study provides compelling evidence that the anticancer potential of noscapine derivatives may be substantially improved when it is used in a combined application with DOX for breast cancer.

A Comprehension into Target Binding and Spatial Fingerprints of Noscapinoid Analogues as Inhibitors of Tubulin.

BACKGROUND: Owing to its potential to interfere in microtubule dynamics in the mitotic phase of cell cycle and selectively induce apoptosis in cancer cells without affecting normal cells, noscapine and its synthetic analogues have been investigated by other research groups in different cell lines for their capability to be used as anti-cancer agents. OBJECTIVE: The present study is focused on the investigation of the mode of binding of noscapinoids with tubulin, prediction of target binding affinities and mapping of their spatial fingerprints (shape and electrostatic). METHODS: Molecular docking assisted alignment based 3D-QSAR was used on a dataset (43 molecules) having an inhibitory activity (IC50 = 1.2-250 µM) against human lymphoblast (CEM) cell line. RESULTS AND CONCLUSION: Key amino acid residues of target tubulin were mapped for the binding of most potent noscapine analogue (Compound 11) and were compared with noscapine. Spatial fingerprints of noscapinoids for favorable tubulin inhibitory activity were generated and are proposed herewith for further pharmacophoric amendments of noscapine analogues to design and develop novel potent noscapine based anti-cancer agents that may enter into drug development pipeline.

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.

Structural Basis of Noscapine Activation for Tubulin Binding.

Noscapine is a natural alkaloid that is used as an antitussive medicine. However, it also acts as a weak anticancer agent in certain in vivo models through a mechanism that is largely unknown. Here, we performed structural studies and show that the cytotoxic agent 7A-O-demethoxy-amino-noscapine (7A-aminonoscapine) binds to the colchicine site of tubulin. We suggest that the 7A-methoxy group of noscapine prevents binding to tubulin due to a steric clash of the compound with the T5-loop of α-tubulin. We further propose that the anticancer activity of noscapine arises from a bioactive metabolite that binds to the colchicine site of tubulin to induce mitotic arrest through a microtubule cytoskeleton-based mechanism.

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.

Novel noscapine derivatives stabilize the native state of insulin against fibrillation.

Protein aggregation to form amyloid is associated with many human diseases, increasing the need to develop inhibitors of this process. Here we evaluate the ability of derivatives of the small organic compound noscapine, derived from the opium poppy, to inhibit fibrillation of the model protein insulin. We combined biophysical methods to assess insulin stability and aggregation with computational docking and cell viability studies to identify the most potent derivatives. The best aggregation inhibitor (a phenyl derivative of N-nornoscapine) also demonstrated the highest ability to stabilize native insulin against thermal denaturation. This compound maintained insulin largely in the monomeric and natively folded state under fibrillation conditions and also decreased insulin aggregate toxicity against human neuroblastoma SH-SY5Y cells. The inhibitory effects were specific for insulin fibrillation, as the noscapine compounds did not inhibit fibrillation of other proteins such as α-synuclein, Aß, and FapC. Our data demonstrate that compounds which stabilize the folded native state of a protein can not only inhibit fibrillation but also decrease the toxicity of the mature fibrillar aggregates of insulin protein.

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.

Mechanistic Interaction Study of Bromo-Noscapine with Bovine Serum Albumin employing Spectroscopic and Chemoinformatics Approaches.

Bromo-Noscapine (BrNs) is a tubulin-binding cytotoxic agent with significant activity against breast and lung cancer. The mechanistic interaction insight into the binding of bovine serum albumin (BSA) with BrNs can provide critical information about the pharmacodynamics and pharmacokinetics properties. Here, various spectroscopic techniques and computational methods were employed to understand the dynamics of BrNs and BSA interaction. The intrinsic fluorescence of BSA was quenched by BrNs through a static quenching procedure. The stoichiometry of BrNs-BSA complex was 1:1 and binding constant of the complex was in the order of 103 M-1 at 298 K. Based on thermodynamic analysis, it was deduced that binding process of the BrNs with BSA was spontaneous and exothermic, and the major forces between BrNs and BSA were van der waals forces and hydrogen bonding. Moreover, results of FT-IR, CD, UV spectra concluded significant conformational change in BSA on binding with BrNs. The in vitro findings were further confirmed by in silico assays. Molecular docking showed strong interactions with score of -8.08 kcal/mol. Molecular dynamics simulation analysis also suggested the stable binding with lower deviation in RMSD and RMSF values through persistent long simulation run. This study suggests optimal efficiency of diffusion of the BrNs into the bloodstream for the treatment of cancer.

Synthesis and Pharmacological Evaluation of Noscapine-Inspired 5-Substituted Tetrahydroisoquinolines as Cytotoxic Agents.

A series of 5-substituted tetrahydroisoquinolines was synthesized via a 10-step linear synthesis to assess whether replacement of noscapine's southern isobenzofuranone with other moieties resulted in retained cytotoxic activity. One such molecule, 18g, bearing a para-methoxybenzyl functionality with N-ethylcarbamoyl substitution, produced cell-cycle arrest at the G2/M phase with an EC50 of 2.7 µM in the MCF-7 breast-cancer cell line, a 7-fold increase compared with that of noscapine (5). This molecule had similar activity (EC50 of 2.5 µM) against the resistant NCI/AdrRES cell line, demonstrating its potential to overcome or avert known resistance mechanisms, unlike current cytotoxic agents. Compound 18g was found to modify the drug-efflux activity of P-gp and, in combination studies, potentiate the antiproliferative activity of vinblastine. These results provide insights into structural modifications to noscapine that will guide future development toward more potent cytotoxic agents that are active against resistant cancer cells.

Noscapinoids bearing silver nanocrystals augmented drug delivery, cytotoxicity, apoptosis and cellular uptake in B16F1, mouse melanoma skin cancer cells.

PURPOSE: Noscapine (Nos) and reduced brominated analogue of noscapine (Red-Br-Nos) prevent cellular proliferation and induce apoptosis in cancer cells either alone or in combination with other chemotherapeutic drugs. However, owing to poor physicochemical properties, Nos and Red-Br-Nos have demonstrated their anticancer activity at higher and multiple doses. Therefore, in present investigation, silver nanocrystals of noscapinoids (Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals) were customized to augment drug delivery, cytotoxicity, apoptosis and cellular uptake in B16F1 mouse melanoma cancer cells. METHODS AND RESULTS: Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals were prepared separately by precipitation method. The mean particle size of Nos-Ag2+ nanocrystals was measured to be 25.33±3.52nm, insignificantly (P>0.05) different from 27.43±4.51nm of Red-Br-Nos-Ag2+ nanocrystals. Furthermore, zeta-potential of Nos-Ag2+ nanocrystals was determined to be -25.3±3.11mV significantly (P<0.05) different from -15.2±3.33mV of Red-Br-Nos-Ag2+ nanocrystals. The shape of tailored nanocrystals was slightly spherical and or irregular in shape. The architecture of Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals was crystalline in nature. FT-IR spectroscopy evinced the successful interaction of Ag2+ nanocrystals with Nos and Red-Br-Nos, respectively. The superior therapeutic efficacy of tailored nanocrystals was measured in terms of enhanced cytotoxicity, apoptosis and cellular uptake. The Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals exhibited an IC50 of 16.6µM and 6.5µM, significantly (P<0.05) lower than 38.5µM of Nos and 10.3µM of Red-Br-Nos, respectively. Finally, cellular morphological alterations in B16F1 cells upon internalization of Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals provided the evidences for accumulation within membrane-bound cytoplasmic vacuoles and in enlarged lysosomes and thus triggered mitochondria mediated apoptosis via caspase activation. CONCLUSION: Preliminary investigations substantiated that Nos-Ag2+ nanocrystals and Red-Br-Nos-Ag2+ nanocrystals must be further explored and utilized for the delivery of noscapinoids to melanoma cancer cells.

Elucidation of the Tubulin-targeted Mechanism of Action of 9-(3-pyridyl) Noscapine.

We have recently reported the synthesis and antiproliferative potential of a series of biaryl type α-noscapine congeners. Among them, 9-(3-pyridyl) noscapine 3f (9-PyNos, henceforth), which was synthesized by adding pyridine unit to the tetrahydroisoquinoline part of natural α-noscapine core, was found to be the most effective one to inhibit proliferation of a variety of cancer cell lines. However, details of its interactions with its cellular target, tubulin, remain poorly understood. In this report, we examined the nature of interactions of 9-PyNos with tubulin based on the methodologies of spectrofluorimetry, circular dichroism, and turbidimetry techniques. Far-UV circular dichroism spectra indicated perturbation of tubulin secondary structure in the presence of 9-PyNos, not amounting, however, to the perturbation induced by noscapine. The noscapinoid nevertheless altered the surface configuration of the protein considerably, as indicated by an anilinonaphthalene sulphonate binding assay, and promoted colchicine binding to tubulin, the latter indicating its adjacent binding site with colchicine. 9-PyNos however, did not alter microtubule assembly considerably. Investigating the possible reason behind this apparent lack of strong inhibition of microtubule assembly, we found that the binding interactions of tubulin with 9-PyNos do not involve modification of cysteine residues of tubulin. Taken together, our data suggest that the antiproliferative mechanism of action of 9-PyNos involves disruption of structural integrity of tubulin without strong inhibition of tubulin assembly.

Noscapine and its Analogs as Chemotherapeutic Agent: Current updates.

Recently, noscapine was reported as anticancer drug. Unlike, colchicine and podophyllotoxin, noscapine did not depolymerize microtubules even at stoichiometric concentrations but rather only mitigated their dynamics. Other microtubule-interacting chemotherapeutics, although quite effective, have therapy-limiting toxicities including immunosuppression and peripheral neuropathies. Recurrent cancers often become resistant. Noscapine however remains effective in some such instances, e.g., taxane-resistant ovarian cancer. Noscapine and analogs also do not show signs of neurotoxicity or immunosuppression. In addition, 9-bromo noscapine, Red-9-Br-Nos and other analogs were characterized for their structure and further studied in detail. On the other hand, noscapine was shown to be neuroprotective in mouse model of neurodegenerative disease and in stroke patients. Like low doses of colchicine, noscapine and its analog 9-Br-Noscapine also show anti-inflammatory activities. There are indications of a preventive use of noscapine in ischemiareperfusion injury and fibrosis. The entire biosynthetic pathway of noscapine is encoded as gene cluster within 401 kilo bases of genomic DNA, opening up opportunities for the large-scale biotechnological production of noscapine for medicinal needs. Thus, noscapine and its derivatives (noscapinoids) might be cost-effective and safe components for cancer chemotherapy. Owing to its low toxicity, it also might be useful for preventive use in high-risk situations. This brief review is an update of current research activity and patents on noscapine and its analogs.

Noscapine targets EGFRp-Tyr1068 to suppress the proliferation and invasion of MG63 cells.

Osteosarcoma, the most common primary malignant bone tumor, usually arises in the metaphysis of long bones. Amplification and mutation of the epidermal growth factor receptor (EGFR) gene represent signature genetic abnormalities encountered in osteosarcoma. Noscapine is a benzylisoquinoline alkaloid derived from the opium poppy Papaver somniferum. Recently several studies have suggested its anti-cancer effect in melanoma, ovarian cancer, gliomas, breast cancer, lung cancer, and colon cancer. However, the underlying molecular mechanism for its anti-cancer effect still remains unclear. In this paper, we found the mechanism of noscapine effectively suppressed proliferation and invasion of MG63 cell line by inhibiting the phosphorylation of EGFR and its downstream pathway.

A new antiproliferative noscapine analogue: chemical synthesis and biological evaluation.

Noscapine, a naturally occurring opium alkaloid, is a widely used antitussive medication. Noscapine has low toxicity and recently it was also found to possess cytotoxic activity which led to the development of many noscapine analogues. In this paper we report on the synthesis and testing of a novel noscapine analogue. Cytotoxicity was assessed by MTT colorimetric assay using SKBR-3 and paclitaxel-resistant SKBR-3 breast cancer cell lines using different concentrations for both noscapine and the novel compound. Microtubule polymerization assay was used to determine the effect of the new compound on microtubules. To compare the binding affinity of noscapine and the novel compound to tubulin, we have done a fluorescence quenching assay. Finally, in silico methods using docking calculations were used to illustrate the binding mode of the new compound to α,ß-tubulin. Our cytotoxicity results show that the new compound is more cytotoxic than noscapine on both SKBR-3 cell lines. This was confirmed by the stronger binding affinity of the new compound, compared to noscapine, to tubulin. Surprisingly, our new compound was found to have strong microtubule-destabilizing properties, while noscapine is shown to slightly stabilize microtubules. Our calculation indicated that the new compound has more binding affinity to the colchicine-binding site than to the noscapine site. This novel compound has a more potent cytotoxic effect on cancer cell lines than its parent, noscapine, and hence should be of interest as a potential anti-cancer drug.

Nanoparticles Based on Linear and Star-Shaped Poly(Ethylene Glycol)-Poly(ε-Caprolactone) Copolymers for the Delivery of Antitubulin Drug.

PURPOSE: Biodegradable polymeric nanoparticles of different architectures based on polyethylene glycol-co-poly(ε-caprolactone) block copolymers have been loaded with noscapine (NOS) to study their effect on its anticancer activity. It was intended to use solubility of NOS in an acidic environment and ability of the nanoparticles to passively target drugs into cancer tissue to modify the NOS pharmacokinetic properties and reduce the requirement for frequent injections. METHODS: Linear and star-shaped copolymers were synthetized and used to formulate NOS loaded nanoparticles. Cytotoxicity was performed using a sulforhodamine B method on MCF-7 cells, while biocompatibility was determined on rats followed by hematological and histopathological investigations. RESULTS: Formulae with the smallest particle sizes and adequate entrapment efficiency revealed that NOS loaded nanoparticles showed higher extent of release at pH 4.5. Colloidal stability suggested that nanoparticles would be stable in blood when injected into the systemic circulation. Loaded nanoparticles had IC50 values lower than free drug. Hematological and histopathological studies showed no difference between treated and control groups. Pharmacokinetic analysis revealed that formulation P1 had a prolonged half-life and better bioavailability compared to drug solution. CONCLUSIONS: Formulation of NOS into biodegradable polymeric nanoparticles has increased its efficacy and residence on cancer cells while passively avoiding normal body tissues. Graphical Abstract ᅟ.