Non-coding RNAs in Regulation of Protein Aggregation and Clearance Pathways: Current Perspectives Towards Alzheimer's Research and Therapy.

Alzheimer's disease (AD) is the leading cause of dementia, affecting approximately 45.0 million people worldwide and ranking as the fifth leading cause of mortality. AD is identified by neurofibrillary tangles (NFTs), which include abnormally phosphorylated tau-protein and amyloid protein (amyloid plaques). Peptide dysregulation is caused by an imbalance between the production and clearance of the amyloid-beta (Aß) and NFT. AD begins to develop when these peptides are not cleared from the body. As a result, understanding the processes that control both normal and pathological protein recycling in neuronal cells is critical. Insufficient Aß and NFT clearance are important factors in the development of AD. Autophagy, lysosomal dysfunction, and ubiquitin-proteasome dysfunction have potential roles in the pathogenesis of many neurodegenerative disorders, particularly in AD. Modulation of these pathways may provide a novel treatment strategy for AD. Non-coding RNAs (ncRNAs) have recently emerged as important biological regulators, with particular relevance to the emergence and development of neurodegenerative disorders such as AD. ncRNAs can be used as potential therapeutic targets and diagnostic biomarkers due to their critical regulatory functions in several biological processes involved in disease development, such as the aggregation and accumulation of Aß and NFT. It is evident that ncRNAs play a role in the pathophysiology of AD. In this communication, we explored the link between ncRNAs and AD and their regulatory mechanisms that may help in finding new therapeutic targets and AD medications.

Neuron navigators: A novel frontier with physiological and pathological implications.

Neuron navigators are microtubule plus-end tracking proteins containing basic and serine rich regions which are encoded by neuron navigator genes (NAVs). Neuron navigator proteins are essential for neurite outgrowth, neuronal migration, and overall neurodevelopment along with some other functions as well. The navigator proteins are substantially expressed in the developing brain and have been reported to be differentially expressed in various tissues at different ages. Over the years, the research has found neuron navigators to be implicated in a spectrum of pathological conditions such as developmental anomalies, neurodegenerative disorders, neuropathic pain, anxiety, cancers, and certain inflammatory conditions. The existing knowledge about neuron navigators remains sparse owing to their differential functions, undiscovered modulators, and unknown molecular mechanisms. Investigating the possible role of neuron navigators in various physiological processes and pathological conditions pose as a novel field that requires extensive research and might provide novel mechanistic insights and understanding of these aspects.

Myrica esculenta Buch.-Ham. (ex D. Don): A Review on its Phytochemistry, Pharmacology and Nutritional Potential.

Myrica esculenta is an important ethnomedicinal plant used in the traditional system of medicine and as an important nutraceutical. Several studies on the plant justify its use in alternative systems of medicine and establish a scientific rationale for its possible therapeutic application. The plant contains a range of biologically active classes of compounds, particularly diarylheptanoids, flavonoids, terpenes, tannins, and glycosides. The nutraceutical potential of the plant can be particularly attributed to its fruit, and several studies have demonstrated the presence of carbohydrates, proteins, fats, fiber content, and minerals like sodium, potassium, calcium, manganese, iron, copper, and zinc, in it. The current review aims to provide complete insight into the phytochemistry, pharmacological potential, and nutritional potential of the plant, which would not only serve as a comprehensive source of information but also will highlight the scope of isolation and evaluation of these molecules for various disease conditions.

Assessment of Anti-inflammatory Activity of 3-Acetylmyricadiol in LPSStimulated Raw 264.7 Macrophages.

BACKGROUND: Pentacyclic triterpenoids are a biologically active class of phytoconstituents with diverse pharmacological activities, including anti-inflammatory action. OBJECTIVE: In the current study, we isolated 3-Acetylmyricadiol, a pentacyclic triterpenoid, from the ethyl acetate bark extract of Myrica esculenta and evaluated it for anti-inflammatory potential. METHODS: The ethyl acetate bark extract of the M. esculenta was subjected to column chromatography to isolate 3-Acetylmyricadiol. MTT assay was performed to check cell viability. The production of proinflammatory mediators like nitric oxide, IL-6, TNF-α were observed after the administration of 5, 10, 20 µM of 3-Acetylmyricadiol in LPS-activated raw 246.7 macrophages by the reported methods. RESULTS: MTT assay indicated more than 90% cell viability up to 20 µM of 3-Acetylmyricadiol. The administration of 3-Acetylmyricadiol inhibited the production of nitric oxide, IL-6, TNF-α in a dose-dependent manner significantly in comparison to LPS treated cells. The maximum effect was observed at 20 µM of 3-Acetylmyricadiol which resulted in 52.37, 63.10, and 55.37 % inhibition of nitric oxide, IL-6, and TNF-α, respectively. CONCLUSION: Our study demonstrated the anti-inflammatory action of 3-Acetylmyricadiol and can serve as a potential candidate in the development of the clinically efficient anti-inflammatory molecule.

Protein-Based Nanohydrogels for Bioactive Delivery.

Hydrogels possess a unique three-dimensional, cross-linked network of polymers capable of absorbing large amounts of water and biological fluids without dissolving. Nanohydrogels (NGs) or nanogels are composed of diverse types of polymers of synthetic or natural origin. Their combination is bound by a chemical covalent bond or is physically cross-linked with non-covalent bonds like electrostatic interactions, hydrophobic interactions, and hydrogen bonding. Its remarkable ability to absorb water or other fluids is mainly attributed to hydrophilic groups like hydroxyl, amide, and sulphate, etc. Natural biomolecules such as protein- or peptide-based nanohydrogels are an important category of hydrogels which possess high biocompatibility and metabolic degradability. The preparation of protein nanohydrogels and the subsequent encapsulation process generally involve use of environment friendly solvents and can be fabricated using different proteins, such as fibroins, albumin, collagen, elastin, gelatin, and lipoprotein, etc. involving emulsion, electrospray, and desolvation methods to name a few. Nanohydrogels are excellent biomaterials with broad applications in the areas of regenerative medicine, tissue engineering, and drug delivery due to certain advantages like biodegradability, biocompatibility, tunable mechanical strength, molecular binding abilities, and customizable responses to certain stimuli like ionic concentration, pH, and temperature. The present review aims to provide an insightful analysis of protein/peptide nanohydrogels including their preparation, biophysiochemical aspects, and applications in diverse disciplines like in drug delivery, immunotherapy, intracellular delivery, nutraceutical delivery, cell adhesion, and wound dressing. Naturally occurring structural proteins that are being explored in protein nanohydrogels, along with their unique properties, are also discussed briefly. Further, the review also covers the advantages, limitations, overview of clinical potential, toxicity aspects, stability issues, and future perspectives of protein nanohydrogels.

Myricanol-9-acetate, a Novel Naturally Occurring Derivative of Myricanol, Induces ROS-dependent Mitochondrial-mediated Apoptosis in MCF-7 Cancer Cells.

BACKGROUND: Low therapeutic efficacy and drug-induced systemic toxicity of currently used anti-cancerous chemotherapeutic agents are major compelling factors for finding out clinically efficient molecules with high efficiency and less toxicity. OBJECTIVE: The current research work was undertaken to evaluate the anticancer potential of Myricanol- 9-acetate (MA), a novel naturally occurring derivative of myricanol. METHODS: MCF-7, MiaPaCa-2, and HCT 116 were used for cytotoxicity determination of the MA and ML (Myricanol) by MTT assay. The mechanistic study involved the determination of cell cycle arrest, Δψm loss, ROS generation, western blot assay, flow cytometry by reported methods on MCF-7 cells. RESULTS: MA exhibited anticancer activity against all three cell lines, however, the molecule was found most active against the MCF-7 cell line. We observed IC5020 µM with MA treatment as compared to the IC50 of 42 µM for myricanol treatment. Detailed mechanistic studies revealed that MA induces apoptosis of MCF-7 cell line through ROS generation and dose-dependent drop in mitochondrial membrane potential associated with cell cycle arrest at G0/G1 phase. Our results further demonstrated that down-regulation of Bcl2 and activation of the caspase cascade are the events involved in the MA-induced apoptosis. Flow cytometry results indicated an increase in early and late apoptotic population in a dose-dependent manner with an apoptotic population of about 20% at 30 µM of MA, thus, supporting our results. CONCLUSION: Present findings suggest that MA might serve as a promising novel drug candidate with high scope for taking it to further evaluation in preclinical and clinical studies.

Lipid Nanoparticles as Carriers for Bioactive Delivery.

Nanotechnology has made a great impact on the pharmaceutical, biotechnology, food, and cosmetics industries. More than 40% of the approved drugs are lipophilic and have poor solubility. This is the major rate-limiting step that influences the release profile and bioavailability of drugs. Several approaches have been reported to administer lipophilic drugs with improved solubility and bioavailability. Nanotechnology plays a crucial role in the targeted delivery of poorly soluble drugs. Nanotechnology-based drug delivery systems can be classified as solid lipid nanoparticulate drug delivery systems, emulsion-based nanodrug delivery systems, vesicular drug delivery systems, etc. Nanotechnology presents a new frontier in research and development to conquer the limitations coupled with the conventional drug delivery systems through the formation of specific functionalized particles. This review presents a bird's eye view on various aspects of lipid nanoparticles as carriers of bioactive molecules that is, synthesis, characterization, advantage, disadvantage, toxicity, and application in the medical field. Update on recent development in terms of patents and clinical trials of solid lipid nanoparticles (SLNs) and nanostructure lipid carriers (NLCs) have also been discussed in this article.

Papaverine ameliorates prenatal alcohol-induced experimental attention deficit hyperactivity disorder by regulating neuronal function, inflammation, and oxidative stress.

Attention deficit hyperactivity disorder (ADHD) is a neurodevelopmental disorder with complex aetiology and phenotypes. Phosphodiesterase10A (PDE10A) has been shown to provide benefits in various brain conditions. We investigated the role of papaverine, a selective PDE10A inhibitor on core phenotypes in prenatal alcohol exposure (PAE) model of ADHD. In order to identify probable mechanisms involved, the effects on several protein markers of neuronal function such as, neuronal survival-BDNF, neuronal transcription factor-pCREB, brain inflammation (IL-6, IL-10, and TNF-α), and brain oxidative stress (TBARS and GSH) were studied in frontal cortex, cerebellum, and striatum. PAE resulting hyper-locomotion, inattention, and anxiety were studied by the use of open-field, y-maze, and elevated plus maze, respectively. Administration of papaverine (15/30 mg kg-1 ) to PAE group of animals resulted in amelioration of hyperactivity, inattention, and anxiety. Also, papaverine resulted in significant increase of the levels in BDNF, pCREB, IL-10, and GSH along with significant decrease of TNF-α, IL-6, and TBARS in different brain areas of PAE group. Papaverine, a selective PDE10A inhibitor rectified behavioural phenotypes associated with ADHD, possibly by altering the protein markers associated with neuronal survival, neuronal transcription factor, brain inflammation, and brain oxidative stress. Implicating PDE10A as a possible target for furthering our understanding of ADHD phenotypes.

Biological Evaluation of Noscapine analogues as Potent and Microtubule-Targeted Anticancer Agents.

In present investigation, an attempt was undertaken to modify the C-9 position of noscapine (Nos), an opium alkaloid to yield 9 -hydroxy methyl and 9 -carbaldehyde oxime analogues for augmenting anticancer potential. The synthesis of 9-hydroxy methyl analogue of Nos was carried out by Blanc reaction and 9-carbaldehyde oxime was engineered by oxime formation method and characterized using FT-IR, 1H NMR, 13C NMR, mass spectroscopy, and so on techniques. In silico docking techniques informed that 9-hydroxy methyl and 9-carbaldehyde oxime analogues of Nos had higher binding energy score as compared to Nos. The IC50 of Nos was estimated to be 46.8 µM signficantly (P < 0.05) higher than 8.2 µM of 9-carbaldehyde oxime and 4.6 µM of 9-hydroxy methyl analogue of Nos in U87, human glioblastoma cells. Moreover, there was significant (P < 0.05) difference between the IC50 of 9-carbaldehyde oxime and 9-hydroxy methyl analogue of Nos. Consistent to in vitro cytotoxicity data, 9-hydroxy methyl analogue of Nos induced significantly (P < 0.05) higher degree of apoptosis of 84.6% in U87 cells as compared to 78.5% and 64.3% demonstrated by 9-carbaldehyde oxime and Nos, respectively. Thus the higher therapeutic efficacy of 9-hydroxy methyl analogue of Nos may be credited to higher solubility and inhibitory constant (K).

Pharmacognostic and pharmacological evaluation of Eulaliopsis binata plant extracts by measuring in vitro/in vivo safety profile and anti-microbial potential.

The present investigation emphasizes the pharmacognostic and phytochemical screening of Eulaliopsis binata and further evaluates the extracts of this plant for toxicological profile and anti-bacterial potential based on in vivo/in vitro assays. Microscopy, powder characteristics of the leaf material, and physicochemical and phytochemical screening were assessed for pharmacognostic evaluation. Dry leaves of Eulaliopsis binata were extracted using different solvents (methanol, ethyl acetate, and hexane), and the extracts obtained were further investigated for in vitro/in vivo toxicological study. Moreover, acute toxicity was assessed by evaluating the anti-oxidant defense system and anatomical damage in vital organs. In addition, anti-bacterial activity of all the extracts was assessed by the Kirby-Bauer method. Physicochemical and microscopic observations showed the unique identification mark for leaf powder and leaf transverse section. Phytochemical investigation evidenced the presence of flavonoids and phenolic contents in the methanolic extract. All extracts were found to be hemocompatible and exhibited no induction of behavioral alteration and no alteration in the anti-oxidant potential and anatomical structure of the vital organs. On the other hand, the methanolic extract showed a significant upsurge in the reduced glutathione level, whereas all extracts showed significant anti-bacterial potential in a dose-dependent manner. Eulaliopsis binata has inimitable pharmacognostical characteristics, good safety profile and significant anti-oxidant and anti-bacterial potential that show immense possibility for its further investigation for pharmacological use.

Long-circulating poly(ethylene glycol)-grafted gelatin nanoparticles customized for intracellular delivery of noscapine: preparation, in-vitro characterization, structure elucidation, pharmacokinetics, and cytotoxicity analyses.

Noscapine, the tubulin-binding anticancer agent, when administered orally, requires high ED(50) (300-600 mg/kg), whereas intravenous administration (10 mg/kg) results in rapid elimination of the drug with a half-life of 0.39 h. Hence, the development of long-circulating injectable nanoparticles can be an interesting option for designing a viable formulation of noscapine for anticancer activity. Noscapine-enveloped gelatin nanoparticles and poly(ethylene glycol)-grafted gelatin nanoparticles were constructed and characterized. Data indicate that smooth and spherical shaped nanoparticles of 127 ± 15 nm were engineered with maximum entrapment efficiency of 65.32 ± 3.81%. Circular dichroism confirms that nanocoacervates retained the α-helical content of gelatin in ethanol whereas acetone favored the formation of a random coil. Moreover, the Fourier transform infrared and powder X-ray diffraction pattern prevents any significant change in the noscapine-loaded gelatin nanoparticles in comparison with individual components. In-vitro release kinetic data suggest a first-order release of noscapine (85.1%) from gelatin nanoparticles with a release rate constant of 7.611×10(-3). It is to be noted that there is a 1.43-fold increase in the area under the curve up to the last sampling point for the noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles over the noscapine-loaded gelatin nanoparticles and a 13.09-fold increase over noscapine. Cytotoxicity analysis of the MCF-7 cell line indicated that the IC(50) value of the noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles was equivalent to 20.8 µmol/l, which was significantly (P<0.05) lower than the IC(50) value of the noscapine-loaded gelatin nanoparticles (26.3 µmol/l) and noscapine (40.5 µmol/l).Noscapine-loaded poly(ethylene glycol)-grafted gelatin nanoparticles can be developed as a promising therapeutic agent for the management of breast cancer.

Non-toxic melanoma therapy by a novel tubulin-binding agent.

(S)-3-((R)-9-bromo-4-methoxy-6-methyl-5,6,7,8-tetrahydro-[1,3]dioxolo[4,5-g]isoquino-lin-5-yl)-6,7-dimethoxyisobenzofuran-1(3H)-one (EM011) is a tubulin-binding agent with significant anticancer activity. Here we show that EM011 modulates microtubule dynamics at concentrations that do not alter the total polymer mass of tubulin. In particular, EM011 decreases the transition frequencies between growth and shortening phases and increases the duration microtubules spend in an idle 'pause' state. Using B16LS9 murine melanoma cells, we show that EM011 briefly arrests cell-cycle progression at the G2/M phase by formation of multiple aster spindles. An aberrant mitotic exit without cytokinesis then occurs, leading to the accumulation of abnormal multinucleated cells prior to apoptosis. Our pharmacokinetic studies conformed to a linear dose-response relationship upto 150 mg/kg. However, non-linearity was observed at 300 mg/kg. In a syngeneic murine model of subcutaneous melanoma, better antitumor responses were seen at 150 mg/kg compared to 300 mg/kg of EM011. Unlike currently available chemotherapeutics, EM011 is non-toxic to normal tissues and most importantly, does not cause any immunosuppression and neurotoxicity. Our data thus warrant a clinical evaluation of EM011 for melanoma therapy.

Inclusion complexes of noscapine in beta-cyclodextrin offer better solubility and improved pharmacokinetics.

PURPOSE: Noscapine (NOS) is a unique class of tubulin-binding anticancer agents. Their potential usefulness as anticancer drugs is however limited by the poor bioavailability, thus necessitating administration of a higher dose regime in the range of 300-600 mg/kg for tumor growth inhibition. To augment bioavailability, we prepared an inclusion complex of NOS in beta-cyclodextrin (beta-CD) and evaluated its physico-chemical characteristics. METHOD AND RESULTS: Our phase-solubility analysis shows a 1:1-complexation (Kc approximately 0.454 mM(-1)) of NOS with beta-CD that offers better dissolution properties. We confirmed complex formation in solid state by differential scanning calorimetry, powder X-ray diffractometry, Fourier-transform infrared spectroscopy, 1H nuclear magnetic resonance spectroscopy, rotating frame Overhauser enhancement spectroscopy and by molecular modeling methods. Based upon theoretical calculations in gas phase, we propose O-CH2-O- in orientation of NOS in the beta-CD cavity. The thermal behavior data also provides complementary evidences of complex formation. The pharmacokinetic studies showed a 1.87-fold increase in bioavailability of NOS upon complexation in the beta-CD inclusion complex state as compared to free NOS. Furthermore, the complex retains the anticancer attributes of NOS. CONCLUSION: Our studies propose for the first time a stable NOS-beta-CD inclusion complex as an effective approach to enhance the solubility and bioavailability of NOS for anticancer therapy.

Preclinical pharmacokinetics and bioavailability of noscapine, a tubulin-binding anticancer agent.

BACKGROUND: Noscapine, a naturally occurring antitussive phthalideisoquinoline alkaloid, is a tubulin-binding agent currently in Phase I/II clinical trials for anticancer therapy. Unlike currently available antimitotics such as taxanes and vincas, noscapine is water-soluble, well tolerated, and shows no detectable toxicity. OBJECTIVE: The goal was to develop a simple, sensitive, quantitative, selective, and less time-consuming high-performance liquid chromatography (HPLC) method for determination of noscapine and to study its pharmacokinetics in mice models. METHOD: Noscapine was extracted from mice plasma using the protein-precipitation method and detected using a reversed-phase C8 column with mobile phase consisting of 35% acetonitrile and 65% ammonium acetate buffer (pH 4.5) at 232 nm wavelength. Pharmacokinetic studies of noscapine were performed in mice following intravenous bolus at 10 mg/kg and oral administrations at 75, 150, and 300 mg/kg. RESULTS: The standard curves for noscapine estimation were linear between 390 and 50,000 ng/ml (lower limit of quantification was 390 ng/ml) and the recovery was approximately 80%. Following 10 mg/kg intravenous dose, mean plasma concentrations of 7.88 microg/ml were achieved at 5 min in mice and declined with undetectable levels at 4 h. The mean total body clearance was 4.78 l/h. The mean volume of distribution (V (d)) was 5.05 l. Non-compartmental analysis yielded the mean area under the plasma concentration-time curve (AUC) for noscapine as 53.42, 64.08, and 198.35 h microg/ml reaching maximum plasma concentrations (C (max)) of 12.74, 23.24, and 46.73 microg/ml at a t (max) of 1.12, 1.50, and 0.46 h at the linearly increasing dose levels. CONCLUSION: A rapid and simple HPLC/UV method for the quantification of noscapine in plasma has been developed to study pharmacokinetics of noscapine at tumor-suppressive doses in the mouse. Since orally available anticancer drugs are rare, therefore, noscapine, an innocuous agent, having a mean oral bioavailability of 31.5% over the studied dose range merits its further advancement in humans for anticancer therapy.

Synthesis of microtubule-interfering halogenated noscapine analogs that perturb mitosis in cancer cells followed by cell death.

We have previously identified the naturally occurring non-toxic antitussive phthalideisoquinoline alkaloid, noscapine as a tubulin-binding agent that arrests mitosis and induces apoptosis. Here we present high-yield efficient synthetic methods and an evaluation of anticancer activity of halogenated noscapine analogs. Our results show that all analogs display higher tubulin-binding activity than noscapine and inhibit proliferation of human cancer cells (MCF-7, MDA-MB-231 and CEM). Surprisingly, the bromo-analog is approximately 40-fold more potent than noscapine in inhibiting cellular proliferation of MCF-7 cells. The ability of these analogs to inhibit cellular proliferation is mediated by cell cycle arrest at the G2/M phase, in that all analogs except 9-iodonoscapine, caused selective mitotic arrest with a higher efficiency than noscapine followed by apoptotic cell death as shown by immunofluorescence and quantitative FACS analyses. Furthermore, our results reveal the appearance of numerous fragmented nuclei as evidenced by DAPI staining. Thus, our data indicate a great potential of these compounds for studying microtubule-mediated processes and as chemotherapeutic agents for the management of human cancers.