Photo-Excited Dyes: Emerging Technique Against Tau Protein Aggregation.

Tau aggregates are considered a pathological hallmark of Alzheimer's disease. The screening of molecules against Tau aggregation is a novel strategy for Alzheimer's disease. The photo-excited molecules have proven to be effective as a therapeutic agent in several diseases. In recent studies, the photo-excited dyes showed an inhibitory effect on Alzheimer's disease-related Tau protein aggregation and toxicity. The present chapter deals with the effect of rose bengal on the aggregation of Tau. The in vitro studies carried out with the help of electron microscopy, ThS fluorescence, and circular dichroism suggested that RB attenuated the Tau aggregation under in vitro conditions, whereas PE-RB disaggregated the mature Tau fibrils. Photo-excited rose bengal and the classical rose bengal induced a low degree of toxicity in cells. Thus, for the treatment of Alzheimer's disease, the rose bengal could be considered a potential molecule.

Photo-Excited Toluidine Blue Disaggregates the Repeat Tau and Modulates End-Binding Protein EB1, Cytoskeletal Structure in Neuronal Cells.

BACKGROUND/AIMS: Alzheimer's disease is a progressive neurological disorder characterized by the intracellular accumulation of Tau protein aggregates. In the present work, we studied the effect of Toluidine Blue and photo-excited Toluidine Blue on the aggregation of repeat Tau using in vitro assays. METHODS: The in vitro experiments were carried out on recombinant repeat Tau which was purified by cation exchange chromatography. The ThS fluorescence analysis was used to study the aggregation kinetics of Tau. CD spectroscopy and electron microscopy were used to study the secondary structure and morphology of Tau respectively. The actin cytoskeleton modulation was studied in Neuro2a cells with help of immunofluorescent microscopy. RESULTS: Results showed that Toluidine Blue efficiently inhibited the formation of higher-order aggregates, which was evidenced by Thioflavin S fluorescence assay, SDS-PAGE, and TEM. Immunofluorescence studies on the cytoskeleton of Neuro2a cells showed that Toluidine Blue and photo-excited Toluidine Blue treatment at a non-toxic concentration of 0.5 µM stimulated the formation of actin-rich lamellipodia and filopodia structures. Tubulin networks were also differentially modulated after the treatment of Toluidine Blue and photo-excited Toluidine Blue. End-binding protein 1 (EB1) levels were observed to increase after Toluidine Blue and photo-excited Toluidine Blue treatment indicating accelerated microtubule polymerization. CONCLUSION: The overall study suggested that Toluidine Blue inhibited the aggregation of soluble Tau and photo-excited Toluidine Blue disaggregated the pre-formed Tau filaments. In our study, TB and PE-TB were observed to be potent against Tau aggregation. We observed a distinctive modulation of actin, tubulin networks, and EB1 levels after TB and PE-TB treatment, which suggested that TB and PE-TB have potency against cytoskeleton deformities.

Bacopa monnieri reduces Tau aggregation and Tau-mediated toxicity in cells.

Alzheimer's disease is a neurodegenerative disease characterized by progressive memory loss and behavioral impairments. In the present study, the ethanolic extract of Bacopa monnieri was studied for its potency to inhibit Tau aggregation and rescuing of the viability of Tau-stressed cells. Bacopa monnieri was observed to inhibit the Tau aggregation in vitro. The cells exposed to Bacopa monnieri were also observed to have a low level of ROS and caspase-3 activity. The immunoblot and immunofluorescence analysis showed that Bacopa monnieri acts as an antioxidant and restored the Nrf2 levels in Neuro2a cells. Bacopa monnieri treatment to Neuro2a cells was observed to reduce the phospho-Tau load in formaldehyde-stressed cells. Furthermore, the treatment of Bacopa monnieri reduced the phosphorylation of GSK-3ß in formaldehyde-stressed cells. Ran and NUP358 are the key proteins involved in nuclear transport. It was observed that formaldehyde treatment impaired the nuclear transport by missorting the NUP358 arrangement in Neuro2a cells. On the contrary, Bacopa monnieri treatment restored the NUP358 arrangement in cells. The overall results of the present study suggested that Bacopa monnieri could be considered a potent herb against Tau phosphorylation and Tau aggregation, which projects it as a promising formulation for Alzheimer's disease.

The inhibitory effect of Curcumin-Artemisinin co-amorphous on Tau aggregation and Tau phosphorylation.

Tau is a natively unfolded microtubule-associated protein. Tau neurofibrillary tangles are one of the hallmarks of Alzheimer's disease. The post-translational modifications of Tau lead to its pathological state. Phosphorylation is the key post-translational modification associated with Tauopathy. Curcumin is a polyphenolic compound present in the rhizomes of Curcuma longa. Curcumin has been reported to have remarkable medicinal properties in several diseases, but its poor solubility limits its therapeutic potency. Artemisinin is a sesquiterpene lactone, which has been known sience ancient times for its applications as a treatment for various diseases such as malaria, cancer, autoimmune disease, etc. In the present study, the potency of crystalline curcumin, crystalline artemisinin, and Cur-Art co-amorphous dispersion were evaluated against Tau pathology. The in-vitro ThS/ANS fluorescence and electron microscopy results suggested that curcumin and Cur-Art efficiently inhibited Tau aggregation. Furthermore, exposure to curcumin and Cur-Art co-amorphous restored the impaired nuclear transport in formaldehyde-stressed cells. Curcumin was also found to modulate the phosphorylation of Tau, which indicated the neuroprotective potency. Thus, curcumin and Cur-Art co-amorphous exhibit therapeutic potential against Tau protein in Alzheimer's disease.

Post-Traumatic Bilateral Superolateral Dislocation of Intact Mandibular Condyle with Symphysis Fracture Causing Typical Bird Facies Resembling TMJ Ankylosis and Asphyxia: An Unusual Case Report.

This article reports a unique case of superolateral dislocation having a posterior component also, causing severe mandibular retrognathia (bird face deformity) and airway compression (asphyxia). Contemporary literature was also reviewed extensively, and it was found that no such type of case has been reported until date. The article also reviews etiology, causative mechanism of injury, clinical features, diagnosis and treatment planning of superolateral dislocations.

Photodynamic treatment modulates various GTPase and cellular signalling pathways in Tauopathy.

The application of photo-excited dyes for treatment is known as photodynamic therapy (PDT). PDT is known to target GTPase proteins in cells, which are the key proteins of diverse signalling cascades which ultimately modulate cell proliferation and death. Cytoskeletal proteins play critical roles in maintaining cell integrity and cell division. Whereas, it was also observed that in neuronal cells PDT modulated actin and tubulin resulting in increased neurite growth and filopodia. Recent studies supported the role of PDT in dissolving the extracellular amyloid beta aggregates and intracellular Tau aggregates, which indicated the potential role of PDT in neurodegeneration. The advancement in the field of PDT led to its clinical approval in treatment of cancers, brain tumour, and dermatological acne. Although several question need to be answered for application of PDT in neuronal cells, but the primary studies gave a hint that it can emerge as potential therapy in neural cells.

Influence of sodium caseinate, maltodextrin, pectin and their Maillard conjugate on the stability, in vitro release, anti-oxidant property and cell viability of eugenol-olive oil nanoemulsions.

The influence of protein (sodium caseinate-SC), polysaccharide (maltodextrin-MD; pectin-PC) and their Maillard conjugates (sodium caseinate maltodextrin conjugate-SCMDC; sodium caseinate pectin conjugate-SCPCC) were studied on the physico-chemical and biological properties of eugenol nanoemulsions/powder. The chemical composition was optimized using Taguchi design. The particles size of eugenol nanoemulsions with SC, MD, PC, SCMDC and SCPCC were 104.6, 323.5, 1872, 181.7, and 454.4 nm, respectively while their zeta potentials were -31.2, -28.5, -21.4, -40.1 and -25.1 mV, respectively. Turbidity studies revealed higher stability of nanoemulsion prepared with Maillard conjugate (SCMDC) compared to protein or polysaccharides alone. The dispersion of SCMDC eugenol nanoparticles in buffer was prepared to study its stability at different pH (3.0, 5.0, and 7.0) and temperature (4°, 37°, 60 °C) range. In-vitro enzymatic release study showed 31 and 74% release of eugenol after 6 h at pH 2.4 and 7.4, respectively. In vitro antioxidant capacity of SCMDC encapsulated eugenol was higher than native eugenol, as demonstrated by free radical scavenging assays. In comparison to native eugenol, E:SCMDC eugenol showed reduced toxicity. These findings suggested that nanoencapsulated eugenol (E:SCMDC) have a huge potential in nutraceutical and therapeutic applications.

Photodynamic sensitizers modulate cytoskeleton structural dynamics in neuronal cells.

The neuronal cytoskeleton plays a crucial role in maintaining cell integrity and functioning of neurons. Cytoskeleton deformities have been reported to be associated with neurodegenerative diseases thus; cytoskeleton can be targeted for therapeutic strategies. The therapeutic application of photosensitive molecule is termed as photodynamic therapy (PDT). PDT has been applied in the field of dermatology, cancer biology, and antimicrobial therapy. PDT induces several changes in cells, which include induction of apoptosis, DNA damage, and induction of inflammatory response. PDT has been also reported to modulate cytoskeleton such as actin dynamics. The in vitro studies suggested that PDT using dyes such as Toluidine Blue and Rose Bengal effectively modulated the actin cytoskeleton, neurite outgrowth, tubulin, and Tau aggregation. In this review, we focused on the effect of photosensitized molecules on various cytoskeleton proteins. We hypothesize that PDT could have potency against Alzheimer's disease and other neurodegenerative disorders.

Comparative Evaluation of Altered Taste Perception among Oral Submucous Fibrosis Patients.

BACKGROUND: Taste perception is an important factor in sustaining human life. Impairment of taste is one of the important features of oral submucous fibrosis (OSMF), and it has not received much attention, owing to limited research work in the field. Therefore, the present study was conducted to determine taste alteration in OSMF patients. MATERIALS AND METHODS: A total of 200 participants, both males and females with the age range of 20 years to 55 years, were included in the study. Four basic tastants (i.e., sweet, salt, sour, and bitter) were prepared as follows: sucrose for sweet (0.1-1.0 mol/l), sodium chloride for salty (0.01-1.0 mol/l), citric acid for sour (0.320-0.032 mol/l), and quinine sulfate for bitter (0.01-1.0 mol/l) and full mouth rinse test was performed for a complete taste response examination, after which punch biopsy was taken from buccal mucosa to determine histopathological staging. The data obtained were tabulated and analyzed by the Pearson Chi-square test; P < 0.05 was considered statistically significant. RESULTS: The overall results suggested that there was a significant alteration of taste. The sweet taste was altered followed by salty and bitter was least affected. CONCLUSION: The study points out at the significance of alteration in taste perception is OSMF patients related to sweet, salt, sour, and bitter taste by using physiological stimuli tastants.

α-Linolenic acid inhibits Tau aggregation and modulates Tau conformation.

Alzheimer's disease is characterized by important patho-proteins, which being composed of Amyloid-ß plaques and intracellular neurofibrillary tangles of Tau. Intrinsically disordered protein tau has several interacting partners, which are necessary for its normal functioning. Tau has been shown to interact with various proteins, nucleic acid, and lipids. α-Linolenic acid (ALA) a plant-based omega-3 fatty acid has been studied for its role as neuroprotective and beneficial fatty acid in the brain. In this study, we are focusing on the ability of ALA to induce spontaneous assembly in tau protein. ALA inhibited the Tau aggregation as indicated by reduced ThS fluorescence kinetics, which indicates no aggregation of Tau. Similarly, SDS-PAGE analysis supported that ALA exposure inhibited the aggregation as no higher-order tau species were observed. Along with its ability to impede the aggregation of Tau, ALA also maintains a native random coiled structure, which was estimated by CD spectroscopy. Finally, TEM analysis showed that the formation of Tau fibrils was found to be discouraged by ALA. Hence, conclusion of the study suggested that ALA profoundly inhibited aggregation of Tau and maintained it's the random-coil structure.

Combination of Articaine and Ketamine V/S Articaine Alone After Surgical Extraction of Impacted Third Molars.

OBJECTIVE: Local anesthetics are the most effective drugs available for the management of pain while performing operative procedures. This study was performed to compare the clinical efficacy of treatment with local anesthetic articaine (4%) with ketamine and local anesthetic articaine alone (4%) for the relief or prevention of postoperative pain, swelling, and trismus after the surgical extraction of impacted mesioangular third molars. MATERIALS AND METHODS: Sixty patients undergoing the extraction of impacted mesioangular mandibular third molars were included in the study. The patients were randomly divided into two groups: local anesthetic alone (LAA) and local anesthetic plus ketamine (LAK). RESULTS: Facial swelling following surgery on postoperative days was significantly lower in the LAK group than in the LAA group on 3rd and 7th postoperative days (P < 0.05). Mouth opening on the postoperative days was significantly greater in the LAK group than in the LAA group on 3rd and 7th postoperative days (P < 0.05). The pain scores on the visual analog scale at 30 min and 1 h, 4 h, 12 h, and 24 h after the surgery were significantly higher in the LAA group than in the LAK group and there was no significant difference in heart rate, oxygen saturation, and blood pressure in both the groups. CONCLUSION: In this present study, the effect of articaine with ketamine in comparison with articaine alone intraoperatively and postoperatively was observed, and it revealed that the combination of articaine with ketamine produced good local anesthesia and provide good postoperative analgesia with less swelling and significantly less trismus.

Photodynamic exposure of Rose-Bengal inhibits Tau aggregation and modulates cytoskeletal network in neuronal cells.

The intracellular Tau aggregates are known to be associated with Alzheimer's disease. The inhibition of Tau aggregation is an important strategy for screening of therapeutic molecules in Alzheimer's disease. Several classes of dyes possess a unique property of photo-excitation, which is applied as a therapeutic measure against numerous neurological dysfunctions. Rose Bengal is a Xanthene dye, which has been widely used as a photosensitizer in photodynamic therapy. The aim of this work was to study the protective role of Rose Bengal against Tau aggregation and cytoskeleton modulations. The aggregation inhibition and disaggregation potency of Rose Bengal and photo-excited Rose Bengal were observed by in-vitro fluorescence, circular dichroism, and electron microscopy. Rose Bengal and photo-excited Rose Bengal induce minimal cytotoxicity in neuronal cells. In our studies, we observed that Rose Bengal and photo-excited Rose Bengal modulate the cytoskeleton network of actin and tubulin. The immunofluorescence studies showed the increased filopodia structures after photo-excited Rose Bengal treatment. Furthermore, Rose Bengal treatment increases the connections between the cells. Rose Bengal and photo-excited Rose Bengal treatment-induced actin-rich podosome-like structures associated with cell membranes. The in-vivo studies on UAS E-14 Tau mutant Drosophila suggested that exposure to Rose Bengal and photo-excited Rose Bengal efficiency rescues the behavioural and memory deficit in flies. Thus, the overall results suggest that Rose Bengal could have a therapeutic potency against Tau aggregation.

Basic Limonoid modulates Chaperone-mediated Proteostasis and dissolve Tau fibrils.

The Alzheimer's disease pathology is associated with accumulation of intracellular neurofibrillary tangles and extracellular senile plaques. The formation of initial nucleus triggers conformational changes in Tau and leads to its deposition. Hence, there is a need to eliminate these toxic proteins for proper functioning of neuronal cells. In this aspect, we screened the effect of basic limonoids such as gedunin, epoxyazadiradione, azadirone and azadiradione on inhibiting Tau aggregation as well as disintegration of induced Tau aggregates. It was observed that these basic limonoids effectively prevented aggregates formation by Tau and also exhibited the property of destabilizing matured Tau aggregates. The molecular docking analysis suggests that the basic limonoids interact with hexapeptide regions of aggregated Tau. Although these limonoids caused the conformational changes in Tau to ß-sheet structure, the cytological studies indicate that basic limonoids rescued cell death. The dual role of limonoids in Tau aggregation inhibition and disintegration of matured aggregates suggests them to be potent molecules in overcoming Tau pathology. Further, their origin from a medicinally important plant neem, which known to possess remarkable biological activities was also found to play protective role in HEK293T cells. Basic limonoids were non-toxic to HEK293T cells and also aided in activation of HSF1 by inducing its accumulation in nucleus. Western blotting and immunofluorescence studies showed that HSF1 in downstream increased the transcription of Hsp70 thus, aggravating cytosolic Hsp70 levels that can channel clearance of aberrant Tau. All these results mark basic limonoids as potential therapeutic natural products.

Photoexcited Toluidine Blue Inhibits Tau Aggregation in Alzheimer's Disease.

The aggregates of microtubule-associated protein Tau are considered as a major hallmark of Alzheimer's disease. Tau aggregates accumulate intracellularly leading to neuronal toxicity. Numerous approaches have been targeted against Tau protein aggregation, which include application of synthetic and natural compounds. Toluidine blue is a basic dye of phenothiazine family, which on irradiation with a 630 nm light gets converted into a photoexcited form, leading to generation of singlet oxygen species. Methylene blue is the parent compound of toluidine blue, which has been reported to be potent against tauopathy. In the present work, we studied the potency of toluidine blue and photoexcited toluidine blue against Tau aggregation. Biochemical and biophysical analyses using sodium dodecyl sulfate-polyacrylamide gel electrophoresis, ThS fluorescence, circular dichroism spectroscopy, and electron microscopy suggested that toluidine blue inhibited the aggregation of Tau in vitro. The photoexcited toluidine blue potentially dissolved the matured Tau fibrils, which indicated the disaggregation property of toluidine blue. The cell biology studies including the cytotoxicity assay and reactive oxygen species (ROS) production assay suggested toluidine blue to be a biocompatible dye as it reduced ROS levels and cell death. The photoexcited toluidine blue modulates the cytoskeleton network in cells, which was supported by immunofluorescence studies of neuronal cells. The studies in a UAS Tau E14 transgenic Drosophila model suggested that photoexcited toluidine blue was potent to restore the survival and memory deficits of Drosophila. The overall finding of our studies suggested toluidine blue to be a potent molecule in rescuing the Tau-mediated pathology by inhibiting its aggregation, reducing the cell death, and modulating the tubulin levels and behavioral characteristics of Drosophila. Thus, toluidine blue can be addressed as a potent molecule against Alzheimer's disease.

Brahmi (Bacopa monnieri): An ayurvedic herb against the Alzheimer's disease.

Ayurveda is the medicinal science, dealing with utilization of naturally available plant products for treatment. A wide variety of neuroprotective herbs have been reported in Ayurveda. Brahmi, Bacopa monnieri is a nootropic ayurvedic herb known to be effective in neurological disorders from ancient times. Numerous approaches including natural and synthetic compounds have been applied against Alzheimer's disease. Amyloid-ß and Tau are the hallmarks proteins of several neuronal dysfunctions resulting in Alzheimer's disease. Tau is a microtubule-associated protein known to be involved in progression of Alzheimer's disease. The generation of reaction oxygen species, increased neuroinflammation and neurotoxicity are the major physiological dysfunctions associated with Tau aggregates, which leads to dementia and behavioural deficits. Bacoside A, Bacoside B, Bacosaponins, Betulinic acid, etc; are the bioactive component of Brahmi belonging to various chemical families. Each chemical component known have its significant role in neuroprotection. The neuroprotective properties of Brahmi and its bioactive components including reduction of ROS, neuroinflammation, aggregation inhibition of Amyloid-ß and improvement of cognitive and learning behaviour. Here on basis of earlier studies we hypothesize the inhibitory role of Brahmi against Tau-mediated toxicity. The overall studies have concluded that Brahmi can be used as a lead formulation for treatment of Alzheimer's disease and other neurological disorders.

Is treatment with platelet-rich fibrin better than zinc oxide eugenol in cases of established dry socket for controlling pain, reducing inflammation, and improving wound healing?

OBJECTIVES: To appraise the effectiveness of platelet-rich fibrin (PRF) in the management of established dry socket in terms of pain, inflammation, and wound healing. MATERIALS AND METHODS: Two hundred patients with established alveolar osteitis were studied to determine the efficacy of PRF and zinc oxide eugenol (ZOE) for pain control, inflammation reduction, and wound healing. Patients were randomly allocated to Group A (PRF) or Group B (ZOE). Patients were examined on the 1st, 3rd, 7th, and 14th postoperative day and evaluated for pain using visual analogue scale scores, inflammation with a gingival index score, and wound healing through a determination of the number of bony walls exposed. RESULTS: Group A showed better results in terms of pain remission, control of inflammation, and wound healing compared to Group B. Results between groups were statistically significant (P<0.05). CONCLUSION: PRF is a better alternative than ZOE for the effective management of alveolar osteitis.

Retraction: Is treatment with platelet-rich fibrin better than zinc oxide eugenol in cases of established dry socket for controlling pain, reducing inflammation, and improving wound healing?

[This retracts the article on p. 76 in vol. 45, PMID: 31106135.].

SpliceVec: Distributed feature representations for splice junction prediction.

Identification of intron boundaries, called splice junctions, is an important part of delineating gene structure and functions. This also provides valuable insights into the role of alternative splicing in increasing functional diversity of genes. Identification of splice junctions through RNA-seq is by mapping short reads to the reference genome which is prone to errors due to random sequence matches. This encourages identification of splicing junctions through computational methods based on machine learning. Existing models are dependent on feature extraction and selection for capturing splicing signals lying in the vicinity of splice junctions. But such manually extracted features are not exhaustive. We introduce distributed feature representation, SpliceVec, to avoid explicit and biased feature extraction generally adopted for such tasks. SpliceVec is based on two widely used distributed representation models in natural language processing. Learned feature representation in form of SpliceVec is fed to multilayer perceptron for splice junction classification task. An intrinsic evaluation of SpliceVec indicates that it is able to group true and false sites distinctly. Our study on optimal context to be considered for feature extraction indicates inclusion of entire intronic sequence to be better than flanking upstream and downstream region around splice junctions. Further, SpliceVec is invariant to canonical and non-canonical splice junction detection. The proposed model is consistent in its performance even with reduced dataset and class-imbalanced dataset. SpliceVec is computationally efficient and can be trained with user-defined data as well.

Global QSAR modeling of logP values of phenethylamines acting as adrenergic alpha-1 receptor agonists.

Global QSAR models predict biological response of molecular structures which are generic in particular class. A global QSAR dataset admits structural features derived from larger chemical space, intricate to model but more applicable in medicinal chemistry. The present work is global in either sense of structural diversity in QSAR dataset or large number of descriptor input. Forty phenethylamine structure derivatives were selected from a large pool (904) of similar phenethylamines available in Pubchem database. LogP values of selected candidates were collected from physical properties database (PHYSPROP) determined in identical set of conditions. Attempts to model logP value have produced significant QSAR models. MLR aided linear one-variable and two-variable QSAR models with their respective R(2) (0.866, 0.937), R(2)A (0.862, 0.932), F-stat (181.936, 199.812) and Standard Error (0.365, 0.255) are statistically fit and found predictive after internal validation and external validation. The descriptors chosen after improvisation and optimization reveal mechanistic part of work in terms of Verhaar model of Fish base-line toxicity from MLOGP, i.e. (BLTF96) and 3D-MoRSE -signal 15 /unweighted molecular descriptor calculated by summing atom weights viewed by a different angular scattering function (Mor15u) are crucial in regulation of logP values of phenethylamines.