Hesperidin Methyl Chalcone reduces extracellular Aß(25-35) peptide aggregation and fibrillation and also protects Neuro 2a cells from Aß(25-35) induced neuronal dysfunction.

In the present study, we evaluated the neuroprotective potential of Hesperidin Methyl Chalcone (HMC) against the neurotoxicity induced by Aß(25-35) peptide. HMC demonstrated higher free-radical scavenging activity than Hesperidin in initial cell-free studies. Investigations using the fluorescent dye thioflavin T with Aß(25-35) peptide showed that HMC has the ability to combat extracellular amyloid aggregation by possessing anti-aggregation property against oligomers and by disaggregating mature fibrils. Also, the results of the molecular simulation studies show that HMC ameliorated oligomer formation. Further, the anti-Alzheimer's property of HMC was investigated in in vitro cell conditions by pre-treating the neuro 2a (N2a) cells with HMC before inducing Aß(25-35) toxicity. The findings demonstrate that HMC increased cell viability, reduced oxidative stress, prevented macromolecular damage, allayed mitochondrial dysfunction, and exhibited anticholinesterase activity. HMC also reduced Aß induced neuronal cell death by modulating caspase-3 activity, Bax expression and Bcl2 overexpression, demonstrating that HMC pre-treatment reduced mitochondrial damage and intrinsic apoptosis induced by Aß(25-35).In silico evaluation against potential AD targets reveal that HMC could be a potent inhibitor of BACE-1, inhibiting the formation of toxic Aß peptides. Overall, the findings imply that the neuroprotective efficacy of HMC has high prospects for addressing a variety of pathogenic consequences caused by amyloid beta in AD situations and alleviating cognitive impairments.

Chitosan based encapsulation increased the apoptotic efficacy of thymol on A549 cells and exhibited non toxic response in swiss albino mice.

Thymol is a plant-derived natural phenolic compound abundantly present in Thymus vulgaris species. In the present study, we developed a chitosan-based drug delivery system to deliver thymol to A549 cells. The physicochemical properties of thymol-loaded chitosan nanoparticles (thymol-NP) were characterized using polyphasic techniques viz., FTIR, XRD, DLS, and SEM. Thymol-NP exhibited a size of 282.5 nm and encapsulation efficiency of 74.08 ± 0.73%. The IC50 of thymol-NP against A549 cells was 99.57 µg/ml at 24 h, which was lower than that of the pure form. Clear apoptotic features such as cellular morphology, cell shrinkage, and augmentation of dead cells were observed in both the thymol and thymol-NP treated A549 cells. The percentage of apoptotic cells in the thymol-NP IC50 treated cells was >90% which was considerably higher than the group treated with thymol alone. In vivo toxicity study showed that the swiss albino mice treated up to a concentration of 1000 mg/kg of thymol-NP neither showed signs of toxicity nor death up to 14 days. Also, no significant influence was observed on behavior, body weight, organ weight, and organ histology. Overall, the data concluded that thymol-NP can be considered a safe and potent drug candidate against A549 cells.

Phytol loaded PLGA nanoparticles ameliorate scopolamine-induced cognitive dysfunction by attenuating cholinesterase activity, oxidative stress and apoptosis in Wistar rat.

OBJECTIVE: Alzheimer's disease (AD) is an acquired neurological disorder of cognitive and behavioral impairments, with a long and progressive route. Currently, efforts are being made to develop potent drugs that target multiple pathological mechanisms that drive the successful treatment of AD in human beings. The development of nano-drug delivery systems has recently emerged as an effective strategy to treat AD. METHODS: In the present study, the protective effect of Phytol and Phytol loaded Poly Lactic-co-Glycolic Acid nanoparticles (Phytol-PLGANPs) were evaluated in Wistar rat scopolamine model of AD. RESULTS AND DISCUSSION: The consumption of Phytol and Phytol-PLGANPs significantly ameliorated the cognitive deficits caused by scopolamine on spatial and short term memory. Phytol and Phytol-PLGANPs significantly enhanced the cholinergic effect by inhibiting both acetylcholinesterase and butyrylcholinesterase (AChE & BuChE), ß-secretase 1 (BACE1) activity, attenuating macromolecular damage, reducing reactive oxygen species (ROS) and reactive nitrogen species (RNS) level by activating antioxidative defense system (Superoxide dismutase and catalase) and restoring glutathione metabolizing enzyme systems (Glutathione S-transferase) and also regulating the apoptotic mediated cell death. Moreover, in vivo toxicity study suggests that Phytol and Phytol-PLGANPs did not cause any adverse pathological alteration in rats treated with a higher concentration of Phytol-PLGANPs (200 mg/kg). Pharmacokinetic study revealed that Phytol-PLGANPs enhanced the biodistribution and sustained the release profile of phytol in the brain and plasma. CONCLUSION: Overall, the outcome of the study suggests that Phytol and Phytol-PLGANPs act as a potent candidate with better anti-amnesic effects and multi-faceted neuroprotective potential against scopolamine-induced memory dysfunction in Wistar rats.

Thymol induces mitochondrial pathway-mediated apoptosis via ROS generation, macromolecular damage and SOD diminution in A549 cells.

BACKGROUND: Thymol is a monoterpene phenol found in thyme species plants. The present study was carried out to investigate the effect of thymol and its molecular mechanism on non-small lung cancer (A549) cells. METHODS: The cytotoxic effect of thymol on A549 cells was assessed via MTT assay. ROS production, macromolecular damage, apoptosis were determined using DCF-DA, PI, AO/EtBr stains, respectively. ROS-dependent effect of thymol was confirmed using NAC. The expression of caspase-9, Bcl-2, Bax and cell cycle profile was analyzed via western blot and FACS, respectively. RESULTS: The antiproliferative effect of thymol on A549 cells was found to be both dose and time dependent with IC50 values of 112 µg/ml (745 µM) at 24 h. Thymol treatment favored apoptotic cell death and caused G0/G1 cell cycle arrest. It mediated cellular and nuclear morphological changes, phosphatidylserine translocation, and mitochondrial membrane depolarization. Additionally, upregulation of Bax, downregulation of Bcl-2, and apoptotic fragmented DNA were also observed. Thymol induced ROS by reducing the SOD level which was confirmed via in vitro and in silico analysis. Furthermore, the levels of lipid peroxides and protein carbonyl content were elevated in thymol-treated groups. Notably, N-acetyl cysteine pretreatment reversed the efficacy of thymol on A549 cells. Moreover, thymol-treated human PBMC cells did not show any significant cytotoxicity. CONCLUSION: Overall, our results confirmed that thymol can act as a safe and potent therapeutic agent to treat NSCLC.

New Trends in the Pharmacological Intervention of PPARs in Obesity: Role of Natural and Synthetic Compounds.

Obesity is a major health concern for a growing fraction of the population, as its prevalence and related metabolic disorders are not fully understood. Over the last decade, many attempts have been undertaken to understand the mechanisms at the basis of this condition, in which the accumulation of fat occurring in adipose tissue leads to the pathogenesis of obesity- related disorders. Among the most recent studies, those on Peroxisome Proliferator Activated Receptors (PPARs) revealed that these nuclear receptor proteins acting as transcription factors, among others, regulate the expression of genes involved in energy, lipid, and glucose metabolisms, and chronic inflammation. The three different isotypes of PPARs, with different tissue expression and ligand binding specificity, exert similar or overlapping functions directly or indirectly linked to obesity. In this study, we reviewed the available scientific reports concerning the PPARs structure and functions, especially in obesity, considering both natural and synthetic ligands and their role in the therapy of obesity and obesity-associated disorders. On the whole, the collected data suggest that there are both natural and synthetic compounds that show beneficial and promising activity as PPAR agonists in chronic diseases related to obesity.

Deciphering the anti-apoptotic potential of α-bisabolol loaded solid lipid nanoparticles against Aß induced neurotoxicity in Neuro-2a cells.

Nanoparticles based drug delivery system offers an alternative strategy to overcome several therapeutic limitations of various human ailments, particularly in age-linked Alzheimer's disease. Results of our previous cell-free studies indicated that α-bisabolol loaded solid lipid nanoparticles (ABS) significantly inhibited the aggregation of Aß25-35. The present study intended to evaluate the neuroprotective effect of ABS against Aß25-35 induced toxicity in Neuro-2a cell lines. The results of in vitro cell line study revealed that pretreatment of Neuro-2a cell lines with ABS (5 & 10 µg/ml) significantly suppressed the production of free radicals such as reactive oxygen species (ROS)/reactive nitrogen species (RNS), and also augmented the ROS mediated macromolecular damages and loss of mitochondrial membrane potential induced by toxic Aß peptide when compared to the standard drug donepezil (50 µg/ml). Moreover, reduced ß-secretase, caspase-3, and cholinesterase activities were observed in the cells pretreated with ABS, which clearly evidenced the neuroprotective effect of ABS. Reduced expression of Bax and induced expression of Bcl-2 proteins observed through western blot analysis and live/dead cell viability analysis of Neuro-2a cells through confocal microscope further validated that ABS protects the cells from Aß induced apoptosis. Taken together, the outcome of the present study signifies the neuroprotective effect of ABS against the Aß induced toxicity in in vitro model of Neuro-2a cells.

Phytol loaded PLGA nanoparticles regulate the expression of Alzheimer's related genes and neuronal apoptosis against amyloid-ß induced toxicity in Neuro-2a cells and transgenic Caenorhabditis elegans.

Amyloid ß (Aß) induced neurotoxicity has been postulated to initiate synaptic loss and subsequent neuronal degeneration in Alzheimer's disease (AD). The nanoparticles based drug carrier system is considered as a promising therapeutic strategy to combat this incurable disease. It was also found to inhibit cholinesterase activity and apoptosis mediated cell death in Neuro-2a cells. The in vivo study further revealed that the Phytol and Phytol-PLGA NPs (Poly Lactic-co-Glycolic Acid Nanoparticles) was found to increase the lifespan, chemotaxis behavior and decrease Aß deposition & ROS (Reactive oxygen species) production in transgenic Caenorhabditis elegans models of AD (CL2006, CL4176). Phytol and Phytol-PLGA NPs treatment downregulated the expression of AD associated genes viz Aß, ace-1 and hsp-4 and upregulated the gene involved in the longevity to nematodes (dnj-14) and it also reduced the expression of Aß peptide at the protein level. Our results of in vitro and in vivo studies suggest that Phytol and Phytol-PLGA NPs hold promising neuroprotective efficacy and targets multiple neurotoxic mechanisms involved in the AD progression.

Amyloid-ß induced neuropathological actions are suppressed by Padina gymnospora (Phaeophyceae) and its active constituent α-bisabolol in Neuro2a cells and transgenic Caenorhabditis elegans Alzheimer's model.

The inhibition of Aß peptide development and aggregation is a hopeful curative approach for the discovery of disease modifying drugs for Alzheimer's disease (AD) treatment. Recent research mainly focuses on the discovery of drugs from marine setting due to their immense therapeutic potential. The present study aims to evaluate the brown macroalga Padina gymnospora and its active constituent α-bisabolol against Aß25-35 induced neurotoxicity in Neuro2a cells and transgenic Caenorhabditis elegans (CL2006 and CL4176). The results of the in vitro study revealed that the acetone extract of P. gymnospora (ACTPG) and its active constituent α-bisabolol restores the Aß25-35 induced alteration in the oxidation of intracellular protein and lipids. In addition, ACTPG and α-bisabolol inhibited cholinesterase and ß-secretase activity in Neuro2a cells. Moreover, the intracellular reactive oxygen species (ROS) and reactive nitrogen species (RNS) production was reduced by ACTPG and α-bisabolol in Neuro2a cells. The decrease in the expression level of apoptotic proteins such as Bax and caspase-3 in ACTPG and α-bisabolol treated group indicates that the seaweed and its bioactive compound have anti-apoptotic property. Further, the in vivo study revealed that the ACTPG and α-bisabolol exerts neuroprotective effect against Aß induced proteotoxicity in transgenic C. elegans strains of AD. Moreover it altered the Aß mediated pathways, lifespan, macromolecular damage and down regulated the AD related gene expression of ace-1, hsp-4 and Aß, thereby preventing Aß synthesis. Overall, the outcome of the study signifies the neuroprotective effect of ACTPG and α-bisabolol against Aß mediated AD pathology.

α-bisabolol ß-D-fucopyranoside as a potential modulator of ß-amyloid peptide induced neurotoxicity: An in vitro &in silico study.

Alzheimer's disease (AD) is a multifaceted neurodegenerative disorder affecting the elderly people. For the AD treatment, there is inefficiency in the existing medication, as these drugs reduce only the symptoms of the disease. Since multiple pathological proteins are involved in the development of AD, searching for a single molecule targeting multiple AD proteins will be a new strategy for the management of AD. In view of this, the present study was designed to synthesize and evaluate the multifunctional neuroprotective ability of the sesquiterpene glycoside α-bisabolol ß-D-fucopyranoside (ABFP) against multiple targets like acetylcholinesterase, oxidative stress and ß-amyloid peptide aggregation induced cytotoxicity. In silico computational docking and simulation studies of ABFP with acetylcholinesterase (AChE) showed that it can interact with Asp74 and Thr75 residues of the enzyme. The in vitro studies showed that the compound possess significant ability to inhibit the AChE enzyme apart from exhibiting antioxidant, anti-aggregation and disaggregation properties. In addition, molecular dynamics simulation studies proved that the interacting residue between Aß peptide and ABFP was found to be involved in Leu34 and Ile31. Furthermore, the compound was able to protect the Neuro2 a cells against Aß25-35 peptide induced toxicity. Overall, the present study evidently proved ABFP as a neuroprotective agent, which might act as a multi-target compound for the treatment of Alzheimer's disease.

Anti-amyloidogenic and anti-apoptotic effect of α-bisabolol against Aß induced neurotoxicity in PC12 cells.

Alzheimer's disease (AD) is a life-threatening neurodegenerative disorder leading to dementia, with a progressive decline in memory and other thinking skills of elderly populace. Of the multiple etiological factors of AD, the accumulation of senile plaques (SPs) particularly as Aß oligomers correlates with the relentlessness cognitive impairment in AD patients and play a vital role in AD pathology. Since natural essential oil constituents have successfully served as a source of drugs for AD treatment, the present study aims at the in vitro and in silico investigation of anti-amyloidogenic potential and anti-apoptotic property of the α-bisabolol against Aß25-35 induced neurotoxicity in PC12 cells. Treatment with α-bisabolol (5 µg/ml) after 24 h incubation with Aß25-35 reduced the aggregation propensity of Aß (p < 0.05), as observed by the reduced fluorescence intensity of thioflavin T (ThT). Confocal laser scanning microscopy (CLSM) analysis, Transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopic analysis and molecular dynamics simulation study also substantiated the Aß fibril formation hampering ability of α-bisabolol even after 9 days of incubations. The results of antiaggregation and disaggregation assay showed an increase in fluorescence intensity in Aß treated group, whereas the co-treatment of α-bisabolol (5 µg/ml) with Aß25-35 showed an extensive decrease in the fluorescence intensity, which suggests that α-bisabolol prevents the oligomers formation as well as disaggregates the matured fibrils. FACS analysis of the cells revealed the competency of α-bisabolol in rescuing the PC12 cells from Aß induced neurotoxicity and chromosomal damage and clonogenic assay proved its ability to retain the colony survival of cells. Overall, the anti-amyloidogenic and anti-apoptotic effect of α-bisabolol proves that it could be used as an excellent therapeutic drug to combat AD.

Phytol-loaded PLGA nanoparticle as a modulator of Alzheimer's toxic Aß peptide aggregation and fibrillation associated with impaired neuronal cell function.

Alzheimer's disease (AD) is an unfavourable neurological condition of the brain leading to the loss of behavioural and cognitive skills of the aging population. At present, drugs representing cholinesterase inhibitors provide lateral side effects to AD patients. Hence, there is a need for improved fabrication of drugs without side effects, for which nanoencapsulated bioactive compounds that can cross the blood-brain barrier offer new hope as novel alternative treatment strategy for AD. This study involved synthesis of phytol loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles by solvent evaporation method. Physico-chemical characterization of phytol-PLGA NPs through the field emission scanning electron microscope, dynamic laser scattering (DLS) measurement revealed that the particles were nanosize range with smooth surface and spherical morphology. Furthermore, the biocompatibility of drug/polymer ratio was investigated by power X-ray diffraction (PXRD) and Fourier-transform infrared spectroscopic (FT-IR) analysis. The in vitro drug release study showed that the phytol was released in a sustained manner. Moreover, phytol-PLGA NPs were able to disrupt amyloid aggregates, exhibit anti-cholinesterase and anti-oxidative property and are non-cytotoxic in Neuro2a cells.

Antiaggregation Potential of Padina gymnospora against the Toxic Alzheimer's Beta-Amyloid Peptide 25-35 and Cholinesterase Inhibitory Property of Its Bioactive Compounds.

Inhibition of ß-amyloid (Aß) aggregation in the cerebral cortex of the brain is a promising therapeutic and defensive strategy in identification of disease modifying agents for Alzheimer's disease (AD). Since natural products are considered as the current alternative trend for the discovery of AD drugs, the present study aims at the evaluation of anti-amyloidogenic potential of the marine seaweed Padina gymnospora. Prevention of aggregation and disaggregation of the mature fibril formation of Aß 25-35 by acetone extracts of P. gymnospora (ACTPG) was evaluated in two phases by Thioflavin T assay. The results were further confirmed by confocal laser scanning microscopy (CLSM) analysis and Fourier transform infrared (FTIR) spectroscopic analysis. The results of antiaggregation and disaggregation assay showed that the increase in fluorescence intensity of aggregated Aß and the co-treatment of ACTPG (250 µg/ml) with Aß 25-35, an extensive decrease in the fluorescence intensity was observed in both phases, which suggests that ACTPG prevents the oligomers formation and disaggregation of mature fibrils. In addition, ACTPG was subjected to column chromatography and the bioactivity was screened based on the cholinesterase inhibitory activity. Finally, the active fraction was subjected to LC-MS/MS analysis for the identification of bioactive compounds. Overall, the results suggest that the bioactive compound alpha bisabolol present in the alga might be responsible for the observed cholinesterase inhibition with the IC50 value < 10 µg/ml for both AChE and BuChE when compared to standard drug donepezil (IC50 value < 6 µg/ml) and support its use for the treatment of neurological disorders.