RESUMEN
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.
Asunto(s)
Enfermedad de Alzheimer , Chalconas , Hesperidina , Fármacos Neuroprotectores , Humanos , Péptidos beta-Amiloides/toxicidad , Péptidos beta-Amiloides/metabolismo , Chalconas/farmacología , Hesperidina/farmacología , Amiloide , Fragmentos de Péptidos/toxicidad , Fármacos Neuroprotectores/farmacología , Fármacos Neuroprotectores/química , Enfermedad de Alzheimer/tratamiento farmacológico , Enfermedad de Alzheimer/patologíaRESUMEN
BACKGROUND: Plants are important sources of bioactive peptides. Among these, angiotensin converting enzyme (ACE) inhibitory peptides have a major focus on their ability to prevent hypertension. Inhibition of ACE has been established as an effective approach for the treatment of ACE associated diseases. HYPOTHESIS/PURPOSE: Some synthetic ACE inhibitory drugs cause side effects and hence there is a constant interest in natural compounds as alternatives. STUDY DESIGN: The study was designed to identify and characterize a peptide molecule from pigeon pea which has the biological property to inhibit ACE and can be developed as a therapeutic approach towards hypertension. METHODS: Seeds of pigeon pea (Cajanus cajan (L.) Millsp.) was fermented with Aspergillus niger, a proteolytic fungus isolated from spoiled milk sweet. The extract was purified by size exclusion chromatography by FPLC system. The fractions that showed ACE inhibition was subjected to LC-MS/MS for sequence identification. The stability of the peptide was analyzed by molecular dynamic simulations and the interaction sites with ACE were identified by molecular docking. RESULTS: The study report a novel ACE inhibitory octapeptide Val-Val-Ser-Leu-Ser-Ile-Pro-Arg with a molecular mass of 869.53â¯Da. The Lineweaver-Burk plot indicated that the inhibition of ACE by this peptide is in competitive mode. Also, molecular docking and simulation studies showed a strong and stable interaction of the peptide with ACE. CONCLUSION: The results clearly show the inhibitory property of the peptide against ACE and hence it can be explored as a therapeutic strategy towards hypertension and other ACE associated diseases.
Asunto(s)
Inhibidores de la Enzima Convertidora de Angiotensina/química , Inhibidores de la Enzima Convertidora de Angiotensina/farmacología , Cajanus/química , Péptidos/farmacología , Peptidil-Dipeptidasa A/química , Aspergillus niger/metabolismo , Cajanus/metabolismo , Dominio Catalítico , Cromatografía en Gel , Simulación por Computador , Evaluación Preclínica de Medicamentos/métodos , Humanos , Simulación del Acoplamiento Molecular , Peso Molecular , Péptidos/química , Péptidos/aislamiento & purificación , Peptidil-Dipeptidasa A/metabolismo , Espectrometría de Masas en TándemRESUMEN
Caenorhabditis elegans is a sterol auxotroph requires minute amount of exogenous sterol for their growth and development. To culture the C. elegans, cholesterol was given as sterol molecule to maintain the optimum survival of worms. Diosgenin (DG), a plant derived steroidal saponin, structurally similar to cholesterol has been used as a precursor for the synthesis of steroidal hormones. In this study, worms were cultured with cholesterol (Cho+) and cholesterol-free (Cho-) medium with DG (5, 10 and 50µg/mL) at 20°C. It was observed that worms cultured in (Cho-) exhibits late egg production, reduced lipid level and short lifespan, while addition of DG overcomes all defective facts. Combinations of both cholesterol and DG further extend the lifespan (20.8%), hinder lipid level and resistance to oxidative, thermal and high glucose stress. The intracellular ROS quantification was done by flouroscenic probe H2DCF-DA and confirmed that DG had significantly reduced ROS level (35.85%). Increased lifespan of worms were observed in the medium treated with DG which activates the nuclear translocation of DAF-16/FOXO transcription factor, followed by downstream antioxidant gene sod-3 as evidenced by GFP tagged strain. The expression of Phase II detoxification enzyme GST-4 significantly (p<0.001) increased in transgenic worms exposed to DG with 50mM glucose, and storage of lipid in intestinal cells was reduced in N2 wild type worms. Genetic requirement of DG induced longevity was studied with different mutant strains of mev-1, daf-16, skn-1, and eat-2. These studies have proved that DG is a sterol source to worms and modulate the DAF-16, SOD-3 and GST-4 expression levels to extend the lifespan of worms. The present study has also highlighted the use of phytosterols as an alternative to cholesterol.
Asunto(s)
Proteínas de Caenorhabditis elegans/metabolismo , Diosgenina/farmacología , Factores de Transcripción Forkhead/metabolismo , Glutatión Transferasa/metabolismo , Estrés Oxidativo/efectos de los fármacos , Animales , Caenorhabditis elegans , Colesterol/metabolismo , Diosgenina/administración & dosificación , Relación Dosis-Respuesta a Droga , Glucosa/metabolismo , Metabolismo de los Lípidos/fisiología , Longevidad/efectos de los fármacos , Especies Reactivas de Oxígeno/metabolismoRESUMEN
A novel, poly(ethyl ethylene ether) inhibitor to trypsin was purified from marine cyanobacteria, Lyngbya confervoides from the coastal areas of Thalassery, North Kerala. The kinetics and the thermodynamic parameters of its interactions with the enzyme were also studied. It was demonstrated that the substrate binding, catalytic triad of the enzyme could be blocked by the inhibitor, as expressed by molecular simulation studies. The study also showed that the cyanobacterial group could prove to be a potential source of novel enzyme inhibitors for various applications.