scholarly journals The Impact of Natural Compounds on S-Shaped Aβ42 Fibril: From Molecular Docking to Biophysical Characterization

2020 ◽  
Vol 21 (6) ◽  
pp. 2017 ◽  
Author(s):  
Stefano Muscat ◽  
Lorenzo Pallante ◽  
Filip Stojceski ◽  
Andrea Danani ◽  
Gianvito Grasso ◽  
...  

The pursuit for effective strategies inhibiting the amyloidogenic process in neurodegenerative disorders, such as Alzheimer’s disease (AD), remains one of the main unsolved issues, and only a few drugs have demonstrated to delay the degeneration of the cognitive system. Moreover, most therapies induce severe side effects and are not effective at all stages of the illness. The need to find novel and reliable drugs appears therefore of primary importance. In this context, natural compounds have shown interesting beneficial effects on the onset and progression of neurodegenerative diseases, exhibiting a great inhibitory activity on the formation of amyloid aggregates and proving to be effective in many preclinical and clinical studies. However, their inhibitory mechanism is still unclear. In this work, ensemble docking and molecular dynamics simulations on S-shaped Aβ42 fibrils have been carried out to evaluate the influence of several natural compounds on amyloid conformational behaviour. A deep understanding of the interaction mechanisms between natural compounds and Aβ aggregates may play a key role to pave the way for design, discovery and optimization strategies toward an efficient destabilization of toxic amyloid assemblies.

2019 ◽  
Vol 20 (9) ◽  
pp. 2313 ◽  
Author(s):  
Stephanie Andrade ◽  
Maria João Ramalho ◽  
Joana Angélica Loureiro ◽  
Maria do Carmo Pereira

Alzheimer’s Disease (AD) is a neurodegenerative disorder related with the increase of age and it is the main cause of dementia in the world. AD affects cognitive functions, such as memory, with an intensity that leads to several functional losses. The continuous increase of AD incidence demands for an urgent development of effective therapeutic strategies. Despite the extensive research on this disease, only a few drugs able to delay the progression of the disease are currently available. In the last years, several compounds with pharmacological activities isolated from plants, animals and microorganisms, revealed to have beneficial effects for the treatment of AD, targeting different pathological mechanisms. Thus, a wide range of natural compounds may play a relevant role in the prevention of AD and have proven to be efficient in different preclinical and clinical studies. This work aims to review the natural compounds that until this date were described as having significant benefits for this neurological disease, focusing on studies that present clinical trials.


Author(s):  
Priyastiwi Priyastiwi

The purpose of this article is to provide the basic model of Hofstede and Grays’ cultural values that relates the Hofstede’s cultural dimensions and Gray‘s accounting value. This article reviews some studies that prove the model and develop the research in the future. There are some evidences that link the Hofstede’s cultural values studies with the auditor’s judgment and decisions by developing a framework that categorizes the auditor’s judgments and decisions are most likely influenced by cross-cultural differences. The categories include risk assessment, risk decisions and ethical judgments. Understanding the impact of cultural factors on the practice of accounting and financial disclosure is important to achieve the harmonization of international accounting. Deep understanding about how the local values may affect the accounting practices and their impacts on the financial disclosure are important to ensure the international comparability of financial reporting. Gray’s framework (1988) expects how the culture may affect accounting practices at the national level. One area of the future studies will examine the impact of cultural dimensions to the values of accounting, auditing and decision making. Key word : Motivation, leadership style, job satisfaction, performance


Author(s):  
Ilma Robo

The treatment of periodontal diseases, mainly of their origin, with the most common clinical manifestation in form of gingival inflammation, is manifold and powerful, including: mechanical therapy, antibiotic, antiseptic and various approaches to treatment, which are recommended to be used within a short period of time. New therapeutic approaches have been proven as alternative treatment to conventional therapy, or in combination with conventional therapies, to reduce the number of periodontopathic pathogens in gingival sulcus. HBOT has a detrimental effect on periodontal microorganisms, as well as beneficial effects on the healing of periodontal tissue, increasing oxygen pressure in gingival pockets. Our study is aimed at reviewing the current published literature on hyperbaric oxygen therapy and focuses on role of HBOT as a therapeutic measure for the individual with periodontal disease in general and for the impact on the recovery of gingival inflammation. HBOT and periodontal treatment together, reduce up to 99% of the gram-negative anaerobic load of subgingival flora. HBOT, significantly reduces subgingival anaerobic flora. Clinical effects in 2-year follow-up of treated patients are sensitive. Reduction of gingival hemorrhage indexes, depth of peritoneum, plaque index, occurs in cases of combination of HBOT and detraction. Reduced load persists up to 2 months after therapy. The significant increase in connective tissue removal starts at the end of 2nd week, to achieve the maximum in week 3-6 of application. HBOT used for re-implantation, stimulates the healing of periodontal membrane, pulp, prevents root resorption, healing of periodontal lining tissues. HBOT, significantly reduces the hemorrhage index with 1.2 value difference, 0.7mm probe depth, reduces gingival fluid by 2. HGH exposure is increased by gingival blood flow, with a difference of 2 in measured value. The therapeutic effects of HBOT in the value of the evaluation index can be saved up to 1-year post treatment.


2020 ◽  
Vol 26 (39) ◽  
pp. 4953-4954
Author(s):  
Mallikarjuna Korivi ◽  
Betty Revon Liu

Metabolic syndrome (MetS) which is caused by poor dietary habits and sedentary behavior is a serious global health problem. MetS is a cluster of risk factors, represented by central obesity, hyperglycemia, dyslipidemia, and hypertension. In the 21st century, MetS and associated comorbidities, including obesity, diabetes and cardiovascular diseases, are the major threats to human health. Practical dietary strategies, nutritional bioactive compounds and a healthy lifestyle are claimed to be efficient in the management of one or more components of MetS. Nevertheless successful management of MetS and commodities is still a major concern. Since hyperglycemia, inflammation and redox imbalance are intrinsically involved in the progression of MetS comorbidities, finding effective strategies that precisely target these systems is highly warranted. In this scenario, pharmacological and non-pharmacological approaches with or without dietary patterns, phytochemicals or exercise interventions are the practical strategies to combat MetS and associated diseases. However, designing and prescribing of optimal nutritional patterns and exercise regimens remains a big challenge to achieve the maximum beneficial effects. This thematic issue addressed the concerns and provided practical strategies to overcome the malady of MetS in the modern world.


2020 ◽  
Vol 30 (Supplement_5) ◽  
Author(s):  
C Dupré ◽  
N Barth ◽  
A El Moutawakkil ◽  
F Béland ◽  
F Roche ◽  
...  

Abstract Background Few previous cohorts have studied the different type of physical activities and the degree of cognitive decline. The objective of this work was to analyze the leisure, domestic and professional activities with mild and moderate cognitive disorders in older people living in community. Methods The study used data from the longitudinal and observational study, FrèLE (FRagility: Longitudinal Study of Expressions). The collected data included: socio-demographic variables, lifestyle, and health status (frailty, comorbidities, cognitive status, depression). Cognitive decline was assessed by using: MMSE (Mini-Mental State Examination) and MoCA (Montreal Cognitive Assessment). MoCA was used with two cut-offs (26 and 17) so as to define mild and moderate cognitive disorders Physical activity was assessed by the PASE (Physical Activity Scale for the Elderly), structured in three sections: leisure, domestic and professional activities. Spline and proportional hazards regression models (Cox) were used to estimate the risk of cognitive disorders. Results At baseline, 1623 participants were included and the prevalence of cognitive disorders was 6.9% (MMSE) and 7.2% (MoCA), mild cognitive disorders was 71.3%. The mean age was 77 years, and 52% of the participants were women. After a 2 years long follow-up, we found 6.9% (MMSE) and 6% (MoCA) cognitive disorders on participants. Analyses showed that domestic activities were associated to cognitive decline (HR = 0.52 [0.28-0.94] for MMSE and HR = 0.48 [0.28-0.80] for MoCA). No association were found with leisure and professional activities, and no spline were significant with mild cognitive disorders. Conclusions Analysis showed a relationship between cognitive disorders and type of physical activity, thanks to the use of specific questionnaire of elderly and two global test of cognition. These findings will contribute to the debate on the beneficial effects of physical activity on cognition. Key messages This work allowed to compare two test of cognition and their link with physical activity. It contributes to the debate on the beneficial effects of physical activity on cognition. The work allowed us to see the effect of the different types of physical activity and the impact of the statistical method on the results.


Materials ◽  
2021 ◽  
Vol 14 (7) ◽  
pp. 1751
Author(s):  
Rosa María Tremiño ◽  
Teresa Real-Herraiz ◽  
Viviana Letelier ◽  
José Marcos Ortega

One of the most popular ways to lessen the impact of the cement industry on the environment consists of substituting clinker by additions. The service life required for real construction elements is generally long, so it would be interesting to obtain information about the effects of new additions after a hardening period of several years. Analyzed here are the effects of the incorporation of volcanic ashes, coming from Calbuco volcano’s last eruption (Chile), as clinker replacement, in the durability and pore structure of mortars, after approximately 4 hardening years (1500 days), in comparison with reference specimens without additions. The substitution percentages of clinker by volcanic powder studied were 10% and 20%. The microstructure was characterized with mercury intrusion porosimetry and impedance spectroscopy. In order to evaluate the pozzolanic activity of the volcanic powder after 1500 days, differential thermal analyses were performed. Water absorption after immersion, steady-state diffusion coefficient and length change were also studied. In accordance with the results obtained, the 10% and 20% substitution of clinker by volcanic powder from the Calbuco volcano showed beneficial effects in the mortars after 4 years, especially regarding the microstructure and chloride diffusion, without noticeable influence in their water absorption.


Biochar ◽  
2021 ◽  
Author(s):  
Ngitheni Winnie-Kate Nyoka ◽  
Ozekeke Ogbeide ◽  
Patricks Voua Otomo

AbstractTerrestrial and aquatic ecosystems are increasingly threatened by pesticide pollution resulting from extensive use of pesticides, and due to the lack of regulatory measures in the developing world, there is a need for affordable means to lessen environmental effects. This study aimed to investigate the impact of biochar amendment on the toxicity of imidacloprid to life-cycle parameters and biomarker responses of the earthworm Eisenia fetida. E. fetida was exposed to 10% biochar-amended and non-amended OECD artificial soils spiked with 0, 0.75, 1.5, 2.25 and 3 mg imidacloprid/kg for 28 days. An LC50 of 2.7 mg/kg was only computed in the non-amended soil but not in the biochar-amended soil due to insignificant mortality. The EC50 calculated in the non-amended soil (0.92 mg/kg) for reproduction (fertility) was lower than the one computed in the biochar amended (0.98 mg/kg), indicating a decrease in toxicity in the biochar-amended substrate. Significant weight loss was observed at the two highest imidacloprid treatments in the non-amended soil and only at the highest treatment in the biochar-amended substrate, further highlighting the beneficial effects of biochar. Catalase activity decreased significantly at the two highest concentrations of non-amended soil. Yet, in the amended soil, the activity remained high, especially in the highest concentration, where it was significantly higher than the controls. This indicated more severe oxidative stress in the absence of biochar. In all non-amended treatments, there was a significant acetylcholinesterase inhibition, while lower inhibition percentages were observed in the biochar-amended soil. In most endpoints, the addition of biochar alleviated the toxic effects of imidacloprid, which shows that biochar has the potential to be useful in soil remediation. However, there is still a need for field studies to identify the most effective application rate of biochar for land application.


2021 ◽  
Vol 43 (4) ◽  
Author(s):  
Agnieszka Ostrowska ◽  
Maciej T. Grzesiak ◽  
Tomasz Hura

AbstractSoil drought is a major problem in plant cultivation. This is particularly true for thermophilic plants, such as maize, which grow in areas often affected by precipitation shortage. The problem may be alleviated using plant growth and development stimulators. Therefore, the aim of the study was to analyze the effects of 5-aminolevulinic acid (5-ALA), zearalenone (ZEN), triacontanol (TRIA) and silicon (Si) on water management and photosynthetic activity of maize under soil drought. The experiments covered three developmental stages: three leaves, stem elongation and heading. The impact of these substances applied during drought stress depended on the plant development stage. 5-ALA affected chlorophyll levels, gas exchange and photochemical activity of PSII. Similar effects were observed for ZEN, which additionally induced stem elongation and limited dehydration. Beneficial effects of TRIA were visible at the stage of three leaves and involved leaf hydration and plant growth. A silicon preparation applied at the same developmental stage triggered similar effects and additionally induced changes in chlorophyll levels. All the stimulators significantly affected transpiration intensity at the heading stage.


2021 ◽  
Author(s):  
Camila Dossi ◽  
Romina Vargas ◽  
Rodrigo Valenzuela ◽  
Luis Videla

Liver ischemia-reperfusion injury (IRI) is a phenomenon inherent to hepatic surgery that severely compromises the organ functionality, whose underlying mechanisms involve cellular and molecular interrelated processes leading to the development...


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Patricia Soriano Roque ◽  
Mehdi Hooshmandi ◽  
Laura Neagu-Lund ◽  
Shelly Yin ◽  
Noosha Yousefpour ◽  
...  

AbstractLong-lasting cognitive impairment in juveniles undergoing repeated general anesthesia has been observed in numerous preclinical and clinical studies, yet, the underlying mechanisms remain unknown and no preventive treatment is available. We found that daily intranasal insulin administration to juvenile mice for 7 days prior to repeated isoflurane anesthesia rescues deficits in hippocampus-dependent memory and synaptic plasticity in adulthood. Moreover, intranasal insulin prevented anesthesia-induced apoptosis of hippocampal cells, which is thought to underlie cognitive impairment. Inhibition of the mechanistic target of rapamycin complex 1 (mTORC1), a major intracellular effector of insulin receptor, blocked the beneficial effects of intranasal insulin on anesthesia-induced apoptosis. Consistent with this finding, mice lacking mTORC1 downstream translational repressor 4E-BP2 showed no induction of repeated anesthesia-induced apoptosis. Our study demonstrates that intranasal insulin prevents general anesthesia-induced apoptosis of hippocampal cells, and deficits in synaptic plasticity and memory, and suggests that the rescue effect is mediated via mTORC1/4E-BP2 signaling.


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