Editors Choice Article | Crossing the Blood-Brain Barrier: A Review on Drug Delivery Strategies for Treatment of the Central Nervous System Diseases

Journal Name: Current Drug Delivery

Author(s): Nur Izzati Mansor, Norshariza Nordin*, Farahidah Mohamed, King Hwa Ling, Rozita Rosli, Zurina Hassan.

 

 

 

Graphical Abstract:

 

Abstract:

Many drugs have been designed to treat diseases of the central nervous system (CNS), especially neurodegenerative diseases. However, the presence of tight junctions at the blood-brain barrier has often compromised the efficiency of drug delivery to target sites in the brain. The principles of drug delivery systems across the blood-brain barrier are dependent on substrate-specific (i.e. protein transport and transcytosis) and non-specific (i.e. transcellular and paracellular) transport pathways, which are crucial factors in attempts to design efficient drug delivery strategies. This review describes how the blood-brain barrier presents the main challenge in delivering drugs to treat brain diseases and discusses the advantages and disadvantages of ongoing neurotherapeutic delivery strategies in overcoming this limitation. In addition, we discuss the application of colloidal carrier systems, particularly nanoparticles, as potential tools for therapy for the CNS diseases. To read out more, please visit: http://www.eurekaselect.com/174513/article

Science Alert | This Photo Is Black And White. Here’s The Science That Makes Your Brain See Colour

 

A bizarre and brilliantly effective optical illusion going viral on the internet tricks your brain into seeing a colour image… but if you look closer, you’ll notice the photo you’re staring at is only black and white.

“An over-saturated coloured grid overlaid on a grayscale image causes the grayscale cells to be perceived as having colour,” Kolås explains on his Patreon page.

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So what’s going on here to make our brains actually interpret this black-and-white picture as if it’s full colour image?

According to vision scientist Bart Anderson from the University of Sydney, the effect we’re seeing in this illusion isn’t particularly surprising.

“The colour system is what vision scientists refer to as ‘low pass’, i.e., many of the receptive fields that code colour are quite large,” Anderson told ScienceAlert.

“So the grids get ‘averaged’ with the achromatic background, which then gets attributed to that part of the image.”

In other words, our brain kind of compresses visual information when we look at things, giving us an overall impression of what’s there if we don’t take the time to examine objects closely.

If you’ve seen this illusion doing the rounds, you might notice this isn’t the main image being shared.

Some of the people in that photo hadn’t given permission for it to be shared online, and Kolås has asked for it not to be used, which is why we’ve put up one of his other examples instead.

The illusion isn’t just created by using coloured grids, either. While Kolås finds grids offer the best effect, he’s also played around with other ways of achieving the visual trick, using alternatives like dots and lines:

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“The raster of dots gives a nice analogy to half-toning as used in print, where colour assimilation aids the optical mixture of colours that already happens before our visual system gets involved,” Kolås explains on his Patreon page.

And here’s an example using lines to create the same effect:

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And another:

Another one, with horizontal lines instead of a grid.

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Most impressively of all, the way this illusion works doesn’t seem to require static images.

In the video below, Kolås shows how even full-motion video with the grid overlay is able to trick the brain into thinking its seeing a colour image, all by virtue of the ‘low pass’ way our visual system attributes colour:

 

To read out more, please visit: https://bit.ly/33feqSB

Editor’s Choice Article | Statins and the Brain: More than Lipid Lowering Agents?

Journal Name: Current Neuropharmacology

Author(s): Anna Fracassi, Martina Marangoni, Pamela Rosso, Valentina Pallottini, Marco Fioramonti, Silvia Siteni, Marco Segatto*.

Graphical Abstract:

Abstract:

Background: Statins represent a class of medications widely prescribed to efficiently treat dyslipidemia. These drugs inhibit 3-βhydroxy 3β-methylglutaryl Coenzyme A reductase (HMGR), the rate-limiting enzyme of mevalonate (MVA) pathway. Besides cholesterol, MVA pathway leads to the production of several other compounds, which are essential in the regulation of a plethora of biological activities, including in the central nervous system. For these reasons, statins are able to induce pleiotropic actions, and acquire increased interest as potential and novel modulators in brain processes, especially during pathological conditions.

Objective: The purpose of this review is to summarize and examine the current knowledge about pharmacokinetic and pharmacodynamic properties of statins in the brain. In addition, effects of statin on brain diseases are discussed providing the most up-to-date information.

Methods: Relevant scientific information was identified from PubMed database using the following keywords: statins and brain, central nervous system, neurological diseases, neurodegeneration, brain tumors, mood, stroke.

Results: 315 scientific articles were selected and analyzed for the writing of this review article. Several papers highlighted that statin treatment is effective in preventing or ameliorating the symptomatology of a number of brain pathologies. However, other studies failed to demonstrate a neuroprotective effect.

Conclusion: Even though considerable research studies suggest pivotal functional outcomes induced by statin therapy, additional investigation is required to better determine the pharmacological effectiveness of statins in the brain, and support their clinical use in the management of different neuropathologies.

 

 

Read out more at: http://www.eurekaselect.com/153651/article

Most Accessed Articles – Nanomedicine for Intranasal Delivery to Improve Brain Uptake

Journal Name: Current Drug Delivery

Author(s): Amit A. Patel*, Ravish J. Patel*, Shachi R. Patel.

Graphical Abstract:

 

Abstract:

Intranasal drug delivery system provides distinct advantage over conventional drug delivery system for a drug that is pharmacokenetically or biologically unstable. Major concern for the treatment of central nervous system diseases is, low concentration of therapeutically active molecule within brain as blood brain barrier is creating obstacle, where intranasal drug delivery provides direct transport of therapeutically active moiety into brain via olfactory or trigeminal pathway. Nasal mucosa provides distinct advantages like improved bioavailability, law dose and quick onset of action and high patient compliance, and the major disadvantage is residence time of drug and irreversible entrapment of drug. This article provides anatomical and physiological information about nasal route and various factors. Article discusses various types of nanoparticles used intranasally and moreover article also emphasizes patents, formulation under development and some.

 

For more details, please visit: http://www.eurekaselect.com/156384

EDITOR’S CHOICE – Coping with Stress During Aging – Current Neuropharmacology

Journal: Current Neuropharmacology

Author(s): P. Sampedro-Piquero*, P. Alvarez-Suarez, A. Begega

Graphical Abstract:

 

Abstract:

Background: Resilience is the ability to achieve a positive outcome when we are in the face of adversity. It supposes an active resistance to adversity by coping mechanisms in which genetic, molecular, neural and environmental factors are involved. Resilience has been usually studied in early ages and few is known about it during aging.

Methods: In this review, we will address the age-related changes in the brain mechanisms involved in regulating the stress response. Furthermore, using the EE paradigm, we analyse the resilient potential of this intervention and its neurobiological basis. In this case, we will focus on identifying the characteristics of a resilient brain (modifications in HPA structure and function, neurogenesis, specific neuron types, glia, neurotrophic factors, nitric oxide synthase or microRNAs, among others).

Results: The evidence suggests that a healthy lifestyle has a crucial role to promote a resilient brain during aging. Along with the behavioral changes described, a better regulation of HPA axis, enhanced levels of postmitotic type-3 cells or changes in GABAergic neurotransmission are some of the brain mechanisms involved in resilience.

Conclusion: Future research should identify different biomarkers that increase the resistance to develop mood disorders and based on this knowledge, develop new potential therapeutic targets.

Read more here: http://www.eurekaselect.com/155614/article

 

EDITOR’S CHOICE – Environment and Neurodegenerative Diseases – MicroRNA

Journal: MicroRNA 

Author(s): Margherita Ferrante*, Gea Oliveri Conti

Graphical Abstract:

 

Abstract:

Introduction: The importance of neurodegenerative diseases on the management of public health is growing and the real role of the environment and miRNA in their occurrence is still unclear. miRNA can significantly affect the regulatory network. The complex variety and gene-regulatory capacity of miRNAs are particularly valuable in the brain, being a very complex organ with a functional specialization of neurons highly adaptable to environmental stimuli. In particular, an miRNAs role is demonstrated in neurological diseases as an effect to toxic and mutagenic substances exposure by the environment.

Objective: The focus was on the three most important neurodegenerative diseases: Alzheimer, Parkinson and Amyotrophic lateral sclerosis.

Materials and Methods: A brief critical review on scientific papers of the last ten years using PuBMED, Scopus, Web of Science and Cochrane databases was carried out.

Results: Several studies have shown that miRNAs may contribute to neurodegeneration process in response to environmental risks. The miRNAs are known to play a dynamic role in many biochemical pathways of mammalian’s brain, including neuroplasticity, stress responses, cellular signaling, etc. miRNAs have a role in neurodegenerative phenotype of AD, PD and ALS.

The environmental chemicals such as metals and pesticides and then behavior can cause miRNA alterations via increasing oxidative stress and/or triggering inflammatory responses.

Conclusion: A discussion with theoretical and possible future research directions is provided and it is clear that the need is not only of longitudinal population studies and of better knowledge of epigenetics markers but, especially, of environmental policy interventions based on the green economy.

 

Read more here: http://www.eurekaselect.com/154912

 

Top Foods for Your Brain

What you eat doesn’t just affect your physical health, but also your brain and memory. Here are some amazing foods that you can eat to boost your brainpower and memory.

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Whole Grains

The brain obtains its energy in the form of glucose which is derived from carbohydrates. Our brains need energy to focus and concentrate which it gets from carbohydrates. Healthy ways to acquire complex carbohydrates with low Glycemic Index (GI) is to eat whole-wheat products, granary bread, bulgur, oats, beans, wild rice, barley, and soy.

Fish

The most useful omega-3 fats are found naturally in fish as Eicosapentaenoic acid (EPA) and Docosahexaenoic acid (DHA). Salmon, trout, mackerel, herring, sardines, pilchards and kippers all contain EPA and DHA. Low DHA levels can cause dementia, Alzheimer’s disease and memory loss whereas adequate levels of EPA and DHA can assist in lower stress and aid in the production of serontin, the feel good chemical.

Green Leafy Vegetables

Now we know why Popeye liked spinach so much. Green leafy vegetables such as spinach, turnip, kale, romaine, collard greens, mustard greens, and broccoli contain a lot of folic acid and healthy vitamins. Shortages in folate and B vitamins are believed to aggravate depression, lethargy and sleeplessness. So, have green leafy vegetables in order to have a healthy brain.

Berries

Latest research has shown that berries such as blueberries, strawberries, and acai berries contain antioxidants and other phytochemicals and have been shown to improve learning, reasoning, and recollection. They may also stop mental deterioration in its track by preserving the brain’s natural mechanism. They also aid in averting memory loss which comes with age.

So enjoy these healthy foods and sustain a strong brain!

Editor’s Choice – Differences in Relative Levels of 88 microRNAs in Various Regions of the Normal Adult Human Brain – MicroRNA

Journal: MicroRNA

Author(s): Elena V. Filatova, Anelya Alieva, Maria I. Shadrina, Petr A. Slominsky.

Graphical Abstract:

 

Abstract:

Aim of Study: Since the discovery of microRNAs (miRNAs) in the 1990s, our knowledge about their biology has grown considerably. The increasing number of studies addressing the role of miRNAs in development and in various diseases emphasizes the need for a comprehensive catalogue of accurate sequence, expression and conservation information regarding the large number of miRNAs proposed recently in all organs and tissues. The objective of this study was to provide data on the levels of miRNA expression in 15 tissues of the normal human brain.

Materials and Methods: We conducted an analysis of the relative levels of 88 of the most abundantly expressed and best characterized miRNA derived postmortem from well-characterized samples of various regions of the brains from five normal individuals.

Results: The cluster analysis revealed some differences in the relative levels of these miRNAs among the brain regions studied. Such diversity can be explained by different functioning of these brain regions.
Conclusion: We hope that the data from the current study are a resource that will be useful to our colleagues in this exciting field, as more hypotheses will be generated and tested with regard to small noncoding RNA in the human brain in healthy and disease states.

 

Most Accessed Article – Nanosized Drug Delivery Systems for Direct Nose to Brain Targeting – Recent Patents on Drug Delivery & Formulation

Journal: Recent Patents on Drug Delivery & Formulation

Author(s): Kunjan Phukan, Marika Nandy, Rupanjali B. Sharma, Hemanta K. Sharma.

Graphical Abstract:

 

Abstract:

Background: Drug targeting to brain has always been problematic due to Blood-Brain Barrier (BBB), which, does not allow most of the drugs to pass through it as they are hydrophilic and macromolecular drugs. So, in order to bypass the BBB, alternative modes of administration were searched and nasal to brain delivery route was tried by many workers. Such studies yielded patented nano-formulations with the ability to cross blood brain barrier.

Methods: Nanoparticles being smaller in size and large surface area help in increasing the rate of drug permeation to the brain. In this review work, emphasis has been laid on discussion on various works done in the field of nasal delivery of drugs to brain over the last decade.

Results: The works that are discussed in this paper show better drug targeting of brain when given through nasal route as nanoparticles. Experiments performed in animal models have clearly exhibited that nano-sized formulations are able to facilitate the delivery of drugs to brain through nose in comparison to tantamount drug solutions.

Conclusion: However, it is not yet confirmed whether the drug is freed from the formulation in the nasal cavity and then absorbed or the nanoparticles themselves are absorbed and then the drug is released in the CNS. Furthermore, the toxicity studies were not carried out extensively in suitably designed model, which should be considered before going for further studies and application.

To access the article, please visit: http://www.eurekaselect.com/140558

Food Enhances Intelligence!

We have always known the fact that food is essential for keeping us alive and healthy. But this is a general statement, so the scientists have been on the mission to understand how food keeps us healthy – both physically and mentally. Keeping our focus on mental health we need to understand how food and nutrition keeps our brain healthy.

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Recently, scientists from the University of Illinois studied the Mediterranean diet and found out that the oils and nuts carry nutrients that are very good for the brain. The dorsal networks in the brain is the key area concerned with intelligence and cognitive thinking. The Mediterranean diet includes nutrients called monounsaturated fatty acids MUFAs that the researchers found, were responsible for building the networks and enhancing thinking abilities.

The study is just the beginning and has loads to offer for scientists as they progress in this direction.

To read the latest research articles on neurology, visit: http://benthamscience.com/browse-by-subject/medicine/#ANCHSC34

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