Cannabidiol could help deliver medications to the brain
Cannabidiol (CBD), a non-psychoactive compound in cannabis, is being touted as beneficial for many health conditions, ranging from anxiety to epilepsy. Although much more research is needed to verify these claims, scientists have now shown that CBD could have a different use as a “Trojan horse”: helping slip medications across the blood-brain barrier (BBB) and into mouse brains. The researchers report their results in the ACS journal Molecular Pharmaceutics.
The BBB consists of a layer of tightly linked cells that line capillaries in the brain, preventing substances from exiting the blood and entering the brain. However, the BBB does permit some molecules to pass, such as glucose and certain amino acids and neurotransmitters. For example, a class of neurotransmitters called endocannabinoids bind to proteins called cannabinoid receptors in the BBB, and the receptors help transport the molecules across the barrier and into the brain. Ana Torres-Suárez and colleagues wanted to make use of this system to sneak drug nanocarriers into the brains of mice.
To do so, the researchers attached CBD, which resembles endocannabinoids made by both mice and humans, to the outside surfaces of lipid nanocapsules. Instead of loading the nanocapsules with a medication, the researchers packaged them with a fluorescent molecule so they could track the particles. In experiments with human brain cells that mimic the BBB, the researchers showed that the CBD-displaying nanocarriers caused more of the fluorescent molecule to pass through the cells than nanocarriers of equal size that lacked CBD. Similarly, when injected into healthy mice, the CBD-nanocapsules targeted about 2.5 times more of the fluorescent molecule to the animals’ brains.
Cannabidiol (CBD), a non-psychoactive compound in cannabis, is being touted as beneficial for many health conditions, ranging from anxiety to epilepsy. Although much more research is needed to verify these claims, scientists have now shown that CBD could have a different use as a ‘Trojan horse’: helping slip medications across the blood-brain barrier (BBB) and into mouse brains.
CBD’s Role in Beating Deadly Disease Uncovered in Blood-Brain Barrier Study
Just a spoonful of CBD helps the medicine go up.
In a modern twist on Mary Poppins, scientists have found that just a spoonful of CBD helps the medicine go up вЂ” into the brain. A huge barrier for doctors who want to deliver drugs to the human brain is quite literally a physical obstacle: The blood-brain barrier, which primarily functions to protect the brain. ItвЂ™s very good at its job, preventing most molecules in the bloodstream from getting to our brains вЂ” life-saving drugs included вЂ” but recent research in Molecular Pharmaceutics suggests that CBD could sneak past the bodyвЂ™s natural defense systems.
In a paper published March 13, scientists demonstrated that attaching drug-carrying nanocapsules to CBD вЂ” that is, cannabidiol, the minimally psychoactive chemical found in cannabis and hemp вЂ” allowed them to slip them past the blood-brain barrier.
The researchers, from Complutense University of Madrid and The Open University in the UK, performed their experiments both in a lab model of the blood-brain barrier and in real mice, showing that their technique was much more effective at penetrating the blood-brain barrier than existing methods. ItвЂ™s promising for doctors trying to treat diseases of the central nervous system, as the blood-brain barrier has so far proven to be an extremely challenging obstacle to successful drug delivery.
Lipid nanocapsules are drug-loaded nanoparticles that have become popular in cancer treatment for delivering chemotherapy drugs into patientsвЂ™ bloodstreams. They have no problem reaching most organs in the human body, but the blood-brain barrier leaves the brain off-limits, making it difficult to treat brain tumors or multiple sclerosis.
This project may change all that.
The team built lipid nanocapsules, but they then вЂњdecoratedвЂќ twhem ith CBD molecules. Their first experiment tested whether these CBD-decorated nanocapsules could get through a lab model of the human blood-brain barrier made of the same type of cells that constitute the real thing. After this test showed that they were on the right track, they then injected the nanocapsules into mice.
In the mice, they observed that when the lipid nanocapsules were decorated with CBD, 2.5 times more of them reached the miceвЂ™s brains than when nanocapsules were injected by themselves. This improvement indicates that theyвЂ™re onto something.
The researchers report that this technique is six times more effective at crossing the blood-brain barrier than G-Technology, a similar type of nanoparticle delivery system designed to evade the blood-brain barrier that is currently undergoing clinical trials.
The researchers arenвЂ™t totally sure why CBD is allowed to pass the blood-brain barrier, but they suspect it has to do with the human bodyвЂ™s endocannabinoid system. This system of neurotransmitters and receptors is involved in all sorts of biological processes, including appetite, mood, and memory. Since the body is well-accustomed to letting its naturally occurring endocannabinoids through the blood-brain barrier, it would make sense that plant-based cannabinoids like CBD would be allowed to slip through вЂ” even if theyвЂ™re bringing along a plus-one.
Obviously these results need to be validated further in animal and вЂ” eventually вЂ” human trials, but this paper suggests that treating brain tumors and multiple sclerosis with drugs may not be as much of a medical fantasy as it once was.
Abstract: Diseases affecting the central nervous system (CNS) should be regarded as a major health challenge due to the current lack of effective treatments given the hindrance to brain drug delivery imposed by the bloodвЂ“brain barrier (BBB). Since efficient brain drug delivery should not solely rely on passive targeting, active targeting of nanomedicines into the CNS is being explored. The present study is devoted to the development of lipid nanocapsules (LNCs) decorated with nonpsychotropic cannabinoids as pioneering nonimmunogenic brain-targeting molecules and to the evaluation of their brain-targeting ability both in vitro and in vivo. Noticeably, both the permeability experiments across the hCMEC/D3 cell-based in vitro BBB model and the biodistribution experiments in mice consistently demonstrated that the highest brain-targeting ability was achieved with the smallest-sized cannabinoid-decorated LNCs. Importantly, the enhancement in brain targeting achieved with the conjugation of cannabidiol to LNCs outperformed by 6-fold the enhancement observed for the G-Technology (the main brain active strategy that has already entered clinical trials for the treatment of CNS diseases). As the transport efficiency across the BBB certainly determines the efficacy of the treatments for brain disorders, small cannabinoid-decorated LNCs represent auspicious platforms for the design and development of novel therapies for CNS diseases.
Just a spoonful of CBD helps the medicine go up.