Marijuana compound may offer treatment for Alzheimer's disease
August 27, 2014
Science Daily/University of South Florida (USF Health)
Extremely low levels of the compound in marijuana known as delta-9-tetrahydrocannabinol, or THC, may slow or halt the progression of Alzheimer's disease, a recent study from neuroscientists at the University of South Florida shows.
Findings from the experiments, using a cellular model of Alzheimer's disease, were reported online in the Journal of Alzheimer's Disease.
Researchers from the USF Health Byrd Alzheimer's Institute showed that extremely low doses of THC reduce the production of amyloid beta, found in a soluble form in most aging brains, and prevent abnormal accumulation of this protein -- a process considered one of the pathological hallmarks evident early in the memory-robbing disease. These low concentrations of THC also selectively enhanced mitochondrial function, which is needed to help supply energy, transmit signals, and maintain a healthy brain.
"THC is known to be a potent antioxidant with neuroprotective properties, but this is the first report that the compound directly affects Alzheimer's pathology by decreasing amyloid beta levels, inhibiting its aggregation, and enhancing mitochondrial function," said study lead author Chuanhai Cao, PhD and a neuroscientist at the Byrd Alzheimer's Institute and the USF College of Pharmacy.
"Decreased levels of amyloid beta means less aggregation, which may protect against the progression of Alzheimer's disease. Since THC is a natural and relatively safe amyloid inhibitor, THC or its analogs may help us develop an effective treatment in the future."
The researchers point out that at the low doses studied, the therapeutic benefits of THC appear to prevail over the associated risks of THC toxicity and memory impairment.
Neel Nabar, a study co-author and MD/PhD candidate, recognized the rapidly changing political climate surrounding the debate over medical marijuana.
"While we are still far from a consensus, this study indicates that THC and THC-related compounds may be of therapeutic value in Alzheimer's disease," Nabar said. "Are we advocating that people use illicit drugs to prevent the disease? No. It's important to keep in mind that just because a drug may be effective doesn't mean it can be safely used by anyone. However, these findings may lead to the development of related compounds that are safe, legal, and useful in the treatment of Alzheimer's disease."
The body's own system of cannabinoid receptors interacts with naturally-occurring cannabinoid molecules, and these molecules function similarly to the THC isolated from the cannabis (marijuana) plant.
Dr. Cao's laboratory at the Byrd Alzheimer's Institute is currently investigating the effects of a drug cocktail that includes THC, caffeine as well as other natural compounds in a cellular model of Alzheimer's disease, and will advance to a genetically-engineered mouse model of Alzheimer's shortly.
"The dose and target population are critically important for any drug, so careful monitoring and control of drug levels in the blood and system are very important for therapeutic use, especially for a compound such as THC," Dr. Cao said.
https://www.sciencedaily.com/releases/2014/08/140827131801.htm
New insights into the neural risks and benefits of marijuana use
Compounds in cannabis can impair or improve memory depending on age, disease
November 6, 2018
Science Daily/Society for Neuroscience
Research released today underscores both the dangers and the therapeutic promise of marijuana, revealing different effects across the lifespan. Marijuana exposure in the womb or during adolescence may disrupt learning and memory, damage communication between brain regions, and disturb levels of key neurotransmitters and metabolites in the brain. In Alzheimer's disease, however, compounds found in marijuana, such as the psychoactive compound delta-9-tetrahydrocannabinol (THC), may improve memory and mitigate some of the disease's symptoms.
Research released today underscores both the dangers and the therapeutic promise of marijuana, revealing different effects across the lifespan. Marijuana exposure in the womb or during adolescence may disrupt learning and memory, damage communication between brain regions, and disturb levels of key neurotransmitters and metabolites in the brain. In Alzheimer's disease, however, compounds found in marijuana, such as the psychoactive compound delta-9-tetrahydrocannabinol (THC), may improve memory and mitigate some of the disease's symptoms. The findings were presented at Neuroscience 2018, the annual meeting of the Society for Neuroscience and the world's largest source of emerging news about brain science and health.
Marijuana is the most commonly used illicit drug in the United States and its popularity is expected to rise as it is legalized in more places. It is also the illegal drug most commonly used by pregnant women, despite the potential for long-term harm to the fetus. Many people start using marijuana as teenagers -- a particularly vulnerable time as the brain is still developing -- when there is evidence for increased risk. At the same time, a growing number of people are turning to marijuana for the relief of symptoms of chronic diseases such as epilepsy and multiple sclerosis. These use patterns highlight the need to better understand the long-term effects of marijuana, particularly in sensitive populations such as unborn children and adolescents.
Today's new findings show that:
· Prenatal exposure to THC in rats has lasting effects on metabolites in the brain, making the animal more vulnerable to stress later in life (Robert Schwarcz, abstract 609.12).
· Rats exposed to synthetic compounds that are similar to THC during fetal development show impaired formation of the neural circuits involved in learning and memory as adolescents (Priyanka Das Pinky, abstract 424.17).
· Cannabinoid use by adolescent rats boosts activity in brain pathways responsible for habit formation (José Fuentealba Evans, abstract 602.07).
· In adolescent rats, cannabinoids may disturb the development of a protein lattice important for balancing excitatory and inhibitory activity in a brain region involved in decision-making, planning, and self-control (Eliza Jacobs-Brichford, abstract 645.09).
· Long-term cannabinoid use alters metabolism and connectivity of brain regions involved in learning and memory in adult mice (Ana M. Sebastião, abstract 778.08).
· Treating Alzheimer's disease mice with the psychoactive compound found in marijuana improves memory and reduces neuronal loss, suggesting a possible therapy for the human disease (Yvonne Bouter, abstract 467.14).
"Today's findings lend new understanding of the complex effects that cannabis has on the brain," said press conference moderator Michael Taffe, PhD, of Scripps Research Institute and an expert in substance abuse research. "While it may have therapeutic potential in some situations, it is important to get a better understanding of the negative aspects as well, particularly for pregnant women, teens, and chronic users."
https://www.sciencedaily.com/releases/2018/11/181106150418.htm