Recent scientific advancements have shown that a lesser-known compound from the cannabis plant, cannabinol (CBN), may hold promise for treating neurological disorders such as Alzheimer’s and Parkinson’s disease. Researchers at the Salk Institute discovered that not only does CBN protect brain cells from age-related damage, but its chemically modified versions could be even more effective. These findings, detailed in the journal Redox Biology, suggest a new frontier in the treatment of traumatic brain injuries and other neurodegenerative diseases.
With the prevalence of neurological disorders rising among the aging population, there is a pressing need for effective treatments. These diseases are characterized by the progressive degeneration of brain cells, leading to severe cognitive and motor function impairments.
Currently, treatments are largely limited to symptomatic relief rather than addressing the underlying disease progression. Given this gap in treatment options, there is a significant need for new therapies that can protect brain cells and potentially reverse damage.
Cannabinol (CBN), a compound derived from the cannabis plant, has emerged as a candidate for such treatments due to its neuroprotective properties, which are evident without the psychoactive effects associated with other cannabinoids like THC.
Previous studies indicated that CBN could help preserve mitochondrial function in brain cells, an essential factor for cell survival and energy production. Mitochondrial dysfunction is a common feature in several neurodegenerative diseases, often leading to cell death. By focusing on CBN and its derivatives, researchers aimed to develop new pharmacological strategies to prevent or mitigate the cellular mechanisms that lead to neurodegeneration.
To explore the therapeutic potential of CBN, the researchers first broke down CBN into smaller chemical fragments to determine which parts of the molecule were most effective at protecting neurons. This step involved fragment-based drug discovery, a technique that allows for the identification and optimization of the most potent components of a molecule.
Once the key protective fragments of CBN were identified, the team synthesized four novel analogs. These derivatives were designed to enhance the neuroprotective attributes of the original CBN molecule, with modifications intended to increase their ability to penetrate the brain, act faster, and provide stronger effects in protecting against cell death.
“Not only does CBN have neuroprotective properties, but its derivatives have the potential to become novel therapeutics for various neurological disorders,” said Research Professor Pamela Maher, the senior author of the study. “We were able to pinpoint the active groups in CBN that are doing that neuroprotection, then improve them to create derivative compounds that have greater neuroprotective ability and drug-like efficacy.”
The efficacy of these CBN derivatives was first tested in vitro using cultured nerve cells from mice and humans. The researchers induced three types of cell death processes that mimic those occurring in neurodegenerative diseases. By applying the newly created CBN analogs to these cultures, they could assess their protective capabilities compared to standard CBN.
“We were looking for CBN analogs that could get into the brain more efficiently, act more quickly, and produce a stronger neuroprotective effect than CBN itself,” explained Zhibin Liang, the study’s first author and postdoctoral researcher in Maher’s lab. “The four CBN analogs we landed on had improved medicinal chemical properties, which was exciting and really important to our goal of using them as therapeutics.”
Following successful in vitro tests, the analogs were further evaluated in a live model using Drosophila fruit flies. This model was chosen because it allows for rapid, cost-effective testing of neurological resilience and recovery. The fruit flies were subjected to conditions that simulated traumatic brain injury, and the researchers measured the survival rates to gauge the effectiveness of the CBN analogs, particularly noting the standout performance of one analog, CP1, in enhancing survival post-injury.
Among the four CBN derivatives, one analog, referred to as CP1, demonstrated particularly strong protective effects. In the cell culture tests, CP1 and its counterparts successfully reduced the incidence of cell death triggered by neurotoxic conditions.
CP1 showed superior performance in the fruit fly model of traumatic brain injury, significantly increasing survival rates compared to flies that did not receive treatment. This result suggests that CP1 could potentially be developed into a therapeutic agent capable of offering protection against the acute impacts of brain injuries.
“Our findings help demonstrate the therapeutic potential of CBN, as well as the scientific opportunity we have to replicate and refine its drug-like properties,” Maher said. “Could we one day give this CBN analog to football players the day before a big game, or to car accident survivors as they arrive in the hospital? We’re excited to see how effective these compounds might be in protecting the brain from further damage.”
While the findings are promising, further testing in more complex animal models is necessary to confirm the efficacy and safety of CBN derivatives before progressing to human clinical trials.
Cultured nerve cells provided a controlled environment for detailed molecular studies, while the fruit fly model allowed for rapid, high-throughput testing of the compounds’ efficacy in a live organism. However, these models also have limitations. Cell cultures lack the complexity of whole organisms, making it difficult to predict how findings will translate to humans. Similarly, despite their genetic convenience, fruit flies differ significantly from humans in physiology and disease progression, which can affect the applicability of the results to human conditions.
In future studies, the researchers plan to further investigate and optimize the chemical structures of CBN)analogs. They aim to enhance the effectiveness of these compounds in promoting cell health and preventing age-related neuronal dysfunction. Specifically, they will focus on understanding and mitigating changes in brain cells, with a particular emphasis on mitochondrial function, to develop more targeted and effective treatments for neurodegenerative diseases.
The study, “Fragment-based drug discovery and biological evaluation of novel cannabinol-based inhibitors of oxytosis/ferroptosis for neurological disorders,” was authored by Zhibin Liang, Alec Candib, David Soriano-Castell, Wolfgang Fischer, Kim Finley, and Pamela Maher.
