A new study in the Journal of Neglected Tropical Diseases found that two substances from cannabis, Cannabidiol (CBD) and Cannabidivarin (CBDV), can kill harmful fungi, including Cryptococcus neoformans, which can cause serious lung and brain infections. These discoveries could pave the way for the development of more effective over-the-counter medicines for common fungal infections. 

According to data from the United States Centres for Disease Control and Prevention's (CDC) and regional estimates, over one billion individuals worldwide contract fungal infections each year, with 53 million instances documented in India. Current antifungal medicines can be slow-acting and are increasingly resistant to fungus. 

This study was led by Macquarie University researchers, including Dr Hue Dinh and Associate Professor Amy Cain, who collaborated with medical professionals from the University of Sydney and UNSW. Their strategy centred on repurposing already-approved cannabis chemicals known for other medical applications, potentially speeding up public availability. 

In laboratory testing, both CBD and CBDV quickly killed Cryptococcus neoformans. This pathogen is a common cause of fungal meningitis in individuals with compromised immune systems. We also tested the chemicals on 33 fungal species, including the dermatophytes responsible for athlete's foot. The results demonstrated that CBD and CBDV responded faster than conventional antifungal medications. 

Dr Dinh stated, "Hundreds of natural substances can be taken from the cannabis plant, and we do not yet know which ones are effective. However, these two stood out due to their quickness and efficacy. 

The researchers also examined the chemicals on living species, using wax moth larvae as a model. In this trial, cannabinoids effectively cured infections, paving the way for human use. 

However, administering marijuana via injection remains a difficulty. "Cannabinoids are difficult to dissolve for intravenous use," Dr Dinh noted. As a result, her team focuses on topical treatments for skin infections, such as lotions or oils. 

"If we can demonstrate that these ones work well for common infections, you could actually just get some CBD oil and then rub it on your skin to treat it," Dr Dinh explained. A commercial product is now in development for public sale. 

The study also found that fungi are less likely to acquire resistance to marijuana, which is an increasing issue with standard antifungals. If confirmed in larger clinical trials, this could lead to a significant change in the treatment of skin and other fungal diseases.