Smoking marijuana is believed to reduce the body’s ability to fight infections. But cannabidiol (CBD), a compound extracted from cannabis, might work as a powerful antibiotic against certain drug-resistant bacteria, scientists in Australia have found.
BTX1801, a new CBD-based therapy being developed by Australian biotech Botanix Pharmaceuticals, is effective against several Gram-positive bacteria, including Staphylococcus aureus and Streptococcus pneumoniae, in lab dishes and animal models, according to a team led by Mark Blaskovich at the University of Queensland.
Results from the preclinical study were presented at the annual conference of the American Society for Microbiology in San Francisco.
Even at low concentrations, the drug showed action against a diverse panel of 132 clinical isolates of S. aureus, including the difficult-to-treat methicillin-resistant S. aureus (MRSA), the researchers reported. What’s more, the bacteria didn’t develop resistance to the drug after 21 days of continuous treatment. Such an industry standard, extended-exposure challenge often leads to resistance against common antibiotics vancomycin and daptomycin.
The drug was also effective in a mouse wound model of skin infection, according to Botanix.
The exact mechanism of CBD’s antibacterial effect isn’t 100% clear—researchers did notice that CBD disrupted biofilms that bacteria use to shield themselves from antibiotics. But results from a phase 1b study on Botanix’s other therapy, BTX1308, in psoriasis, offered some clues that may also be relevant to infections.
Based on skin biopsies collected from 10 of the 15 patients enrolled in the phase 1b study, Rockefeller University researcher Jim Krueger and colleagues found that the p38 MAP kinase pathway and interleukin-6 (IL-6), both key pathways known to be involved in psoriasis, were significantly lowered in treated with BTX1308.
“This anti-inflammatory and immune modulation activity potentially makes BTX 1308 a very important treatment option for patients, not only with psoriasis, but other skin diseases that have an inflammation and/or an immune response component,” Krueger said (PDF) in a statement.
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Since GW Pharmaceuticals won the first FDA nod for CBD drug Epidiolex in epilepsy, the interest in marijuana-based drugs has been mounting. Kalytera Therapeutics, for one, is testing its CBD therapy in graft-versus-host disease in a phase 3 trial.
As antibiotic-resistant bacteria, or superbugs, quickly develop, there’s been an urgent need to add new weapons to the antibiotic arsenal. And investments have followed. Novo Nordisk’s holding company recently unveiled investments in three antibiotic resistance startups under its REPAIR Impact Fund. Each shop gets about $16 million of the fund’s $165 million pool for research into antibiotics and vaccines.
Botanix’s quest is still in early stages with only preclinical results. The biotech is now conducting research aimed at finding the best dosing strategy for clinical development of BTX1801, with a plan to target skin infections.
“The fact that cannabidiol kills resistant bacteria quickly, when combined with the drug’s newly validated anti-inflammatory properties, gives us confidence that BTX 1801 has significant potential as a powerful new antimicrobial for use in skin and other infections,” Botanix founder and executive director, Matt Callahan, said in a statement (PDF).