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Medicinal cannabis kills cancer cells
Lab tests have shown that a modified form of medicinal cannabis can kill or inhibit cancer cells without affecting normal cells.
The finding follows three years of study by cancer researcher Dr Matt Dun, senior lecturer in biomedicine at the University of Newcastle, together with the Hunter Medical Research Institute and biotech company Australian Natural Therapeutics Group (ANTG). ANTG produces a variety of cannabis with less than 1 per cent THC — the psychoactive part that gets people high.
“ANTG wanted me to test it against cancer, so we initially used leukaemia cells and were really surprised by how sensitive they were,” Dr Dun says. “At the same time, the cannabis didn’t kill normal bone marrow cells, nor normal healthy neutrophils [white blood cells].”
Dun’s team has run comparisons between THC-containing cannabis, and THC-free cannabis but with elevated levels of cannabidiol (CBD). They found that, for both leukaemia and paediatric brainstem glioma, the CBD-enriched variety was more effective at killing cancer cells than THC varieties.
In a paper ‘Can Hemp Help?’ published in Cancers, Dr Dun and his team also undertook a literature review of more than 150 academic papers that investigated the health benefits, side effects, and possible anti-cancer benefits of both CBD and THC.
“There are trials around the world testing cannabis formulations containing THC as a cancer treatment, but if you’re on that therapy your quality of life is impacted,” Dr Dun says. “You can’t drive, for example, and clinicians are justifiably reluctant to prescribe a child something that could cause hallucinations or other side effects. The CBD variety looks to have greater efficacy, low toxicity and fewer side effects, which potentially makes it an ideal complementary therapy to combine with other anti-cancer compounds.”
The next phase for the study includes investigating what makes cancer cells sensitive and normal cells not, whether it is clinically relevant, and whether a variety of cancers respond.