According to a new study published by Cancer Reports, combining cisplatin with delta-9 tetrahydrocannabinol (THC) and cannabidiol (CBD) enhanced the chemotherapy drug’s anticancer effects in cervical cancer cells.

Researchers from the University of Pretoria examined how THC and CBD interacted with cisplatin, a commonly used chemotherapy drug for cervical cancer that can be limited by severe side effects and treatment resistance. The study tested the combinations in HeLa and SiHa cervical cancer cells, along with MCF-12A non-cancerous breast epithelial cells.

The strongest results came from the triple combination of THC, CBD and cisplatin. According to the study, the combination produced an apoptotic response in 53% of HeLa cells and 58% of SiHa cells, while having a smaller effect on MCF-12A cells, at 32%.

Researchers said cannabinoid co-treatment increased cisplatin’s ability to reduce cell proliferation and trigger programmed cell death in the cervical cancer cell lines. The combination also caused cell cycle disruptions, including G2/M arrest in HeLa cells and sub-G1 accumulation in SiHa cells.

The study also found increased autophagic activity after THC and CBD exposure, along with reduced expression of the DNA repair genes XRCC1 and RAD51 when cannabinoids were combined with cisplatin.

The authors concluded by stating:

These findings demonstrate that combining THC and CBD with cisplatin results in enhanced and mechanistically diverse anticancer effects, with a higher degree of selectivity for cervical cancer cells compared to non-cancerous MCF-12A cells by inducing apoptosis and autophagy while inhibiting DNA repair capacity. This study highlights the potential of cannabinoid-based combination therapies as a promising approach for cervical cancer treatment.