Abstract

Background: Cancer patients use cannabidiol (CBD) for chemotherapy and cancer symptoms, though research of CBD safety and efficacy for these conditions are ongoing and mixed. We sought to determine endometrial (ECC1) and epithelial ovarian cancer (Kuramochi) cell proliferation when exposed to different concentrations of CBD, for the broader goal to establish if CBD can safely be utilized to treat the symptoms of cancer, including those caused by chemotherapy.

Methods: ECC1 and Kuramochi cells were kept in media (RPMI with 10% bovine serum and 1% penicillin/streptomycin). We passaged cells when > 90% confluent by adding tryspin-EDTA, incubating at 37C for 3 minutes, then spinning down with media to harvest the cell pellet. Cells were re-suspended in media, counted and apportioned to 96 well plates. Plates were incubated at 37C x 24 hours. CBD (from Cayman Chemical) was suspended in DMSO per manufacturer instruction then used to treat cells x72 hours at different concentrations (2.5-50uM). MTT was added to cells, cells incubated at 37C x 3 hours, media and MTT were removed and DMSO was added. Optical depth (OD) was calculated for plates using SoftMaxPro version 6.2.2. ODs were used to calculate inhibitory concentration for 50% cell death (IC50).

Results: Kuramochi and ECC1 demonstrated decreased cell proliferation when exposed to CBD for 72hours. ECC1 IC50 fell between 2.5-5uM. Kuramochi IC50 fell between 15-20uM. Nearly all ECC1 growth was inhibited at concentrations 10uM or greater. Kuramochi proliferation was 15% that of controls at concentrations of 40 and 50uM CBD.

Conclusions: ECC1 and Kuramochi cells demonstrated decreased proliferation in the presence of CBD. This bodes well for future studies of concurrent exposure to CBD and cytotoxic chemotherapy. Further preclinical research needed on CBD effects in endometrial and ovarian cancer, as patients turn to CBD for symptomatic relief from cancer and chemotherapy side effects.