“Background/Objectives: Cannabidiol (CBD) is known for its anti-cancer properties in preclinical models and is increasingly used alongside conventional chemotherapy in cancer treatment. This study aims to evaluate the anti-cancer activity of CBD from Lebanese Cannabis sativa as a monotherapy and in combination with cisplatin or paclitaxel on human ovarian adenocarcinoma cells.
Methods: Cytotoxicity of CBD was tested on OVCAR-3 and SK-OV-3 cell lines using the MTS assay. The Chou-Talalay method and CompuSyn software were used to determine the combination indices (CIs) for predicting interactions between CBD and chemotherapeutic agents. CBD showed dose-dependent tumor growth inhibition at 72 h with comparable IC50 values for both cell lines.
Results: The combination of CBD with cisplatin or paclitaxel showed significant antagonistic interaction in SK-OV-3 cells (CI > 1), but mild synergism (CI < 1) at high growth inhibition rates (95% and 97%) was observed in SK-OV-3 cells with CBD/cisplatin. Pure antagonism was found in OVCAR-3 cells with CBD/cisplatin. Priming SK-OV-3 cells with CBD reduced the IC50 values of both drugs significantly, with a similar effect seen when cells were primed with cisplatin or paclitaxel before CBD treatment.
Conclusions: Integrating CBD with chemotherapy could improve cancer therapy and address drug resistance. Sequential administration of CBD and chemotherapeutic agents is more beneficial than simultaneous administration. Further in vivo studies are necessary to validate these findings and understand CBD’s interactions with other drugs fully.”
https://pubmed.ncbi.nlm.nih.gov/40002932/
“This study explores the anti-cancer activity of CBD, as monotherapy and in combination with two commonly used chemotherapeutic agents, cisplatin and paclitaxel, against platinum-resistant ovarian cancer OVCAR-3 and SK-OV-3 cell lines.
CBD monotherapy showed promising and significant tumor growth inhibitory effect against both cell lines. The current study demonstrated that the combination of CBD with cisplatin or paclitaxel displayed diminished inhibition of cell proliferation as compared to individual treatment.
CBD and paclitaxel exhibited an antagonistic interaction on all effect levels. In contrast, although antagonism was prominent over most of the inhibitory effect levels with concurrent treatment of CBD and cisplatin, synergy was detected at the highest effect levels, highlighting the potential benefit of combining the two agents at specific concentrations. However, priming with CBD, cisplatin, or paclitaxel has shown significant sensitization of SK-OV-3 cells to the subsequent treatment, stressing the importance of sequential, rather than simultaneous, administration of the drugs.
These findings offer valuable insights for optimizing current therapeutic options when integrating CBD with conventional chemotherapy by adopting priming regimens to circumvent the antagonism observed during co-treatment. Further investigations are necessary to validate the current results in vivo and elucidate the mechanism underlying the interaction of CBD with various anticancer drugs.”