“Purpose: Cannabidiol (CBD) is a primary bioactive, non-intoxicating cannabinoid found in the cannabis plant. Studies have shown that CBD causes anticancer activity by inhibiting the expression of growth factors and inducing apoptosis, leading to cell cycle arrest. In this study, we aimed to determine how CBD influences the expression of genes that affect cancer pathways in doxorubicin-sensitive (MCF-7) and doxorubicin-resistant (MCF-7/Adr) breast cancer cells. 

Materials and Methods: IC₅₀ concentrations of CBD in MCF-7 and MCF-7/Adr cell lines were determined by the MTT cell cytotoxicity assay. RNA isolation and subsequent cDNA synthesis were performed for qPCR experiments with the determined IC₅₀ values. The effects of CBD on the cell cycle and apoptosis were studied using flow cytometry. IC₅₀ values of CBD were determined in MCF-7 and MCF-7/Adr breast cancer cell lines at eight different concentrations and at three different incubation periods (24 h, 48 h, and 72 h) with different doses. RT-qPCR was used to investigate the molecular mechanisms underlying the expression of genes involved in cancer pathway analysis. 

Results: Treatment with CBD at concentrations of 17.57 μM (MCF-7) and 11.41 μM (MCF-7/Adr) for 48 h decreased colony formation, induced apoptosis, and inhibited cell invasion in both cell lines. In addition, we observed significant alterations of angiogenesis, apoptosis, cell cycle, cellular senescence, DNA damage and repair, epithelial-to-mesenchymal transition, hypoxia, metabolism, telomeres, and telomerase in both cell lines. 

Conclusions: Our research indicates that CBD could be an effective natural bioactive compound for breast cancer treatment, inhibiting tumor cell proliferation and inducing apoptosis.”

https://pubmed.ncbi.nlm.nih.gov/42075870

“The plant Cannabis sativa has been used medicinally for several thousand years.”

“These findings support the relevance of CBD as a potential therapeutic agent in breast cancer and provide a basis for further investigation “

https://www.mdpi.com/1424-8247/19/4/615

“Triple-negative breast cancer (TNBC) remains a major clinical challenge due to its aggressive nature and limited treatment options, while therapeutic resistance in estrogen receptor-positive (ER+) breast cancer continues to limit treatment efficacy.

Although olaparib is primarily effective in BRCA-mutated cancers, its activity in BRCA-wild type (BRCA-wt) tumors is limited. Therefore, this study aimed to investigate whether cannabidiol (CBD) can enhance the response of BRCA-wt breast cancer cells to PARP inhibition.

The effects of olaparib (OLAP) and CBD, alone and in combination, were evaluated in MDA-MB-231 (TNBC) and MCF-7 (ER+) cell lines using comprehensive two-dimensional (2D) mechanistic analyses and three-dimensional (3D) spheroid models, including HCC-70 cells to extend TNBC validation.

The results demonstrate that combined OLAP and CBD treatment enhanced cytotoxic effects compared to single treatments, with more pronounced responses observed in 3D spheroid models, particularly in TNBC models. Flow cytometry and caspase 3/7 assays indicated increased apoptosis and G2​/M phase arrest following combination treatment. Gene expression analysis revealed downregulation of key DNA damage response and cell cycle-related genes (ATM, ATR, BRCA1/2, RAD51, and CDK1/2/4/6), supporting a role for cell cycle arrest and DNA damage modulation in mediating these effects. Functional assays showed reduced colony formation and migratory capacity, although these effects may reflect both cytotoxic and cytostatic responses under the selected experimental conditions.

Overall, these findings suggest that CBD may enhance the efficacy of olaparib in BRCA-wt breast cancer models and highlight its potential as a combinational therapeutic strategy in breast cancer treatment.”

“Cannabinoids have been reported to enhance the effects of conventional cancer treatments, including chemotherapy and radiotherapy, thereby improving therapeutic efficacy while potentially reducing treatment-related toxicity.”

“CBD, in particular, has shown promising antitumor activity in triple-negative breast cancer (TNBC) by inducing apoptosis, autophagy, and oxidative stress through modulation of signaling pathways such as AKT/mTOR.”

https://link.springer.com/article/10.1007/s11010-026-05550-w

“Triple-negative breast cancer (TNBC) remains highly aggressive and refractory to conventional treatments, underscoring the need for novel combination strategies.

Here, we employed 2D and 3D in vitro models, transcriptomic profiling, and in vivo xenograft studies to evaluate the anticancer efficacy of cannabinoids combined with the terpene β-caryophyllene (BC) in resistant TNBC models.

Among the tested cannabinoids, cannabichromene (CBC) exhibited the greatest potency, and its combination with BC at sub-toxic concentrations significantly reduced IC₅₀ values, enhanced cytotoxicity in spheroids, and suppressed colony formation and migration. The combination treatment induced pronounced G1 cell cycle arrest and increased apoptotic cell death. Western blot analyses revealed downregulation of PARP, Survivin, mTOR, Vimentin, Glypican-5, and PD-L1, while RNA sequencing demonstrated suppression of proliferative and migratory signaling pathways alongside activation of apoptosis, autophagy, and ferroptosis-related pathways. In vivo, CBC + BC significantly inhibited tumor growth in MDA-MB-231 xenografts, outperforming single-agent treatments.

Collectively, these findings demonstrate that BC synergistically enhances cannabinoid activity, yielding superior antiproliferative and anti-migratory effects, and highlight this combination as a promising therapeutic strategy for resistant TNBC.”

https://pubmed.ncbi.nlm.nih.gov/41898593

“Our findings indicate that BC significantly enhances the anticancer effects of cannabinoids, particularly in resistant TNBC cells.”

https://www.mdpi.com/1422-0067/27/6/2730

“Breast cancer (BCa) remains a leading cause of cancer-related deaths in women worldwide. Triple-negative BCa (TNBC) is highly metastatic with treatment limited by off-target toxicity.

Cannabidiol (CBD) has anti-cancer and anti-inflammatory activity in BCa.

This study addresses the poor oral bioavailability of CBD by utilizing exosomes (Exo) as a drug delivery system.

CBD was loaded onto non-functionalized exosomes and folic acid-functionalized exosomes (FA-Exo), achieving an average CBD drug load of ∼20%. The FA-ExoCBD averaged 136 ± 2.9 nm in size. TNBC cell lines MDA-MB-231 and taxol-resistant MDA-MB-231TR were sensitive to growth inhibition by CBD than estrogen receptor positive (ER+) MCF-7 and its taxol-resistant derivative MCF-7TR. Exosomal formulations (ExoCBD and FA-ExoCBD) demonstrated time-dependent CBD release under physiologically relevant simulated gastric and intestinal conditions and withstand acidic conditions, retained canonical exosomal markers (CD81 and Alix) as well as physical parameters of exosomes including size, PDI and zeta potential.

CBD downregulated key anti-apoptotic and anti-inflammatory markers.

Oral FA-ExoCBD showed enhanced tumor targeting, tumor retention and inhibition of orthotopic MDA-MB-231-tumor growth in NOD Scid mice than ExoCBD or free CBD. RNA-Seq analysis of tumor tissues revealed that both CBD and FA-ExoCBD treatments modulated over 1000 genes, with FA-ExoCBD significantly downregulating IL13RA2 (associated with lung metastasis) and tumor biomarkers TRPM2 and SAMHD1, while upregulating tumor suppressors PRDM1, PCDHGB2, and ICAM1.

These findings highlight the potential of FA-ExoCBD to enhance CBD’s anticancer efficacy through targeted gene modulation. Overall, FA-ExoCBD improves CBD’s therapeutic profile by enhancing efficacy, tumor selectivity, improved bioavailability and anticancer efficacy.”

https://pubmed.ncbi.nlm.nih.gov/41812824

https://www.sciencedirect.com/science/article/abs/pii/S0304383526001795?via%3Dihub

“Background: Breast cancer progression involves key processes such as uncontrolled cell proliferation, resistance to apoptosis, metastasis, and angiogenesis. Cannabidiol (CBD), a non-psy-choactive compound from Cannabis sativa, has shown promise for its anti-cancer properties. This study aimed to explore the interaction of CBD with proteins involved in these processes.

Methods: Molecular docking was performed to assess the binding affinity of CBD to four critical proteins: CDK6 (cell cycle regulator), BCL2 (anti-apoptotic protein), MMP2 (invasion-related en-zyme), and VEGFR2 (angiogenesis-related receptor). Known inhibitors, palbociclib, ABT-199, doxycycline, and axitinib, were used as reference compounds for comparison.

Results: Cannabidiol exhibited strong binding affinities for CDK6, BCL2, MMP2, and VEGFR2. The docking scores were comparable to those of the respective standard inhibitors, suggesting effec-tive interactions with the active sites of the target proteins.

Discussion: These findings suggest that CBD may simultaneously target multiple cancer-related pathways, offering a potential multi-target therapeutic approach for breast cancer. Its comparable efficacy to standard inhibitors, combined with a favorable safety profile, supports its potential for further development. However, experimental validation through in vitro and in vivo studies is neces-sary to confirm its therapeutic effectiveness.

Conclusion: CBD demonstrates promising multi-target activity against critical signaling molecules in breast cancer and may serve as a safer, natural therapeutic candidate. Further preclinical and clin-ical investigations are warranted.”

https://pubmed.ncbi.nlm.nih.gov/41830580

https://www.eurekaselect.com/article/153254

“Triple-negative breast cancer (TNBC) is highly aggressive with limited treatment options, and resistance to doxorubicin (DOX) further compromises outcomes.

Cannabinoids such as cannabichromene (CBC) and cannabidiol (CBD) possess anticancer properties, but their combined effects in resistant TNBC remain unexplored. This study evaluated the antitumor efficacy of a CBC + CBD combination against DOX-resistant (DOX-RT) TNBC using in vitro, in vivo, and pharmacokinetic models.

Cytotoxicity was assessed in DOX-RT MDA-MB-231 cells using 2D and 3D assays, with synergy confirmed by combination index (CI) analysis. Cell cycle and invasion assays were performed. Xenograft studies were conducted in BALB/c nude mice bearing DOX-RT tumors treated intraperitoneally with CBC (10 mg/kg), CBD (20 mg/kg), or CBC + CBD. Pharmacokinetics were evaluated in rats, complemented by GastroPlus™ simulations.

CBC + CBD synergistically inhibited cell growth induced G0/G1 arrest, and reduced invasiveness by ~ 55% in a Transwell Matrigel invasion assay. In xenografts, combination therapy reduced tumor volume by two-folds compared to single treatments and fourfolds versus control. Western blotting revealed downregulation of MEK/ERK, PI3K/AKT/mTOR, Cyclin D1, CDK6, SOD2, and NF-κB. Pharmacokinetic studies showed co-administration increased Cmax and AUC without altering Tmax, supported by simulations predicting enhanced jejunal absorption. CBC + CBD co-therapy demonstrates synergistic efficacy against resistant TNBC by inhibiting oncogenic pathways and enhancing systemic exposure.

This first study of its kind highlights CBC + CBD as a promising strategy to overcome DOX resistance in TNBC.”

https://pubmed.ncbi.nlm.nih.gov/41670942

https://link.springer.com/article/10.1007/s13346-026-02057-1

“HER2 (human epidermal growth factor receptor 2) is a well-established oncogenic driver and therapeutic target in breast cancer.

Cannabidiol (CBD), a non-psychoactive phytocannabinoid, has demonstrated anticancer potential, yet its mechanisms of action in HER2-positive breast cancer remain insufficiently characterized.

In this study, we examined the effects of CBD on HER2-positive (SK-BR-3, BT-474) and HER2-negative (MCF-7, MDA-MB-231) breast cancer cell lines, with a focus on its interaction with HER2.

CBD selectively reduced the viability of HER2-positive cells, an effect associated with increased intracellular reactive oxygen species (ROS) and a marked reduction in HER2 protein levels. Mechanistically, CBD triggered non-apoptotic cell death pathways, including paraptosis and ferroptosis, as indicated by the modulation of specific molecular markers such as reduced Alix and elevated ATF4 and CHOP for paraptosis, and downregulated GPX4 and SLC7A11 with upregulated TFRC for ferroptosis. HER2 knockdown attenuated CBD-induced cytotoxicity, while HER2 overexpression sensitized cells to CBD, underscoring the HER2-dependence of these effects. Molecular docking predicts the binding conformation and key interactions of ligand with target proteins providing initial insights into potential molecular recognition. Subsequently, molecular dynamics simulations extend this analysis by assessing the stability, flexibility, and energetic characteristics of the ligand-protein complex within a dynamic biological environment.

These findings support a model in which CBD downregulates HER2 and, in a HER2-dependent context, promotes paraptosis and ferroptosis. In addition, docking and molecular dynamics analyses suggested a potential interaction between CBD and HER2, providing mechanistic insights into possible molecular recognition relevant to HER2-positive breast cancer.”

https://pubmed.ncbi.nlm.nih.gov/41621547

“These results suggest that CBD targets HER2, offering a new therapeutic strategy for HER2-positive breast cancer management.”

https://www.sciencedirect.com/science/article/abs/pii/S0925443926000256?via%3Dihub