Bilberry (Vaccinium myrtillus L.) Peel-Enriched Pomace as Natural Anticancer Agents: Preclinical Evidence from Breast Carcinoma Models Supporting Preventive and Personalized Treatment Strategies.

BACKGROUND

Breast cancer (BC) is the most commonly diagnosed malignancy in women (∼25% of new cases). Plants adapted to specific niches accumulate secondary metabolites with bioactivity, including anticancer effects.

OBJECTIVE

The objective of this study was to evaluate the chemopreventive and treatment potential of Vaccinium myrtillus (bilberry) peel-enriched pomace powder in BC models, hypothesizing system-level effects and synergy with standard therapy.

METHODS

Chemistry was profiled by liquid chromatography with diode-array detection-mass spectrometry (LC-DAD-MS)/liquid chromatography with diode-array detection (LC-DAD) from 2 extracts: BILHEX (hexane) and BILMeOH (methanol). Biology was tested in the following: 1) 4T1 triple-negative mouse model (treatment); 2) NMU rat mammary carcinogenesis (chemoprevention); and 3) in vitro assays with MCF-7 and MDA-MB-231, including 3D spheroids and cisplatin combinations.

RESULTS

BILMeOH was enriched for phenolics; BILHEX for unsaturated triacylglycerols/triterpene acids. Compared with control, bilberry diet reduced 4T1 tumor volume by 51% and 91% (low/high dose; P < 0.05/0.001), lowered mitotic index (P < 0.001), and reduced necrosis:tumor ratio (P < 0.05). In NMU rats, chemoprevention increased cleaved caspase-3 (P < 0.05) and Bax/Bcl-2 (P < 0.001), and decreased Ki-67 (P < 0.05), MDA, and CD133 (P < 0.01). Histone marks shifted (↓H3K4me3 P < 0.05; ↑H4K20me3 P < 0.01; ↑H4K16ac P < 0.001). Promoter methylation was gene-specific (e.g., RASSF1 +12% absolute, P < 0.05); low-baseline loci were treated as low magnitude. miRNA profiling (758 features) identified significant dysregulation (|FC| ≥ 2) of let-7d-5p, let-7i-5p, miR-1224-3p, miR-494-3p, and miR-6216. TGF-β and IL-10 increased (both P < 0.001), IL-6 rose (P < 0.05), indicating selective immunomodulation. Metabolomics showed shifts in lactate (P < 0.05), branched-chain ketoacids (P < 0.05/0.01), and histidine (P < 0.001). In vitro, BILHEX suppressed proliferation, induced G2/M arrest, activated intrinsic apoptosis (cytochrome-c → caspase-9 → caspase-3/7 → PARP), and synergized with cisplatin in 3D spheroids (Bliss).

CONCLUSIONS

Bilberry pomace shows multitarget anticancer activity across BC models; translational studies should confirm mechanisms, refine dosing, and explore biomarker-guided use.