Polyphenol Contents, Antibacterial and Antioxidant Effects of Four Palestinian Honey Samples, and their Anticancer Effects on Human Breast Cancer Cells

Abstract

The phenolic compounds of four Palestinian honey samples (PH1-PH4) and their antibacterial effects as well as their cytotoxic, cytostatic, and antimigration effects in human breast cancer cell line (MDA) were evaluated here. HPLC analysis of PH2 (Cornflower), PH3 (Milk thistle), and PH4 (Ziziphus) revealed 15 phenolic compounds, namely, caffeic acid, carvacrol, chrysin, ellagic acid, galangin, gallic acid, kaempferol, p-coumaric acid, pinobanksin, pinocembrin, protocatechuic acid, quercetin, rutin, salicylic acid, and silydamin. The minimum inhibitory concentration (MIC) method applied to Pseudomonas aeruginosa (P. aeruginosa), Staphylococcus aureus (S. aureus), and Escherichia coli (E. coli). A strong positive correlation was detected between antimicrobial activity (E. coli) and p-coumaric acid, quercetin, and silydamin. IC50 values for DPPH neutralization varied from 0.19 w/w% to 10 w/w%. The potential anticancer properties of the honey samples were evaluated on MDA cells. Samples PH2 and PH3 demonstrated cytostatic activity, reducing cell viability by about 43% at non-toxic concentration of 4 mg/mL. The cytostatic effects were strongly correlated with the presence of caffeic acid, chrysin, protocatechuic acid, rutin, and salicylic acid (p < 0.01). Moreover, the cell migration rate was significantly reduced (by up to 85%) with PH2 and PH3 compared to untreated cells (p < 0.05). A strong positive correlation was observed between the cytostatic effects of the concentration of carvacrol and Pinocembrin (p < 0.01). Our findings validate honey’s antibacterial properties and suggest its anticancer benefits may stem from cytostatic and antimigration effects.