The research also found that the bioactive compounds of honeys depend on its floral sources, geographical origins, and seasonal and environmental factors which have a significant impact on their antiproliferative and antioxidant potential.
“Our results indicate that strawberry tree honey and Manuka honey can induce cell growth inhibition and reactive oxygen species (ROS) generation in colon adenocarcinoma and metastatic cells, which could be due to the presence of phytochemicals with antioxidant properties,” wrote researchers in the International Journal of Molecular Sciences.
“These preliminary results are interesting and suggest a potential chemopreventive action which could be useful for further studies in order to develop chemopreventive agents for colon cancer.”
Academics at the University of Marche in Italy said there were over one million new cases of colon cancer each year worldwide and that the survival rate was only five years due to its resistance to cytostatic drugs.
“Therefore, there is an urgent need to establish novel preventive and therapeutic approaches for this disease,” they wrote.
In this study, strawberry honey samples samples were collected from five different areas of Sardinia, Italy, while Manuka honey from New Zealand was used as a standard for comparison.
Researchers then compared the cytotoxic effect and ROS modulation by both honeys on human colon carcinoma (HCT-116) and Dukes’ type C, grade IV, colon metastasis (LoVo) cell lines.
Cells were treated for 24, 48 or 72 hours with various concentrations of honeys ranging from three to 20 mg/mL for HCT-116 cells and five to 60 mg/mL for LoVo cells.
Both honeys decreased cell viability in a dose and time dependent manner. However, in both cell lines, the treatment with strawberry tree honey caused a greater decrease on cellular viability at lower concentrations than Manuka honey.
In terms of ROS, this can provide a chemotherapeutic effect in suppressing cancer growth by promoting apoptosis and cell death.
In order to determine the intracellular ROS levels, HCT-116 and LoVo cells were treated with various concentrations of honey for 24, 48 and 72 hours.
In HCT-116 cells, both honeys induced similar ROS production, but in LoVo cells strawberry tree honey resulted in a higher percentage compared to Manuka honey.
The researchers concluded that strawberry tree honey from the Berchidda area of Sardinian induced more cytotoxic effects compared to Manuka honey, possibly due to its significant amount of phytochemical and antioxidant activity.
“Molecular studies elucidating the pathways for the chemo-preventive activity of this honey are underway in our laboratory,” they added.
“These persuasive results increase our knowledge of honey and could be useful for the development of a therapeutic candidate for targeting colon cancer.”
Source: International Journal of Molecular Sciences
"Strawberry-Tree Honey Induces Growth Inhibition of Human Colon Cancer Cells and Increases ROS Generation: A Comparison with Manuka Honey."
Authors: Sadia Afrin, et al.