Honey Inhibits Growth of Cancer Cells

Cytotoxic and Genotoxic Evaluation of Honey in Normal Human Fibroblast and 3 Human Tumorogenic Cell Lines
New Biotechnology, Volume 25, Supplement 1, September 2009, Page S284

Bee honey has been known to have therapeutic applications in traditional medicine to treat variety of diseases. Its anti-inflammatory and antitumor effects against bladder cancer were examined in vitro and in vivo.

We sought to evaluate the cytotoxicity of honey obtained from Astragallus spp. from Feraydonshahr, Isfahan province, Iran against normal human lung tissue fibroblast-like (MRC-5), a human bone tumor (G-292) and two epithelial-like cell lines, one from human cervix carcinoma (Hela) and one from colon tumor (HT-29).

In an in vitro study, the cytotoxic activity of honey and sugars were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Comet assay was used to evaluate the genotoxicity of honey solutions against normal and tumorogenic cells. Different concentrations of honey (3.12, 6.25, 12.5, 25 and 50 %) in phosphate buffered solution (PBS) were exposed to 50,000 cells/ml of each cell lines.

In vitro studies revealed significant inhibition of the proliferation of all cell lines by 50% honey whereas the proliferation inhibition of Hela and G-292 were obtained by a honey concentration of higher that 6.25%. HT-29 was much more resistant to the cytotoxic effect of honey solutions.

The IC50 of MRC-5 as a normal cell line was not obtained by any concentrations lower than 50%. A mixture of 4 sugars with similar concentration to honey were tested as controls and just 50% solution was reduced the cell survival percent to less than 50. Weak genotoxicity were seen with honey solution (12.5%) in normal cells, but moderate in tumor cell lines.

Honey obtained from Austragallus is an effective agent for inhibiting the growth of Hela, G-292 and to lesser extent HT-29 cell lines in vitro. It is not a cytotoxic agent in normal cell line (MRC-5) at concentrations <50%. Since honey selectively inhibited the proliferation of tumor cells in lower concentrations and not effective in normal cells, our results will be promising and further researches are needed to clarify the mechanisms of the antitumor activity of honey.