Honey Constituents and their apoptotic effect in colon cancer cells
Saravana Kumar Jaganathan, Mahitosh Mandal.
Honey finds a vital role in various applications using its antibacterial and anti-inflammatory properties. Our objective was to study the constituents and explore the apoptotic effect of the selected crude honey samples in colon cancer cell lines namely HCT 15 and HT 29. Phenolic content and various functional groups in the honey were analysed using Folin-Ciocalteau method and Fourier Transformed Infrared Spectrophotometer (FTIR). The phenolic content of the honey varied among the different samples. Phenolic content expressed as Gallic acid equivalent (GAE) ranged from 29.96 ± 1.54 to 65.08 ± 4.56 mg of GAE/ 100 g of honey. FTIR results indicated the honey sample to be a mixture of numerous compounds including carboxylic acids, aldehydes, alkynes and nitrites. We had also investigated the fluorescence compounds present in the honey after excitation set at 250 nm (emission: 280-750 nm), 290 nm (emission: 305-750 nm). Fluorescence spectroscopy depicted the variation of physio-chemical properties of honey according to their origin as observed by the varying intensity of fluorescent compounds present in the samples. The anti-proliferative effect of the samples in colon cancer cells was explored using 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT) assay. MTT assay revealed the honey sample containing higher phenolic content showed significant anti-proliferative effect against colon cancer cells. Propidium iodide (PI) staining of 3 % honey treated cells indicated a significant number of cells accumulating in Sub-G1 phase (indicator of apoptosis) after 24 hours. Further, in HT 29 cells, honey elevated the caspase-3 level and displayed typical ladder pattern confirming apoptosis. Most of the drugs used in the cancer are apoptotic inducers, hence apoptotic nature of honey is considered vital.
honey, India, apoptosis, colon, cancer, FTIR, fluorescence, spectroscopy