EFFECT OF ROYAL JELLY(RJ) ON HUMAN INTERFERON-Alpha (HuIFN-α) INHIBITION OF HUMAN COLON CANCER CELLS (CaCo-2) PROLIFERATION IN VITRO

Background. Royal jelly is a milky material secreted by the pharyngeal glands of young worker bees , which when fed as a sole nutrient to larvae causes the development of sexual mature queen bees. The unusual nature of this material has prompted different investigations into its biological/pharmacological/microbiological properties. As an part of the biological activity of royal jelly, an investigation of its possible antitumor activity was performed. Interferon-Alpha (HuIFN-α) was used clinically in the treatment of different cancers but the molecular mechanism behind its cytoreductive action is still unknown. The anti-proliferative effect of HuIFN-α was suggested to be the main factor in its antitumor activity. The experiments presented were aimed to investigate the effect of royal jelly on HuIFN-α induced inhibition of human colon cancer cells proliferation in vitro, and the effect on intracellular Glutathione (GSH) and Lipid peroxidation (MDA – assay) Material and methods. Fresh Royal jelly (Medex d.d.),(0.1g/10 ml PBS(Phosphate buffer saline)) was used; Human Interferon-Alpha (HuIFN-α) (1000 I.U./ml) was from SigmaAldrich, 10-HDA (100 μM /ml) (10-Hidroxy-2-decenoic acid) was from Sigma-Aldrich. Experiments were performed on CaCo-2 cells cultivated in Eagle's medium+10% of FCS and antibiuotics (Penicilline, Streptomycine, Gentamycine). The anti proliferative (AP) activity was measured with number of the well with cca. 50% cell growth inhibition. The concentrations at AP50 were determined. Cells were treated as follows: (a) Royal jelly, (b) HuIFN-α, (c) 10-HDA, (č) Royal jelly + IFNα 1:1, 1:2, 2:1, (d) Royal jelly + 10-HDA 1:1, 1:2, 2:1. The effect on the Glutathion level was measured by Sigma-Aldrich glutathione assay kit. The lipid peroxidation was measured by MDA (Malondialdehyde) assay. Results. The following results of AP activity and concentrations at AP50 were obtained: (1) Royal jelly: 2,0(0,005)g/ml), (2)HuIFN-α: 2,5 (208,33 I.U./ml)(3) 10-HDA: 1,5(37,5μM/ml) ; (4) Royal jelly+HuIFN-α 1:1 0.9, 1:2 0.9, 2:1 3,9; (5) Royal jelly + 10-HDA: 1:1 1,8,1:2 1,5, 2:1 3.2; (6)HuIFNα + 10-HDA: 1:1 1.8, 1:2 1,5, 2:1 3,2. The RJ-F(M), HuIFN-α and 10-HDA and their combinations decrease the level of Glutathione and increase the lipid peroxidation via the MDA Conclusions. From the presented experiments it can be concluded: (1) Royal jelly alone, has low AP activity: 1.0 (0,01g/ml) ; (2) HuIFN-α alone, has AP activity of 2.5 (208,33 I.U./ml) (3) The optimal combination between Royal jelly and HuIFN-α was 2:1 where the AP activity was 3.5. (4) It seems that the 10-Hidroxy-2-decenoic acid , as the main component of the Royal jelly is responsbile for the influence of royall jelly on Interferon' s Alpha (HuIFN-α) inhibiton of Human colon cancer cells (CaCo-2) proliferation in vitro. The moust active was the combination of RJ-F(M) and HuIFN-α 2:1, where the level of GSH was 24,9±2,4