Replacing sucrose with non-caloric sweeteners is an approach to avoid overweight and diabetes development. Non-caloric sweeteners are classified into either artificial as sucralose or natural as stevia. Both of them have been approved by FDA, but the effects of their chronic consumption are controversial. The present study aimed to evaluate the effects of these two sweeteners, in male and female albino mice, on different blood biochemical parameters, enzymes activities and immunological parameters after 8 and 16 weeks of sweeteners administration. 40.5 mg/ml of sucrose, 5.2 mg/ml of sucralose and 4.2 mg/ml of stevia were dissolved individually in distilled water. Mice were administrated by sweetener's solution for 5 h daily. Male and female mice showed a preference for water consumption with sucralose or stevia. Both of the two sweeteners significantly reduced the hemoglobin level, HCT%, RBCs and WBCs count. After 18 weeks, significant elevations in liver and kidney function enzymes were observed in male and female mice administrated with both non-caloric sweeteners. Histopathological examination in sucralose and stevia administrated groups confirmed the biochemical results; where it revealed a severe damage in liver and kidney sections. While, sucrose administration elevated, only, the levels of ALT, AST and cholesterol in male mice. A vigorous elevation in levels of different immunoglobulin (IgG, IgE and IgA) and pro-inflammatory cytokines (IL-6 and -8), that was accompanied by a significant reduction in level of anti-inflammatory cytokine IL-10, was observed in male and female mice groups administrated with sucralose or stevia. On the other hand, sucrose administration led to an elevation in IgA and reduction in IL-10 levels.

Background: Spleen is the largest lymphatic organ that is seriously affected during irradiation. Radiation exposure reduces both of spleen size and weight; that in turn decreases the numbers of immune cells. Melatonin is an effective free radicals scavenger. Therefore, this study aimed to evaluate the effects of melatonin on both blood and spleen of whole body γ-irradiated male Sprague dawley rats. Materials and methods: Animals were intraperitoneally injected with 100 mg/kg melatonin prior to radiation exposure by 30 minutes. Experimental groups were group I: control rats, group II: irradiated rats, group III: melatonin administrated unirradiated rats and group IV: melatonin administrated irradiated rats. Blood and spleen samples were collected 24 hours post irradiation for biochemical, immunological and blastogenesis measurements. Apoptosis, pro-and anti-apoptotic proteins of spleen cells were measured by flow cytometry techniques. Results: Melatonin significantly upregulated the activities of superoxide dismutase (SOD), glutathione (GSH) and catalase (CAT); and reduced malondialdehyde (MDA). It down regulated the expression of pro-apoptotic proteins (p53, Bax, caspase -3 and caspase-8) and up regulated the expression of anti-apoptotic protein Bcl-2 in spleen cells; that in turn reduced the radiation-induced apoptosis. Levels of pro-inflammatory cytokines (TNF-α, IFN-γ and IL-1β) were significantly reduced in group IV. Blastogenesis assay showed that melatonin protects PBMC and spleen B lymphocytes and stabilized their proliferation. Conclusion: Melatonin administration prior to whole body γ-radiation successfully protected rat's spleen from the consequences of radiation exposure. This was due to its free radicle scavenger nature, its reduction of lipid peroxidation and its anti-apoptotic effects.