BACKGROUND: Several studies have examined the correlation between iron oxidation and H(2)O(2) degradation. The present study was carried out to examine the protective effects of MRN-100 against stress-induced apoptosis in murine splenic cells in vitro. MRN-100, or HydroFerrate fluid, is an iron-based beverage composed of bivalent and trivalent ferrates. METHODS: Splenic lymphocytes from mice were cultured in the presence or absence of MRN-100 for 2 hrs and were subsequently exposed to hydrogen peroxide (H(2)O(2) ) at a concentration of 25 microM for 14 hrs. Percent cell death was examined by flow cytometry and trypan blue exclusion. The effect of MRN-100 on Bcl-2 and Bax protein levels was determined by Western blot. RESULTS: Results show, as expected, that culture of splenic cells with H(2)O(2) alone results in a significant increase in cell death (apoptosis) as compared to control (CM) cells. In contrast, pre-treatment of cells with MRN-100 followed by H(2)O(2) treatment results in significantly reduced levels of apoptosis.In addition, MRN-100 partially prevents H(2)O(2) -induced down-regulation of the anti-apoptotic molecule Bcl-2 and upregulation of the pro-apoptotic molecule Bax. CONCLUSION: Our findings suggest that MRN-100 may offer a protective effect against oxidative stress-induced apoptosis in lymphocytes.