Protective effect of curcumin against arsenic-induced apoptosis in murine splenocytes in vitro

Arsenic is a potent environmental pollutant and immunotoxic agent. Curcumin is a natural anti-oxidant used to treat a broad variety of diseases. Here, the effects were investigated of curcumin on sodium arsenite-induced apoptosis in murine splenocytes in vitro. Cells were exposed to sodium arsenite (NaAsO₂, 5 µM) with and without curcumin (5 and 10 µg/ml) and incubated at 37°C for 12 h. NaAsO₂ caused a decrease in cell viability and induction of apoptosis. These outcomes were concurrent with increases in the numbers of cells with reactive oxygen species generation, loss of mitochondrial transmembrane potential, an increase in the frequency of cells with sub-G₁ DNA content, and DNA fragmentation. Co-administration of curcumin with the NaAsO₂ caused significant recoveries in cell viability values and mitigation of the induced apoptosis-related molecular changes. A significant protection against apoptosis parameters in murine splenocytes simultaneously treated with NaAsO₂ and curcumin suggested a protective efficacy of curcumin. From the results it is concluded that the immuno-modulation exerted by curcumin might be attributed to its multifaceted effects including its anti-oxidative and anti-apoptotic properties. These findings have implications not only for the under-standing of the toxicity of arsenic to murine splenocytes in vitro but are also potentially important for developing preventive and/or corrective strategies against/during chronic arsenicosis.