Suppressive effect of Punica granatum on the production of tumor necrosis factor (Tnf) in BV2 microglial cells.

While the anti-oxidant properties of Punica granatum methanol extract (PGMF) are well documented, little is known concerning the anti-inflammatory effect of Punica granatum. PGMF was pretreated in BV2 microglial cells and cells were stimulated to induce inflammation by lipopolysaccharide (LPS). The effect of PGME on the production and expression of tumor necrosis factor alpha (Tnf, previously known as Tnf alpha) was determined by enzyme-linked immunosorbent assay (ELISA), western blotting, and reverse transcription-polymerase chain reaction (RT-PCR). In addition, the expression of nuclear factor kappa b (Nfkappab) was measured using an electrophoretic mobility shift assay (EMSA). By ELISA, PGME at the concentrations of 1, 5, 10, and 50 microg/ml inhibited Tnf production in LPS-stimulated cells by 30.2, 42.3, 57.6, and 88.4%, respectively, compared to LPS-stimulated cells. The LPS-stimulated Tnf production was reduced with a dose-dependent manner. Immuno blot and RT-PCR analyses revealed that PGME of 5 and 50 microg/ml inhibited the expression of both protein and mRNA levels of Tnf compared to LPS-stimulated cells. EMSA revealed that PGME of 5 and 50 microg/ml blocked the LPS-stimulated activation of Nfkappab. These data suggest that PGME may suppress LPS-stimulated Tnf production through inhibition of Nfkappab in BV2 microglia cells.