Effect of Perilla frutescens extract on nitric oxide production by cultured murine mesangial cells

The effects of a water extract of perilla (Perilla frutescens Britton) leaves on nitric oxide (NO) production by cultured murine mesangial cells were investigated. Perilla extract significantly induced NO production from mesangial cells, which was enormously augmented without cytotoxity by combination with interferon (IFN)-gamma or tumor necrosis factor-alpha. On the other hand, perilla extract suppressed a large amount of NO production induced by IFN-gamma combined with lipopolysaccharide. Northern blot analysis revealed that such effects of perilla extract were dependent on inducible NO synthase mRNA expression. Perilla extract exhibited an inhibitory effect on cytokine-induced mesangial cell proliferation, and this effect was significantly decreased upon combination with N(G)-monomethyl-L-arginine (L-NMMA), a non-specific NO synthase inhibitor, suggesting that perilla extract inhibits mesangial cell proliferation partially through the induction of NO production. Such results indicate that perilla may be a promising agent for the prevention of the progression of glomerulonephritis.