Inhibitory effects of rosmarinic acid on the proliferation of cultured murine mesangial cells

Background. Rosmarinic acid is a phenolic compound widely distributed in Labiatae herbs such as rosemary, sweet basil, and perilla, which are frequently used with meat and fish dishes in Western and Asian countries. In the present study we investigated the effects of rosmarinic acid on cultured murine mesangial cell proliferation. Methods. Cultured murine mesangial cells were stimulated by growth factors with or without rosmarinic acid, and [H-3]thymidine incorporation was measured in regard both to signal transduction and to cell cycle dependency. In other experiments, mRNA extracted from the cells was analysed by Northern blotting. Results. Rosmarinic acid inhibited the cell proliferation induced by platelet-derived growth factor (PDGF) (P<0.01; IC50 values, 1.4 mu g/ml) or tumour necrosis factor-alpha (P<0.01; IC50 values, 3.8 mu g/ml), and these effects involved both the G(0)/G(1) and G(1)/S phases of the cell cycle. Rosmarinic acid also suppressed the mRNA expressions of PDGF and c-myc in PDGF-stimulated mesangial cells. Conclusions. Rosmarinic acid inhibits cytokine-induced mesangial cell proliferation and suppresses PDGF and c-myc mRNA expression in PDGF-stimulated mesangial cells. Rosmarinic acid in Labiatae herbs might be a promising agent to prevent mesangial cell proliferation.