Blocking of cell proliferation, cytokines production and genes expression following administration of Chinese herbs in the human mesangial cells

In the hope of identifying agents of therapeutic value in immunoglobulin A nephropathy (IgA-N), we tested crude methanol extracts of 15 Chinese herbs for their effect on human mesangial cell proliferation. The results indicat ed that 4 out of the 15 crude extracts inhibited human cells proliferation activated by IL-1 beta and IL-6. The extracts and their median inhibitory c oncentrations were as follows (in mu g/ml): Ludwiga octovalvis (MLS-052), 4 9.9 +/- 1.8; Rhus semialata (MLS-053), 31.2 +/- 1.6; Tabernaemontana divari cata (MLS-054), 50.0 +/- 2.1; Amepelopsis brevipedunculata (MLS-059), 42.9 +/- 1.1. These findings indicate that human mesangial cells were most sensi tive to MLS-053 treatment. These herbs also decreased interleukin-1 beta (I L-1 beta) and tumor necrosis factor-alpha (TNF-alpha) production. Moreover, IL-1 beta mRNA expression was inhibited by Rhus semialata (R. semialata; M LS-053). It is unlikely that cytotoxicity was involved, because no cell dea ths were observable. We hypothesize that the inhibitory mechanisms of these Chinese herbs may be related to the impairments of gene expression and pro duction of cytokines in human mesangial cells. Plans are underway for the i solation of pure compounds from these Chinese herbs and the elucidation of their mechanisms of action.