The inhibitory effects of aqueous extract of Magnolia officinalis on human mesangial cell proliferation by regulation of platelet-derived growth factor-BB and transforming growth factor-beta1 expression.

Mesangial cell (MC) proliferation, mediated by platelet-derived growth factor (PDGF)-BB, transforming growth factor (TGF)-beta1, and cyclin-dependent kinases (CDK), is the common feature of glomerulosclerosis. Magnolia officinalis, stem bark of Machilus thunbergii S., has multiple pharmacological effects. In this study, we investigated the influence of aqueous extract of Magnolia officinalis on MC proliferation, DNA synthesis, and expression of PDGF-BB, TGF-beta1, CDK1, CDK2, and CDK4 in fetal bovine serum (FBS)-activated human MC. Magnolia officinalis inhibited the MC proliferation, DNA synthesis, and the expression of PDGF-BB, CDK1, and CDK2 gene and CDK1, CDK2, and TGF-beta1 protein. These results suggest that the inhibitory effect of Magnolia officinalis on MC proliferation may be mediated by regulation of PDGF-BB and TGF-beta1expressions and by modulation of CDK1 and CDK2 expression.