The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) inhibit atherogenic events: a study of the combination effects of the 2-herb formula.

The roots of Salvia miltiorrhiza (Danshen) and Pueraria lobata (Gegen) are principle herbs of Chinese herbal formulae which have long been used to treat cardiovascular diseases.The present study validated the anti-atherogenic effects of three extracts, Danshen alone (DE), Gegen alone (GE) as well as DGE and interpreted their combination effects statistically.The anti-atherogenic effects of the three extracts were studied in three assays with regards to inflammation, foam cell formation and vascular smooth muscle cell (vSMC) proliferation using lipopolysaccharide (LPS)-induced nitric oxide production model, macrophage foam cell formation model and platelet-derived growth factor (PDGF)-induced vSMC proliferation model, respectively. The combination effects of DGE were statistically analyzed using combination index (CI) and fixed-ratio experimental design.The anti-atherogenic effects of the three extracts including anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were demonstrated in this study. Their combination effects in anti-inflammation, anti-foam cell formation and anti-vSMC proliferation were found to be synergistic, additive and antagonistic, respectively.This study provided scientific support for the combination use of DGE on atherosclerosis and presented one of the first applications of statistical interpretations of the combination effects of the 2-herb formula.