The Korean genuine medicine "Seonghyangjeongkisan" (SHJKS) has long been used for various cerebrovascular diseases. However, very little scientific investigation has been carried out. Cytokines involved in the regulation of inflammatory reactions and immune responses may play a role in the pathogenesis of cerebral infarction (CI). The aim of the present study is to elucidate how SHJKS modulates the inflammatory reaction in lipopolysaccaride (LPS) plus phytohaemagglutinin (PHA)-stimulated peripheral mononuclear cells (PBMCs) from CI patients. The amount of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6, and IL-8 in PBMC culture supernatant was significantly increased in the LPS plus PHA treated cells compared to unstimulated cells. SHJKS inhibited the TNF-alpha, IL-1beta, IL-6, and IL-8 production in dose dependent manner. Maximal inhibition rate of the TNF-alpha, IL-1beta, IL-6, and IL-8 by SHJGS (1.0 mg/ml) was 68.01 +/- 0.28% (P < 0.01), 52.11 +/- 0.56 % (P < 0.01), 53.42 +/- 0.46 % (P < 0.01), and 46.70 +/- 0.37% (P < 0.05), respectively. In addition, we show that SHJKS suppressed nuclear factor (NF)-kappaB activation induced by LPS plus PHA, leading to suppression of IkappaB-alpha phosphorylation and degradation. These results suggest that SHJKS might have regulatory effects on LPS plus PHA-induced cytokine production and NF-kappaB activation, which might explain its beneficial effect in the treatment of CI.