Figure 1. GpS inhibits LPS-induced NO production and iNOS expression without affecting the cell viability of RAW 264.7 macrophages.

Cells were treated with GpS at concentrations ranging from 3.1 to 200 μg/ml in the (A) absence or (B) presence of LPS (1 μg/ml) for 24 hrs. Cell viability was determined by MTT assay. Cells were pre-treated for 1 hr with indicated the concentrations of GpS and further incubated for 24 hrs with or without LPS (1 μg/ml) before assement of (C) NO production and (D) iNOS protein expression by Griess assay and Western blotting respectively. Representative immunoblot results and their quantifications are shown. β-actin was used as an internal loading control. Data are expressed as means ± SD of three independent experiments. ^*P < 0.05, ^**P < 0.01, ^***P < 0.001 compared to LPS-induced control.