Objective: To investigate the effect of Liangge San, a recipe of traditional Chinese herbal medicine, on lipopolysaccharide (LPS)-induced nuclear factor kB (NF-kB) activation in mouse macrophages cultured in vitro and explore the signal transduction mechanism of the detoxifying effect of Liangge San.
Methods: The mice were given oral administration of concentrated decoction of Liangge San to obtain the drug-containing serum. Macrophages from mouse abdominal cavity were collected, incubated and subsequently re-incubated with LPS and the prepared serum at different doses. Immunofluorescence method was adopted to examine the expression of NF-kB subunit p65 in the nuclei of the macrophages, and the fluorescence intensity of p65 expression was measured by laser scanning confocal microscope (LSCM).
Results: The fluorescence intensity of p65 expression in the nuclei of macrophages incubated with LPS for 1 h was significantly increased compared with that in the cells without LPS stimulation and Liangge San serum-treated cells. The fluorescence intensities were significantly decreased in cells treated with the inhibitor TLCK and different doses of Liangge San serum in comparison with those in LPS-stimulated cells. The fluorescence intensities were the lowest in cells treated with TLCK and high-dose Liangge San serum, and the cells treated with moderate and low doses of the serum both showed lower intensity compared with that of LPS-stimulated cells. p65 expression was similar between the macrophages incubated with LPS and those treated with serum that contained no Liangge San.
Conclusions: Mouse serum containing Liangge San can inhibit LPS-induced p65 expression in mouse macrophages in a dose-dependent manner, which may be one of the signal transduction mechanisms of the detoxifying effect of Liangge San.