Abstract:

Abstract:Objective To investigate the protective effects of Xuebijing(XBJ)on  the injury of vascular endothelial cells(VEC) induced by lipopolysaccharide (LPS), and to study the mechanisms of the production of nitric oxide (NO) and the expressions of inducible nitric oxide sytnhase (iNOS) and signal transduction under XBJ intervention condition. Methods   The cultured VEC were divided into control group, LPS(1 mg?L-1)group, LPS(1 mg/L)　+XBJ(25 g/L)group,LPS(1 mg/L)+pyrrolidine dithiocarbamate(PDTC, 20 μmol/L)group; XBJ and PDTC were  administrated 1 h before incubation of with LPS. Western blotting method was used to detect the expressions of iNOS and NF-κB p65 protein. The level of  NO in the supernatant was measured by Griess reagent. Results   Comparaed with control group, the NO level and the expression levels of iNOS protein and NF-κB p65 protein in VEC in LPS group were significantly increased(P<0.01). Compared with LPS group, the NO level and the expression levels of iNOS protein and NF-κB p65 protein in VEC in LPS+XBJ group were significantly decreased (P<0.05 or P<0.01); the NO level and the expression levels of NF-κB p65 protein and iNOS protein in VEC in LPS+PDTC group were significantly decreased(P<0.05 or P<0.01). There were no significant differences of  the NO levels　 and the expression levels of iNOS protein between LPS+XBJ group and LPS +PDTC group (P>0.05), but the expression level of NF-κB p65 protein in LPS+PDTC group was  lower than  that in LPS+XBJ  group(P<0.05). Conclusion  XBJ can inhibit the  production of NO and the expression of iNOS protein  in VEC; its  mechanism may be related to  inhibiting the activation of NF-κB to control inflammation.

Key words: Xuebijing, nuclear factor κB, inducible nitric oxide synthase, nitric oxide, vascular endothelial cells