ABSTRACT
Aim To investigate the effect of MAPK signal transduction pathway on the expression of TNF-? in AM(alveolar macrophage) of CB(chronic bronchitis) rats,meanwhile,to initially discuss the possible regulated target of TAL(triterpene acids of loquat.leaf),to explain the mechanism about anti-inflammatory action of TAL on CB rats.Methods The depurated AM was incubated with the special inhibitors of MAPK signal transduction pathway respectively(ERK,p38 or JNK) and the expression of TNF-? was observed by RT-PCR and Western blot.Using factorial design,TNF-? level in AM culture supernatant was detected by ELISA.Results The special inhibitors of ERK(PD98059) and p38(SB203580) could change the expression of TNF-? in AM of CB rats apparently.Factorial analysis shows there is statistical significance between TAL,PD98059/SB203580 and mixture of them.Conclusions TAL reducing the expression of TNF-? may be related with the inhibition of ERK and p38 signal transduction pathway.It may be one of the mechanisms by which TAL has the preventive and therapeutic effects on chronic bronchitis.