IN VITRO AND IN VIVO THERAPEUTICS OF β-THUJAPLICIN ON LPS-INDUCED INFLAMMATION IN MACROPHAGES AND SEPTIC SHOCK IN MICE

beta-thujaplicin, an active constituent from Chamaecyparis obtusa, has been shown to have acaricidal and antimicrobial effects. Very few studies have focused on the potential of the anti-inflammatory effect of beta-thujaplicin. Moreover, its capability of inhibiting inflammatory mediators e.g. TNF-alpha gene transcription, nitric oxide (NO) and prostaglandin E2, remains unknown. Besides those molecular mechanisms behind the anti-inflammatory effect of beta-thujaplicin, solid proof of its effectiveness in vivo has not yet been studied. In our study, in vitro effects of beta-thujaplicin were verified on RAW 264.7 macrophages which were stimulated by LPS. Indomethacin was used as a positive control. The inducible NO production after stimulation was measured by Griess reagent. PGE2, IL-6 and TNF-alpha were measured by ELISA methods. Protein expressions of iNOS, COX2, and NF-kappa B were evaluated by Western blotting. Septic ICR mice were administered 20 mg/kg of LPS and then the mortality rate was monitored. Within the concentration range which was devoid of cytotoxicty, beta-thujaplicin exhibited a clear dose-dependent inhibition on LPS-induced NO production. Furthermore, beta-thujaplicin inhibited LPS-induced PGE2, IL-6, and TNF-alpha production as well as iNOS, COX2, and NF-kappa B protein expression more substantially potent than indomethacin. In agreement with the in vitro study, beta-thujaplicin was shown to be effective in vivo for inhibiting LPS-induced NO and TNF-alpha production and a significant decrease in mortality rate of mice suffering from septic shock was observed. This study demonstrates the potential of beta-thujaplicin in treatment of inflammation and sepsis. These effects occur through an efficient blockage of TNF-alpha and iNOS production. beta-thujaplicin efficacy is comparable to that of indomethacin thus it can be a substitution but bear less depletion of PGE2, making this compound very promising in clinical applications.