In vitro and in vivo anti-inflammatory activity of 17-O-acetylacuminolide through the inhibition of cytokine production and nuclear factor kappa B translocation
M Achoui
Department of Pharmacology 1, Molecular Medicine 2, and Chemistry 3, University of Malaya, Malaysia
Abstract:
Introduction: 17-O-acetylacuminolide (AA), a diterpenoid labdane, was isolated for the first time from the plant Neouvaria foetida. The anti-inflammatory effects of this compound were studied both in vitro and in vivo.
Methods: Plant extracts were tested for tumor necrosis factor alpha (TNF-a) release inhibition from LPS-stimulated macrophages. Using bioassay-guided fractionation, AA was isolated. AA was tested for its ability to reduce nitric oxide (NO) production, and the inducible nitric oxide synthase (iNOS) expression. The inhibition of a panel of inflammatory cytokines (TNF, IL-1ß, IL-6, KC, and GM-CSF) by AA was assessed at the expression and the mRNA levels. Moreover, the effect of AA on the translocation of the transcription factor NF-?B was evaluated in LPS-stimulated RAW264.7 cells and in TNF-stimulated L929 cells. Lastly, the anti-inflammatory activity of AA in vivo was evaluated by testing TNF production in LPS-stimulated Balb/c mice.
Results & Discussion: 17-O-acetylacuminolide effectively inhibited TNF-a release with an EC50 of 2.7µg/mL. Moreover, the compound significantly inhibited both NO production and iNOS expression. It significantly and dose-dependently inhibited TNF and IL-1ß proteins and mRNA expression; as well as IL-6 and KC proteins. Additionally, AA prevented the translocation of NF-?B in both cell lines; suggesting that it is acting at a post receptor level, hence providing an insight on the mechanism of its activity. Finally, AA at 100mg/kg significantly reduced TNF production in vivo.
Conclusion: This study presents the potential utilization of this compound, with further testing, as a lead for an anti-inflammatory drug development.
