Diterpenoids as potential anti-inflammatory agents from Ajuga pantantha

A phytochemical survey to obtain bioactive natural products from Ajuga pantantha afforded five new neo-clerodane diterpenoids (1-5). The structures were established by analysis of their NMR spectroscopic data, and electronic circular dichroism calculations were applied to define their absolute configurations. Compounds 2 and 5 were found to have the property of inhibiting NO production (IC₅₀ values < 40 μM). Molecular docking and Western blotting were used to study the mechanism of anti-inflammatory action. Furthermore, compound 5 with the highest activity was tested for its in vivo anti-inflammatory effects using a zebrafish model.

Keywords: Ajuga pantantha; Diterpenoids; Inflammation; Molecular docking; Nitric oxide inhibitory effects; Zebrafish model.