Simaroubaceae family had been reported to possess numerous biological activities due to the presence of quassinoids. This
study was carried out to assess the potential anti-inflammatory properties of extracts from Quassia borneensis, an unexplored
indigenous plant from Sabah. Bark and root samples of Q. borneensis were soxhlet or macerated in methanol and partitioned
with n-hexane, chloroform and water to yield hexane, chloroform and aqueous extracts, respectively. Anti-inflammatory
activity was evaluated from the production of nitric oxide following treatment of extracts on lipopolysaccharide-stimulated
RAW 264.7 murine macrophage cells using Griess assay. Expression of inflammatory protein was detected by immunoblotting.
Results showed that the chloroform extract of Q. borneensis root demonstrated the most potent inhibition of nitric oxide
production with IC50 0.3 μg/ml. In conclusion, Q. borneensis possessed anti-inflammatory activity and have a potential to be
further developed as chemopreventive agent..