Isolation and Characterization of Anti-Inflammatory Compounds from Ficus microcarpa L.f. Stem Bark

The anti-inflammatory effect of the ethyl acetate extract of F. microcarpa bark (EAFMB) was investigated in acute and chronic (21 days) inflammation induced in Wistar albino rats. EAFMB (200 mg/kg b.w.) exhibited comparable anti-inflammatory effects to the reference drug, with a reduction of 59.48% at 4 h in acute inflammation and 83.96% on day 21 in chronic inflammation. Bioassay-guided fractionation using DPPH radical scavenging activity led to isolating and identifying three compounds from EAFMB: oleanolic acid, catechin, and p-hydroxycinnamic acid. All these compounds demonstrated the concentration-dependent inhibition of COX enzymes and the protection of egg albumin from heat-induced denaturation. Catechin exhibited the highest COX inhibition (COX-1 and COX-2 IC(50) = 9.02 and 50.38 μM, respectively) and anti-denaturation effect (IC(50) = 27.13 μg/mL) compared to oleanolic acid and p-hydroxycinnamic acid. These isolated compounds are likely responsible for the anti-inflammatory activities of F. microcarpa bark.