Comparison of Anti-inflammatory Activities of Six Curcuma Rhizomes: A Possible Curcuminoid-independent Pathway Mediated by Curcuma phaeocaulis Extract

Abstract

We aimed to compare the anti-inflammatory activities of six species ofCurcumadrugs using adjuvant arthritis model mice. When orally administered 1 day before the injection of adjuvant, the methanol extract ofCurcuma phaeocaulissignificantly inhibited paw swelling and the serum haptoglobin concentration in adjuvant arthritis mice. Also when orally administered 1 day after the injection of adjuvant, the methanol extract ofCurcuma phaeocaulissignificantly inhibited paw swelling. OtherCurcumaspecies (Curcuma longa, Curcuma wenyujin, Curcuma kwangsiensis, Curcuma zedoariaandCurcuma aromatica) had no significant inhibitory effects on adjuvant-induced paw swelling. Cyclooxygenase (COX)-2 activity was significantly inhibited by the methanol extract ofC. phaeocaulis. Curcuminoids' (curcumin, bis-demethoxycurcumin and demethoxycurcumin) were rich inC. longa, but less inC. phaeocaulisandC. aromatica, not inC. wenyujin, C. kwangsiensisandC. zedoaria, suggesting that curcuminoids' contents do not relate to inhibition of arthritis swelling. Therefore,C. phaeocaulismay be a useful drug amongCurcumaspecies for acute inflammation, and the active constituents ofC. phaeocaulisare not curcuminoids.