Naturally occurring biflavonoid, ochanflavone, inhibits cyclooxygenases-2 and 5-lipoxygenase in mouse bone marrow-derived mast cells

Ochnaflavone is a medicinal herbal product isolated from Lonicera japonica that inhibits cyclooxygenase-2 (COX-2) dependent phases of prostaglandin D-2 (PGD(2)) generation in bone marrow-derived mast cells (BMMC) in a concentration-dependent manner with IC50 values of 0.6 mu M. Western blotting probed with specific anti-COX-2 antibodies showed that the decrease in quantity of the PGD2 product was accompanied by a decrease in the COX-2 protein level. In addition, this compound consistently inhibited the production of leukotriene Q(4) (LTC4) in a dose dependent manner, with an IC50 value of 6.56 mu M. These results demonstrate that ochnaflavone has a dual cyclooxygenase-2/5-lipoxygenase inhibitory activity. Furthermore, this compound strongly inhibited degranulation reaction in a dose dependent manner, with an IC50 value of 3.01 mu M. Therefore, this compound might provide a basis for novel anti-inflammatory drugs.